Can Whole-Body Magnetic Resonance Imaging Predict Relapse in Juvenile Idiopathic Arthritis? A Longitudinal Pilot Study.

OBJECTIVE: To determine the utility of whole-body magnetic resonance imaging (WB MRI) to predict relapse in children with juvenile idiopathic arthritis (JIA) in clinical remission. METHODS: Consecutive patients with JIA who fulfilled the Wallace criteria for remission were recruited into this longitudinal pilot study and underwent WB MRI. A radiological score was devised, incorporating synovitis, bone marrow edema, sacroiliitis, enthesitis, and bone erosions. Two readers independently scored the MR data sets. The same score was calculated for both knee joints individually and correlated with outcome for that joint. Score-based models incorporating clinical and laboratory variables were generated. Logistic regression analysis was done to determine predictors for relapse. Receiver operating characteristic curve was drawn for significant variables. RESULTS: Twenty-two children (median age, 12 years; interquartile range, 9.5-14.25 years) were included in the final analysis. At 24 months' follow-up, 15 joints in 5 children relapsed; knee was the most common site. Seven knee joints had disease relapse. On univariate analysis, synovitis and total score on WB MRI were significant predictors of relapse at follow-up, with odds ratios of 9.46 (bias-corrected 95% confidence interval, 3.07-29.13) and 2.8 (bias-corrected 95% confidence interval, 1.23-6.39) respectively. Two models, which included a higher number of joints involved at presentation and abrupt drug withdrawal strategy as predictor variables, were also statistically significant (odds ratio, approximately 1.9). On multivariate analysis of the predictors variables in models where p < 0.6, it was found that only synovitis score and total score were near statistical significance ( p = 0.06); no clinical or laboratory variables were significant. The areas under the receiver operating characteristic curve for relapse prediction were approximately 0.82, 0.87, 0.79, and 0.81 for synovitis score, total MRI score, and both models, respectively. CONCLUSION: Synovitis on WB MRI is the strongest independent predictor for disease relapse in children with JIA in remission.

Diagnostic accuracy of whole-body magnetic resonance imaging versus positron emission tomography-computed tomography for the staging of pediatric lymphoma: a systematic review and meta-analysis.

BACKGROUND: Whole-body magnetic resonance imaging (MRI) has been investigated by multiple authors as a radiation-free alternative to positron emission tomography computed tomography (PET-CT) in children with lymphoma. OBJECTIVE: To evaluate the sensitivity, specificity, and diagnostic odds ratio of whole-body MRI compared to PET-CT for the staging of pediatric lymphoma. METHODS: The databases PubMed, Embase, and Scopus were searched for studies that reported the accuracy of whole-body MRI compared to PET-CT for lymphoma staging in children. Data was collected from included studies to formulate 2 × 2 contingency tables, including the number of true positive, true negative, false positive, and false negative. The pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated. Summary receiver operating characteristic curves were drawn and the area under the curve (AUC) calculated. In addition, the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS 2) tool was used to assess the risk of bias and applicability concerns. RESULTS: A total of seven studies were included in the final analysis. Of these, six studies used unenhanced whole-body MRI. The pooled sensitivity of whole-body MRI-based staging was 95.8%, while the pooled specificity was 21.8%. The DOR for whole-body MRI was 1.19. For extranodal staging, the pooled sensitivity was 88.9%, specificity was 97.4%, and DOR was 25.29. The partial AUC for overall staging was 0.63, whereas that for extranodal staging stood at 0.88. Based on the QUADAS 2 tool, all seven studies were at risk of bias (six at high risk, one at unclear risk). CONCLUSION: Whole-body MRI has high sensitivity for staging of pediatric lymphoma and may be a useful alternative to PET-CT.

Transperineal Ultrasound as an Adjunctive Modality in the Evaluation of 'H or N' Type of Recto-urethral Fistula: Technical Note.

Anorectal malformations (ARMs) encompass a complex spectrum of congenital anomalies and H/N type anorectal malformations are extremely rare. In the presence of colostomy, an augmented pressure colostogram with or without retrograde or micturating cystourethrogram is the investigation of choice. Transperineal ultrasound is an imaging technique that allows a fairly accurate morphological assessment of ARMs along with dynamic evaluation of the anorectal structures and pelvic floor anatomy. Here we describe the role of transperineal ultrasound as an adjunctive modality in diagnosis of one such complex anomaly.

Basic principles of AI simplified for a Medical Practitioner: Pearls and Pitfalls in Evaluating AI algorithms.

With the rapid integration of artificial intelligence into medical practice, there has been an exponential increase in the number of scientific papers and industry players offering models designed for various tasks. Understanding these, however, is difficult for a radiologist in practice, given the core mathematical principles and complicated terminology involved. This review aims to elucidate the core mathematical concepts of both machine learning and deep learning models, explaining the various steps and common terminology in common layman language. Thus, by the end of this article, the reader should be able to understand the basics of how prediction models are built and trained, including challenges faced and how to avoid them. The reader would also be equipped to adequately evaluate various models, and take a decision on whether a model is likely to perform adequately in the real-world setting.

