Anu Eapen

Portal annular pancreas. A rare variant and a new classification.

CONTEXT Portal annular pancreas is a rare congenital anomaly resulting from fusion of the pancreatic parenchyma around the portal vein/superior mesenteric vein. It is asymptomatic, but could have serious consequences during pancreatic surgery, if unrecognized. We describe a variant of this anomaly encountered during pancreaticoduodenectomy and propose a new classification. CASE REPORT We report a 51-year-old male who underwent a pancreaticoduodenectomy for periampullary carcinoma. After division of the pancreatic neck, a sheath of tissue was found posterior and extending to the left of the portal vein. When we divided this tissue, a large duct was encountered; this duct communicated with the main pancreatic duct. On review of the CT images, the main pancreatic duct was seen to be passing posterior to the portal vein and a smaller accessory pancreatic duct was present anterior to the portal vein. We describe the surgical implications. CONCLUSION This variant of portal annular pancreas has not yet been reported during pancreaticoduodenectomy and we propose a new classification for this fusion anomaly.

Endoscopic ultrasonography--a sensitive tool in the preoperative localization of insulinoma.

OBJECTIVE A number of imaging modalities have been used in the preoperative localization of insulinomas. Computed tomography (CT) is the most commonly employed modality. Endoscopic ultrasound (EUS) allows the transducer to be placed in close proximity to the pancreas, thereby yielding higher quality images, which facilitates accurate localization, minimally invasive surgery, and a lower occurrence of residual tumors, all of which contribute to a better clinical outcome. METHODS We analyzed the hospital records of all adult patients (age >18 years) diagnosed with insulinoma between October 2004 and September 2010. The diagnosis was based on the clinical practice guidelines of the American Endocrine Society. We compared the sensitivities of EUS and multidetector computed tomography (MDCT) in lesion. RESULTS Eighteen patients were seen over a period of 6 years, and all underwent EUS. MDCT scans were carried out in 17 patients. EUS had greater sensitivity (89%) in localizing insulinomas compared to CT (69%). In this series, the lesions that were missed on CT but picked up on EUS were smaller (<12 mm, P<.001). Lesions that were near mesenteric vessels and those located in the head of the pancreas were more likely to be missed on CT. CONCLUSIONS EUS has a greater sensitivity in identifying and localizing insulinomas. As availability increases, EUS should be part of a preoperative insulinoma workup.

Best MRI predictors of complete response to neoadjuvant chemoradiation in locally advanced rectal cancer

OBJECTIVE To identify the MRI parameters which best predict complete response (CR) to neoadjuvant chemoradiotherapy (CRT) in patients with locally advanced rectal cancer (LARC) and to assess their diagnostic performance. METHODS This was a prospective study of pre- and post-CRT MRI and diffusion-weighted imaging (DWI) of 64 patients with LARC who underwent neoadjuvant CRT and subsequent surgery. Histopathological tumour regression grade was the reference standard. Multivariate regression analysis was performed to identify the best MRI predictors of CR to neoadjuvant CRT, and their diagnostic performance was assessed. RESULTS The study cohort comprised 48 males and 16 females (n = 64), with mean age of 49.48 ± 14.3 years, range of 23-74 years. 11 patients had pathological complete response. The following factors predicted CR on univariate analysis: low initial (pre-CRT) tumour volume on T2 weighted high-resolution (HR) images and DWI, tumour volume-reduction rate (TVRR) of >95% on DWI and CR on post-CRT DWI (ydwiT0) as assessed by the radiologist. However, the best MRI predictors of CR on multivariate regression analysis were CR on post-CRT DWI (ydwiT0) as assessed by the radiologist and TVRR of >95% on DWI, and these parameters had an area under the curve (95% confidence interval) of 0.881 (0.74-1.0) and 0.843 (0.7-0.98), respectively. The sensitivity, specificity, positive-predictive value, negative-predictive value and accuracy of DWI in predicting CR was 81.8%, 94.3%, 75%, 96.1% and 76%; the sensitivity, specificity and accuracy of TVRR of >95% as a predictor of CR was 80%, 84.1% and 64.1%, respectively; however, this difference was not statistically significant. The interobserver agreement was substantial for ydwiT0. CONCLUSION Visual assessment of CR on post-CRT DWI and TVRR of >95% on DWI were the best predictors of CR after neoadjuvant CRT in patients with LARC, and the former being more practical can be used in daily practice. ADVANCES IN KNOWLEDGE In rectal cancer, ydwiT0 as assessed by the radiologist was the best and most practical imaging predictor of CR and scores over standard T2W HR images.

