Enteroscopy-Assisted EUS-Guided Trans-gastric Intervention After Roux-en-Y Gastric Bypass Surgery.

Endoscopic ultrasound-directed trans-gastric interventions (EDGI) using lumen apposing metal stent (LAMS) have been increasingly utilized in patients with Roux-en-Y gastric bypass surgery. We present a case of a 71-year-old woman with Roux-en-Y anatomy presenting with choledocholithiasis and enlarged retroperitoneal lymph nodes. Given inability to identify the excluded stomach on routine EUS, enteroscopy was performed with retrograde filling of the excluded stomach to allow for its localization on EUS. The patient underwent LAMS placement to create a jejuno-gastric anastomosis. Subsequently, she had an ERCP (via the LAMS) for removal of bile duct stone and an EUS with fine needle aspiration of the para-aortic lymph node (via the LAMS) confirming malignancy. The LAMS was removed after 2 weeks and the defect closed with APC and clips. An upper GI series obtained at 4 weeks did not show any residual leak. Patient continues to follow up with oncology for workup of primary malignancy.

Circumportal pancreas: imaging findings in 40 patients.

PURPOSE: To analyze the CT and MR imaging features of circumportal pancreas (CP) with emphasis on the relative frequency of variants of parenchymal fusion, ductal anatomy, and vascular anatomy. METHODS: A retrospective review of CT and MR imaging findings of 40 patients with CP was performed. CT and MR images were reviewed by two radiologists in consensus. The course of the pancreatic duct in relation to the portal vein (anteportal vs. retroportal), location of the circumvenous pancreatic parenchyma in relation to the splenic vein (suprasplenic vs. infrasplenic), presence or absence of a visible accessory duct posterior to the portal vein, presence of vascular variants, history of pancreatitis and pancreatic surgery were recorded. Cases were classified into four categories: anteportal suprasplenic, retroportal suprasplenic, anteportal infrasplenic, and retroportal infrasplenic. RESULTS: One case of suprasplenic fusion was excluded from the classification due to non-visualization of the pancreatic duct. 32/39(82%) of cases were classified as anteportal suprasplenic, 2/39(5%) as retroportal suprasplenic, 4/39(10%) as anteportal infrasplenic, and 1/39(3%) as retroportal infrasplenic. There were 12 vascular variants including nine with an intraparenchymal course (through the pancreatic head) of the common hepatic artery, one with an intraparenchymal course of the right hepatic artery, two replaced right hepatic arteries from the superior mesenteric artery, and one with an intraparenchymal course of the left gastric vein. CONCLUSION: Circumportal pancreas is an important pancreatic fusion anomaly with distinctive imaging features. The most common variant of CP is the anteportal suprasplenic subtype, with other subtypes being much less common. Intraparenchymal course of the common hepatic artery is a common variant associated with CP. Recognition of CP is important to avoid potential complications in patients who undergo pancreatic surgery.

Extracolonic findings at virtual colonoscopy: an important consideration in asymptomatic colorectal cancer screening.

BACKGROUND: Virtual colonoscopy has been evaluated for use as a colorectal cancer screening tool, and in prior studies, it has been estimated that the evaluation of extra-colonic findings adds $28-$34 per patient studied. METHODS: As an ancillary study to a prospective cohort study comparing virtual colonoscopy to conventional colonoscopy for colorectal cancer detection, the investigators retrospectively determined the number and estimated costs of all clinic visits, imaging and laboratory studies, and medical procedures that were generated as a direct result of extra-colonic findings at virtual colonoscopy. RESULTS: We enrolled 143 subjects who underwent CTC followed by conventional colonoscopy. Data were available for 136 subjects, and 134 (98%) had at least one extra-colonic finding on CT. Evaluation of extra-colonic findings was performed in 32 subjects (24%). These subjects underwent 73 imaging studies, 30 laboratory studies, 44 clinic visits, 6 medical procedures, and 44 new or return outpatient visits over a mean of 38 months following the CTC. The most common findings causing further evaluation were lung nodules and indeterminate kidney lesions. No extra-colonic malignancies were found in this study. A total of $33,690 was spent in evaluating extra-colonic findings, which is $248 per patient enrolled. CONCLUSIONS: The cost of the evaluation of extra-colonic findings following virtual colonoscopy may be much higher in actual practice than is suggested by prior studies. This will impact the cost-effectiveness of using virtual colonoscopy for asymptomatic colorectal cancer screening and underscores the importance of standardizing the reporting of extra-colonic findings to encourage appropriate follow-up.

Antibiotic prophylaxis for percutaneous radiologic gastrostomy and gastrojejunostomy insertion in outpatients with head and neck cancer.

