Contrast-enhanced computed tomography colonography in preoperative distinction between T1-T2 and T3-T4 staging of colon cancer.

RATIONALE AND OBJECTIVES: To predict the T stage of nonrectal colon cancer using contrast-enhanced computed tomography colonography. MATERIALS AND METHODS: Sixty-one patients with 67 nonrectal colon cancers consecutively underwent contrast-enhanced computed tomography colonography after an incomplete colonoscopy. Two readers evaluated wall deformity and perilesional fat abnormality on three-dimensional double contrast enema-like views and multiplanar reconstructions. Pathology was used as the standard of reference. McNemar, Fisher, and Cohen κ statistics were used. RESULTS: At pathologic examination, we found the following stages: T1 (n = 5), T2 (n = 10), T3 (n = 41), T4a (n = 6), and T4b (n = 5). Intraobserver and interobserver reproducibilities were almost perfect for wall deformity (κ = 1.00 and κ = 0.88, respectively), substantial for perilesional fat abnormality (κ = 0.79 and κ = 0.74, respectively). Using the results of the more experienced reader, accuracy of wall deformity ≥50% (apple-core) alone for T ≥ 3 was 62 of 67 (0.93, 95% confidence interval [CI] 0.83-0.97) and that of perilesional fat abnormality alone was 37 of 67 (0.55, 95% CI 0.43-0.67) (P < .001). Predictive value for ≥ T3 of the association wall deformity ≥50% with perilesional fat abnormality was 22 of 22 (1.00, 95% CI 0.85-1.00), higher, but not significantly, than that of wall deformity ≥50% with normal perilesional fat 29 of 33 (0.88, 95% CI 0.72-0.97) (P = .148, Fisher exact test). CONCLUSIONS: The presence of apple-core wall deformity, regardless of perilesional fat abnormality, is highly predictive of stage T3 or higher.

Impact of contrast-enhanced computed tomography colonography on laparoscopic surgical planning of colorectal cancer.

AIM: To evaluate the impact of contrast-enhanced computed tomography colonography (CE-CTC) on laparoscopic surgery planning in patient with stenosing colorectal cancer. MATERIALS AND METHODS: Sixty-nine patients with endoscopically proven colorectal cancer underwent CE-CTC, after incomplete conventional colonoscopy. Two experienced radiologists evaluated site, length, and TNM staging of colorectal cancers on three-dimensional double contrast enema-like views, 2D axial and multiplanar reconstructions. All the patients underwent colorectal resection and surgery bulletin, pathology of surgical specimens, and radiological follow-up at about 8 months were used as reference standard. RESULTS: The detection rate of colorectal cancer was 100 % (75/75); CE-CTC allowed for a diagnosis of a synchronous colorectal cancer in five patients (7 %). CE-CTC correctly judged the site of the lesions in all the cases; clinically significant localization errors at conventional colonoscopy were noted in 3 out of 69 patients (4 %). Additional colonic polyps greater than 6 mm in diameter were found in 21 out of 69 patients (30 %); in two patients (3 %) the surgeon performed an enlarged colectomy to include synchronous polyps proximal to colorectal cancer. Sensitivity, specificity, PPV, NPV, and accuracy were for T1-T2 vs. T3-T4: 96 %, 71 %, 92 %, 87 %, and 91 %, respectively; for N: 94 %, 42 %, 64 %, 86 %, and 70 %; for M: 100 %, 100 %, 83 %, 100 %, and 97 %. There were no complications associated with CE-CTC. CONCLUSION: Information given by CE-CTC concerning colorectal cancer location and synchronous colonic cancers and polyps changed the laparoscopic surgical strategy in almost 14 % of patients.

Technical quality of CT colonography in relation with diverticular disease.

