فهرست مطالب

Iranian Journal of Radiology - Volume:14 Issue: 2, 2017
  • Volume:14 Issue: 2, 2017
  • تاریخ انتشار: 1396/05/02
  • تعداد عناوین: 36
|
  • Faezeh Vedaei, Mohammad Ali Oghabian, Kavous Firouznia, Mohammad Hossein Harirchian, Younes Lotfi, Mohammad Fakhri Page 1
    Background
    Functional magnetic resonance imaging (fMRI) is a non-invasive and convenient method of mapping brain activity associated with the human sensory systems. Among these systems there is a lack of data from olfactory studies, which could be attributed to technical difficulties in odor delivery during scanning. The current study took advantage of an olfactometer to evaluate brain activity during the odor-smelling process.
    Objectives
    This study aimed to investigate the brain regions of the human olfactory system via fMRI brain imaging. A speculative survey was used to highlight the differences between studies conducted in healthy populations using olfactory tasks, as well as conducting literature survey in terms of the technical principles applying through these tasks in fMRI studies.
    Subjects and
    Methods
    A functional map of the olfactory system that used a block design, alternating between odor and non-odor phases, was examined in 15 healthy volunteers. The general linear model was used to identify statistically significant voxels that showed activation during the activation blocks.
    Results
    Primary and secondary olfactory regions, including the piriformis, insula, amygdala, parahippocampal gyrus, caudate nucleus, inferior frontal gyrus, middle frontal gyrus, superior temporal gyrus, and cerebellum, demonstrated significant activation in response to odor stimulation.
    Conclusion
    Activation of the aforementioned brain areas, and the pattern of activation, is largely in accordance with previous published olfactory studies carried out in healthy individuals.
    Keywords: Cortex, Olfactory, fMRI, Healthy Human, Odor, Smell Sense
  • Mojtaba Miri, Meysam Mohseni, Alireza Madadi, Kavous Firouznia, Hamidreza Saligheh Rad, Farid Azmoudeh Ardalan, Anahita Fathi Kazerooni, Ali Haidari, Reza Taslimi, Hossein Ghanaati Page 2
    Background
    Distinguishing low-grade from high-grade gliomas can aid in optimal treatment planning and prognostication. Diffusion-weighted imaging (DWI) and magnetic resonance spectroscopy (MRS) have been applied in several studies for non-invasive glioma grading. However, these studies focused on limited aspects of these imaging techniques and used different study setups, resulting in occasionally inconsistent and incomparable conclusions in the literature.
    Objectives
    This study was designed to introduce the optimal imaging setup and the most reliable and applicable imaging parameters in glioma grading, using DWI and MRS.
    Patients and
    Methods
    During this prospective study, using a 3T-MR scanner, 55 glioma patients underwent brain MRS with short, intermediate, and long echo times (TEs), as well as DWI using low, intermediate, and high b-values. Postoperatively, all of the specimens were graded pathologically using light microscopy.
    Results
    We found that Max (Chol/Cr)/ Min (NAA/Cr) ((maximum choline to creatine ratio)/(minimum N-acetyl aspartate to creatine ratio)), followed by Max (Chol/ Cr), both in long-TE, were the most reliable metabolite ratios on MRS for accurate glioma grading. These had values for area under the curve (AUC) of 0.92 (P
    Conclusion
    Max (Chol/Cr)/Min (NAA/Cr) in long-TE was the most reliable of all of the MRS parameters studied, while DWI showed no superiority over cMRI in glioma grading. No significant differences existed among the various b-values applied, or between the minimum and mean tumor apparent diffusion coefficient values used in DWI-based glioma grading.
    Keywords: Apparent Diffusion Coefficient, Brain Tumor, Diffusion-Weighted Imaging, Glioma Grading, Glioma, Magnetic Resonance Spectroscopy
  • Haleh Khoshkhouy Delshad, Reza Nilipour, Majid Barekatain, Mohammad Ali Oghabian Page 3
    Background
    Neural correlates of visual confrontation naming (VCN) have received considerable attention in previous literature. Recently, there have been a few studies that have reported the activation of the hippocampus during VCN tasks. Whether or not the hippocampus is directly involved in picture naming has clinical importance for patients with refractory mesial temporal lobe epilepsy (MTLE) who should undergo anterior temporal lobe resection (ATLR).
    Objectives
    In this study, we investigated the neural network of VCN and the role of the hippocampus in Persian-speaking individuals by functional magnetic resonance imaging (fMRI) VCN paradigm.
    Subjects and
    Methods
    Twenty right-handed, healthy, Persian-speaking adults underwent fMRI while performing VCN task. Pictures were selected from a Snodgrass and Vanderwart dataset that was normed for Persian speakers. VCN performance was assessed and entered as a covariate in whole-brain analysis. Region of interest (ROI)-based analysis was also used to obtain more accurate results.
    Results
    Activation in the left hippocampus was significantly correlated with VCN performance. Participants with higher scores showed greater fMRI activation in their left hippocampus. Activation in left occipitotemporal regions, such as the left occipital fusiform gyrus, left temporal occipital fusiform gyrus, left temporal pole, left middle temporal gyrus, and left superior temporal gyrus also showed significant correlation with VCN performance. The main effects of VCN were also found in frontal and occipital regions, such as the left inferior frontal gyrus, right inferior frontal gyrus, right orbital frontal gyrus, right lateral occipital gyrus, right occipital fusiform gyrus, and right occipital pole. Activation in the inferior frontal gyrus was significantly left lateralized among all of the subjects.
    Conclusion
    These findings suggest that good naming ability depends on fMRI activation in the speech-dominant hippocampus. We also found that a left-dominant network of occipitotemporal regions plays a dominant role in VCN performance in healthy Persian-speaking individuals.
    Keywords: fMRI, Naming, Occipitotemporal Regions, Hippocampus
  • Myeong Seong Kim, Jong-Woong Lee, Sun Geun Kim, Dae Cheol Kweon Page 4
    Background
    Bolus timing monitoring scans used for computed tomography angiography (CTA) repetitively expose the same region of the body to radiation with a view to determining the appropriate threshold attenuation level of the contrast material (CM). Therefore, for an effective CT scan, it is necessary to minimize repetitive radiation exposures from bolus timing.
    Objectives
    This study aims to effectively identify and reduce the radiation dose needed for repetitive monitoring scans utilized in CT involving the bolus timing method.
    Patients and
    Methods
    To investigate the currently employed protocols and the number of monitoring scans in bolus timing CT studies, 983 patients (581 males and 402 females; mean age 62.7) were retrospectively analyzed from October 1, 2013 to March 31, 2014. To identify the appropriate kVp and mA change in the hounsfield unit (HU) and measure the contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) in the bolus timing method, a 2 mL syringe containing CM diluted with saline at a ratio of 1 to 300 was inserted into cavities of a CT dose index (CTDI) head phantom and scanned with a 64-section multi-detector row CT system. The dose variation was analyzed using results from the ionization chamber and CTDI.
