Iranian Journal of Radiology
Volume:19 Issue: 4, Oct 2022

 Contrast-enhanced chest computed tomography (CT) is useful for the detection and follow-up of patients with lung cancer. However, reaching balance between diagnostic image quality, radiation dose, and iodixanol dose is a cause of concern.

 To investigate the clinical value of adaptive statistical iterative reconstruction (ASIR) in reducing the iodixanol content and radiation dose during contrast-enhanced chest CT scan for patients diagnosed with lung masses/nodules based on the analysis of image quality.

 This prospective study was conducted on 80 patients diagnosed with nodules or masses, who required contrast-enhanced chest CT scans. The experimental group (n = 40) was subjected to iohexol at a high concentration (350 mgI/L) with a tube voltage of 120 kVp and a filter back projection (FBP) reconstruction algorithm. The comparison group (n = 40) was subject to iodixanol at a lower concentration (270 mgI/L) with a tube voltage of 100 kVp and ASIR (blending ratio, 40%). The radiation dose and total iodixanol content, as well as subjective and objective evaluations of image quality, were analyzed and compared.

 The two groups obtained non-significantly different subjective scores for five structures detected in the lung window and five structures detected in the mediastinal window, as well as the overall image (P > 0.05 for all). Both the two-group images obtained diagnosis-acceptable scores (≥ 3 points) on displays of 10 structures and overall image quality. The mean CT value of vessels (100 kVp vs. 120 kVp: 314.90 ± 23.42 vs. 308.93 ± 21.40; P > 0.05), standard deviation (13.03 ± 0.88 vs. 12.83 ± 0.90; P > 0.05), and contrast-to-noise ratio (20.77 ± 2.20 vs. 20.36 ± 1.94; P > 0.05) were not significantly different between two groups. However, the CT dose index, dose-length product, effective dose, and total iodine dose were reduced by 27.58%, 36.65%, 36.59%, and 22.86% in the 100-kVp group compared to the 120-kVp group.

 The ASIR showed great potential in reducing the radiation dose and iodine contrast dose, while maintaining good image quality and providing strong confidence for the diagnosis of lung cancer.

 Most brain gliomas are high-grade and likely to spread locally. Consequently, these patients commonly have a poor prognosis. Accurate identification of the malignancy grade of brain glioma before treatment is of great clinical significance.

 This study aimed to explore the correlation of diffusion tensor imaging (DTI) parameters, fractional anisotropy (FA), and apparent diffusion coefficient (ADC) with the pathological grade of brain glioma and expression of vascular endothelial growth factor (VEGF) and Ki-67.

 A total of 116 patients were selected for this study from January 2018 to December 2019. All the participants underwent magnetic resonance imaging (MRI) and DTI before surgery, and the FA and ADC values were measured for the regions of interest. Surgically resected tumor specimens were collected for immunohistochemical assay. Finally, the FA and ADC values and positive expression rates of VEGF and Ki-67 were compared.

 A significantly higher FA, besides the positive expression of VEGF and Ki-67, was reported in the high-grade group, whereas a lower ADC was found in this group compared to the low-grade group (P < 0.05). Areas of normal white matter and peritumoral edema had higher FA values, whereas lower ADCs were measured in these areas compared to the cerebrospinal fluid (P < 0.05). The FA of tumor parenchymal area was positively correlated with the World Health Organization (WHO) WHO class of tumors (r = 0.588, P = 0.028), and the expression of VEGF and Ki-67 was positively correlated with the WHO grade (r = 0.843, P = 0.002 and r = 0.743, P = 0.006, respectively). The FA of tumor parenchymal area was positively correlated with the expression of VEGF and Ki-67 (r = 0.654, P = 0.008 and r = 0.567, P = 0.012, respectively). However, the ADC of tumor parenchymal area was not significantly correlated with the WHO grade, VEGF expression, or Ki-67 expression (r = 0.143, P = 0.156, r = 0.232, P = 0.116, and r = 0.054, P = 0.179, respectively).

