OLORECTAL CANCER (CRC) accounts for approximately 210 000 deaths each year in Europe. 1 The majority of CRCs arise within adenomatous polyps, 2 and polypectomy is associated with a reduction in CRC incidence and mortality. 3 The target lesions in mass screening programs are advanced adenomas, which harbor the greatest cancer risk, and early stage CRC, 4 but adherence to screening procedures remains suboptimal. 5,6 Computed tomographic (CT) colonography has been shown to be sufficiently accurate in detecting colorectal neoplasia. 7,8 Less invasive and better tolerated than colonoscopy, 9,10 CT colo-nography is now considered a valid alternative for CRC screening in the general population. 11 Individuals with first-degree family history of advanced colorectal neoplasia, those who have had resection of co-For editorial comment see p 2498. Context Computed tomographic (CT) colonography has been recognized as an alternative for colorectal cancer (CRC) screening in average-risk individuals, but less information is available on its performance in individuals at increased risk of CRC. Objective To assess the accuracy of CT colonography in detecting advanced colorectal neoplasia in asymptomatic individuals at increased risk of CRC using unblinded colonoscopy as the reference standard. Design, Setting, and Participants This was a multicenter, cross-sectional study. Individuals at increased risk of CRC due to either family history of advanced neoplasia in first-degree relatives, personal history of colorectal adenomas, or positive results from fecal occult blood tests (FOBTs) were recruited in 11 Italian centers and 1 Belgian center between December 2004 and May 2007. Each participant underwent CT colonography followed by colonoscopy on the same day. Main Outcome Measures Sensitivity and specificity of CT colonography in detecting individuals with advanced neoplasia (ie, advanced adenoma or CRC) 6 mm or larger. Results Of 1103 participants, 937 were included in the final analysis: 373 cases in the family-history group, 343 in the group with personal history of adenomas, and 221 in the FOBT-positive group. Overall, CT colonography identified 151 of 177 participants with advanced neoplasia 6 mm or larger (sensitivity, 85.3%; 95% confidence interval [CI], 79.0%-90.0%) and correctly classified results as negative for 667 of 760 participants without such lesions (specificity, 87.8%; 95% CI, 85.2%-90.0%). The positive and negative predictive values were 61.9% (95% CI, 55.4%-68.0%) and 96.3% (95% CI, 94.6%-97.5%), respectively; after group stratification, a significantly lower negative predictive value was found for the FOBT-positive group (84.9%; 95% CI, 76.2%-91.3%; PϽ.001). Conclusions In a group of persons at increased risk for CRC, CT colonography compared with colonoscopy resulted in a negative predictive value of 96.3% overall. When limited to FOBT-positive persons, the negative predictive value was 84.9%.

To evaluate diagnostic performance of endorectal magnetic resonance (eMR) for diagnosing local recurrence of prostate cancer (PC) in patients with previous radical prostatectomy (RP) and to assess whether contrast-enhanced (CE)-eMR improved diagnostic accuracy in comparison to unenhanced study. Unenhanced eMR data of 72 male patients (mean of total PSA: 1.23 +/- 1.3 ng/ml) with previous RP were interpreted retrospectively and classified either as normal or suspicious for local recurrence. All eMR examinations were re-evaluated also on CE-eMR 4 months after the first reading. Images were acquired on a 1.5-T system. These data were compared to the standard of reference for local recurrence: prostatectomy bed biopsy results; choline positron emission tomography results; PSA reduction or increase after pelvic radiotherapy; PSA modification during active surveillance. Sensitivity, specificity, predictive positive value, negative predictive value and accuracy were 61.4%, 82.1%, 84.4%, 57.5% and 69.4% for unenhanced eMR and 84.1%, 89.3%, 92.5%, 78.1% and 86.1% for CE-eMR. A statistically significant difference was found between accuracy and sensitivity of the two evaluations (chi(2) = 5.33; p = 0.02 and chi(2) = 9.00; p = 0.0027). EMR had great accuracy for visualizing local recurrence of PC after RP. CE-eMR improved diagnostic performance in comparison with T2-weighted imaging alone.

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Objectives To compare the diagnostic accuracy and sensitivity of Gd-EOB-DTPA MRI and diffusion-weighted (DWI) imaging alone and in combination for detecting colorectal liver metastases in patients who had undergone preoperative chemotherapy. Methods Thirty-two consecutive patients with a total of 166 liver lesions were retrospectively enrolled. Of the lesions, 144 (86.8 %) were metastatic at pathology. Three image sets (1, Gd-EOB-DTPA; 2, DWI; 3, combined Gd-EOB-DTPA and DWI) were independently reviewed by two observers. Statistical analysis was performed on a per-lesion basis. Results Evaluation of image set 1 correctly identified 127/ 166 lesions (accuracy 76.5 %; 95 % CI 69.3-82.7) and 106/ 144 metastases (sensitivity 73.6 %, 95 % CI 65.6-80.6). Evaluation of image set 2 correctly identified 108/166 (accuracy 65.1 %, 95 % CI 57.3-72.3) and 87/144 metastases (sensitivity of 60.4 %, 95 % CI 51.9-68.5). Evaluation of image set 3 correctly identified 148/166 (accuracy 89.2 %, 95 % CI 83.4-93.4) and 131/144 metastases (sensitivity 91 %, 95 % CI 85.1-95.1). Differences were statistically significant (P<0.001). Notably, similar results were obtained analysing only small lesions (<1 cm). Conclusions The combination of DWI with Gd-EOB-DTPAenhanced MRI imaging significantly increases the diagnostic accuracy and sensitivity in patients with colorectal liver metastases treated with preoperative chemotherapy, and it is particularly effective in the detection of small lesions. Key Points • Accurate detection of colorectal liver metastases is essential to determine resectability.• Almost 80 % of patients are candidates for neoadjuvant chemotherapic treatment at diagnosis. After chemotherapy, metastases usually decrease, and drug-induced liver steatosis may be present.• The sensitivity of imaging is significantly inferior to that in chemotherapy-naïve patients.• DWI combined with Gd-EOB-DTPA increases sensitivity in detecting small metastases after chemotherapy.

Our purpose was to assess the effect of reader experience, fatigue, and scan findings on interpretation time for CT colonography. Nine radiologists (experienced in CT colonography); nine radiologists and ten technicians (both groups trained using 50 validated examinations) read 40 cases (50% abnormal) under controlled conditions. Individual interpretation times for each case were recorded, and differences between groups determined. Multi-level linear regression was used to investigate effect of scan category (normal or abnormal) and observer fatigue on interpretation times. Experienced radiologists (mean time 10.9 min, SD 5.2) reported significantly faster than less experienced radiologists and technicians; odds ratios of reporting times 1.4 (CI 1.1, 1.8) and 1.6 (1.3, 2.0), respectively (P