    Results
    This retrospective analysis of bolus-timing CT studies found that patients underwent an average of 4.5 to 5.4 monitoring scans. Furthermore, while the HU value of the mixed CM syringe in the central CTDI head phantom cavity was inversely proportional to mA, the decrease in the HU value became weaker at a value of 50 mA with 100 kVp and at 30 mA with 120 kVp. Here, the CNR (Pearson correlation r = 0.983, Kendall’s t = 0.978, P
    Conclusion
    It is recommended that minimum level of radiation (100 kVp, 50 mA; 120 kVp, 30 mA) at which the HU value at the trigger threshold is not significantly different from that of the actual helical scans should be used to minimize the radiation dose caused by repetitive monitoring scans in the bolus timing method.
    Keywords: Angiography, Image Analysis, Multidetector Computed Tomography, Radiation Dosage
  • Kyung-Sik Ahn, Chang Ho Kang, Woong-Kyo Jeong Page 5
    Background
    Imaging findings of adhesive capsulitis (AC) have been reported widely with the use of magnetic resonance imaging (MRI) and ultrasonography (US), although diagnosing AC is still based on clinical finding. However, the use of contrast-enhanced ultrasonography (CEUS) has not yet been reported in patients with AC.
    Objectives
    To validate the application of CEUS in patients with AC, and to compare CEUS findings with those of MRI.
    Patients and
    Methods
    Both shoulders of five patients with unilateral AC, who underwent MRI on the affected shoulder, were examined using CEUS (2 men, 3 women; mean age, 54.2 ± 8 years). CEUS was performed after bolus administration of the contrast agent, SonoVue (Bracco, Milan, Italy), followed by a saline flush. Enhancement of the rotator interval was evaluated using a visual enhancement score (0 to 2) and compared with the contrast-enhanced MRI findings. For quantitative analysis, an region of interest was established for each rotator interval, and time-intensity curves were analyzed with parameters including time-to-peak and peak intensity. The difference of peak intensity between the affected and unaffected shoulders was compared.
    Results
    Contrast enhancement of the rotator interval was notable in all CEUS of affected shoulders, whereas no evident enhancement was detected in all asymptomatic shoulders. The mean visual enhancement score of affected shoulders was 1.4 in CEUS and 2.0 in contrast-enhanced MRI. In quantitative analysis, the mean peak intensity was 5.45 ± 2.80 dB (mean time to peak, 30.6 ± 5.39 seconds) in affected shoulders, and 0.72 ± 0.91 dB in unaffected shoulders (P
    Conclusion
    CEUS was capable of demonstrating capsular inflammation in patients with AC, and this was comparable to MRI. CEUS could be a feasible imaging tool for evaluating patients with AC. 
    Keywords: Adhesive Capsulitis, Shoulder, Contrast-Enhanced Ultrasonography, Magnetic Resonance Imaging
  • Byungjun Kim, Namjoon Lee, Keonha Kim, Kyung-Il Jo, Pyoung Jeon Page 6
    Background
    Various endovascular treatment methods have been used to treat ruptured vertebral artery dissecting aneurysms (VADAs). However, the efficacy and long-term durability of the various endovascular techniques have remained unestablished.
    Objectives
    The purpose of the present study is to report the therapeutic efficacy and long-term clinical and angiographic results of various endovascular treatment methods, and to evaluate the predictive factors of favorable outcomes.
    Patients and
    Methods
    Between January 2010 and August 2014, 30 patients with ruptured VADAs were classified according to the dominancy of the affected vertebral artery (VA) and the involved major perforating vessels. Allotted endovascular therapy was performed for each of the ruptured VADA subtypes. Immediate angiographic and follow-up imaging results were retrospectively reviewed, and long-term clinical results were evaluated. Various clinical, angiographic, and procedural factors were evaluated to determine their associations with clinical outcomes.
    Results
    Dissecting aneurysms involving the dominant VA were found in five patients. Of 25 aneurysms involving the non-dominant VA, 12 lesions showed involvement of the posterior inferior cerebellar artery (PICA), and one lesion’s origin was the anterior spinal artery. Stent-assisted coiling (SAC) was performed in seven patients, stent-only therapy (SOT) was conducted for six patients, and the remaining 17 patients were treated with internal coil trapping (ICT). Of the seven patients treated with SAC, five showed partial obliteration and four experienced recurrence. Two of the four patients with recurrence died. One patient with incomplete trapping for patency of the involved PICA experienced rebleeding. No recurrence was observed in six patients treated with SOT, or among 16 patients with ICT. The preoperative neurologic status (represented by the world federation of neurosurgical societies grading) and immediate post-treatment angiographic results were confirmed as significant predictive factors of clinical outcomes (P =0.018 for both variables).
    Conclusion
    Incomplete obliteration of a ruptured VADA using SAC was associated with a higher recurrence rate and fatal clinical outcomes. ICT is a useful technique that completely eliminates the risk of rebleeding. However, under a limited set of conditions, SOT can be an effective alternative.
    Keywords: Aneurysm, Embolization, Stents, Retrospective Studies, Treatment Outcome, Vertebral Artery Dissection, Complications, Surgery
  • Najibullah Rasouly, Rahima Stanekzai, Hidayatullah Hamidi, Rafiullah Ahamdzai Page 7
    Left ventricular pseudoaneurysm is a rare and fatal complication of myocardial infarction. Patients usually die from hemorrhage; therefore, urgent surgical resection is the mainstay of treatment. The most important differential diagnosis for this entity is left ventricular true aneurysm that could be managed with medical treatment. The diagnostic work up of left ventricular abnormal outpouching is well illustrated in the literature; however, less is written about the role of computed tomography angiography (CTA). Hereby, we present a case of left ventricular pseudoaneurysm in a 65-year-old woman who suffered from an ST elevation myocardial infraction six months ago. The echocardiography and chest CTA examinations revealed formation of a large aneurysmal cavity posterolateral to the left ventricle with significant thrombus formation. However, less is written about the role of computed tomography angiography in the diagnostic work up of left ventricular pseudoaneurysm. We present the typical features of left ventricular pseudoaneurysm depicted with CTA.
    Keywords: Left Ventricular Pseudoaneurysm, Left Ventricular outpouching, Myocardial Infarction
  • In Kyeom Kim, Jung Wook Seo Page 8
    A cystic lymphangioma is a rare benign tumor of the lymphatic tissue that mostly affects the head and neck, and usually manifests during childhood. Cystic lymphangioma of the abdominal wall is extremely rare. Herein, we report two young children with cystic lymphangioma of the abdominal wall. In one of the cases, the properitoneal fat layer of the abdominal wall was affected. We hereby analyze radiologic features of cystic lymphangioma of the abdominal wall.
