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.

Leiomyomatous Lesions of the Colon: Two Case Reports with Radiological Features, Pathological Correlations, and Literature Review.

Colonic leiomyomatous lesions are smooth muscle tumors including both benign leiomyoma and malignant leiomyosarcoma. They usually occur in elderly and middle-aged groups. They are rare, representing 3% of all gastrointestinal leiomyomas. Descending and sigmoid colon are the most commonly affected segments of colon. Patients are usually asymptomatic but occasionally they may present with abdominal pain, hemorrhage, and intestinal obstruction. Radiological findings for these lesions are variable and overlapping with other diagnoses but usually manifest as large lesions with lobulated margins, extra-colic growth, and heterogeneous enhancement. Final diagnosis is achieved by tissue diagnosis in which immunohistochemistry is used to differentiate them from other types of mesenchymal tumors like gastrointestinal stromal tumor. A complete surgical/endoscopic resection is usually curative with an excellent prognosis in cases of benign leiomyoma. In cases of leiomyosarcoma, post-surgical chemotherapy and radiotherapy are usually needed with a five-year survival of about 50%. We report the radiological findings with pathological correlation and literature review of two cases of colonic leiomyomatous lesions that presented with nonspecific abdominal pain. The lesions were resected surgically and confirmed histopathologically as leiomyoma and leiomyosarcoma of the colon, respectively. To the best of our knowledge, these cases are the first of colonic leiomyomatous lesions to be reported in Oman.

COVID-2019 Pneumonia: Severity and distribution of lung changes observed on the initial chest X-ray as an indicator of final outcomes.

Objectives: This study aimed to assess the correlation between the severity of the initial chest x-ray (CXR) abnormalities in patients with a confirmed diagnosis of COVID-19 and the final outcomes. Methods: This retrospective study was conducted at the Royal Hospital, Oman between mid-March and May 2020 and included patients who had been admitted with a confirmed diagnosis of COVID-19 and had a final outcome. Serial CXRs were identified and examined for presence, extent, distribution and progression pattern of radiological abnormalities. Each lung field was divided into three zones on each CXR and a score was allocated for each zone (0 is normal and 1-4 is mild-severe). The scores for all six zones per CXR examination were summed to provide a cumulative chest radiographic score (range: 0-24). Results: A total of 64 patients were included; the majority were male (89.1%) and the mean age was 50.22 ± 14.86 years. The initial CXR was abnormal in 60 patients (93.8%). The most common finding was ground glass opacity (n = 58, 96.7%) followed by consolidation (n = 50, 83.3%). Most patients had bilateral (n = 51, 85.0%), multifocal (n = 57, 95.0%) and mixed central and peripheral (n = 36, 60.0%) lung abnormalities. The median score of initial CXR for deceased patients was significantly higher than recovered patients (17 versus 11; P = 0.009). Five CXR evolution patterns were identified: type I (initial radiograph deteriorates then improves), type II (fluctuate), type III (static), type IV (progressive deterioration) and type V (progressive improvement). Conclusion: A higher baseline CXR score is associated with higher mortality rate and poor prognosis in those with COVID-19 pneumonia.

Prospective evaluation of the value of dynamic contrast enhanced (DCE) imaging for prostate cancer detection, with pathology correlation.

INTRODUCTION: The aim of this study was to evaluate the value of dynamic contrast enhanced (DCE) imaging in multi-parametric prostate MRI (mpMRI) for the detection and staging of prostate cancer in comparison with T2W and DWI images alone in biparametric MRI (bpMRI) in treatment naïve patients. MATERIALS AND METHODS: One hundred consecutive patients who underwent a prostate MRI at our institution from June-August 2017, as well as a systematic ultrasound-guided prostate biopsy or prostatectomy, were included. Strictly following PIRADSv2, the MRI studies were independently interpreted by a body radiologist and a body-imaging fellow on two different occasions 8-10 weeks apart. Initially, with all mpMRI sequences and then without the DCE sequence (bpMRI). The readers were blinded to the clinical information. Ethics approval was obtained. RESULTS: One hundred treatment-naïve patients were included (median age 64, age range 48-81, mean PSA 10.3). There was almost perfect intra-observer agreement for mpMRI versus bpMRI for both readers [Cohen's Kappa (k) 0.88-0.86] and substantial inter-observer agreement (k = 0.74 for mpMRI and 0.76 for bpMRI). The sensitivity and specificity did not significantly change between multi-parametric and bi-parametric MRI (Sensitivity 91.7% and 90%, Specificity of 85.5% and 85% for mpMRI and bpMRI, respectively). CONCLUSION: Based on our findings, prostate MRI without DCE (bpMRI) is of comparable diagnostic accuracy to mpMRI in treatment-naïve patients. Performing prostate MRI without DCE (bpMRI) will reduce acquisition time, decrease cost and potentially improve patient safety.

Validation of Region of Interest Measurements for the Objective Assessment of Post-Contrast Enhancement of Renal Lesions on MRI.

