Diffusion-weighted magnetic resonance imaging in locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy.

PURPOSE: To analyze diffusion-weighted magnetic resonance imaging (DW-MRI) for treatment response assessment in locally advanced rectal cancer (LARC). PATIENTS AND METHODS: Patients with histologically proven rectal adenocarcinoma, stage II-III disease, were enrolled and underwent surgery following neoadjuvant chemoradiotherapy (nCRT). All patients were referred for a DW-MRI protocol on a 3 Tesla MR-system, consisting of axial T2-weighted and DWI sequences prior (I), during (II) and after (III) nCRT. Corresponding apparent diffusion coefficient (ADC) values were calculated. RESULTS: Between February 2011 and June 2015, 37 patients participated in the study. All patients completed programmed treatment. Overall, 11 patients (29.7%) had pathologic complete response (pCR). No correlation between the mean pre- (ADC-I), during (ADC-II), post- (ADC-III) ADC and the reduction in tumor size after nCRT was recorded. No substantial difference in the ADC distribution was found between pCR and no-pCR patients. The ADC-II level significantly increased in the pCR cases (T = 1.675; p < 0.05). CONCLUSION: ADC value could be useful for discriminating between the pCR patients and the no-pCR patients. Further studies are necessary to identify the optimal MRI parameters combination to predict tumor response to nCRT. It is hoped that these data will provide the basis for a more solid scientific evidence.

Bowel cleansing before CT colonography: comparison between two minimal-preparation regimens.

AIM: To compare two regimens of reduced bowel preparation and faecal tagging for CT colonography. MATERIALS AND METHODS: Single centre, prospective, randomized, noninferiority study, in which 52 consecutive adults underwent routine CT colonography. Patients, following a three-day low-fibre diet, received one of the two reduced preparations: 1-L polyethylene glycol and four tablets of bisacodyl in association with 90 mL of Iopamidol for faecal tagging administered on the same day as CTC examination (group 1); or a standard "iodine-only" preparation, consisting in 180 ml of Iopamidol the day before the examination (group 2). Primary outcome was the overall quality of bowel preparation. RESULTS: Twenty-six patients per group were included. Per segment analysis showed preparation of diagnostic quality in 97.4% of segments in group 1 and in 95.5% in group 2 (p = ns). Per-patient analysis showed optimal quality of preparation in 76.9% of patients in group 1 and in 84.6% in group 2 (p = ns). Patient tolerability to both preparations was not different. CONCLUSION: A limited bowel preparation consisting of 1-L PEG and four tablets of bisacodyl in association with 90 mL of Iodine for faecal tagging administered on the same day as CTC examination is feasible and offers bowel cleansing comparable to "iodine-only" preparation. KEY POINTS: • Low-dose PEG bisacodyl and Iopamidol preparation is feasible, providing adequate bowel cleansing. • Faecal tagging is not different from the two limited preparations. • Patient tolerability to the two colon cleansing regimens is similar.

Gallbladder and muscular endometriosis: a case report.

A 55-year-old woman referred to Radiology Department, with abdominal mass and chronic indefinite and vague abdominal pain, most severe in right hypochondrium and accentuated during menstruation. A history of two cesarean sections was revealed. The patient underwent an ultrasound and Computed Tomography with intravenous contrast media revealing the presence of gallbladder and abdominal wall hyperenhancing masses. Finally, Magnetic Resonance study with intravenous administration of paramagnetic contrast media confirmed the involvement of gallbladder by a solid tissue and the presence of a solid nodule on the abdominal wall. Considering imaging features and the contrast enhancement of the nodules, the patient was sent to surgery. Surgical removal of both gallbladder and abdominal solid implant was performed and histology confirmed the diagnosis of gallbladder and abdominal wall endometriosis.

Peritoneal carcinomatosis: imaging with 64-MDCT and 3T MRI with diffusion-weighted imaging.

Peritoneal carcinomatosis is usually associated with a poor overall survival rate. Recently, introduction of more aggressive surgical treatment and intraperitoneal chemotherapy appears to significantly increase the overall survival rate for these patients. A detailed preoperative assessment of peritoneal carcinomatosis could be very challenging in the field of imaging, but a new aggressive surgical approach requires an accurate preoperative assessment of the disease. Cross-sectional imaging using CT and MRI with diffusion-weighted imaging (DWI) sequences is important for appropriate management of patients with peritoneal carcinomatosis. Appreciation of the spectrum of diagnostic patterns and pitfalls as well as different sites of involvement of peritoneal carcinomatosis using CT and DWI is crucial for appropriate surgical treatment.

High positive predictive value of CT colonography in a referral centre.

AIM: To assess the positive predictive value (PPV) of CTC in the clinical routine of a dedicated referral centre. MATERIAL AND METHODS: All consecutive patients referred for CTC between May 2009 and May 2010 were considered for inclusion in this study. All the patients who, following the diagnosis of a>6 mm polyp or mass at CTC, underwent a post-CTC colonoscopy within eight weeks from diagnosis were included. Per patient PPV for lesions, adenomas and advanced neoplasia was calculated. Chi-square test was used for statistical comparison, and a p value<0.05 was considered to be statistically significant. RESULTS: 516 patients were included in the study. Of them, 76 (14%) patients had at least one lesion≥6 mm on CTC. Overall, 59 (11%) patients were diagnosed at CTC with at least one polyp, 12 (2%) with a flat lesions, and 5 (1%) with a mass. Per-patient PPVs for any lesion>6 mm, neoplasia, and advanced neoplasia were 96% (95% CI: 92-100%), 68.4% (95% CI: 58-79%), and 30% (95% CI: 20-41%), respectively. PPV for neoplasia and advanced neoplasia was substantially higher for >10 mm lesions. CONCLUSION: In dedicated centers, CTC appears to be a highly specific procedure, characterized by a very low rate of false-positive results for >6 mm lesions.