    Keywords: Abdominal Wall, Child, Lymphangioma, Cystic
  • Fatma Kulali, Safak Firat Kulali, Aslihan Semiz-Oysu, Muberra Segmen-Yilmaz, Yasar Bukte Page 9
    Ovotesticular disorder of sex development (DSD) is a very rare chromosomal anomaly characterized by the presence of both ovarian and testicular tissues.
    We reported a case of delayed diagnosis in a 18-year-old man presenting with nonpalpable testes. Pre-operative magnetic resonance imaging (MRI) demonstrated associated anomalies (agenesis of seminal vesicle, configuration of urethra) and Mullerian duct remnants. The presence and location of both ovary and testis, and restricted diffusions of gonads were detected on MRI. On histopathology, malignancies were found in both gonads.
    Pre-operative MRI findings were helpful for surgical approach. We emphasized the importance of pre-operative MRI on treatment planning.
    Keywords: Cryptorchidism, Magnetic Resonance Imaging, Ovotesticular Disorder, Testicular Neoplasms
  • Hilwati Hashim, Azlindarita Aisyah Mohd Abdullah, Effat Omar, Rofiah Ali Page 10
    A 6-year-old boy was referred with symptoms of right partial ptosis, blurred vision and a two-week history of poor coordination and frequent falls. No symptoms of raised intracranial pressure were demonstrated. Imaging showed a large sella mass with extension into the posterior fossa and suprasellar region, suggestive of a craniopharyngioma. Histopathological examination of the post-surgical resection specimen revealed a small blue cell tumor consistent with a medulloblastoma. This case aims to highlight a posterior fossa tumor with an unusual spread and thus clinical presentation.
    Keywords: Medulloblastoma, Pediatrics
  • Dong Kyun Kim, Joon-Il Choi, Moon Hyung Choi, Chandana Lall, Eun Sun Jung, In Seok Lee Page 11
    Pancreatic metastasis of malignant melanoma is rare and porto-splenic tumor thrombus associated with malignant melanoma is even less frequent. We report a case of metastatic malignant melanoma involving the pancreas, portal vein, splenic vein and superior mesenteric vein. A 60-year-old man showed an elevated amylase level. He had a history of sigmoid colon adenocarcinoma and malignant melanoma. Computed tomography (CT) and magnetic resonance imaging (MRI) showed extensive thrombosis involving the intra- and extrahepatic portal veins extending into the superior/inferior mesenteric vein and splenic vein. On T1 weighted images, tumor thrombi demonstrated diffusely high signal intensity, which is a characteristic finding in malignant melanoma. Also, thrombus showed prominent diffusion restriction on diffusion weighted images and intense uptake of 18F-fluorodeoxyglucose (18F-FDG) on positron emission tomography (PET). Ultrasound-guided biopsy confirmed the metastatic, malignant melanoma involving the pancreas and the veins. We report an unusual manifestation of metastatic, malignant melanoma to the pancreas with extensive tumor thrombi. Specific MR features including high signal intensity on T1 weighted images and diffusion restriction on diffusion weighted images were helpful in reaching a conclusion.
    Keywords: Malignant Melanoma, Magnetic Resonance Imaging, Pancreas, Tumor Thrombus
  • Hyun Kyung Lim, Hong Il Ha, Kyueng-Whan Min Page 12
    Peliosis hepatis (PH) is a rare benign disease of the liver and is characterized by the dilatation of the sinusoids of the liver parenchyma. Here, we present a rare case of PH presenting as a solitary mass with a large central cystic change mimicking a solitary hepatic malignant neoplasm. In addition, we review the literature, focusing on the particular usefulness of the Gd-EOB-DTPA hepatocyte-specific magnetic resonance imaging contrast agent.
    Keywords: Peliosis Hepatis, Liver, Gadolinium Ethoxybenzyl DTPA, Magnetic Resonance Imaging
  • Maryam Rahmani, Faeze Salahshour, Reza Taslimi, Ali Borhani, Sina Kianoush Page 13
    Heterotaxy syndrome with polysplenia is a congenital abnormality with malposition of the visceral organs and multiple associated abnormalities. The majority of affected individuals die during childhood due to severe cardiovascular anomalies. However, affected individuals who reach adulthood are usually asymptomatic. Anomalies of the abdominal venous system, including interruption of the inferior vena cava with azygos or hemiazygos continuation, congenital absence of the portal vein with a portosystemic shunt, preduodenal portal vein, and abnormalities of renal veins are frequent findings. Heterotaxy syndrome usually has no clinical significance except in the setting of planned vascular intervention or surgery. We are reporting an extremely rare case of heterotaxy syndrome (polysplenia) that presented with massive variceal hemorrhage due to associated venous malformation and systemic to portal venous system collaterals.
    Keywords: Left Isomerism, Heterotaxy, Interruption of Inferior Vena Cava, Azygos Continuation, Gastroesophageal Varices, Congenital Absence of Portal Vein, Congenital Venous Stenosis
  • Soo Hyun Kim, Hyun Ju Seon, Yoo-Duk Choi, Sang-Yun Song Page 14
    Neoplasm is one of the primary causes of spontaneous hemothorax. When spontaneous hemothorax is present, it is essential to detect the surgically corrective cause in order to successfully control this life-threatening condition. Undergoing an imaging evaluation, such as by enhanced computed tomography (CT), is especially important in a patient with spontaneous hemothorax. Herein, we report on a case of spontaneous hemothorax that was caused by a ruptured atypical carcinoid tumor in the right lower lobe. This hypervascular and peripherally located tumor was initially missed by both an unenhanced and enhanced chest CT because intra-tumoral bleeding and the hypervascular nature of this tumor caused similar high density when compared to the loculated hemothorax along the right major fissure and the surrounding atelectatic lung. Consequently, the tumor was obscured by the massive hemothorax and surrounding atelectatic lung on the initial chest CT. However, a second chest CT taken after tube drainage of the massive hemothorax informed the correct diagnosis.
    Keywords: Spontaneous Hemothorax, Carcinoid Tumor, Atypical, Rupture
  • Cheng-Fu Ni, Liang-Kung Chen Page 15
    Nasal-type extranodal natural killer (NK)/T-cell lymphoma (ENKTL) is a rare type of lymphoma that is endemic to East Asia. It typically demonstrates as a destructive mass involving the midline facial tissues that causes rhinosinusitis symptoms such as nasal obstruction, sinusitis, ulcer, and epistaxis. The diagnostic tendency of nasal-type ENKTL is to use computed tomography (CT), but this may present infiltrative patterns without a prominent mass, making it difficult to distinguish ENKTL from benign inflammatory diseases. Here, we report a 59-year-old male with a chief complaint of rhinosinusitis symptoms, mimicking chronic sinusitis and a CT scan showing a typical right sinusitis pattern. Functional endoscopic sinus surgery was performed and a positive culture was consistent with the diagnosis. However, histopathological and immunohistochemical evaluation established the diagnosis of nasal type ENKTL. Follow-up positron emission tomography-computed tomography (PET-CT) also corresponded with this diagnosis, and therefore, radiotherapy and chemotherapy were indicated.