PURPOSE: To determine the effect of antibiotic prophylaxis on the postprocedural infection rate after fluoroscopically guided percutaneous radiologic gastrostomy and gastrojejunostomy with gastropexy performed as an outpatient procedure in ambulatory patients with head and neck cancer. MATERIALS AND METHODS: Medical and imaging records of all outpatients with head and neck cancer referred for gastrostomy or gastrojejunostomy from February 2003 to November 2004 were retrospectively reviewed. A 14-F percutaneous gastrostomy was inserted through the anterior abdominal wall after T-fastener gastropexy. Fifty-seven patients (36 men; mean age, 57.2 years; age range, 17-76 y) had 53 percutaneous radiologic gastrostomies and four percutaneous radiologic gastrojejunostomies. Mean follow-up was 27 weeks (range, 4-62 weeks). Thirty-seven patients received antibiotic prophylaxis with 1 g cefazolin intravenously and twice-daily cephalexin 500 mg for 5 days orally or via gastrostomy (n = 35) or clindamycin 600 mg intravenously and 600 mg twice daily orally or via gastrostomy for 5 days (n = 2). RESULTS: Ten minor postprocedural complications occurred in 8 patients (14%). There was a 15% peristomal infection rate (n = 3) in patients who did not receive antibiotic prophylaxis; none occurred in those who received antibiotic prophylaxis. There were significantly fewer infections in the group that received antibiotic prophylaxis (P = .039). No major complications or deaths occurred. CONCLUSIONS: Administration of prophylactic antibiotics for percutaneous radiologic gastrostomy placement reduces peristomal infection in patients with head and neck cancer.

Tagging-based, electronically cleansed CT colonography: evaluation of patient comfort and image readability.

PURPOSE: To prospectively compare the homogeneity, adequacy, and patient acceptance of nonionic iodine-based regimens with those of a barium-based regimen for computed tomographic (CT) colonography with electronic subtraction cleansing. MATERIALS AND METHODS: After institutional review board approval and informed consent were obtained, 68 subjects (41 men (60%) men, 27 (40%) women; mean age, 60 years +/- 6 [standard deviation]) with average or moderate risk factors for development of colorectal carcinoma were recruited and placed into three study groups. Group 1 (n = 25) ingested 150-mL aliquots of 2% barium sulfate suspension with meals and snacks for 48 hours prior to imaging, without other diet modification or a cathartic. Group 2 (n = 21) ingested 10-mL aliquots of nonionic iodinated contrast material (iopromide) with a concentration of 300 mg per milliliter with meals and snacks for 2 days before imaging, without diet modification or a cathartic. Group 3 (n = 22) ingested nonionic iodinated contrast material (iohexol) with a concentration of 300 mg per milliliter with meals and snacks for 2 days before imaging and ingested 34 g of magnesium citrate the evening prior to imaging. CT colonography was also performed on 10 control subjects who ingested polyethylene glycol electrolyte solution prior to imaging. Subjective and numerical measures of bowel preparation quality, homogeneity, and patient comfort among the noncathartic and cathartic cohorts were compared with nonparametric analysis of variance, the Fisher exact test, and the F test, as appropriate. The study was HIPAA compliant. RESULTS: Study subjects who received tagging preparations reported significantly improved discomfort scores when compared with those of the control subjects (P < .05, each comparison). There was no significant difference in discomfort scores among groups 1, 2, and 3. For each reader, scores of subtracted image readability were highest for group 3. Dichotomized rates of preparation "success" were also greatest for group 3. CONCLUSION: In this series, the patient discomfort scores were significantly improved with tagging preparations for CT colonography. Nonionic iodinated contrast material in conjunction with a hyperosmotic laxative (magnesium citrate) was associated with the best subjective and numerical indices of readability.

Computer-aided detection for virtual colonoscopy.

Colon cancer is one of the leading causes of cancer deaths in the developed countries. Most colon cancers can be prevented if precursor colon polyps are detected and removed. Virtual colonoscopy, or CT colonography, has shown promise to be the future screening tool for polyp detection, with a number of studies performed at academic institutions showing high sensitivity and specificity. Two main factors limiting CT colonography in general use are its excessive interpretation time and the variable sensitivity among readers. This article discusses the potential of computer-aided detection to address these problems. We also review the current state of research in this field and the future roles and challenges of CAD for CT colonography.

Polyp size at CT colonography after electronic subtraction cleansing in an anthropomorphic colon phantom.