 The FA value, as a DTI parameter, is valuable for assessing the malignancy grade of tumor cells and can provide a proper reference for formulating treatment regimens for brain gliomas.

 Postpartum hemorrhage (PPH), a serious labor-related complication, is the leading cause of maternal mortality, which requires an emergent intervention. Uterine arterial embolization (UAE) is an effective treatment for hemostasis of intractable PPH. Several risk factors have been reported for the failure of UAE.

 To evaluate the clinical outcomes of UAE for the treatment of primary PPH following cesarean section (CS) and to determine the risk factors associated with the failure of this procedure.

 This retrospective, single-center study was approved by the institutional review board, and the requirement to obtain informed consent was waived. All patients referred to a tertiary care center, who underwent UAE for primary PPH between January 2018 and December 2020, were included. The patients’ medical records and radiological findings, including the patients’ characteristics, mode of delivery, initial vital signs and laboratory findings after hospitalization, procedure details, and embolization outcomes, were evaluated for data collection. Technical success was defined as appropriate embolization of target vessels on a completion angiogram. Clinical success was defined as adequate cessation of bleeding after the first embolization, without any need for subsequent embolization or surgical intervention. Statistical analysis was performed to determine factors related to the clinical failure of UAE in CS cases.

 UAE was performed for 25 patients (mean age, 37.2 years; range, 25 - 45 years). The technical success rate was estimated at 100% (n = 25), and the clinical success rate was 76% (n = 19). There were no patients with permanent adverse sequelae or death. The univariate analyses showed that hemodynamic instability (P = 0.006), lower hemoglobin levels (P = 0.02), and prolonged activated partial thromboplastin time (aPTT) (P = 0.017) were related to clinical failure. The logistic regression analysis adjusted for age showed that the area under the curve (AUC) was 0.86 for hemoglobin (95% CI: 0.7 - 1; cutoff value: 0.667), 0.816 for aPTT (95% CI: 0.625 - 1; cutoff value: 0.411), and 0.868 for hemodynamic instability (95% CI: 0.661 - 1; cutoff value: 0.622).

 UAE is a safe and effective treatment for primary PPH following CS. Hemodynamic instability, low hemoglobin levels, and prolonged aPTT can be predictive factors for the poor outcomes of UAE in CS patients. These factors are rapid and straightforward criteria, which can be simply applied, even in emergency situations.

 Ataxia is a symptom of a wide range of disorders, which manifests as a lack of coordinated movements. It is commonly associated with cerebellar disorders.

 To evaluate the neuroimaging findings of children with acute ataxia (AA) and to identify the association between these findings and clinical results.

 This cross-sectional study was conducted using the electronic medical records of patients, presenting to a major pediatric referral center over 10 years from March 2009 to February 2020. Patients were included in the study if they were younger than 18 years, were diagnosed with AA (< 30 days), and underwent magnetic resonance imaging (MRI), computed tomography (CT) scan, or both. The exclusion criteria were as follows: A history of neurological or medical disorders, explaining ataxia; pseudo-ataxia; a traumatic brain injury; severe loss of consciousness; and missing key information in the medical records (e.g., no brain imaging findings). Patient data, including the demographic data, clinical history, laboratory findings, imaging results, and in-hospital outcomes, were collected. A P-value less than 0.05 was considered statistically significant, and the confidence interval was set at 95%.