    Keywords: Lymphoma, Extranodal NK-T-Cell, Sinusitis, Functional Endoscopic Sinus Surgery, Computed Tomography
  • Eun Jee Song, Se Hwan Kwon, Hyo Chul Youn, Soo Cheol Kim, Jong Soo Shin, Joo Hyeong Oh Page 16
    Primary cardiac osteosarcoma is a very rare malignancy with nonspecific symptoms, making early diagnosis a challenge. We report the computed tomography and magnetic resonance imaging findings of a primary cardiac osteosarcoma arising from the left atrium and posterior mitral leaflet in a 58-year-old woman with multiple metastases to the brain, skull, clavicle, lung, ribs, liver, lymph nodes, and thyroid gland.
    Keywords: Cardiac Tumor, Cardiac Osteosarcoma, Metastasis, Surgery, Computed Tomography, Magnetic Resonance Imaging
  • Hye Rin Kim, Seung Min Yoo, Hwa Yeon Lee, Jae Youn Moon, Woo In Yang, Charles S. White Page 17
    We present two cases of hyperthyroid cardiomyopathy (CMP) caused by Graves’ disease in which multidetector computed tomography (MDCT) findings provided specific diagnostic clues, guiding the attending physician to a prompt diagnosis and allowing rapid initiation of therapy. We believe that a combination of diffuse thyroid enlargement, with decreased attenuation on non-enhanced chest CT, thymic hyperplasia and cardiomegaly (i.e. predominantly right heart failure with enlargement of the left atrium) are suspicious CT findings of hyperthyroid CMP.
    Keywords: Grave's Disease, Cardiomyopathy, Multidetector Computed Tomography, Hyperthyroidism
  • Ayca Ata Korkmaz, Hakan Erkan, Aysegul Karadeniz, Cihan Orem Page 18
    An anomaly of the left coronary artery, originating from the pulmonary trunk, is called anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) syndrome. This syndrome is an infrequent congenital anomaly, mostly seen in children. Usually, because of the anomaly, myocardial perfusion failure occurs. This anomaly presents even less frequently in adults. The symptoms of ALCAPA develop in the early ages. Congestive heart failure is an important result of ALCAPA, as well as mitral insufficiency and left ventricular (LV) dysfunction. If there is a patent ductus arteriosus (PDA) or ventricular septal defect (VSD), high pulmonary artery pressures decreases and the coronary anomaly and perfusion defect can be hidden. Here we present a case of a large PDA combined with ALCAPA, as seen in one of the oldest patients ever reported. Recognizing PDA in patients with ALCAPA is very important, since closure of the PDA may cause catastrophic conditions. ALCAPA combined with PDA is very rare and has been reported mostly in infants. To the best of our knowledge, there is no such case diagnosed in adulthood.
    Keywords: Coronary Artery Anomalies, Patent Ductus Arteriosus, Computerized Tomography
  • Serkan Guneyli, Celal Cinar, Halil Bozkaya, Mehmet Korkmaz, Turker Acar, Mustafa Parildar, Ismail Oran Page 19
    Renal arteriovenous malformations are rare, as is their embolization with Onyx. Endovascular curative embolization of renal arteriovenous malformations with Onyx is a relatively new procedure. Herein we present two cases of congenital and one case of acquired renal arteriovenous malformation embolized with Onyx 18 and their good results in the follow-up period. We used detachable microcatheters, which may be more advantageous than the nondetachable ones, during the superselective embolizations. Onyx, as an efficient embolic material, can be commonly used for curative embolization of the renal arteriovenous malformations.
    Keywords: Arteriovenous Malformations, Congenital, Detachable Microcatheter, Endovascular Procedures, Onyx 18
  • Kyeong A. Kim, Yang Shin Park, Jongmee Lee, Jae Woong Choi, Chang Hee Lee, Cheol Min Park Page 20
    Background
    Neuroendocrine carcinomas (NECs) of the stomach are poorly differentiated, high-grade endocrine tumors, including small cell and large cell carcinomas. They are deeply invasive and metastatic, with a poor prognosis. The purpose of this study is to describe the computed tomography (CT) findings of gastric NECs with pathologic features.
    Patients and
    Methods
    CT examinations of 32 patients with gastric NECs from January 2004 to January 2015 were reviewed retrospectively for tumor morphology, size, and CT attenuation. CT attenuation of the lymph nodes, peritumoral infiltration, and associated findings, such as liver metastasis and peritoneal carcinomatosis were also reviewed. The ages of patients ranged from 45 to 79 years (mean: 62 years). Twenty-seven patients (84%) were men. Pathologic diagnosis was made using gastrectomy (n = 28) and endoscopic biopsy (n = 4). Nineteen patients underwent multidetector CT with water as an oral contrast agent, and 13 patients underwent helical CT with water.
    Results
    Among the three CT morphologic types of gastric NEC (polypoid, ulcerofungating, and ulceroinfiltrative), 63% of those in our study were ulcerofungating (n = 20), 37% were ulceroinfiltrative, and none were polypoid. All were larger than 5 cm in the greatest diameter (mean size: 7.8 cm). The characteristic features at presentation were focal (n = 3) or diffuse (n = 15) low attenuation within the mass, extensive low attenuation lymphadenopathy (n = 13), and liver metastasis (n = 6). There were no significant differences between the small cell (n = 10) and the large cell NEC groups (n = 22).
    Conclusion
    Although differential diagnosis between gastric adenocarcinoma and gastric NEC is difficult, gastric NEC should be considered when CT shows a large ulcerofungating tumor with low attenuation areas (pathologically mucinous or necrotic), especially combined with extensive necrotic lymphadenopathy and frequent hepatic metastases.
    Keywords: Stomach, Neuroendocrine, Neoplasm, Computed Tomography
  • Cheng-Zhou Zhang, Quan Li, Ping Wang, Jia Bian, Xin-Jiang Liu, Xing-Yue Jiang, Xin-Shan Cao, Lin Zhang, Chuan-Ting Li Page 21
    Background
    Magnetic resonance spectroscopy (MRS) of infants with bilirubin encephalopathy shows abnormal changes in the metabolite concentrations in various parts of the brain. Diffusional kurtosis imaging (DKI) is an extension of diffusion tensor imaging (DTI), which includes non-Gaussian diffusion effects, thereby allowing more comprehensive characterization of microstructural changes in pathological analysis.
    Objectives
    Our study retrospectively analyzed DKI data to determine whether the DKI profiles of newborns with bilirubin encephalopathy can evaluate microstructural changes and illustrate related mechanisms. This study also verified whether DKI parametrics can serve as an in vivo marker for neonatal bilirubin encephalopathy.
