Colonic perforation at CT colonography: assessment of risk in a multicenter large cohort.

PURPOSE: To assess retrospectively the incidence, clinical features, and treatment of colonic perforation at computed tomographic (CT) colonography in a large multicenter cohort. MATERIALS AND METHODS: The study was performed in accordance with the institutional ethics committees' requirements of a retrospective review in each of the participating centers, and no informed consent was required. A review of all patients who underwent CT colonography between January 2001 and December 2004 in 11 medical centers representing more than 95% of studies performed in a single country was performed to determine the rate of colorectal perforation. Data about patient demographics and patient- and procedure-related risk were recorded. Information about the location of the perforation, its likely mechanism, and treatment was collected. Analysis included calculation of rates of colonic perforation and surgical treatment and of 95% confidence intervals. RESULTS: A total of 11 870 CT colonographic studies were performed in 6837 (57.6%) men and 5033 (42.4%) women (mean age, 59.9 years; range, 38-90 years) with seven cases of colorectal perforation, yielding a risk rate of 0.059% (one of 1696 studies; 95% confidence interval: one of 974, 971 of 6537). The mean age of the patients with perforation was 77.8 years. Six (84%) of seven cases of perforation occurred in symptomatic patients at high risk for colorectal neoplasia, and one (16%) occurred in an asymptomatic average-risk patient. All studies were performed after insufflation of room air. Six (84%) cases of perforation occurred in patients in whom a rectal tube was inserted, and in five of them, a balloon was inflated. Five (71%) cases of perforation occurred in the sigmoid colon; and two (29%), in the rectum. Four (57%) patients (one in 2968 patients; 95% confidence interval: 1.5 in 10 000, 14.7 in 10 000) required surgical treatment. Possible factors that contributed to perforation were left inguinal hernia containing colon (n = 4), severe diverticulosis (n = 3), and obstructive carcinoma (n = 1). CONCLUSION: Perforation of the colon and rectum is a rare complication of CT colonography. Older age and underlying concomitant colonic disease were present in patients with perforation.

Preauthorization of CT and MRI examinations: assessment of a managed care preauthorization program based on the ACR Appropriateness Criteria and the Royal College of Radiology guidelines.

PURPOSE: To evaluate computed tomography (CT) and magnetic resonance imaging (MRI) utilization patterns before and after the implementation of a preauthorization program based on the ACR Appropriateness Criteria((R)) and the guidelines of the Royal College of Radiologists. MATERIALS AND METHODS: All CT and MRI requests received at the preauthorization center and CT and MRI examinations actually performed were identified by our health care service's centralized computerized database between January 1, 2000, and December 31, 2003. The obligatory preauthorization of CT and MRI requests was established for CT in September 2001 and for MRI in February 2002. All ambulatory CT and MRI examination requests sent for approval during the study period by most of our health care physicians were included in the study. The preauthorization program model is presented, and multiple parameters were evaluated from January 2000 to December 2003, before and after preauthorization was established. RESULTS: Before preauthorization was required, the CT and MRI utilization rates were constantly increasing by 20% and 5% per year for CT and MRI, respectively. After preauthorization was implemented, CT and MRI annual performance rates decreased from 25.9 and 7 examinations per 1,000, respectively, in 2000 to 17.3 and 5.6 examinations per 1,000, respectively, in 2003. The decreases in the utilization of MRI and CT imaging between 2001 and 2003 were 9% (12,129 compared with 11,070 MRI examinations) and 33% (81,223 compared with 57,204 CT examinations), respectively, resulting in substantial, statistically significant cost savings. The deferral rate ranged from 7.5% to 12.2% (mean = 9.8%) for CT and 13.9% to 21.4% (mean = 17%) for MRI. Deferred cases in CT were most commonly in neuroradiology, musculoskeletal radiology, and CT angiography (ranges of deferred cases 9% to 12%, 11% to 12%, and 10% to 12%, respectively). Deferred cases in MRI were most commonly in abdominal and chest radiology (ranges of deferred cases 32% to 37% and 20% to 31%, respectively). Computed tomography was more commonly utilized inappropriately by pediatric professions, and MRI was more commonly utilized inappropriately by medical subspecialty professions. CONCLUSION: Preauthorization of CT and MRI requests results in a substantial decrease in utilization of these modalities with reduction in imaging costs.

Clinical and duplex US assessment of effects of sildenafil on cavernosal arteries of the penis: comparison with intracavernosal injection of vasoactive agents--initial experience.

PURPOSE: To prospectively evaluate the clinical response and hemodynamic changes in cavernosal arteries after oral administration of sildenafil without and with audiovisual sexual stimulation and to compare those responses with responses from intracavernosal injections of vasoactive agents. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained. Thirteen consecutive patients (age range, 22-77 years; mean, 60.4 years) with erectile dysfunction were evaluated with clinical assessment and cavernosal duplex ultrasonography (US). The patients were examined at two sessions 3 weeks apart. First, each patient received 100 mg of sildenafil citrate orally and was examined 60 minutes later without any sexual stimulation. Each patient then underwent repeat clinical and duplex US assessment after audiovisual sexual stimulation. Three weeks later, the patients underwent identical clinical evaluation and duplex US after intracavernosal injection of a commercially available combination of papaverine, prostaglandin E1, and phentolamine. Clinical and duplex US data (ie, peak systolic velocity [PSV]) were examined by using the Wilcoxon signed rank test for matched pairs. RESULTS: At rest, the overall mean cavernosal artery PSV was 1.08 cm/sec and remained unchanged after intake of sildenafil without any audiovisual stimulation, with no clinical evidence of erection. With the addition of audiovisual sexual stimulation, eight (62%) of 13 patients had penile congestion or erection, and six (46%) had a PSV greater than 25 cm/sec. With intracavernosal injection of the combination of three drugs, all 13 patients achieved congestion or erection, and 10 (77%) had a PSV greater than 25 cm/sec. Both clinical and duplex US responses to intracavernosal injection were significantly greater than they were to sildenafil with audiovisual sexual stimulation (P = .04 and .003, respectively). CONCLUSION: Oral sildenafil with audiovisual sexual stimulation led to a significant clinical response and increment in blood flow in the cavernosal arteries. However, more patients responded to intracavernosal injection of the combination of three drugs than to sildenafil, and the clinical response was significantly better.