Colon capsule versus computed tomography colonography for colorectal cancer screening in patients with positive fecal occult blood test who refuse colonoscopy: a randomized trial.

OBJECTIVE: Some patients (10 % - 32 %) with a positive guaiac fecal occult blood test (gFOBT) do not undergo the recommended colonoscopy. The aim of this study was to compare video capsule endoscopy (VCE) and computed tomography colonography (CTC) in terms of participation rate and detection outcomes when offered to patients with a positive gFOBT who did not undergo the recommended colonoscopy. METHODS: An invitation letter offering CTC or VCE was sent to selected patients after randomization. Acceptance of the proposed (or alternative) procedure and procedure results were recorded. Sample size was evaluated according to the hypothesis of a 13 % increase of participation with VCE. RESULTS: A total of 756 patients were targeted. Following the invitation letter, 5.0 % (19/378) of patients underwent the proposed VCE and 7.4 % (28/378) underwent CTC, (P = 0.18). Following the letter, 9.8 % (37/378) of patients in the VCE group underwent a diagnostic procedure (19 VCE, 1 CTC, 17 colonoscopy) vs. 10.8 % in the CTC group (41/378: 28 CTC, 13 colonoscopy; P = 0.55). There were more potentially neoplastic lesions diagnosed in the VCE group than in the CTC group (12/20 [60.0 %] vs. 8/28 [28.6 %]; P = 0.04). Thus, 15/20 noninvasive procedures in the VCE group (19 VCE, 1 CTC; 75.0 %) vs. 10/28 in the CTC group (35.7 %; P = 0.01) resulted in a recommendation of further colonoscopy, but only 10/25 patients actually underwent this proposed colonoscopy. CONCLUSION: Patients with a positive gFOBT result who do not undergo the recommended colonoscopy are difficult to recruit to the screening program and simply proposing an additional, less-invasive procedure, such as VCE or CTC, is not an effective strategy.ClinicalTrials.govNCT02558881TRIAL REGISTRATION: Randomized, controlled trial NCT02558881 at clinicaltrials.gov.

3D contrast-enhanced MR angiography of the abdominal aorta and its distal branches: Interobserver agreement of radiologists in a routine examination.

RATIONALE AND OBJECTIVES: To evaluate the quality of images of the aorta and visceral arteries made at a high level of spatial resolution with thin slices and an optimized acquisition time by three-dimensional contrast-enhanced magnetic resonance angiography (3D CE-MRA). MATERIALS AND METHODS: 3D CE-MRA with a 1.4-mm slice thickness and 512-pixel base matrix was done on 62 consecutive patients with a 1.5-T magnetic resonance imaging MRI unit. A bolus test with a power injector was used to calculate the optimal scan delay time. For quantitative evaluation, the signal-to-noise ratio (SNR) was measured in 3 regions of interest. Qualitative image analysis was evaluated independently by two radiologists and graded on a scale of 0-3. Separate analyses were done for the aorta and distal visceral arterial branches. RESULTS: The means SNR values were respectively 56.2 +/- 15.2 (mean +/- SD) for the aorta, 59.2 +/- 15.1 for the celiac trunk, and 57 +/- 15.2 for the superior mesenteric artery, with a homogeneous distribution (P = .99). Consistent enhancement was confirmed by the lack of statistically significant differences between the SNR values. The average score for vessel visualization on source images ranged from good to excellent for different segments. After post-processing of images, the average score for distal arterial segments was significantly improved. The overall agreement between the 2 reviewers in the visualization of definite artery segments was excellent (k = .91). CONCLUSION: 3D CE-MRA with a 512-pixel base matrix and thin slices can be applied in a reproducible way with excellent depiction and delineation of small vessels. Such a protocol could be used routinely.

Mangafodipir-enhanced magnetic resonance cholangiography for the diagnosis of bile duct leaks.

BACKGROUND: The purpose of this prospective study was to assess the value of contrast-enhanced magnetic resonance cholangiography with mangafodipir trisodium perfusion for detection and localization of trauma-induced and postoperative bile duct leaks. METHODS: Eleven patients with suspected bile duct leaks after trauma (n=5) or surgery (n=6) were included. Patients with suspected leaks after cholecystectomy were excluded. All patients underwent contrast-enhanced magnetic resonance cholangiography with two-dimensional axial and three-dimensional coronal gradient-echo images acquired 1 to 3 hours after intravenous administration of mangafodipir trisodium perfusion. Contrast-enhanced magnetic resonance cholangiography findings were correlated with direct cholangiography obtained in all patients, including endoscopic retrograde (n=7) and percutaneous transhepatic cholangiography (n=4). RESULTS: Biliary tract enhancement was identified in all patients on contrast-enhanced magnetic resonance cholangiography. Peritoneal cavity fluid and bile collections that contained extravasated mangafodipir trisodium (increased signal intensity on gradient-echo sequences) were demonstrated in 6 patients. Direct cholangiography confirmed the presence of bile duct leaks in these 6 patients and the absence of bile duct leaks in 5 patients. There was no false-negative or false-positive contrast-enhanced magnetic resonance cholangiography. CONCLUSIONS: Mangafodipir-enhanced magnetic resonance cholangiography is a noninvasive technique that can provide functional biliary information with excellent depiction of bile duct leaks.