- Volume:12 Issue: 4, 2015
- تاریخ انتشار: 1394/06/03
- تعداد عناوین: 12
Assessment of Lipiodol Deposition and Residual Cancer for Hepatocellular Carcinoma After Transcatheter Arterial Chemoembolization via Iodine-Based Material Decomposition Images with Spectral Computed Tomography Imaging: A Preliminary StudyPage 1BackgroundIt is critical to follow up hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE) in clinical practice. Computed tomography (CT) is used to assess lipiodol deposition, whereas it is difficult to assess hypovascular residual cancer masked by lipiodol. In contrast, magnetic resonance imaging (MRI) is superior to CT in showing residual cancer, but cannot display lipiodol deposition..ObjectivesThe aim of this study was to investigate the value of spectral CT imaging in both lipiodol deposition and residual cancer for HCC patients after TACE..Patients andMethodsTen HCC patients after treated with TACE underwent Discovery CT750 HD and MRI750 3T examination. Receiver operating characteristic (ROC) curves of iodine-based material decomposition images, monochromatic images and conventional CT images were generated..ResultsConsequently, 30 residual lesions were detected in MRI of 10 patients. They were found in iodine-based images and monochromatic images versus 29 in conventional CT images. The area under ROC curves for the lesion-to-normal parenchyma ratio (LNR) on arterial phase (AP) in iodine-based material decomposition images, monochromatic images and conventional CT images were 0.933, 0.833 and 0.817, respectively..ConclusionThe study data highlighted good value of iodine-based material decomposition images of spectral CT in assessment of both lipiodol deposition and residual cancer for follow-up of HCC patients previously treated with TACE..Keywords: Tomography, Magnetic Resonance Imaging, Carcinoma, Hepatocellular
Page 2BackgroundRadiographs, adjunct to clinical examination are always valuable complementary methods for dental caries detection. Recently, progressing in digital imaging system provides possibility of software designing for automatically dental caries detection..ObjectivesThe aim of this study was to develop and assess the function of diagnostic computer software designed for evaluation of approximal caries in posterior teeth. This software should be able to indicate the depth and location of caries on digital radiographic images..Materials And MethodsDigital radiographs were obtained of 93 teeth including 183 proximal surfaces. These images were used as a database for designing the software and training the software designer. In the design phase, considering the summed density of pixels in rows and columns of the images, the teeth were separated from each other and the unnecessary regions; for example, the root area in the alveolar bone was eliminated. Therefore, based on summed intensities, each image was segmented such that each segment contained only one tooth. Subsequently, based on the fuzzy logic, a well-known data-clustering algorithm named fuzzy c-means (FCM) was applied to the images to cluster or segment each tooth. This algorithm is referred to as a soft clustering method, which assigns data elements to one or more clusters with a specific membership function. Using the extracted clusters, the tooth border was determined and assessed for cavity. The results of histological analysis were used as the gold standard for comparison with the results obtained from the software. Depth of caries was measured, and finally Intraclass Correlation Coefficient (ICC) and Bland-Altman plot were used to show the agreement between the methods..ResultsThe software diagnosed 60% of enamel caries. The ICC (for detection of enamel caries) between the computer software and histological analysis results was determined as 0.609 (95% confidence interval [CI] = 0.159-0.849) (P = 0.006). Also, the computer program diagnosed 97% of dentin caries and the ICC between the software and histological analysis results for dentin caries was determined as 0.937 (95% CI=0.906-0.958) (P < 0.001). Bland-Altman plot showed an acceptable agreement for measuring the depth of caries in enamel and dentin..ConclusionsThe designed software was able to detect a significant number of dentin caries and acceptable measuring of the depth of carious lesions in enamel and dentin. However, the software had limited ability in detecting enamel lesions..Keywords: Computer Software, Dental Caries, Digital Radiography