Comparison of radiation doses using weight-based protocol and dose modulation techniques for patients undergoing biphasic abdominal computed tomography examinations

Computed tomography (CT) of the abdomen contributes a substantial amount of man-made radiation dose to patients and use of this modality is on the increase. This study intends to compare radiation dose and image quality using dose modulation techniques and weight- based protocol exposure parameters for biphasic abdominal CT. Using a six-slice CT scanner, a prospective study of 426 patients who underwent abdominal CT examinations was performed. Constant tube potentials of 90 kV and 120 kV were used for all arterial and portal venous phase respectively. The tube current-time product for weight-based protocol was optimized according to patients body weight; this was automatically selected in dose modulations. The effective dose using weight-based protocol, angular and z-axis dose modulation was 11.3 mSv, 9.5 mSv and 8.2 mSv respectively for the patients body weight ranging from 40 to 60 kg. For patients of body weights ranging 60 to 80 kg, the effective doses were 13.2 mSv, 11.2 mSv and 10.6 mSv respectively. The use of dose modulation technique resulted in a reduction of 16 to 28% in radiation dose with acceptable diagnostic accuracy in comparison to the use of weight-based protocol settings.

Spontaneous choledochal cyst rupture in pregnancy with concomitant chronic pancreatitis.

Choledochal cysts are rare cystic transformations of the biliary tree that are increasingly diagnosed in adult patients. We report here a case of spontaneous rupture of a choledochal cyst in a pregnant young lady with chronic pancreatitis.

Achieving reduced radiation doses for CT examination of the brain using optimal exposure parameters

Objectives : Examinations performed using CT scanners impart high radiation dose to patients and use of this modality is on the increase in the present day scenario. This study was intended to evaluate and optimize radiation dose imparted to patients during CT examination of brain performed using spiral CT scanner. Materials and Methods : One hundred and one patients who underwent CT examination of brain were included in the study. The effective dose to patients was calculated using volume computed tomography dose index (CTDIvol) and dose length product (DLP) values. Patients were categorized according to the type of examination involved. Patients who underwent a complete examination of brain (non-contrast as well as contrast) were categorized in Group A and patients who underwent either a non-contrast or contrast examination were categorized as Group B. Results : The effective dose to patients ranged from 0.65 mSv to 0.93 mSv for Group A patients and 0.28 mSv to 0.53 mSv for Group B patients. Conclusion : There was a reduction of doses imparted to patients undergoing CT examination of the brain using optimized exposure parameters without any loss of diagnostic information.

Hepatocellular carcinoma continues to be diagnosed in the advanced stage: profile of hepatocellular carcinoma in a tertiary care hospital in South India

Summary This report is an analysis of 231 patients with hepatocellular carcinoma (HCC) from a tertiary care hospital in India. Most of the HCCs were diagnosed in cirrhotics and at an advanced stage which limited the therapeutic options. Physician awareness of this complication of cirrhosis and regular ultrasound screening of cirrhotic patients will help in detection of early stage cancers and, thus, enhance the survival rates.

MRI findings in cranial eumycetoma

Cranial eumycetoma (CE) due to direct inoculation of Madurella grisea into the scalp is extremely rare. We describe a case of CE caused by direct inoculation of M. grisea with the characteristic MRI findings of the “dot-in-circle” sign and a conglomeration of multiple, extremely hypointense “dots.”

Skull base hydatid cyst with intracranial extension presenting as vocal cord palsy: a case report

Hydatid disease of the skull base is extremely rare, and intracranial extension of hydatid cysts through the skull base is even rarer. We report an interesting case of a 42-year-old man who presented with features of right vocal cord palsy. The diagnosis of hydatid cyst was made based on his history and on pre-operative MRI and was confirmed by surgery and histopathological examination.

Enteric duplication in children: Experience from a tertiary center in South India

Background: Enteric duplications (EDs) are rare aberrations of the embryonic gut. This study was undertaken to define the clinical characteristics and management challenges of this unusual entity in the Indian population. Materials and Methods: Hospital records of 35 children with 38 ED operated between 2003 and 2014 were analyzed and followed up. Results: The median age at presentation was 285 days (range 1-day to 16 years) with male preponderance (71%). Small bowel duplications were the most common (44%), and thoracoabdominal duplications were seen in 8% children compared to 2% in the literature. The median duration of symptoms was 18 days (interquartile range [IQR] 3-210 days). Associated anomalies were seen in 49% children with vertebral and spinal anomalies being the most common. Ultrasonogram (US) was done in 83% children and had a sensitivity of 55%. In the presence of a gastrointestinal bleed, Technetium 99m pertechnetate scintigraphy scan had a positive predictive value of 80%. Thirty-five lesions were completely removed. Mucosectomy was done in two children, and one total colonic duplication was left in situ after providing adequate internal drainage. There was no postoperative mortality. The follow-up was possible in 66% children. Conclusions: EDs are uncommon and have varied, nonspecific symptoms. Thoracoabdominal duplications are more common in the Indian population. The US is a good screening tool but requires a high index of suspicion where complete excision is not possible; the provision of adequate internal drainage is an acceptable alternative. The long-term prognosis of children with ED depends on the extent of physiological disturbance due to associated anomalies.