OBJECTIVE: The aim of the study is to explore how the technical quality of the examination was affected by diverticular disease. MATERIALS AND METHODS: We retrospectively evaluated a consecutive series of 78 subjects who underwent CTC for screening (n=58) or staging (n=20) colorectal cancer, 38 of them (49%) after an incomplete optical colonoscopy. Patients were administered a mild laxative and a iodinated contrast material for fecal tagging. We scored both the bowel preparation and the overall colon distension as poor, good, or optimal and measured the mean sigmoid colon diameter. We counted the number of diverticula and classified patients as having or not a severe diverticular disease (SDD). The number of the prompts of computer aided diagnosis (CAD) per patient was also considered. Mann-Whitney U and χ(2) tests were performed. RESULTS: No CTC complications occurred. The bowel cleansing was poor in 8 (10%) patients, good in 29 (37%) and optimal in 41 (53%); colon distension was poor in 7 (9%) patients, good in 38 (49%), and optimal in 33 (42%). Fifty-four (69%) showed diverticula and 30 (38%) had an SDD. Bowel cleansing and distension were not significantly impaired by neither diverticula (p>0.590) nor the SDD (p>0.110). Mean sigmoid colon diameter was reduced in presence of diverticula (28 mm versus 23 mm, p=0.009) or SDD (26 mm versus 22 mm, p=0.016). The mean number of CAD prompts per patient was not significantly increased by the presence of SDD (p=0.829). CONCLUSIONS: Bowel cleansing and distension at CTC were not influenced by the presence of diverticular disease.

Role of magnetic resonance imaging in evaluation of the activity of perianal Crohn's disease.

AIM: To evaluate the diagnostic ability of contrast-enhanced Magnetic Resonance Imaging (MRI) in assessment of the activity of perianal fistulas in Crohn's disease (CD) patients, compared to clinical data. MATERIALS AND METHODS: Fifty CD patients (25 men; mean[SD] age: 40.4[12.6] years) with known or suspected perianal fistulas underwent perianal space MRI. Radiological activity of disease was measured as the percentage increase (PI) of ROI values of fistulas in relation to ROI values of healthy local fat, after contrast administration. Clinical activity of disease was defined according to Perianal Disease Activity Index (PDAI) and Fistula Drainage Assessment (FDA). RESULTS: Forty-two patients presented perianal disease at MRI (55 fistulas identified). An association between both fistula's PI and PDAI (Pearson's coefficient 0.512, p<0.0001) and between PI and FDA (p=0.003) was demonstrated. Areas under ROC curves of PI values in relation to PDAI and FDA were respectively 0.876 [95%CI=(0.743-1.00), p<0.001] and 0.784 [95%CI=(0.588-0.980), p=0.003]. A cut-off value of PI, calculated on these preliminary data, correctly classified more than 90% of fistulas. CONCLUSIONS: Contrast-enhanced MRI with PI calculation offered practical information about activity of perianal fistulas and might be helpful in providing a comprehensive evaluation of CD perianal disease.

Identification from chest x-rays: reliability of bone density patterns of the humerus.

A critical review of Kahana and Hiss' study on identification from bone trabecular pattern and a test of their method conducted on the humerus are presented. Bone trabecular pattern was studied through the generation of a numerical file representing the gray scale. Using the correlation coefficient, several pairwise comparisons between numerical files were performed. The test gave nearly 30% of incorrect exclusions (the method did not recognize couples of radiographs belonging to the same subject) and 50% of misidentifications (the method recognized couples of radiographs belonging to different subjects, as belonging to the same subject); therefore, this research shows that at the present time, it is not possible to safely quantify identification through bone density patterns, of the proximal humerus taken from thoracic X-rays. Thus, an "easy"-but dangerous-use of trabecular density patterns on this specific type of radiogram as an identification method should be currently avoided.

Regenerative nodules in patients with chronic Budd-Chiari syndrome: a longitudinal study using multiphase contrast-enhanced multidetector CT.

OBJECTIVE: Our aim was to evaluate the serial evolution of regenerative nodules in patients with Budd-Chiari syndrome (BCS) treated with portal-systemic shunts, using multiphasic multidetector computed tomography (MDCT). MATERIALS AND METHODS: Five patients each underwent three MDCT exams over an extended period ranging from 36 to 42 months. Two radiologists in consensus retrospectively reviewed each exam for each patient. Individual nodules were grouped according to size (size I: nodules with diameter < or =15 mm; size II: >15 mm but <30 mm; size III: > or =30 mm), pattern of enhancement (A: homogeneously hypervascular or B: with central scar), and segmental location. Four nodules classified as size II, which increased in size over time, were needle-biopsied. RESULTS: We detected 61 nodules at the first exam, 66 nodules at the second exam (7 nodules disappeared and 12 new nodules), and 85 nodules at the third exam (8 disappeared and 27 new) for a total of 212 findings. Nodules were mostly found in the right hepatic lobe. Fourteen of the 15 nodules that disappeared over time were size I and enhancement pattern A. At unenhanced MDCT, 204 (96%) of the 212 findings were isodense. Overall, 100 nodules, including the 61 initially detected, were considered newly diagnosed; of these 84 (84%) were size I and pattern A. Of 57 nodules considered size I and pattern A at the first or second exam, 24 (42%) changed to pattern B at the third exam and either size II (n=18) or III (n=6). The four biopsied nodules were each confirmed as benign regenerative nodule. No patient developed HCC at 5-year follow-up period. CONCLUSION: Hepatic nodules in BCS patients not only increase in number over time but may also increase in size and develop a central scar.