Fetal Nasal Bone Status In Iranian Women Undergoing First-Trimester Screening For Trisomy 21: A Review and an Observational Study.Page 3BackgroundFailed visualization of the fetal nasal bone (NB) by ultrasound at 11 - 14 weeks of gestation is strongly associated with chromosomal abnormalities. Meanwhile, the incidence of the absent fetal NB in normal fetuses in the first trimester in mothers of different ethnic origins differs significantly. It is, therefore, important to assess ethnic variations in the first-trimester visualization of the fetal NB before introducing this marker into routine screening programs for aneuploidy..ObjectivesThe objectives of this study were to determine the NB length and the prevalence of the NB absence as well as calculating the likelihood ratio (LR) for the absence of the NB in normal fetuses of Iranian women undergoing first-trimester screening for trisomy 21..Patients andMethodsIn 767 normal fetuses, the fetal profile was examined by ultrasound for the absence/presence of the NB. The NB length was also measured, and the LR for the NB absence was also determined..ResultsThe NB was absent in 2/767 (0.26%) of the fetuses. The mean length of the NB was 3.6 ± 0.69 mm for the fetuses of 11 - 14 weeks gestational age. The LR value of the absent NB was equal to 250 in the normal fetuses of the Iranian population living in the North-West provinces..ConclusionThe low prevalence of the NB absence in normal fetuses in the present study is compatible with the larger size of the NB in Iranian people compared to other communities. Meanwhile, the reference range of the NB length in normal Iranian fetuses was established so that basic data could be recorded for further studies regarding the absence or presence of the NB in screening for chromosomal abnormalities (Down syndrome) within the Iranian population..Keywords: Bone, Ultrasonography, First Trimester, Down syndrome
99mTc-IgG-Lung Scintigraphy in the Assessment of Pulmonary Involvement in Interstitial Lung Disease and Its Comparison With Pulmonary Function Tests and High-Resolution Computed Tomography: A Preliminary StudyPage 4BackgroundThe discrimination of inactive inflammatory processes from the active form of the disease is of great importance in the management of interstitial lung disease (ILD)..ObjectivesThe aim of this study was to determine the efficacy of 99mTc-IgG scan for the detection of severity of disease compared to high-resolution computed tomography (HRCT) and pulmonary function test (PFT)..Patients andMethodsEight known cases of ILD including four cases of Mustard gas (MG) intoxication and four patients with ILD of unknown cause were included in this study. A population of six patients without lung disease was considered as the control group. The patients underwent PFT and high-resolution computed tomography scan, followed by 99mTc-IgG scan. They were followed up for one year. 99mTc-IgG scan assessment of IgG uptake was accomplished both qualitatively (subjectively) and semiquantitatively..ResultsAll eight ILD patients demonstrated a strong increase in 99mTc-IgG uptake in the lungs, compared to the control patients. The 99mTc-IgG scan scores were higher in the patient group (0.64[95% confidence interval(CI)=0.61-0.69])) than the control group (0.35(0.35[95% CI=0.28-0.40]), (P<0.05)). In patients, a statistically significant positive correlation was detected between 99mTc-IgG scan and HRCT scores (Spearman’s correlation coefficient = 0.92, P < 0.008). The 99mTc-Human Immunoglobulin (HIG) scores were not significantly correlated with PFT findings (including FVC, FEV1, FEV1/FVC), O2 saturation and age (P values > 0.05). There were no significant correlations between 99mTc-IgG score and HRCT patterns including ground glass opacity, reticular fibrosis and honeycombing (P value > 0.05)..ConclusionThe present results confirmed that 99mTc-IgG scan could be applied to detect the severity of pulmonary involvement, which was well correlated with HRCT findings. This data also showed that the 99mTc-IgG scan might be used as a complement to HRCT in the functional evaluation of the clinical status in ILD; however, further studies are recommended..Keywords: Interstitial Lung Disease, Tomography, X-ray Computed, Respiratory Function Tests, Mustard Gas