Fibrosing Interstitial Lung Disease in Children: An HRCT-Based Analysis.

OBJECTIVE: To determine high resolution CT (HRCT) patterns of pulmonary fibrosis (PF) in children; and their etiological correlates. METHODS: This was a retrospective study involving 149 children with diffuse lung disease (DLD). Patterns of involvement were classified based on dominant lung finding as ground glass opacity (GGO) dominant, nodule dominant, cystic lung disease, or PF. Patterns of PF were classified based on distribution and morphology into airway centric fibrosis (ACF), subpleural fibrosis (SPF), progressive massive fibrosis (PMF) and fibrocavitary. A comparison was made between the two dominant groups for apicobasal distribution, associated findings (GGO, nodules, cysts), and pulmonary artery hypertension (PAH). RESULTS: Nineteen patients showed PF on HRCT. ACF was commonest (52.6%), followed by SPF (42.1%). The common etiology was sarcoidosis (30%) in ACF, and connective tissue disorders (CTD) (50%) in SPF. Significant difference was found between ACF and SPF in apicobasal distribution (p = 0.04), presence of nodules (p = 0.03), and cysts (p = 0.02). CONCLUSION: PF may present as an end stage of several childhood lung diseases. PF on imaging has discernible morphological patterns that correlate with underlying etiology.

Pediatric lung ultrasonography: current perspectives.

Ultrasonography (US) is the workhorse of pediatric imaging; however, lung US is only a recently developed application. US of the lung is based predominantly on the imaging of chest wall-air-fluid interfaces. In this review, we summarize the available literature on applications of lung US in neonatal as well as pediatric care. We describe the imaging appearance of various commonly encountered pathologies including pneumonia and respiratory distress syndrome, among others, and provide illustrative images. Finally, we describe the limitations of the technique that are essential knowledge for radiologists, critical care physicians, sonographers and technologists attempting to use lung US effectively for diagnosis and management.

Ultrasound-guided Percutaneous Embolization of Post Renal Biopsy Gonadal Artery Pseudoaneurysm.

Hemorrhage is the most frequently encountered post renal biopsy complication; reported in 12% to 14% of patients. Although the vast majority of these are due to renal artery injury, involvement of gonadal arteries is also rarely seen. These may be managed by the endovascular route, which has several limitations in this subset of patients. We report a case of a 69-year-old male with rapidly progressive glomerulonephritis, who underwent renal biopsy and developed a testicular artery pseudoaneurysm (PA). Successful embolization of this PA was performed under ultrasound guidance using a direct percutaneous approach. This is the first such case reported in the literature.

Imaging in extremity vascular trauma: can MDCT angiography predict the nature of injury?

OBJECTIVE: This study aims to evaluate the utility of computed tomography angiography (CTA) signs of vascular injury in the differentiation of vessel transection from pure thrombosis with intact vessel wall. METHODS: Retrospective analysis was done on 146 consecutive patients who had undergone CTA and surgical exploration from January 2015 to September 2019. Twelve imaging parameters were assessed. Chi-square was used to test the difference between groups. In addition, a scoring system was devised where one point each was added for the presence of 5 signs and absence of 3 signs. ROC analysis was done for the variables which had shown significant difference between groups and for the composite score. RESULTS: On surgical exploration, 87 patients had transection of vessel, while 59 had thrombosis. Significant difference was found among the two groups in non-opacification, pseudoaneurysm, extravasation (p = 0.04 each), thrombosed cord (p < 0.001), collaterals (p = 0.001) and hematoma (p = 0.002), while other signs did not show significant difference. The AUC value for each of these variables was < 0.650, while for the score, AUC was .843(.773-.913). A cut-off value of ≥ 1.5 gave 83.1% sensitivity and 70% specificity for diagnosing transection. CONCLUSION: CTA is a useful tool to classify the nature of vascular injury. It is advisable to use a composite score for maximum diagnostic value.

Walking the Risk-Benefit Tight Rope: A Case of Post Fine Needle Aspiration Haemorrhage in Extramedullary Plasmacytoma.

BACKGROUND: Primary extramedullary plasmacytomas (EMP) are rare; however, secondary forms may be seen in ~10-15% of patients with systemic multiple myeloma (MM). The diagnosis of EMP is based on the demonstration of monoclonal plasma cells in the lesion, which requires tissue sampling. CASE PRESENTATION: We present a case of a 38 year old female with MM who underwent diagnostic US at our institute. Multiple focal liver lesions were detected, which were suspicious for EMP. She underwent fine needle aspiration cytology (FNAC) for diagnosis, following which she developed hemoperitoneum secondary to deranged clotting parameters (prothrombin time and platelet count). CT angiography revealed active hepatic capsular bleed. She was taken up for percutaneous embolisation, and the supplying vessel successfully embolised using gel foam particles. CONCLUSION: Complications may rarely occur in interventional procedures, particularly in patients with comorbidities. However, prompt diagnosis and management help prevent adverse outcomes.