 A total of 119 patients were included in this study (51% female; mean age, 4.9 years). Clinically urgent neurological pathology (CUNP) was detected in 37 (31.09%) patients. The most common pathologies on images were tumors, acute disseminated encephalomyelitis (ADEM), and stroke. However, the most common diagnosis was acute post-infectious cerebellar ataxia (APCA) (24.4%), followed by brain tumors (16.8%) and Guillain-Barre syndrome (GBS) (15.1%), respectively. Overall, 11 variables were significantly different between patients with and without CUNP. Most notably, the duration of symptoms (P < 0.01), ophthalmoplegia (odds ratio [OR] = 13.93; 95% confidence interval [CI]: 3.5 - 54.7), focal neurologic deficit (OR = 7.26; 95% CI: 2.6 - 20.5), and fever (OR = 3.33; 95% CI: 1.1 - 9.8) were associated with a higher risk of CUNP. On the other hand, some features, such as a recent history of febrile illness (presence of fever or body temperature above 38°C in the last month) (OR = 0.36; 95% CI: 0.16 - 0.8) and hyporeflexia (P < 0.01), were associated with a lower risk of CUNP.

 Acute post-infectious cerebellar ataxia was the most common diagnosis of AA in children, undergoing neuroimaging studies in our center. Nevertheless, tumor was the most common pathology detected on the images of patients with CUNP. Some pathologies might not be detected by some imaging modalities. Considering the associations identified in this study, patients with risk factors, such as a longer duration of symptoms, ophthalmoplegia, focal neurologic deficit, and fever, need to undergo another imaging modality with higher sensitivity if there are no positive findings in the initial imaging study. On the other hand, patients with protective factors, such as hyporeflexia and a recent history of febrile illness, could benefit more from other diagnostic modalities.

 Chest computed tomography (CT) scan is one of the most common tools used for the diagnosis of patients with coronavirus disease 2019 (COVID-19). While segmentation of COVID-19 lung lesions by radiologists can be time-consuming, the application of advanced deep learning techniques for automated segmentation can be a promising step toward the management of this infection and similar diseases in the future.

 This study aimed to evaluate the performance and generalizability of deep learning-based models for the automated segmentation of COVID-19 lung lesions.

 Four datasets (2 private and 2 public) were used in this study. The first and second private datasets included 297 (147 healthy and 150 COVID-19 cases) and 82 COVID-19 subjects. The public datasets included the COVID19-P20 (20 COVID-19 cases from 2 centers) and the MosMedData datasets (50 COVID-19 patients from a single center). Model comparisons were made based on the Dice similarity coefficient (DSC), receiver operating characteristic (ROC) curve, and area under the curve (AUC). The predicted CT severity scores by the model were compared with those of radiologists by measuring the Pearson’s correlation coefficients (PCC). Also, DSC was used to compare the inter-rater agreement of the model and expert against that of 2 experts on an unseen dataset. Finally, the generalizability of the model was evaluated, and a simple calibration strategy was proposed.

 The VGG16-UNet model showed the best performance across both private datasets, with a DSC of 84.23% ± 1.73% on the first private dataset and 56.61% ± 1.48% on the second private dataset. Similar results were obtained on public datasets, with a DSC of 60.10% ± 2.34% on the COVID19-P20 dataset and 66.28% ± 2.80% on a combined dataset of COVID19-P20 and MosMedData. The predicted CT severity scores of the model were compared against those of radiologists and were found to be 0.89 and 0.85 on the first private dataset and 0.77 and 0.74 on the second private dataset for the right and left lungs, respectively. Moreover, the model trained on the first private dataset was examined on the second private dataset and compared against the radiologist, which revealed a performance gap of 5.74% based on DSCs. A calibration strategy was employed to reduce this gap to 0.53%.

 The results demonstrated the potential of the proposed model in localizing COVID-19 lesions on CT scans across multiple datasets; its accuracy competed with the radiologists and could assist them in diagnostic and treatment procedures. The effect of model calibration on the performance of an unseen dataset was also reported, increasing the DSC by more than 5%.

 Flourine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan is employed for initial staging and restaging of esophageal cancer patients.

 The present study aimed to assess the value of a semi-quantitative parameter of 18F-FDG PET/CT scan, that is, maximum standardized uptake value (SUVmax), to determine its correlation with patient survival in two subtypes of esophageal cancer, including squamous cell carcinoma (SCC) and adenocarcinoma.