Page 5BackgroundConsiderable development of MRI technology in diagnostic imaging, high cost of MRI technology and controversial issues concerning official charges (tariffs) have been the main motivations to define and implement this study..ObjectivesThe present study aimed to calculate the unit-cost of MRI services using activity-based costing (ABC) as a modern cost accounting system and to fairly compare calculated unit-costs with official charges (tariffs)..Materials And MethodsWe included both direct and indirect costs of MRI services delivered in fiscal year 2011 in Shiraz Shahid Faghihi hospital. Direct allocation method was used for distribution of overhead costs. We used micro-costing approach to calculate unit-cost of all different MRI services. Clinical cost data were retrieved from the hospital registering system. Straight-line method was used for depreciation cost estimation. To cope with uncertainty and to increase the robustness of study results, unit-costs of 33 MRI services was calculated in terms of two scenarios..ResultsTotal annual cost of MRI activity center (AC) was calculated at USD 400,746 and USD 532,104 based on first and second scenarios, respectively. Ten percent of the total cost was allocated from supportive departments. The annual variable costs of MRI center were calculated at USD 295,904. Capital costs measured at USD 104,842 and USD 236, 200 resulted from the first and second scenario, respectively. Existing tariffs for more than half of MRI services were above the calculated costs..ConclusionAs a public hospital, there are considerable limitations in both financial and administrative databases of Shahid Faghihi hospital. Labor cost has the greatest share of total annual cost of Shahid Faghihi hospital. The gap between unit costs and tariffs implies that the claim for extra budget from health providers may not be relevant for all services delivered by the studied MRI center. With some adjustments, ABC could be implemented in MRI centers. With the settlement of a reliable cost accounting system such as ABC technique, hospitals would be able to generate robust evidences for financial management of their overhead, intermediate and final ACs..Keywords: Health, Care, Magnetic Resonance Imaging, Health Economics, Cost Analysis, Pricing Medical Fees
Page 6Uterine inversion is shortly described as the indentation and depression of the fundic area extending downwards up to the different levels of the birth canal till vaginal opening. Clinical diagnosis of uterine inversion is difficult due to its non-specific symptoms and physical examination. Ultrasonography is the most practical modality for radiological evaluation, but it is inadequate to determine the exact nature of this condition and making the differential diagnosis. In this case, we present the main MRI findings of non-puerperal complete uterine inversion caused by a giant leiomyoma..Keywords: Uterine Inversion, Uterine Prolapse, Magnetic Resonance, Ultrasonography, Uterine Diseases
Organizing Hematoma of the Maxillary Sinus Mimicking Malignancy Diagnosed by Fluorodeoxyglucose Positron-Emission Tomography (FDG PET/CT): A Case ReportPage 7Organizing hematoma of the paranasal sinuses is a diagnostic dilemma clinically and radiographically, mimicking benign or malignant neoplastic processes. Although the diagnostic rate of this disease has increased as characteristic imaging findings are somewhat elucidated, endoscopic examination, preoperative biopsy, and computed tomography (CT) imaging do not give helpful information in differentiating these lesions from malignant neoplastic processes..A 55-year-old man presented with a 4-month history of recurrent nasal bleeding. He also complained of a left-sided nasal obstruction. CT findings were highly suggestive of a malignant tumor of the maxillary sinus. However, based on fluorodeoxyglucose F18 positron-emission tomography (PET/CT) and magnetic resonance imaging (MRI), the provisional diagnosis of benign tumor rather than malignancy was made. Complete resection of the mass was achieved by simple transnasal endoscopic surgery using the Caldwell-Luc approach. Organizing hematoma of the maxillary sinus was diagnosed by histopathologic evaluation. The clinical, radiological, and histopathologic findings of the patient are presented..In this report, we have presented 18FDG-PET findings of organized hematoma of the maxillary sinus (OHMS) that showed an increased FDG uptake in the peripheral rim of the mass with central photopenia. To our knowledge, this is the first case report in the literature reporting FDG-PET/CT findings of OHMS. Careful interpretation of metabolic (FDG-PET/CT) and anatomic (CT and MRI) images should be performed to accurately characterize the expansile lesion of the maxillary sinus in order to increase specificity and reduce equivocal findings significantly..Keywords: Organizing Hematoma, Computed Tomography, Chronic Expanding Hematoma, Fluorodeoxyglucose F18 Positron, Emission Tomography, Magnetic Resonance Imaging, Maxillary Sinus