    Patients and
    Methods
    A total of 17 patients with neonatal bilirubin encephalopathy and 21 healthy, age-matched control newborns were included in this study. Conventional MRI and DKI were performed for all patients and controls. The mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), fractional anisotropy (FA), and mean diffusion (MD) were obtained from the voxels of interest (VOIs) within the bilateral globus pallidus, putamen, and thalamus.
    Results
    Compared with the control group, the MK, AK, RK, and FA in all VOIs were significantly decreased in neonatal bilirubin encephalopathy, whereas MD increased. Among the kurtosis tensor parameters, RK had the largest change between groups (reduced 15.2% in globus pallidus, 8.8% in putamen and 9.0% in thalamus, respectively). Between neonatal bilirubin encephalopathy and control newborns, the values of MK, AK, RK, and MD more markedly varied in the globus pallidus than in the putamen and thalamus. However, FA more obviously changed in the thalamus than in the globus pallidus and putamen.
    Conclusions
    DKI detects significant microstructural changes, which are consistent with known patterns of neurological damage in neonatal bilirubin encephalopathy. DKI parametrics can comprehensively evaluate microstructural changes and may serve as an in vivo marker for neonatal bilirubin encephalopathy.
    Keywords: Neonatal Bilirubin Encephalopathy, Diffusion Kurtosis Imaging, Globus Pallidus, Putamen, Thalamus
  • So Hee Kim, Jae Woong Choi, Yang Shin Park, Jongmee Lee, Chang Hee Lee, Kyeong Ah Kim, Min Ju Kim, Cheol Min Park Page 22
    Background
    Radiofrequency ablation (RFA) is not feasible when hepatocellular carcinoma (HCC) is poorly defined or invisible on conventional gray-scale ultrasonography (GSUS). Recent introduction of contrast-enhanced ultrasonography (CEUS) helps diagnose HCC by showing its typical enhancement pattern.
    Objectives
    The purpose of this study is to demonstrate the added value of CEUS as a RFA planning modality for HCC compared with conventional GSUS.
    Patients and
    Methods
    A total of 64 HCCs from 57 patients (men:women = 41:16; mean age, 62.6) who had undergone GSUS and CEUS for RFA planning in 2011 were retrospectively reviewed. Ultrasound contrast agent was used for CEUS after conventional GSUS. The recorded images of GSUS and CEUS were reviewed retrospectively. On GSUS, the size, location, echogenicity, and margin of each HCC were reviewed. The visibility scores of HCC on GSUS and CEUS were measured using a 3-point scale. GSUS visibility score: score 1, definite nodule with well-defined margin; score 2, slightly hypo-/hyperechoic nodule with partial margin; score 3, isoechoic nodule without margin. CEUS visibility score: score 1, arterial enhancement; score 2, only delay washout; score 3, no arterial enhancement or washout.
    Results
    The mean size of HCCs was 1.8 cm (range, 1.0 - 4.8 cm). Among 64 HCCs, visibility score 1 were 37; score 2, 8; score 3, 19 on GSUS. By performing CEUS, 10 out of 19 HCCs with GSUS visibility score 3 showed CEUS visibility score 1. Seven out of 8 HCCs with GSUS visibility score 2 showed CEUS visibility score 1. Total 37 HCCs showed visibility score 1 on GSUS; whereas, 53 HCCs showed visibility score 1 on CEUS (57.8% vs. 82.8%).
    Conclusions
    CEUS can be an effective RFA planning modality when a target HCC is invisible or questionable on GSUS.
    Keywords: Contrast Agents, Ultrasonography
  • Tugay Tartar, Unal Bakal, Mehmet Ruhi Onur, Mehmet SaraÇ, Ahmet KÜrŞ, Ad Poyraz, Ahmet Kazez Page 23
    Background
    During foreign body aspiration (FBA), identifying the type of object is frequently problematic.
    Objectives
    This study assessed density changes over time in the most common organic, FBA materials using virtual bronchoscopy. We also examined volumetric changes in materials to determine the optimal removal time for each type of foreign body.
    Materials And Methods
    Size-appropriate slots for each type of foreign body were created on a 2 × 30 × 30 cm sponge plate. Objects (shelled and blanched peanuts, roasted chickpeas, hazelnuts, walnuts, almonds, pistachios, watermelon seeds, shelled and unshelled sunflower seeds, shelled and unshelled pumpkin seeds, chickpeas, beans, lemon seeds, and apple seeds) were placed into the slots, after which a second sponge, with identical dimensions, was placed over the top of the first sponge to achieve closure. A moist environment was maintained for 7 days at body temperature (37°C). Multidetector computed tomography (MDCT) images of the sponges, volume and density measurements of objects performed each day were recorded. Intra-object differences in density and volume over time on MDCT were evaluated using time-density and time-volume curves, respectively. The SPSS for Windows software package (ver. 21.0; SPSS Inc., Chicago, IL, USA) was used to perform analyses. Pearson correlation analyses were used to determine differences in the volume and density of FBA materials across days. A time volumetric graph was also obtained. P
    Results
    Following aspiration, organic material volumes on day 7 were below baseline values, although objects exhibited a 30% average increase in volume during the first 4 days. The density values of objects increased between days 2 and 5, and decreased thereafter.
    Conclusions
    Measuring daily changes in density allows for the identification of FBA materials. Our data indicate that object removal during days 1 - 3, and on day 7 should be easier compared to days 4 - 6.
    Keywords: Foreign Body Aspiration, Virtual Bronchoscopy, Density, Volume
  • Mostafa Ghelich Oghli, Maryam Mohammadzadeh, Vahid Mohammadzadeh, Sakineh Kadivar, Ali Mohammad Zadeh Page 24
    Background
    Left ventricle segmentation plays an essential role in computation of cardiac functional parameters such as ventricular end diastolic and end systolic volumes, ejection fraction, myocardial mass, and wall thickness and also wall motion analysis. Manual segmentation is also time consuming and suffers from inter and intra observer variability. Several approaches have been proposed that segment the left ventricle (LV) by automatic and semi-automatic methods, but the problem is still open due to the huge shape variety of the left ventricle and motion artifact.
    Materials And Methods
    A robust semi-automatic approach is hereby presented for addressing the left ventricle segmentation problem. The presented method combines region information of the left ventricle with gradient and edge information in a graph framework. The LV region information is captured using our previously presented region growing method and is embedded into livewire framework.
    Results
    The modified livewire that is presented here shows a great success in quantitative criteria over the publically available MICCAI 2009 left ventricle segmentation challenge database that contains 45 normal and abnormal cases. We have computed dice metric (DM) and average perpendicular distance (APD) for the proposed method and it outperformed the state of the art results over all papers that used the same database. Validation metrics, dice metric and average perpendicular distance were computed as 0.95 mm and 1.48 mm versus those of 0.87 - 0.93 mm and 1.76 - 1.81 mm obtained by other methods, respectively.
    Conclusion
    Using semi-automatic approaches for cardiac segmentation yields satisfying results and this is because of incorporating radiologist’s experiences into the segmentation procedure. Maintaining image information to reduce user interaction is our goal for further researches.
