An update on imaging of colorectal cancer.

Screening of asymptomatic average-risk patients for presence of colon cancer and early detection in precursor stages is of great interest to general population. Comprehensive evaluation of symptomatic or high-risk patients represents another important clinical focus. Available techniques for total colon imaging, rectal cancer staging and the role of positron emission tomography are discussed.

Liver regeneration and surgical outcome in donors of right-lobe liver grafts.

INTRODUCTION: Previous studies of healthy live-liver donors have suggested that complete liver regeneration occurs within a matter of weeks; however, there have been no long-term studies evaluating liver regeneration and few studies documenting long-term donor outcome. MATERIALS AND METHODS: Fifty-one donors who provided right-lobe grafts underwent volumetric spiral computed tomography scans preoperatively and postoperatively at time intervals of 1 week and 1, 3, 6, and 12 months. Patient demographics, surgical data, and postoperative outcome were correlated with liver regeneration data. Donor surgical outcome was followed prospectively and recorded in a comprehensive database. RESULTS: Thirty-three males and 18 females (mean age 36.0+/-9.6 years) provided 51 right-lobe grafts. Mean follow-up was 9.8+/-3.4 months. No donor operation was aborted, and surgical morbidity and mortality rates were 39% and 0%, respectively. Donor remnant liver volume was 49.4+/-5.7% of the original total liver volume (TLV). Overall liver regeneration was 83.3+/-9.0% of the TLV by 1 year. Female donors had significantly slower liver regrowth when compared with males at 12 months (79.8+/-9.3% vs. 85.6+/-8.2%, P<0.01). There was no effect of age, body mass index, operative time, estimated blood loss, postoperative complications, or perioperative liver function tests on liver regeneration. DISCUSSION: Liver regeneration continues throughout the first postoperative year. Only one donor achieved complete liver regeneration during this time period; however, all donors have maintained normal liver function without long-term complications. Longer follow-up is needed to determine whether donors ever achieve original TLV.

Importance of CT in Evaluating Internal Hernias after Roux-en-Y Gastric Bypass Surgery.

As the incidence of obesity increases, laparoscopic Roux-en-Y gastric bypass (REYGB) surgery has become a surgical option for many patients. Although the laparoscopic Roux-en Y procedure has been shown to reduce weight and improve diabetes, hyperlipidemia, hypertension and sleep apnea, it is not without significant risks, as more than 10% of patients who undergo this procedure have postoperative GI complications. This is a case of a 51 year old man who presented with diffuse abdominal pain one month status-post Roux-en-Y gastric bypass. CT imaging proved to be crucial in the diagnosis of this pathology with small bowel volvulus and ischemia. We review some key CT findings that can aid clinicians in diagnosing internal hernias since this complication is often misdiagnosed and have a mortality rate of more than 50%.

Rectal hidrocystoma.

We describe the endorectal sonographic and magnetic resonance (MR) imaging findings of a hidrocystoma of the rectal wall, a tumor that arises in sweat glands and may occur in a perianal location. To our knowledge, occurrence in the rectum has not been reported previously. The unusual appearance of a solid lesion with a central fluid-filled cavity may suggest the diagnosis of a hidrocystoma.

Living donor liver transplantation in adults: vascular variants important in surgical planning for donors and recipients.

OBJECTIVE: The purpose of our study was to explore the frequency with which surgically important hepatic vascular variants occur independently as well as in genetically related adult candidates for donation or receipt of a liver transplant. MATERIALS AND METHODS: We conducted a retrospective study of 107 adult living donor liver transplant candidates. From this pool of candidates, 50 sets of close relatives were selected to undergo transplantation. As part of the preoperative evaluation, all underwent multidetector CT angiography for evaluation of arterial and venous anatomy. Nonionic IV contrast material (180 mL) was given at a rate of 5 mL/sec, and collimations of 1.25 and 2.50 mm were used for true arterial and portal hepatic venous phase scanning, respectively. Image processing included three-dimensional volume renderings and multiplanar reformations. Two radiologists assessed the prevalence of vascular variants that were important for surgical planning and execution. RESULTS: We identified surgically important hepatic vascular variants in 70 (65%) of the 107 patients. A total of 129 variants were identified, of which 27 were important surgical considerations for recipients, 37 were important for donors, and 65 were important for both recipients (19 variants) and donors (46 variants). Of the 50 pairs of close relatives, 10 (20%) of the pairs were found to have the same hepatic vascular variant or one that was similar. However, when the pairs were set randomly, with no genetically related pairs included, similar variants were noted in 11 pairs (22%). The most common hepatic arterial variant in all candidates was an accessory right or left hepatic artery. The most common hepatic venous variant was an accessory right inferior hepatic vein. CONCLUSION: We observed a high prevalence of surgically important vascular variants in living adult candidates for living liver transplant donation and receipt. Because of the frequent occurrence, similar variants are to be expected among these sets of patients, regardless of whether they are closely related.