Chondromyxoid Fibroma of Two Cervical Vertebrae with Involvement of Surrounding Soft Tissue: Radiologic Diagnostic DilemmaPage 8Chondromyxoid fibroma is a rare benign cartilaginous neoplasm that mostly affects the metaphyseal region of the long bones. The tibia, small tubular bones of the foot, the distal femur and pelvis are common locations, but involvement of the vertebral bones, especially the cervical vertebra, is very rare. Radiographic features show typical characteristics and this tumor often presents as a lobulated, eccentric radiolucent lesion with no periosteal reaction. In addition, geographic bone destruction is seen in all cases. We present an adult female with a one-year history of neck pain, and ultrasound findings that suggest a right paravertebral muscular lesion due to inflammatory or neoplastic origins. The histopathological studies confirmed that the biopsied specimen was a chondromyxoid fibroma of the cervical vertebrae laminae and spinous processes (C3 and C4) with abutting soft tissue. Despite the unusual location and soft tissue presentation, a chondromyxoid fibroma should be considered in the differential diagnosis of a cervical bone lesion..Keywords: Tissue, Chondromyxoid Fibroma, Vertebrae
Decidualized Ovarian Endometrioma in a Pregnant Woman Mimicking Ovarian Malignancy: Magnetic Resonance Imaging and Ultrasonographic FindingsPage 9Decidualized ovarian endometrioma is a rare phenomenon in pregnancy, which can mimic ovarian malignancy in imaging and often poses a diagnostic challenge. We report a case of a large ruptured decidualized ovarian endometrioma in a 15 weeks gestation patient, and we will describe the imaging characteristics (ultrasonography and MR imaging findings) and the histopathological findings (macro- and microscopically)..Keywords: Endometrioma, Pregnancy, Magnetic Resonance Imaging, Ultrasonography
Velocity Measurement in Carotid Artery: Quantitative Comparison of Time-Resolved 3D Phase-Contrast MRI and Image-based Computational Fluid DynamicsPage 10BackgroundUnderstanding hemodynamic environment in vessels is important for realizing the mechanisms leading to vascular pathologies.
ObjectivesThree-dimensional velocity vector field in carotid bifurcation is visualized using TR 3D phase-contrast magnetic resonance imaging (TR 3D PC MRI) and computational fluid dynamics (CFD). This study aimed to present a qualitative and quantitative comparison of the velocity vector field obtained by each technique.
Subjects and MethodsMR imaging was performed on a 30-year old male normal subject. TR 3D PC MRI was performed on a 3 T scanner to measure velocity in carotid bifurcation. 3D anatomical model for CFD was created using images obtained from time-of-flight MR angiography. Velocity vector field in carotid bifurcation was predicted using CFD and PC MRI techniques. A statistical analysis was performed to assess the agreement between the two methods.
ResultsAlthough the main flow patterns were the same for the both techniques, CFD showed a greater resolution in mapping the secondary and circulating flows. Overall root mean square (RMS) errors for all the corresponding data points in PC MRI and CFD were 14.27% in peak systole and 12.91% in end diastole relative to maximum velocity measured at each cardiac phase. Bland-Altman plots showed a very good agreement between the two techniques. However, this study was not aimed to validate any of methods, instead, the consistency was assessed to accentuate the similarities and differences between Time-resolved PC MRI and CFD.
ConclusionBoth techniques provided quantitatively consistent results of in vivo velocity vector fields in right internal carotid artery (RCA). PC MRI represented a good estimation of main flow patterns inside the vasculature, which seems to be acceptable for clinical use. However, limitations of each technique should be considered while interpreting results.Keywords: Fluid Dynamics, Time-Resolved Three-Dimensional Phase-Contrast Magnetic Resonance Imaging (TR 3D PC MRI), Carotid Bifurcation
Perianal Fistula With and Without Abscess: Assessment of Fistula Activity Using Diffusion-Weighted Magnetic Resonance ImagingPage 11BackgroundMagnetic resonance imaging (MRI) is highly accurate for the depiction of both the primary tract of fistula and abscesses, in patients with perianal disease. In addition, MRI can be used to evaluate the activity of fistulas, which is a significant factor for determining the therapeutic strategy.