    Keywords: Segmentation, Cardiac Magnetic Resonance Imaging, Livewire, Signed Distance Function
  • Gulgun Yilmaz Ovali, Fatih DÜzgÜn, Mustafa Farasat, Sebnem Orguc Page 25
    Objectives
    The aim of this study was to evaluate the diagnostic accuracy of chemical shift imaging in vertebral compression.
    Patients and
    Methods
    Forty-nine patients with vertebral compression with suspected malignancy or history of trauma were included in this study. MR imaging of the spine with standard conventional MR sequences and additional chemical shift imaging was done with 1.5 Tesla MR Unit. Regions of interest (ROI) were placed on the abnormal marrow of compressed vertebrae both on the opposed phase and on the matching in phase images and signal intensity (SI) ratio values (SI out-phase/SI-in phase) were calculated.
    Results
    Forty-nine patients had 68 spine lesions, consisting of 49 benign and 19 malignant fractures. Student t test, receiver operating characteristic (ROC) analysis and interclass correlation test were used statistically. Mean SI ratio of benign vertebral compression (0. 68 ± 0.29, range 0.13 - 1.53) was significantly lower than malignant SI ratio values (1.06 ± 0.10, range 0.96 - 1.35). With student t-test, there was significant difference between benign compressions compared to malignant compressions (P
    Conclusions
    There is significant difference in signal values between benign and malignant compression fractures in chemical shift MR imaging. Chemical shift MR imaging has much additive data to conventional MRI in vertebral compression.
    Keywords: Vertebral Compression, Chemical Shift Imaging, Spine, MRI
  • Mitra Naseri, Malihe Banihasan, Seyed Ali Alamdaran Page 26
    Background
    Erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP), urinary β2 microglobulin, antibody-coated bacteria in the urine sediment, and urinary lactic dehydrogenase (LDH) are more traditional tests used to diagnose true pyelonephritis. Acute-phase dimercaptosuccinic acid (DMSA) scan is a sensitive method for diagnosis of true pyelonephritis.
    Objectives
    Defining predictive values of traditional inflammatory serologic parameters, urine analysis indexes, kidney ultrasonography and fever in children with febrile urinary tract infection for predicting renal cortical involvement.
    Patients and
    Methods
    In a prospective study, 20 children admitted due to febrile urinary tract infection were assessed for renal cortical involvement by Technetium-99 m-labeled dimercapto succinic acid (TC99-DMSA) scan. Body temperature ≥ 39C, white blood cell count ≥ 15000 cell/µL, positive C-reactive protein, erythrocyte sedimentation rate (first hour) ≥ 30 mm/h, presence of proteinuria, severe pyuria or bacteriuria on urine analysis, urine specific gravity ≤ 1010, and renal ultrasonography were used for predicting renal cortical involvement. Sensitivity, specificity, positive and negative predictive values of these variables were measured by specific formula.
    Results
    The highest measured sensitivity was 100% (erythrocyte sedimentation rate ≥ 30 mm/h). Urine specific gravity 30 mm/h (100%) and proteinuria (11%) respectively. Normal sonography had a low sensitivity for predicting absence of renal involvement (23%).
    Conclusions
    Erythrocyte sedimentation rate ≥ 30 mm/h is a sensitive marker with high negative predictive value for predicting renal involvement in febrile urinary tract infection.
    Keywords: Febrile UTI, Tc99- DMSA Scan, Renal Parenchymal Involvement
  • Fatma Dilek Dellal, Husniye Baser, Dilek Arpaci, Abbas Ali Tam, Didem Ozdemir, Aydan Kilicarslan, Ersin Gurkan Dumlu, Reyhan Ersoy, Bekir Cakir Page 27
    Background
    There are ultrasonography (US) features suggested to be associated with a higher risk of malignancy in thyroid nodules. However, exophytic appearence of thyroid nodules has not been studied previously.
    Objectives
    To evaluate US features, and cytological and histopathological findings in exophytic thyroid nodules.
    Patients and
    Methods
    Patients with an exophytic thyroid nodule who underwent fine needle aspiration biopsy (FNAB) between January and July 2015 were evaluated prospectively. Demographical data, US features, and cytology results were noted and histopathological findings were determined in operated patients. The results were compared with non-exophytic nodules of age and sex matched patients.
    Results
    Data of 253 exophytic nodules in 247 patients and 529 non-exophytic nodules in 357 patients were analyzed. Hypoechogenity, mixed texture, and absence of peripheral halo were significantly higher in exophytic nodules (P
    Conclusions
    Exophytic nodules seem to carry a higher rate of malignancy both cytologically and histopathologically. Suspicous US features except hypoechoic pattern were not higher in malignant compared to benign exophytic nodules.
    Keywords: Exophytic Appearance, Thyroid Nodule, Cytology, Histopathology, Thyroid Ultrasonography
  • Nihat Acar, Ahmet Karaarslan, Ahmet Karakasli, Mehmet Erduran Page 28
    Background
    Many studies in the literature focused on the proximal geometry of the femur using cadaveric samples, X-rays or computed tomography, demonstrated substantial differences in the proximal femoral geometry in different patient groups. Many radiological parameters have been introduced in the literature to aid in diagnosis and surgical interventions.
    Objectives
    We aimed to assess the diameter of the femoral head fovea capitis in both genders with different age groups and to record their variant configurations.
    Patients and
    Methods
    Six-hundred true pelvis anteroposterior radiographs of patients were divided into three different age groups.
    Results
    In group 1, the general average values of fovea capitis index (FCI) in both female and male genders were 25.35% ± 4.12% and 26.82 ± 4.81%, respectively (P = 0.08). The general average FCI value of both sides was 26.08% ± 4.46%. In group 2, the general average values of FCI values in both female and male genders were 26.69% ± 5.27% and 26.88% ± 4.77%, respectively (P = 0.43). The general average FCI value of both sides was 26.78% ± 4.93%. In group 3, the general average values of FCI value in both female and male genders were 28.86% ± 4.98% and 29.16% ± 3.82%, respectively (P = 0.27). The general average value of both sides was 28.93% ± 4.40%.
    Conclusion
    Fovea capitis size increases with aging process. It has four different configurations. Further clinical studies should be conducted to correlate the different configurations with other femoral head pathologies and anatomical variations.
    Keywords: Femoral head, Fovea capitis, Fovea capitis index
  • Imaging Characteristics of Stafne Bone Cavity: Pictorial Essay
    Derya Yildirim, Ozlem Gormez, Esin Bozdemir, Ulkem Aydin, Omer Yilmaz, Ayse Aydogmus Erik, Mukadder Orhan Page 29
    Background
    Stafne bone cavities (SBCs) are typically seen on panoramic radiographs as unilocular, rounded or ovoid shaped, well-defined corticated radiolucencies that are located between the mandibular first molar and the angle of the mandible below the inferior alveolar canal, but they may rarely have different radiographic appearances and locations.
