Validating the diagnostic accuracy of an MRI-based scoring system for differentiating benign uterine leiomyomas from leiomyosarcomas.

OBJECTIVE: Uterine leiomyomas are the most common benign uterine tumors. They are difficult to distinguish from their malignant counterparts-smooth muscle tumors of unknown malignant potential (STUMP) and leiomyosarcoma. The purpose of this study is to propose and validate the diagnostic accuracy of the MRI-based Oman-Canada Scoring System of Myometrial Masses (OCSSMM) to differentiate uterine leiomyomas from STUMP/leiomyosarcomas. METHODS: This is a retrospective study performed at two tertiary care centers. All patients with a pathology-proven uterine mass who underwent pre-operative pelvic MRI between January 2010 and January 2020 were included. Using a 1.5T MRI machine, sequences included were axial/coronal/sagittal T2 and T1 weighted imaging, axial diffusion weighted and apparent diffusion coefficient map, and axial or sagittal dynamic contrast-enhanced sequences. A scoring system was designed based on previously published worrisome MRI features for uterine leiomyosarcoma. Each feature was allocated a score from 0 to 2 according to the strength of association with malignancy. Subsequently, the MR images were blindly and independently reviewed by a fellowship-trained radiologist and a clinical fellow/senior resident. Each uterine mass was scored according to their imaging features. The scores were divided into five categories according to the sum of scores. Category III and above was considered positive for leiomyosarcoma/STUMP. Sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: A total of 244 women were included (age range 20-74 years, mean 40). Of these, 218 patients had benign leiomyoma, 13 had STUMP, and 13 had leiomyosarcoma. The sensitivity and specificity of the scoring system were 92.3% and 64.7%, respectively. The negative predictive value was 98.6%. No leiomyosarcoma was missed using this scoring system. The presence of non-cystic T2 hyperintensity or diffusion restriction in a uterine mass were the most sensitive signs of a leiomyosarcoma/STUMP. CONCLUSION: The proposed multi-parametric MRI scoring system may be useful in differentiating benign uterine leiomyomas from leiomyosarcomas/STUMP.

Multidetector CT in Vascular Injuries Resulting from Pelvic Fractures: A Primer for Diagnostic Radiologists.

Pelvic vascular injuries are typically caused by high-energy trauma. The majority of these injuries are caused by motor vehicle collisions, and the rest are caused by falls and industrial or crush injuries. Pelvic vascular injuries are frequently associated with pelvic ring disruption and have a high mortality rate due to shock as a result of pelvic bleeding. Morbidity and mortality resulting from pelvic vascular injury are due to pelvic hemorrhage and resultant exsanguination, which is potentially treatable and reversible if it is diagnosed early with multidetector CT and treated promptly. The pelvic bleeding source can be arterial, venous, or osseous, and differentiating an arterial (high-pressure) bleed from a venous-osseous (low-pressure) bleed is of paramount importance in stratification for treatment. Low-pressure venous and osseous bleeds are initially treated with a pelvic binder or external fixation, while high-pressure arterial bleeds require angioembolization or surgical pelvic packing. Definitive treatment of the pelvic ring disruption includes open or closed reduction and internal fixation. Multidetector CT is important in the trauma setting to assess and characterize pelvic vascular injuries with multiphasic acquisition in the arterial and venous phases, which allows differentiation of the common vascular injury patterns. This article reviews the anatomy of the pelvic vessels and the pelvic vascular territory; discusses the multidetector CT protocols used in diagnosis and characterization of pelvic vascular injury; and describes the spectrum of pelvic vascular injuries, the differentiation of common injury patterns, mimics, and imaging pitfalls. Online supplemental material is available for this article. ©RSNA, 2019 See discussion on this article by Dreizin.

Diagnostic accuracy of technetium-99m-octreotide in imaging neuroendocrine tumors, Oman hospital experience with literature review.

The aim of this observational cross-sectional study with retrospective review of the data is to evaluate the efficacy of using technetium-99m-octreotide (Tc-99m-OCT) in imaging neuroendocrine tumors (NETs) in our tertiary care hospital. A total of 58 patients had Tc-99m-OCT were identified in our database, from January 2013 to December 2016. Forty-one patients (age range of 15-75 years) meet our inclusion criteria, namely histopathology proven NETs, Tc-99m-OCT scan, computed tomography (CT), or magnetic resonance imaging (MRI) done in our institute for correlation. Twenty-three patients had true positive Tc-99m-OCT scan. In addition to the primary tumors, the octreotide scan revealed metastasis in the lung, liver, and retroperitoneal lymph nodes. The smallest lesion detected on octreotide scan was a 4-mm pulmonary nodule that was missed on lung window CT scan. The Tc-99m-OCT had 17 true negative, one false negative, and no false positive. The CT and MRI scans had 18 true positive, 17 true negative, 5 false negative, and one false positive. The overall sensitivity, specificity, accuracy, positive, and negative predictive values of Tc-99m-OCT scan were 96%, 100%, 97%, 100%, and 94%, respectively. Whereas those of CT and MRI were 78%, 94%, 85%, 94%, and 77%, respectively. Our diagnostic accuracy of Tc-99m-OCT is high. We recommend that, in addition to the conventional radiological investigations, Tc-99m-OCT scan, or other somatostatin receptor imaging (SSR) is a mandate for better and accurate staging of patients with NETs.