ObjectivesThis study aimed to determine the usefulness of diffusion-weighted (DW) MRI for assessing activity and visibility of perianal fistula.
Patients and MethodsFifty-three patients with 56 perianal fistulas were included in the current retrospective study. The T2-weighted imaging (T2WI) and DWMRI were performed and apparent diffusion coefficient (ADC) values of fistulas were measured. Fistulas were classified into two groups: only perianal fistulas and fistulas accompanied by abscess. Fistulas were also classified into two groups, based on clinicalfindingspositive inflammatory activity (PIA) and negative inflammatory activity (NIA).
ResultsMean ADC value (mm2/s) of PIA group was significantly lower than that of NIA group, regarding lesions in patients with abscess-associated fistulas (1.371 × 10-3 ± 0.168 × 10-3 vs. 1.586 × 10-3 ± 0.136 × 10-3; P = 0.036). No statistically significant difference was found in mean ADC values between PIA and NIA groups, in patients with only perianal fistulas (P = 0.507). Perianal fistula visibility was greater with combined evaluation of T2WI and DWMRI than with T2WI, for two reviewers (P = 0.046 and P = 0.014).
ConclusionThe DWMRI is a useful technique for evaluating activity of fistulas with abscess. Perianal fistula visibility is greater with combined T2WI and DWMRI than T2WI alone.Keywords: Magnetic Resonance Imaging, Diffusion, Perianal Fistula, Inflammation, Abscess
Effect of Object Position in Cone Beam Computed Tomography Field of View for Detection of Root Fractures in Teeth with Intra-Canal PostsPage 12BackgroundVertical root fracture (VRF) is a common problem in endodontically treated teeth. Due to its poor prognosis, a reliable technique must be used to make an accurate diagnosis. Cone beam computed tomography (CBCT) has been recently introduced for maxillofacial imaging. Despite the high diagnostic value of this method, metal artifacts resulting from intra-canal posts still make the detection of VRFs challenging.
ObjectivesThis study aimed to assess the effect of object position in the field of view (FOV) of CBCT on detection of VRFs in teeth with intra-canal posts.
Materials and MethodsThe crowns of 60 extracted premolar teeth were cut at the level of cementoenamel junction (CEJ). Root canals were filled with gutta-percha and filling of the coronal 2/3 of the root canals was subsequently removed to fabricate intra-canal cast posts. The teeth were randomly divided into two groups of 30. Fracture was induced in group one using an Instron machine. Group two was considered as the control group with no fracture. All teeth were then randomly positioned and scanned in five different positions starting at the center of the FOV as well as right, left anterior and posterior relative to the center (3, 9, 12, and 6 O’clock) via the New Tom VGI CBCT unit. Two observers evaluated images for VRFs. Sensitivity and specificity of fracture diagnosis in each position was calculated in comparison with the gold standard. Wilcoxon test was used for data analysis.
ResultsConsidering deterministic and probabilistic diagnostic parameters, probabilistic sensitivity was similar in all positions; but probabilistic specificity of the center position (65.1%) was significantly higher than that of 6 and 12 O’clock positions. Considering the deterministic diagnostic parameters, the overall sensitivity and specificity values decreased in all positions in FOV, but sensitivity of the center position of FOV was significantly higher than that of other positions; specificity was significantly higher at the 3 O’clock position (58.5%).
ConclusionConcerning the positions in FOV, the center position is suitable for detection of VRF in teeth with intra-canal posts due to significantly higher sensitivity at this position. The 3 O’clock position would be suitable for assessment of intact teeth without fractures due to significantly higher specificity at this position.Keywords: Tooth Fracture, Cone-Beam Computed Tomography, Post, Core Technique, Position