Ajaykumar C. Morani

Pancreatic tuberculosis: A clinical and imaging review of 32 cases

Background: Tuberculosis of the pancreas is a rare entity, and anecdotal reports describing imaging features of pancreatic tuberculosis have been described in medical literature. The imaging features including computed tomography (CT) and ultrasonography in diagnosed cases of tubercular involvement of the pancreas are described, with an overview of clinical features and laboratory investigations. Materials and Methods: We analyzed records of 384 patients of diagnosed cases of abdominal tuberculosis for involvement of pancreas and detected 32 patients (8.33%) who had pancreatic involvement. This included 22 men and 10 women with an age range of 19 to 64 years (mean age of 42.5 years), who were detected to have pancreatic tuberculosis from 1999 to 2004 in our institute. We reviewed the clinical, radiologic (ultrasonographic and CT features), and laboratory findings of all patients. The criteria for diagnosis of tuberculosis were based on ascitic fluid adenosine deaminase level in 14 patients, fine-needle aspiration cytology of lymph nodes in 9 patients, and presence of pulmonary tuberculosis on chest radiograph, which was found in 9 patients. On follow-up, 6 months after antituberculous treatment, 25 patients showed response to anti-Kochs treatment, 3 patients had drug-resistant tuberculosis, 2 patients died, and 2 patients were lost to follow-up. Results: The male/female ratio was 2.2:1. The maximum number of patients was in the fourth decade (30-39 years). The duration of symptoms was spanning between 2 and 11 months, with a mean duration of 6 months. The most common symptom was abdominal pain localized to the epigastrium. Sixteen patients were seropositive for HIV-1 infection. Fourteen patients had history of tuberculosis of the lungs, whereas 18 patients had pancreatic and peripancreatic involvement as the primary manifestation. Ultrasonography showed bulky inhomogenous pancreas in 5 patients; solitary or multiple hypoechoic collections were observed in all 7 and 20 patients, respectively. CT findings demonstrated hypodense collections within the pancreas associated with peripancreatic lymphadenopathy in 29 patients. Three patients had a complex pancreatic mass lesion. Conclusions: Pancreatic tuberculosis can present with a variable spectrum of imaging findings. Tuberculosis of the pancreas should be considered as a diagnostic possibility in patients who present with a pancreatic space occupying lesion associated with peripancreatic lymphadenopathy.

Abdominal applications of diffusion-weighted magnetic resonance imaging: Where do we stand

Diffusion-weighted imaging (DWI) is one of the magnetic resonance imaging (MRI) sequences providing qualitative as well as quantitative information at a cellular level. It has been widely used for various applications in the central nervous system. Over the past decade, various extracranial applications of DWI have been increasingly explored, as it may detect changes even before signal alterations or morphological abnormalities become apparent on other pulse sequences. Initial results from abdominal MRI applications are promising, particularly in oncological settings and for the detection of abscesses. The purpose of this article is to describe the clinically relevant basic concepts of DWI, techniques to perform abdominal DWI, its analysis and applications in abdominal visceral MR imaging, in addition to a brief overview of whole body DWI MRI.

Adrenal ganglioneuroma: Features and outcomes of 27 cases at a referral cancer centre

Adrenal ganglioneuroma (AGN) is a rare neurogenic tumour that can mimic other adrenal neoplasms. Limited information, mostly derived from small cases series, is available for AGN.

Diffusion-Weighted MRI in Pediatric Inflammatory Bowel Disease

OBJECTIVE Pediatric patients with inflammatory bowel disease (IBD) commonly need repetitive imaging to assess disease activity and complications. Recently, MR enterography has become a first-line radiologic study in children with IBD because of improved image quality, excellent soft-tissue contrast resolution, and lack of ionizing radiation. The purpose of this article is to describe the use of diffusion-weighted imaging (DWI) in MR enterography and the evaluation of pediatric IBD. CONCLUSION Several contemporary publications have shown that DWI can be useful for assessing both pediatric and adult patients with IBD as an important adjunct pulse sequence. Specifically, DWI can be used to identify abnormal bowel segments, assess disease inflammatory activity, and detect and characterize a variety of extraintestinal IBD-related manifestations and complications.