    Objectives
    The purpose of this study was to evaluate the imaging features of SBC presenting various typical and atypical features and to show the contribution of different imaging techniques to diagnosis.
    Patients and
    Methods
    Seventeen patients who had a panoramic radiograph that revealed an image compatible with SBC were investigated in this study. In addition to panoramic radiography, lateral oblique mandible projection for three patients, cone beam computed tomography (CBCT) for nine patients, magnetic resonance imaging (MRI) for two patients were performed to determine the exact location of the cavity and to confirm the diagnosis.
    Results
    Seventeen patients were diagnosed with SBC. Two patients had bilobed SBC, one patient had a SBC on the buccal surface of the posterior mandible, one patient had a SBC located in the ramus mandible, one patient had a SBC located in the canine-premolar region namely anterior lingual variant as rare conditions.
    Conclusion
    Imaging techniques such as CBCT and MRI have provided detailed information about definitive diagnosis of SBC in addition to panoramic radiographs. These techniques show the size, location and content of the SBC. If the SBC is atypical, complementary imaging techniques gain more importance.
    Keywords: Stafne Bone Cavity, Panoramic Radiography, Cone-Beam Computed Tomography, Magnetic Resonance Imaging
  • Yaser Safi, Mahkameh Moshfeghi, Zahra Vasegh, Mohammad Mehdi Aghdasi, Jahanghir Haghani, Mahmood Afsahi Page 30
    Objectives
    Artifacts from various dental materials are a disturbing factor which reduces the quality of images obtained from cone beam computed tomography (CBCT). This study aimed to evaluate the effect of tube current on dental material artifacts in CBCT imaging. To assess the amount of artifacts, signal difference to noise ratio indicator was used.
    Materials And Methods
    In this study, twenty widely-used dental materials were used. The samples were scanned with Soredex SCANORA 3D at two different tube current of 5 and 10 mA while all other conditions remained constant. Using the On-Demand 3D Application software, the circular areas were selected as the region of interest (ROI) at 1, 2 and 4 mm from the edge of the object’s image. In each of these ROI areas, information about mean gray value was obtained and signal difference to noise ratio (SDNR) was calculated. Data regarding two scanning conditions were compared using the Wilcoxon statistical analysis.
    Results
    Regardless of the type of material at 5 mA, SDNR at distances of 1, 2 and 4 mm were .6797, -1.2901, and -2.8608, respectively. SDNR at 10 mA scanning at a distance of 1, 2 and 4 mm were .2363, -1.1889, and -1.1844, respectively. SDNR for all materials at 5 and 10 mA scanning condition were -0.1570, and .2877, respectively and according to the Wilcoxon test there was significant difference (P value = 0.026).
    Conclusions
    By varying tube current from 5 to 10 mA, SDNR index, and regardless of the type of material, the distance and direction increased. This increase reflects the reduction of artifacts from various dental materials following increase in tube current.
    Keywords: Cone-Beam Computed Tomography, Artifact, Dental Material, Affect
  • Sina Izadyar, Saeed Farzanehfar, Mina Ranji Amjad, Mehrshad Abbasi, Alireza Emami Ardekani, Babak Fallahi, Armaghan Fard Esfehani, Javad Esmaeli, Fariba Akhzari, Parham Geramifar Page 31
    Background
    Because of the increasing prevalence of both ischemic heart diseases and vitamin D deficiency and also due to recent evidences on association between these two phenomena, it is vital to clarify the association of ischemic heart disease with vitamin D deficiency and low bone mass.
    Objectives
    The aim of the present study was to assess the relationship between low serum vitamin D and low bone mass measured by dual-energy X-ray absorptiometry (DEXA) with ischemic heart disease assessed by the functional radionuclide myocardial perfusion imaging (MPI).
    Patients and
    Methods
    In this cross-sectional study, 204 consecutive patients aged older than 50 years who were candidates for MPI were included. Blood sample was extracted to measure the level of serum 25-OH vitamin D using a special kit (IDS kit). Then, the patients were assessed by MPI. Within a month of myocardial perfusion scanning, subjects underwent bone mineral density (BMD) measurements by DEXA method.
    Results
    There was no significant difference in serum level of vitamin D between patients with normal and those with abnormal MPI results. In addition, no significant correlation was detected between BMD and myocardial ischemia.
    Conclusion
    Coronary atherosclerosis may not be associated with the severity of low bone mass or level of vitamin D adequacy.
    Keywords: Myocardial Ischemia_Vitamin D Deficiency_Bone Density
  • Sonay Aydin, Erdem Fatihoglu, Hayri Ramadan, Bilge S. Akhan, Enver N. Koseoglu Page 32
    Background
    The aim of the current study was to investigate whether the usage of three diagnostic methods of acute appendicitis which are Alvarado score, C- reactive protein (CRP) levels and ultrasound (US) in combination improves diagnostic accuracy significantly.
    Patients and
    Methods
    Data were analyzed in 254 patients with suspected appendicitis who had a sonographic examination and a CRP value. The patients were classified into four groups according to both Alvarado score and US findings. US results, Alvarado score, and CRP levels were compared.
    Results
    The most specific test among three diagnostic methods was sonography. Combination of an Alvarado score higher or equal to 5, a high CRP level (≥ 0.8) and a sonographic examination as appendicitis with visualization of an inflamed or perforated appendix was more specific than US alone. An Alvarado score higher or equal to 5 (86.2%) was found to be the most sensitive criteria.
    Conclusions
    Using Alvarado score, US and CRP levels in combination provides us to confirm or rule out acute appendicitis safely.
    Keywords: Alvarado Score, Appendicitis, CRP, Ultrasound
  • Bilgin Kadri Aribas, Ramazan Tiken, Ozge Aribas, Tugba Uylar, Ismail Akdulum, Ibrahim Turker, Merve Yildiz Aksoy, Turgut Seber, Burcu Sahin, Haci Uzun, Emrah Caglar Page 33
    Background
    Studies have reported factors affecting the efficacy of subcutaneous venous chest port catheters placed into jugular or subclavian veins using a radiological technique. There is ongoing debate for this efficacy in these series.
    Objectives
    To examine factors on patency times, including complications of subcutaneous venous chest port insertions, using ultrasonography guidance in 1,408 patients over a long-term follow-up.
    Patients and
    Methods
    Between April 2009 and March 2014, subcutaneous venous chest ports were placed in 1,408 patients, 574 women and 834 men (mean age, 55.4 ± 12.1 years). Factors affecting the port patency were examined. Age, gender, access, malignancy site, and coagulation parameters were variables. A multivariable Cox regression test was used. Additionally, the successes were compared by univariate Kaplan-Meier survival analysis.