 This cross-sectional study was performed on patients with esophageal SCC and adenocarcinoma, undergoing 18F-FDG PET/CT scan for initial staging before any treatment. The 18F-FDG PET/CT semi-quantitative parameter (SUVmax) was determined by reviewing the PET/CT images. The patients were reevaluated using 18F-FDG PET/CT scan for restaging within 12 - 24 months.

 No significant difference was observed in the SUVmax values of the primary tumor, metastatic lymph nodes, or distant metastasis between the adenocarcinoma and SCC groups, regardless of response to treatment. Similarly, no significant association was found between the short-term survival of patients with adenocarcinoma and the SUVmax values of the primary tumor, metastatic lymph nodes, or distant metastasis. Based on the survival curve, one- and two-year survival rates were estimated at 75% and 63.9% in patients with SCC and at 80% and 60% in patients with adenocarcinoma, respectively. In the SCC group, a significantly higher SUVmax was detected in deceased patients with distant metastatic lesions compared to cancer survivors. According to the area under the ROC curve, the SUVmax of metastatic lesions showed high potential for predicting the mortality of SCC patients.

 The assessment of SUVmax in distant metastatic lesions by 18F-FDG-PET/CT may help predict the survival of patients with esophageal SCC. However, 18F-FDG-PET/CT findings were not associated with the survival of esophageal adenocarcinoma; therefore, further evaluations on a larger sample size and a longer follow-up are required.

 Endometriosis is one of the most common gynecological diseases worldwide. Significant attention has been drawn to this multiorgan and often painful disorder.

 This study aimed to examine the accuracy of transvaginal sonography (TVS) in the diagnosis of deeply infiltrating endometriosis (DIE) with respect to the presence or absence of ovarian endometrioma (OE).

 This cross-sectional study was performed on all patients undergoing TVS before gynecological laparoscopy. With pathological confirmation as the standard reference, the diagnostic accuracy of TVS for DIE and pouch of Douglas (POD) obliteration was compared with that of laparoscopy in the anterior and posterior pelvic compartments with respect to the presence or absence of OE. Agreement between TVS and laparoscopy was evaluated for each case, and Cohen’s kappa statistic was measured for each site of involvement. Moreover, sensitivity, specificity, negative and positive predictive values, and likelihood ratios of TVS were calculated, with laparoscopy as the reference test.

 A total of 110 patients, with a mean age of 37.20 ± 7.16 years, were recruited in this study. The accuracy, sensitivity, and negative predictive value of TVS for the diagnosis of DIE and POD obliteration were estimated at 89.5%, 58.3%, and 88.9% in the anterior pelvic compartment and 93.3%, 92%, and 70.6% in the posterior pelvic compartment, respectively. Nevertheless, TVS showed lower sensitivity for detecting pelvic adhesions and peritoneal cysts compared to laparoscopy. The presence of OE did not significantly increase the accuracy of TVS for the diagnosis of DIE or POD obliteration (P > 0.05).

 The present study showed that TVS is an adequately accurate and non-invasive diagnostic tool for the detection and mapping of DIE and POD obliteration, regardless of the presence of OE. TVS may waive the need for exploratory laparoscopy in DIE or at least facilitate precise pre-procedural DIE mapping.

 Differentiation of patients with central precocious puberty (CPP) from healthy individuals and patients with CPP-like conditions [isolated premature thelarche (IPT) and isolated premature adrenarche (IPA)] is important for selecting an appropriate treatment. The gonadotropin-releasing hormone stimulation test is used as the gold standard for differentiating CPP from other conditions. Despite its high specificity, this test has disadvantages, such as low sensitivity, time-consuming sampling, and need for multiple blood samples.

 This study aimed to investigate the use of pelvic ultrasonography (US) and its parameters in distinguishing CPP patients from those with similar conditions and healthy individuals.