PURPOSE: To evaluate the effect of various bowel contrast material concentrations and subtraction software on size measurements of well-defined polyp lesions in a colon phantom at CT colonography. MATERIALS AND METHODS: Repeated scanning and a precise reference standard required the use of a colon phantom in which 21 polyps were randomly distributed. Two readers who had each reviewed computed tomographic (CT) colonographic images from more than 100 cases evaluated polyp size on images obtained when the phantom was partially filled with varying concentrations of contrast material, scanned by using CT colonography, and subjected to electronic subtraction cleansing. The single largest dimension was recorded for each reader for a randomized series of polyps. These measurements were compared with a reference standard that was based on a combination of the manufacturer's polyp size specifications and the subsequent verification of these sizes by an independent consensus panel. Six weeks after initial observations, readers evaluated images of the phantom scanned without the presence of contrast material. Polyp size estimations for the two readers for each series were compared with the reference standard to obtain a mean absolute measurement error for each reader for each series. Data for each reader were compared by using a nonparametric Kruskal-Wallis analysis of variance test. A pair-wise comparison of the experimental and control series was then performed by using the Dunn post hoc test. RESULTS: Contrast material dilutions resulting in an average attenuation of less than 500 HU resulted in complete subtraction and the absence of streak artifacts. There was no statistically significant difference between the average measurement error for contrast attenuations between 300 and 500 HU when compared with that of control. Streak artifact was noticeable for the highest dilution (mean, 840 HU). No statistically significant differences were observed for series in which cleansing software was used in the absence of bowel contrast material. CONCLUSION: The combination of electronic cleansing and bowel contrast enhancement in the range of 300-500 HU results in no substantial change in readers' estimations of polyp size at CT colonography.

Low-dose CT colonography in children: initial experience, technical feasibility, and utility.

BACKGROUND: CT colonography (CTC) is utilized as a diagnostic tool in the detection of colon polyps and early colorectal cancer in adults. Large studies in the literature, although focused on adult populations, have shown CTC to be a safe, accurate, non-invasive technique. OBJECTIVE: We evaluated the technical feasibility of CTC in children using a low-dose technique. MATERIALS AND METHODS: From November 2001 to April 2004 we evaluated eight patients (3-17 years) with non-contrast CTC. Seven of the patients had CTC, followed by standard colonoscopy (SC) the same day; in one patient, CTC followed a failed SC. CTC results were compared to results of SC. The estimated effective dose from each CTC was calculated and compared to that of standard barium enema. RESULTS: CTC results were consistent with those of SC. Sensitivity for polyps 5-10 mm was 100%, and sensitivity for polyps 10 mm and larger was 66.7%. The estimated mean effective dose was 2.17 mSv for CTC, compared to the 5-6 mSv for a standard air-contrast barium enema in a small child. CONCLUSION: Our initial experience shows CTC in children is well-tolerated, safe, and useful. The procedure can be performed successfully with a low radiation dose, and preliminary results compare well with SC.

Digital subtraction bowel cleansing for CT colonography using morphological and linear filtration methods.

We describe a method to perform postacquisition processing of computed tomography colonography (virtual colonoscopy) datasets that results in electronic removal of opacified, ingested bowel contents while reconstructing natural appearing boundaries of colon lumen and thereby permitting three-dimensional visual analyses of the resulting colon models.

Techniques, clinical applications and limitations of 3D reconstruction in CT of the abdomen.

Enhanced z-axis coverage with thin overlapping slices in breath-hold acquisitions with multidetector CT (MDCT) has considerably enhanced the quality of multiplanar 3D reconstruction. This pictorial essay describes the improvements in 3D reconstruction and technical aspects of 3D reconstruction and rendering techniques available for abdominal imaging. Clinical applications of 3D imaging in abdomen including liver, pancreaticobiliary system, urinary and gastrointestinal tracts and imaging before and after transplantation are discussed. In addition, this article briefly discusses the disadvantages of thin-slice acquisitions including increasing numbers of transverse images, which must be reviewed by the radiologist.

Sonographic appearance of a congenital parotid gland hemangiolymphangioma simulating malignancy in an infant.

Congenital hemangiolymphangioma, also called mixed angioma, is a benign tumor that very rarely occurs in the parotid gland. We present a rare case of hemangiolymphangioma of the parotid gland in a 4-month-old boy whose clinical and radiologic presentation simulated malignancy. Gray-scale and color Doppler sonography revealed an enlarged left parotid gland and inhomogeneous hypoechoic and hyperechoic areas scattered throughout the gland. Mild internal vascularity was noted on color Doppler sonographic examination. CT revealed a predominantly fatty mass involving the superficial lobe of the parotid gland. The results of fine-needle aspiration cytology were inconclusive, and total parotidectomy was performed. Histopathologic examination of surgical specimens confirmed a diagnosis of hemangio lymphangioma. The patient recovered well and was free of recurrence at the 6-month follow-up visit. To our knowledge, this case report is the first to describe the findings of congenital hemangiolymphangioma of the parotid gland on sonography and CT. This rare diagnosis should be considered in neonates and infants presenting with a rapidly growing parotid gland tumor suggesting malignancy. Histopathologic examination is necessary to confirm the diagnosis.

CT colonography: digital subtraction bowel cleansing with mucosal reconstruction initial observations.

The authors evaluated a computed tomography (CT) colonographic technique with a combination of preexamination orally ingested positive contrast material and postacquisition image processing to subtract out the ingested opacified bowel contents. With this technique, rigorous physical purging of the bowel was not necessary before structural examination of the colon. With images obtained in 20 patients, two readers were able to correctly identify the majority of polyps confirmed at colonoscopy. Their performance for detection of lesions larger than 1 cm was similar to that with conventional CT colonography.