Intranodal cystic changes: A potential radiologic signature/biomarker to assess the human papillomavirus status of cases with oropharyngeal malignancies

Objective The aim of this study was to determine if lymph node imaging findings can predict human papillomavirus (HPV) positivity in oropharyngeal squamous cell cancers. Methods and Materials Pretreatment postcontrast neck computed tomographic scans of 49 patients (male, 35; female, 14; age range, 45–76 years) diagnosed with oropharyngeal malignancies and with available HPV data were retrospectively reviewed. Metastatic lymph nodes were identified based on standardly accepted size and morphological criteria. Various lymph node parameters were studied, including presence of cystic foci in the metastatic lymph nodes, abnormal lymph nodes showing low-attenuation foci, matted lymph nodes, and morphologically normal smaller (<1.5 cm) lymph nodes. These parameters were then independently correlated with the available HPV status of these patients. Finally, an extended criterion, that is, intranodal cystic changes in cases with morphologically normal small (<1.5 cm) lymph nodes, was correlated with HPV status. Sensitivity, specificity, and positive predictive values (PPVs) and negative predictive values (NPVs) were calculated. Results Of these 49 cases with oropharyngeal cancers, 27 were HPV positive, and 22 cases were HPV negative. Eight cases (3 HPV positive and 5 HPV negative) did not have metastatic lymph nodes. Of remaining 41 cases with metastatic abnormal lymph nodes, 26 were HPV positive, and 15 were HPV negative. Of these 41 cases with metastatic lymph nodes, 14 had 1 or more lymph nodes with cystic foci. Of these 14 cases, 10 (71.4%) were HPV positive. Resultant sensitivity, specificity, PPV, and NPV of cystic foci for the presence of HPV status were 38.4%, 73.3%, 71.4%, and 40.7%, respectively. Intranodal cystic changes in cases with morphologically normal small (<1.5 cm) lymph nodes were found in 5 cases; all 5 were HPV positive. Resultant accuracy was specificity and PPV of 100%, sensitivity of 19.2% and NPV of 41.6%. Conclusions Intranodal cystic changes seen on the pretreatment postcontrast neck computed tomographic scan of patients with oropharyngeal malignancies are radiologic signatures strongly associated with the HPV status of the patient. The results in this initial study warrant larger prospective studies to determine if this finding may be used in addition to other molecular biomarkers to help identify those patients who may be amenable to the most appropriate treatment options.

CAIPIRINHA-VIBE and GRAPPA-VIBE for liver MRI at 1.5 T: a comparative in vivo patient study.

Objective Three-dimensional T1-weighted (T1W) gradient recall echo volumetric interpolated breath-hold examination (VIBE) using generalized autocalibrating partially parallel acquisitions (GRAPPA) is one of the key sequences in liver magnetic resonance imaging (MRI) and is used for precontrast, dynamic postcontrast, and delayed postcontrast imaging. The purpose of this study is to compare image quality and liver lesion detection (LLD) on a shorter-duration T1W VIBE sequence using the controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique with the conventional T1W GRAPPA-VIBE sequence during a single liver MRI session on a 1.5-T Seimens scanner. Methods Twenty consecutive patients (9 women and 11 men; age range, 36–85 years) were included in this prospective study. All patients underwent a complete liver MRI on a 1.5-T magnet (Aera; Siemens Medical Systems, Erlangen, Germany) that consisted of a T1W (in/out-of-phase), T2W, DWI, and precontrast and postcontrast multiphasic images (late arterial, 50 seconds, 120 seconds, and 300 seconds) with GRAPPA-VIBE. The CAIPI-VIBE images were acquired for precontrast and at 300 seconds (5 minutes) postcontrast phases (6.9 seconds per phase) in addition to GRAPPA-VIBE (21 seconds per phase). The shorter time for the CAIPI-VIBE was selected to allow postprocessing of image acquisition in the setting of multi–late arterial phase (single breath hold) postcontrast images. Five radiologists independently analyzed image quality with predefined scores for liver edge sharpness, artifacts, fat saturation deficiency, visualization of the portal veins and hepatic veins, and LLD (size, <0.5–3.8 cm). Score 0 was suboptimal (inadequate), 1 was acceptable for diagnosis, and 2 was optimal (excellent). Kappa statistics were used to assess agreement among readers. Generalized linear mixed model with generalized estimation equation method was used to estimate and compare the LLD failure rates. Results No statistically significant difference was seen in the degree of reader variability between CAIPI-VIBE and GRAPPA-VIBE for all evaluated categories using multirater &kgr; statistics. For the precontrast and 5-minutepostcontrast phase sequences, greater than 95% of images were considered to be of acceptable quality in all image quality categories for both sequences. Forty-one lesions were evaluated in 17 patients with total of 204 observations (n = 204) by 5 readers. For 5-minute postcontrast images, the LLD rate of CAIPI-VIBE (80%) was lower than GRAPPA-VIBE (84%) (P = 0.03) for small lesions (0.5–1.7 cm). There was no significant difference in lesion detection on precontrast images. Conclusions At 1.5 T, the CAIPI-VIBE may be helpful in reducing scan time and demonstrates similar image quality compared with the traditional GRAPPA-VIBE. The CAIPI-VIBE has shorter breath-hold time requirement and thus can be an acceptable alternative for the precontrast and 5-minute postcontrast GRAPPA-VIBE in patients with breath-hold difficulties.