Transcutaneous Mediastinal Ultrasonography for Lymphadenopathy in Children: A Pictorial Essay of Technique and Imaging Findings.

Ultrasonography (US) forms the mainstay of imaging in children; however, in the chest, its use has traditionally been limited to evaluation of pleural pathology. US techniques such as endobronchial and endoscopic ultrasound, which are commonly used for detection of mediastinal lymphadenopathy are invasive, aerosol generating, and often require sedation. Transcutaneous mediastinal sonography (TMUS) offers a useful alternative, which is easier to perform and overcomes these limitations. In this review, we summarize the technique, as well as imaging appearances of lymph nodes on TMUS. We also list common problems faced by operators and suggest troubleshooting methods for these.

Predicting Histology of Tracheobronchial Neoplasms: A CT Based Differentiation Model.

BACKGROUND: Tracheobronchial (TB) tumors follow same pathological classification as lung neoplasms; however, some entities are known to favor airways. Distinction of pathological types is necessary for suggesting appropriate management strategy. PURPOSE: To evaluate utility of multidetector CT (MDCT) in differentiation of primary TB tumors; and assess validity of a scoring system based on imaging biomarkers to differentiate tumor types. METHODS: MDCT features of 45 patients were analyzed for location, shape, calcification, attenuation, parenchymal changes, bronchoceles, extraluminal extension, lymphadenopathy, metastases. The two largest groups were compared with each other and remaining entities using Chi square tests. Six-point scoring system combining the differentiating features was devised and receiver operating characteristic curve analysis performed. RESULTS: The most frequent type was neuroendocrine tumors (NET) (51.1%), followed by salivary gland tumors (SGT) (20%); including adenoid cystic carcinoma (ACC) (13.3%) and mucoepidermoid carcinoma (MEC) (6.7%). Comparing NETs with other entities as a whole, and independently with SGTs, significant difference was found among location (p = 0.05 and 0.001 respectively), shape (p < 0.001), calcification (p = 0.038 and 0.041 respectively), attenuation (p = 0.001 and 0.019 respectively), bronchoceles (p = 0.013 and 0.010 respectively). Significant difference was found among ACC and MEC in location (p = 0.01) and morphology (p < 0.001). On receiver operating characteristic (ROC) curve analysis of the score, areas under curve for NET, SGT and ACC were 0.913, 0.872 and 0.962 respectively. Suggested cut-off values were >3.5 for carcinoid (sensitivity 70%, specificity 91%), <2.5 for SGT (sensitivity 78%, specificity 75%), <1.5 for ACC (sensitivity 83%, specificity 92%). CONCLUSION: Use of a scoring system enables maximum diagnostic accuracy in MDCT differentiation of TB tumors.

Can imaging suggest the aetiology in skull base osteomyelitis? A systematic literature review.

PURPOSE: To assess differentiating features between bacterial, Aspergillus, and Mucor skull base osteomyelitis (SBO) with regard to clinical presentation and imaging appearances. MATERIAL AND METHODS: A literature search was performed in April 2020 for studies on SBO with a minimum sample size of 10 patients. Studies that reported presenting symptoms, cross-sectional imaging findings, complications, and mortality were included in the analysis. The quality of included articles was tested using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. A data extraction form was used to retrieve relevant parameters from each of the articles. RESULTS: Thirteen articles were included in the final analysis. Diabetes mellitus was the most common predisposing factor (12.5-91.0%). Presenting complaints in all bacterial SBO studies were otogenic, while fungal SBO patients had nasal/ocular complaints. Rates of mortality and surgical intervention in the fungal group were 50-100% and 50%, respectively, as compared to the bacterial group - 7-87% and 10%, respectively. On imaging, the site of initial infection in bacterial SBO was the external auditory canal, while in fungal SBO it was the paranasal sinus. The incidence of orbital extension was < 5% in bacterial and 44-70% in fungal SBO, among which Mucor had rates of 65-70%. Bone erosion was less extensive in bacterial SBO, and the patterns differed. The highest incidence of vascular involvement and non-enhancing lesions (23-36%) was seen in Mucor. Aspergillus showed highest sino-cranial extension (52-55%) and homogenous bright enhancement. CONCLUSIONS: Systematic analysis of the clinico-radiological parameters in each of the studies revealed differences in presentation, clinical course, extension, bone erosion, and enhancement.

Algorithmic Approach to Sonography of Adnexal Masses: An Evolving Paradigm.

BACKGROUND: Pelvic US remains the workhorse for detection and characterization of adnexal masses in most centers worldwide. While the differentiation of benign from malignant masses remains the foremost concern, it is imperative to narrow the differential diagnosis for management of benign masses as well as prognostication of malignant masses. The IOTA group as well as ACR have described a five category classification system for adnexal lesions based on morphological patterns. In addition, a six category risk stratification has been proposed, incorporating the probability of malignancy as well as management recommendations. LEARNING OBJECTIVES: 1) Understand pattern based approach to adnexal lesion classification and the possible entities fitting into each pattern with the help of illustrations. 2) Classify lesions into appropriate risk categories based on diagnostic algorithms provided at the end of each section.