Safety of unprotected carotid artery stent placement in symptomatic and asymptomatic patients: a retrospective analysis of 30-day combined adverse outcomes.

PURPOSE: To retrospectively evaluate the outcome of carotid artery stent placement (CAS) without the use of embolic protection devices (EPDs) in a large cohort of patients. MATERIALS AND METHODS: Institutional review board approval and informed consent from all patients were obtained. Preprocedure color Doppler ultrasonography (US), magnetic resonance (MR) imaging, or computed tomography (CT) were used to evaluate stenosis severity (70% or greater). Clinical findings and combined 30-day complication rates in 400 patients (289 men, 111 women; mean age, 73 years +/- 8 [standard deviation]) who underwent unprotected CAS for asymptomatic (n = 156; 39%) or symptomatic (n = 244, 61%) stenoses were analyzed. Follow-up at 30 days included neurologic evaluation and color Doppler US. RESULTS: Self-expanding stents were successfully deployed in 397 of 400 (99.25%) patients. Among the 397 patients, nine (2.27%) major complications (all in patients with prior symptoms) had occurred at 30 days, including three (0.76%) major (all in patients who had stopped antiplatelet prophylaxis) and six (1.5%) minor strokes--three intraprocedural and three delayed. Minor complications included 16 (4%) transient ischemic attacks, four in asymptomatic and 12 in symptomatic patients. The 30-day combined adverse outcomes (transient ischemic attack, ipsilateral stroke, death) were significantly correlated with prior presence of symptoms (symptomatic, 8.6%; asymptomatic, 2.6%; P < .03). CONCLUSION: Stent placement without EPD was performed with a high technical success rate. For asymptomatic patients, the combined 30-day adverse-outcomes rate was within the limits recommended by the American Heart Association for carotid endarterectomy and compared favorably with results reported for CAS with EPD. When a transient ischemic attack is excluded, the 30-day combined death and stroke rate among patients with prior symptoms also compared favorably with published results.

Evaluation of different counting methods for use in radiochemical purity testing procedures for 99mTc-labelled radiopharmaceuticals.

The efficiency and accuracy of different methods for quality control of radiopharmaceutical preparations for diagnostic purpose were studied. The radiochemical purity of (99m)Tc Tetrafosmin, (99m)Tc Exametazime, (99m)Tc Sestamibi and (99m)Tc Oxidronate was evaluated by different thin layer chromatography systems, followed by cutting of the strips into two or three sections and by the measurement of radioactivity distribution by dose calibrator or gamma counter. In addition, to confirm the accuracy of these routine procedures, the strips were cut into a number of micro-sections (14-25) and each of them evaluated by the gamma counter. The three tested procedures gave similar results and revealed a good and comparable accuracy. The radioactivity measurement with the dose calibrator remains the most practicable because of the rapidity of execution.

Geometric reconstruction for computational mesh generation of arterial bifurcations from CT angiography.

A methodology for patient-specific model reconstruction and computational mesh generation of arterial bifurcations from angio-CT scans is presented. Three-dimensional models were reconstructed with a level set technique, analyzed with a skeletoning algorithm and automatically decomposed into branches. Cooper scheme was then employed to generate high quality hexahedral mesh. We successfully applied our technique to the carotid bifurcations of two patients affected by severe atherosclerotic plaques. The proposed technique is fast, accurate and reproducible, and can be a useful tool for the evaluation of arterial fluid dynamics within conventional computed tomography investigations.