Dual-energy computed tomography of the abdomen: A reliable trouble-shooter.

Dual-energy computed tomography (CT) systems have undergone significant evolution and advancements in technology since they came into clinical practice in 2006. The basic principle of dual-energy is comparing the attenuation of different materials when exposed to high and low energy levels. In this article, we provide a brief overview of the basics of dual-energy CT systems, a pictorial review of commonly encountered abdominal conditions, and its role as a trouble-shooter in various diagnostic difficulties.

Multiparametric MRI reporting using Prostate Imaging Reporting and Data System version 2.0 (PI-RADSv2) retains clinical efficacy in a predominantly post-biopsy patient population.

OBJECTIVE: To evaluate the efficacy of multiparametric magnetic resonance imaging (mp-MRI) using Prostate Imaging Reporting and Data System version 2.0 (PI-RADSv2) definitions in detecting organ-confined prostate cancer. METHODS: All patients who underwent radical prostatectomy between January 1, 2014 and December 30, 2014 were identified. All underwent mp-MRI within 180 days before surgery. Those with prior pelvic irradiation or androgen deprivation therapy were excluded. Fully embedded, whole-mount histopathology was centrally reviewed and correlated with imaging for tumour location, Gleason score (GS) and stage. RESULTS: There were 39 patients included, of which 35 (90%) had mp-MRI done post-biopsy. A total of 93 cancer foci were identified on whole-mount pathology, of which mp-MRI detected 63 (68%). Of those detected by mp-MRI, 14 were PI-RADS 3 (n = 6 for GS 6, n = 8 for GS 7, no GS ≥ 8) and 49 were PI-RADS 4-5 (n = 7 for GS 6, n = 33 for GS 7, and n = 9 for GS ≥ 8). There were 30 (32%) cancer foci missed by mp-MRI (n = 15 for GS 6, n = 13 for GS 7 and n = 2 for GS ≥ 8). A lesion classified as PI-RADS 4-5 predicted a higher grade cancer on pathology as compared to PI-RADS 3 (for GS 7 lesions, odds ratio [OR] = 3.53, 95% CI: 0.93-13.45, p = 0.064). The mp-MRI size detection limit was 20 mm2 and 100 mm2 for 50% and 75% probability of cancer, respectively. In associating with radiological and pathologic stage, the weighted Kappa value was 0.69 (p < 0.0001). The sensitivity and positive predictive values for this study were 68% (95% CI: 57%-77%) and 78% (95% CI: 67%-86%), respectively. CONCLUSION: In this predominantly post-biopsy cohort, mp-MRI using PI-RADSv2 reporting has a reasonably high diagnostic accuracy in detecting clinically significant prostate cancer.

IgG4 related orbit disease - An unusual cause of an orbital mass

@#IgG4-related disease is a newly described systemic autoimmune and allergic disease, characterized histologically by a fibroinflammatory response with IgG4 plasma cells. It was initially described as affecting the pancreas, but commonly involves the head and neck region as well. While a biopsy is essential for definitive diagnosis, cross sectional imaging may be the initial modality which may suggest this entity. We describe a case of pathologically proven IgG4 related disease which highlights some key radiologic features seen in this entity. Our case highlights some key radiological features of IgG4- related disease in the head and neck, with involvement of the lacrimal glands, pituitary gland and cranial nerves on CT.

Enlarged parietal foramina presenting as scalp swelling in an infant

“Enlarged parietal foramina” is a congenital malformation with autosomal dominant inheritance. The condition is usually self-limiting and doesn’t require any treatment. However, it may also be associated with encephalocele, vascular anomalies or may be a part of syndrome. We present a case of enlarged parietal foramina in a child and discuss its imaging findings and the associated intracranial vascular malformations.