OBJECTIVE: The aim of this study was to validate the use of region of interest (ROI) measurements in MRI to objectively assess for enhancement in suspected solid renal masses and to determine a minimum threshold value for true enhancement. METHODS: Contrast-enhanced renal MRI studies performed between January 2015 and December 2017 for patients with a known renal mass who had subsequent biopsy, or partial/radical nephrectomy were included. Two body imaging fellows independently measured the mean ROI values of renal masses, normal renal parenchyma, the ipsilateral psoas muscle and external air on the pre- and post-contrast sequences. The absolute and percentage changes in the mean ROI values were calculated. The readers were blinded to the pathology results. RESULTS: 104 patients were included in this study (mean age of 65 years; 58 males and 46 females). 74 patients (71%) had a diagnosis of renal cell carcinoma (RCC). Pathology showed clear-cell RCC in 55%, papillary RCC in 22%, and other RCC subtypes in 23%. There were 30 non-RCC renal lesions (29%), including oncocytoma, renal papillary adenoma, and renal metastasis.The minimum percentage change in ROI values in the pre- versus post-contrast images for all pathology-proven RCCs was 23% (range: 23-437%, mean: 143%); this represents relative enhancement and was referred to as the Signal Intensity Index (SII). The percentage change for normal renal parenchyma ranged from 32-317%. The maximum percentage change in ROI values for pathology proven renal cysts was 13% (range: -5-13%, mean: 3.5%). There was excellent inter observer agreement between the two readers [Intra-class correlation coefficient (r) 0.81]. CONCLUSION: The percentage change in ROI values (SII) can be a helpful tool in the objective assessment of true enhancement of renal masses and can supplement subtraction images. The minimum threshold for enhancement in our study was 23%. ADVANCES IN KNOWLEDGE: Enhancement of a renal lesion can be determined using the objective tool of ROI measurements in the pre- and post-contrast MR images with a percentage change of 20% or above indicating enhancement. This is an additional objective tool, which in conjunction with the subtraction images may improve detection and appropriate diagnosis of renal lesions. It could also be helpful in cases where the subtraction images are degraded by motion artefact.

Pelvic congestion syndrome due to agenesis of the infrarenal inferior vena cava.

The inferior vena cava (IVC) is the main conduit of venous return to the right atrium from the lower extremities and abdominal organs. Agenesis of the IVC has an incidence of <1% in the general population [1], although it has been reported in the literature as occurring in up to 8.7% of the population [2]. Patients with absent IVC may present with symptoms of lower extremity venous insufficiency [6], idiopathic deep venous thrombosis [7], or pelvic congestion syndrome. To our knowledge there have only been a few cases reported in the literature of agenesis of the IVC associated with pelvic congestion syndrome [3,10,11]. We present another interesting case of pelvic congestion syndrome due to absent IVC.

Magnetic resonance imaging findings in ovarian torsion post in vitro fertilization.

Patients who get pregnant after being treated with in vitro fertilization (IVF) are at significantly increased risk of ovarian torsion compared to the general population and also in comparison to patients who get pregnant normally [1,2]. The risk is further increased in patients who develop ovarian hyperstimulation syndrome [1]. This possibility should be considered in this group of patients presenting with acute abdominal pain and immediate management should be commenced. Here, we report 2 patients who received treatment for infertility with IVF and developed ovarian torsion and we discuss their management including the imaging workup. The first case is a 34-year-old woman at 11 + 3 weeks of gestation after IVF who presented with a 12-hour acute right lower abdominal pain with nausea and vomiting. She underwent an ultrasound examination and then further evaluated with magnetic resonance imaging which showed asymmetric enlargement of the right ovary and stromal edema and a diagnosis of ovarian torsion was made. The patient underwent laparoscopic detortion and the ovary was salvaged. The second case is a 33-year-old woman at 9 weeks of gestation after IVF who presented with intermittent abdominal pain, vaginal bleeding, and nausea and vomiting for 5 days but became worse on the fifth day. Ultrasound and subsequently magnetic resonance imaging were performed which confirmed hyperstimulation syndrome. Abnormal location of the left ovary anterior to the uterus with higher volume as well as the clinical progression raised the possibility of ovarian torsion and prompted a diagnostic laparoscopy which showed right ovarian torsion and detortion was performed.

Fibrodysplasia ossificans progressiva - radiological findings: a case report.

UNLABELLED: Fibrodysplasia ossificans progressiva formerly known as Myositis ossificans progressiva is a rare hereditary mesodermal disorder. It is characterized by congenital skeletal anomalies and progressive ectopic bone formation in connective tissue, resulting in mature ossification within soft tissues and bridging between osseous structures. It is extremely rare and has an incidence of one in two million people. Usually, it has typical clinical and radiographic features. Here, we present a case of a young patient diagnosed to have an advanced fibrodysplasia ossificans progressiva. Plain radiographs provide characteristic findings, and radiologists may play a major role in diagnosing and preventing invasive procedures or further traumatic insults to the affected patient. Though rare, diagnosis of fibrodysplasia ossificans progressiva should be considered whenever characteristic radiographic features of multifocal heterotopic bone formation is seen along with the valgus deformities of the big toes. Being a rare condition, treatment guidelines are not clear and this condition needs further research. KEYWORDS: Myositis ossificans progressiva; Fibrodysplasia ossificans progressiva; Heterotopic ossification; Myositis ossificans.