    Results
    Fifty-seven patients underwent port removal because of complications. Complication due to catheter patency time, as number of specific complication per 100 catheter days divided by total patency days shown in parenthesis. Ports were explanted in 29 patients because of thrombosis (0.0054), in nine patients because of infection (0.0017), in eight patients because of catheter malposition (0.0015), in five patients because of bleeding (0.0009), in five patients because of skin necrosis with infection (0.0009) and one patient because of a port reservoir flip-over (0.0002), of a total of 57 patients (0.0107). The patency was similar in the two central veins (P = 0.230). No factor was significant except for the malignancy site (P = 0.002). The malignancy site and gender were significant factors for thrombosis. Port removal was significantly higher in extremities involving two regions and in female patients.
    Conclusions
    Patency was not different between two venous access groups. The malignancy site was the only significant factor for success.
    Keywords: Central Venous Port, Interventional Radiology, Cancer, Thrombosis, Catheter
  • Jie Pan, Jiajia Zhou, Ping Liu, Yali Gu, Benyan Luo Page 34
    Background
    The leptomeningeal collateral (LMC) is dynamic in ischemic stroke especially in internal carotid artery (ICA) and middle cerebral artery (MCA) disorders. Transcranial doppler (TCD) is the only noninvasive and portable technique for the LMC; however, there is no standard for TCD in LMC assessment.
    Objectives
    To establish a reference for TCD to assess the LMC in severe occlusive ICA and MCA disorders.
    Patients and
    Methods
    Forty-four patients were divided into two groups according to the LMC flow in digital subtraction angiography (DSA). The velocities of the bilateral MCA, anterior cerebral artery (ACA), and posterior cerebral artery (PCA) were analyzed.
    Results
    In the ACA-LMC group, the ratio of the stenosis-side ACA and MCA were significantly increased for the systolic velocity (P = 0.003). The sensitivities and specificities were 68.4% and 80.0%, respectively, when the ratio was 2.27 (P = 0.006). In the PCA-LMC group, the ratio of the stenosal side PCA and the opposite side PCA were significantly increased for the diastolic velocity (P = 0.031). The sensitivities and specificities were 77.8% and 75.0%, respectively, when the ratio was 1.38 (P = 0.026).
    Conclusion
    TCD is a reliable tool for LMC assessment in patients with severe occlusive ICA and MCA disorders.
    Keywords: Transcranial Doppler Ultrasonography, Collateral Circulation, Internal Carotid Artery Stenosis, Middle Cerebral Artery Occlusion
  • Soheila Majd, Basri Johan Jeet Abdullah, Sazilah Ahmad Sarji, Chai Hong Yeong, Noor Azmi Mat Adenan Page 35
    Background
    Dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) is a relatively new imaging technique that provides additional information on vascularity and permeability of the uterine tissues to improve decision making in patient management.
    Objectives
    The purpose of this study was to obtain the quantitative DCE-MRI parameters of symptomatic uterine fibroids and compare to the parameters obtained from normal myometrium, endometrium, and cervix.
    Patients and
    Methods
    Nineteen patients (aged 40 ± 5 years) with the clinical diagnosis of uterine fibroids were recruited. After routine MRI pelvis scan, DCE-MRI was performed using T1 volumetric liver acquisition with volume acceleration (LAVA) sequence. The data were post-processed using an independent DCE-MRI analysis software. ROI was drawn on the fibroid and the quantitative DCE-MRI parameters i.e. Ktrans (volume transfer between the blood plasma and extracellular fluid), Kep [flux rate constant between the extracellular extravascular space (EES) and blood plasma], Ve (EES fractional volume), and semi-quantitative parameters i.e. TTP (time to peak), and IAUGC (initial area under the gadolinium concentration-time curve) were determined. The patients then underwent hysterectomy and uterine fibroids were confirmed in all the patients by histopathology results. In the control group, fifteen healthy volunteers (aged 32 ± 6 years) who did not have uterine fibroid confirmed by sonography examination were recruited. The volunteers underwent the same DCE-MRI scan as the patients and the quantitative DCE-MRI parameters of the normal myometrium, endometrium and cervix were obtained. The DCE-MRI parameters from these two groups were then compared.
    Results
    The median Ktrans in the myometrium, endometrium and cervix of the healthy volunteers were 0.26 ± 0.13, 0.20 ± 0.15, and 0.30 ± 0.13 min-1, respectively. No statistical significant difference was found in all the DCE-MRI parameters between the myometrium, endometrium and cervix of the healthy volunteers. The median Ktrans in fibroids was 0.50 ± 0.25 min-1. There were statistically significant differences (P
    Conclusions
    The Ktrans and Ve of fibroid tissue were statistically significantly higher than those obtained from the normal myometrium, whereby the suggested cut-off values were 0.47 min-1 (sensitivity 64.7%, specificity 92.3%) and 0.62 (sensitivity 70.6%, specificity 78.6%), respectively. Quantitative DCE-MRI findings from this study may provide a foundation for assessment of other uterine pathologies.
    Keywords: Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DEC-MRI), Quantitative, Semi-Quantitative, Ktrans, Ve, Uterine Fibroids, Uterus
  • Mojtaba Barzegar, Ali Reza Shirazi, Seyed Rabi Mahdavi, Hamid Reza Baghani Page 36
    Background
    The accurate dose delivery in intraoperative radiotherapy (IORT) tightly depends on the precision of measured dose by the ion chamber. Output factor (OF) measurement of dedicated intraoperative electron radiotherapy (IOERT) accelerators using ion chamber faces some technical challenges including determination of Ksat.
    Objectives
    The goal was to evaluate the performance of ethanol chlorobenzene (ECB) dosimeter in measuring the OF of intraoperative electron beam and to compare the results to those of ionometric dosimetry and Monte Carlo simulation. Consequemtly we determined the Ksat of employed ion chamber through comparison of the ECB response to ion chamber.
    Materials And Methods
    LIAC dedicated accelerator (LIAC Sordina SpA, Italy) was used for irradiation. To calculate the Ksat, ECB and Advanced Markus chamber were placed at the depth of maximum dose for different energies of LIAC accelerator. Then, Ksat was calculated through comparison of the obtained results. To measure the OF of electron beam, ECB was placed at the depth of maximum dose for each combination of energy/applicator size, and the absorbed dose was determined. Obtained results were compared to those of Advanced Markus chamber and Monte Carlo simulation.
    Results
    The results of Ksat measurement showed that there is a very good agreement between the practically obtained Ksat and theoretical values determined by Laitano formalism at different energies (the maximum difference between the results was lower than 1%). The results of ECB OF measurement were in accordance to the results of ionometric dosimetry and Monte Carlo simulation (the maximum difference between the results was about 1.5% and 1.7%, respectively).
    Conclusion
    Based on the results, it may be concluded that the ECB dosimeter could be considered as an accurate tool for both OF measurement of intraoperative electron beam and cross calibration of employed ion chambers for absolute dosimetry (determination of the Ksat).
    Keywords: Radiation Dosimetry, Ionizing Radiation, Monte Carlo Method