 In this case-control study, a total of 183 patients, who were referred to the endocrinology department of Ali Asghar Hospital in Tehran, Iran for the evaluation of CPP, were recruited cconsecutively from 2015 to 2019. All the participants were Iranians and classified based on the clinical and laboratory findings. Pelvic US parameters were evaluated in all groups. One-way analysis of variance (ANOVA) was used to compare the mean values of continuous variables between the groups. Moreover, a post-hoc test was performed for pairwise comparisons between the groups if the result of ANOVA test was statistically significant. Finally, the receiver-operating characteristic (ROC) curve analysis was performed to determine the best cutoff points for US parameters.

 Of 183 children, 62 were allocated to the control group (33.87%), 93 to the CPP group (50.81%), 16 to the IPT group (8.74%), and 12 to the IPA group (6.55%). The results showed no significant difference between the groups regarding chronological age and body mass index, while the bone age (107.76 ± 19.81 months) (P < 0.001) and height (129.53 ± 8.97 cm) were significantly higher in the CPP group compared to the other groups (P = 0.003). All US parameters were significantly different between the CPP and control groups. There were also significant differences between CPP patients and those with IPT and IPA in terms of all parameters, except for the cervical anteroposterior diameter and ovarian volume. The best parameters for differentiating CPP from other conditions were the uterine volume (cutoff value, 1.40; 75.27% sensitivity; 75.56% specificity), uterine transverse diameter (cutoff value, 13.5 mm; 72.04% sensitivity; 71.11% specificity), and fundus/cervix (F/C) ratio (cutoff value, 0.98; 78.49% sensitivity; 70% specificity).

 The pelvic US parameters can improve the diagnosis of CPP and play an auxiliary role in distinguishing the treatment needed. Based on the findings, the best diagnostic parameter and its cutoff value can vary depending on ethnicity and type of study.

 Renomedullary interstitial cell tumors are benign tumors of renal medulla. They are usually asymptomatic, and preoperative diagnosis based on radiological findings is challenging. Therefore, in most clinical situations, nephrectomy is ultimately performed for differential diagnosis.

 A 54-year-old woman presented to our hospital with hematuria. An incidental mass in the left kidney was detected on abdominal computed tomography (CT) scan. The mass showed iso-attenuation to renal parenchyma in the pre-contrast image and hypo-attenuation in the portal venous phase; however, some enhancement was observed in the central portion of the mass. Based on contrast-enhanced ultrasonography (CEUS) after one year, a slight septum-like enhancement was observed in the central portion of the mass in the venous phase. In dynamic contrast-enhanced T1- and T2-weighted magnetic resonance images (MRI), the mass showed a low signal intensity, and delayed persistent enhancement was observed in 10- and 15-minute delayed phases. The mass was finally diagnosed as a renomedullary interstitial cell tumor.

 The imaging findings of renomedullary interstitial tumors included a low-signal-intensity mass of renal medulla on T1- and T2-weighted MRI and delayed enhancement on CEUS and dynamic MRI.

 Ethanol ablation (EA) and radiofrequency ablation (RFA) are minimal invasive therapeutic modalities to treat primary hyperparathyroidism (PHPT).

 A 77-year-old man presented a 3.5-cm parathyroid adenoma with mixed cystic and solid components. He was ineligible for parathyroidectomy because of his age and the surgical history of the coronary artery bypass graft. First, EA was performed to remove cystic component. After that, the volume of parathyroid adenoma was decreased (volume reduction rate: 94%); however, the level of serum parathyroid hormone (PTH) was persistently high (88 pg/mL). Subsequent RFA was performed to remove the remaining parathyroid adenoma. Further, it was completely disappeared on the following ultrasound examination, and PTH was normalized. The results during a 2-year follow-up confirmed clinical success, and no relevant complication was reported.

 The combination therapy of EA and subsequent RFA is safe and effective as an alternative therapeutic method to treat PHPT in patients ineligible for parathyroidectomy.