Prognostic factors and patterns of relapse in ewing sarcoma patients treated with chemotherapy and r0 resection.

PURPOSE To identify prognostic factors and patterns of relapse for patients with Ewing sarcoma who underwent chemotherapy and R0 resection without radiation therapy (RT). METHODS AND MATERIALS We reviewed the medical records of patients who underwent surgical resection at our institution between 2000 and 2013 for an initial diagnosis of Ewing sarcoma. The associations of demographic and clinical factors with local control (LC) and patient outcome were determined by Cox regression. Time to events was measured from the time of surgery. Survival curves were estimated by the Kaplan-Meier method and compared by the log-rank test. RESULTS A total of 66 patients (median age 19 years, range 4-55 years) met the study criteria. The median follow-up was 5.6 years for living patients. In 43 patients (65%) for whom imaging studies were available, the median tumor volume reduction was 73%, and at least partial response by Response Evaluation Criteria in Solid Tumors was achieved in 17 patients (40%). At 5 years, LC was 78%, progression-free survival (PFS) was 59%, and overall survival (OS) was 65%. Poor histologic response (necrosis ≤95%) was an independent predictor of LC (hazard ratio [HR] 6.8, P=.004), PFS (HR 5.2, P=.008), and OS (HR 5.0, P=.008). Metastasis on presentation was also an independent predictor of LC (HR 6.3, P=.011), PFS (HR 6.8, P=.002), and OS (HR 6.7, P=.002). Radiologic partial response was a predictor of PFS (HR 0.26, P=.012), and postchemotherapy tumor volume was associated with OS (HR 1.06, P=.015). All deaths were preceded by distant relapse. Of the 8 initial local-only relapses, 5 (63%) were soon followed by distant relapse. Predictors of poor postrecurrence survival were time to recurrence <1 year (HR 11.5, P=.002) and simultaneous local and distant relapse (HR 16.8, P=.001). CONCLUSIONS Histologic and radiologic response to chemotherapy were independent predictors of outcome. Additional study is needed to determine the role of adjuvant radiation therapy for patients who have poor histologic response after R0 resection.

Cushing Syndrome: Diagnostic Workup and Imaging Features, With Clinical and Pathologic Correlation

OBJECTIVE Cushing syndrome (CS) is a constellation of clinical signs and symptoms resulting from chronic exposure to excess cortisol, either exogenous or endogenous. Exogenous CS is most commonly caused by administration of glucocorticoids. Endogenous CS is subdivided into two types: adrenocorticotropic hormone (ACTH) dependent and ACTH independent. CONCLUSION Cushing disease, which is caused by a pituitary adenoma, is the most common cause of ACTH-dependent CS for which pituitary MRI can be diagnostic, with bilateral inferior petrosal sinus sampling useful in equivocal cases. In ectopic ACTH production, which is usually caused by a tumor in the thorax (e.g., small cell lung carcinoma, bronchial and thymic carcinoids, or medullary thyroid carcinoma) or abdomen (e.g., gastroenteropancreatic neuroendocrine tumors or pheochromocytoma), CT, MRI, and nuclear medicine tests are used for localizing the source of ACTH. In ACTH-independent CS, which is caused by various adrenal abnormalities, adrenal protocol CT or MRI is usually diagnostic.

The ABCs of BHD: An In-Depth Review of Birt-Hogg-Dubé Syndrome

OBJECTIVE Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant inherited syndrome involving multiple organs. In young patients, renal neoplasms that are multiple, bilateral, or both, such as oncocytomas, chromophobe renal cell carcinoma (RCC), hybrid chromophobe RCC-oncocytomas, clear cell RCC, and papillary RCC, can suggest BHD syndrome. Extrarenal findings, including dermal lesions, pulmonary cysts, and spontaneous pneumothoraces, also aid in diagnosis. CONCLUSION Radiologists may be one of the first medical specialists to suggest the diagnosis of BHD syndrome. Knowledge of pathogenesis and management, including the importance of the types of renal neoplasms in a given patient, is needed to properly recognize this rare condition.

Practical Approach to Adrenal Imaging

Various pathologies can affect the adrenal gland. Noninvasive cross-sectional imaging is used for evaluating adrenal masses. Accurate diagnosis of adrenal lesions is critical, especially in cancer patients; the presence of adrenal metastasis changes prognosis and treatment. Characterization of adrenal lesions predominantly relies on morphologic and physiologic features to enable correct diagnosis and management. Key diagnostic features to differentiate benign and malignant adrenal lesions include presence/absence of intracytoplasmic lipid, fat cells, hemorrhage, calcification, or necrosis and locoregional and distant disease; enhancement pattern and washout values; and lesion size and stability. This article reviews a spectrum of adrenal pathologies.