Quantitative tumor perfusion assessment with multidetector CT: are measurements from two commercial software packages interchangeable?

Purpose: To prospectively determine the level of agreement between tumor blood volume and permeability measurements obtained with two commercially available perfusion computed tomographic ( CT) software packages.Materials and Methods: This study was performed with institutional review board approval; informed consent was obtained from all participants. A total of 44 patients ( 24 men, 20 women; mean age, 68 years; range, 28-87 years) with proved colorectal cancer were examined prospectively with multi-detector row CT. A 65-second tumor perfusion study was performed after intravenous bolus injection of contrast material. Tumor blood volume and permeability were determined with two methods: adiabatic approximation of distributed parameter analysis and Patlak analysis. Agreement between the results was determined by using Bland-Altman statistics. Within-patient variation was determined by using analysis of variance.Results: The mean values for permeability and blood volume, respectively, were 13.9 mL . 100 mL(-1) . min(-1) +/- 3.7 ( standard deviation) and 6.1 mL/100 mL +/- 1.5, as calculated with distributed parameter analysis, and 17.4 mL . 100 mL(-1) . min(-1) +/- 7.3 and 10.1 mL/100 mL +/- 4.2, as calculated with Patlak analysis. The mean difference and 95% limits of agreement, respectively, were -3.6 mL . 100 mL(-1) . min(-1) and -18.4 to 11.2 mL/100 mL(-1) . min(-1) for permeability and -3.9 mL/100 mL and -10.9 to 3.0 mL/100 mL for blood volume. The coefficient of variation was 37.4% for permeability and 46.5% for blood volume.Conclusion: There was disagreement between the methods used to estimate tumor vascularity, which indicated the measurement techniques were not directly interchangeable

Clinical examination, endosonography, and MR imaging in preoperative assessment pf fistula in ano: comparison with outcome-based reference standard

PURPOSE: To prospectively evaluate the relative accuracy of digital examination, anal endosonography, and magnetic resonance (MR) imaging for preoperative assessment of fistula in ano by comparison to an outcome-derived reference standard. MATERIALS AND METHODS: Ethical committee approval and informed consent were obtained. A total of 104 patients who were suspected of having fistula in ano underwent preoperative digital examination, 10-MHz anal endosonography, and body-coil MR imaging. Fistula classification was determined with each modality, with reviewers blinded to findings of other assessments. For fistula classification, an outcome-derived reference standard was based on a combination of subsequent surgical and MR imaging findings and clinical outcome after surgery. The proportion of patients correctly classified and agreement between the preoperative assessment and reference standard were determined with trend tests and kappa statistics, respectively. RESULTS: There was a significant linear trend (P < .001) in the proportion of fistula tracks (n = 108) correctly classified with each modality, as follows: clinical examination, 66 (61%) patients; endosonography, 87 (81%) patients; MR imaging, 97 (90%) patients. Similar trends were found for the correct anatomic classification of abscesses (P < .001), horseshoe extensions (P = .003), and internal openings (n = 99, P < .001); endosonography was used to correctly identify the internal opening in 90 (91%) patients versus 96 (97%) patients with MR imaging. Agreement between the outcome-derived reference standard and digital examination, endosonography, and MR imaging for classification of the primary track was fair (kappa = 0.38), good (kappa = 0.68), and very good (kappa = 0.84), respectively, and fair (kappa = 0.29), good (kappa = 0.64), and very good (kappa = 0.88), respectively, for classification of abscesses and horseshoe extensions combined. CONCLUSION: Endosonography with a high-frequency transducer is superior to digital examination for the preoperative classification of fistula in ano. While MR imaging remains superior in all respects, endosonography is a viable alternative for identification of the internal opening

CT colonography in the detection of colorectal polyps and cancer: systematic review, meta-analysis, and proposed minimum data set for study level reporting.

PURPOSE: To assess the methodologic quality of available data in published reports of computed tomographic (CT) colonography by performing systematic review and meta-analysis. MATERIALS AND METHODS: The MEDLINE database was searched for colonography reports published between 1994 and 2003, without language restriction. The terms colonography, colography, CT colonoscopy, CT pneumocolon, virtual colonoscopy, and virtual endoscopy were used. Studies were selected if the focus was detection of colorectal polyps verified with within-subject reference colonoscopy by using key methodologic criteria based on information presented at the Fourth International Symposium on Virtual Colonoscopy (Boston, Mass). Two reviewers independently abstracted methodologic characteristics. Per-patient and per-polyp detection rates were extracted, and authors were contacted, when necessary. Per-patient sensitivity and specificity were calculated for different lesion size categories, and Forest plots were produced. Meta-analysis of paired sensitivity and specificity was conducted by using a hierarchical model that enabled estimation of summary receiver operating characteristic curves allowing for variation in diagnostic threshold, and the average operating point was calculated. Per-polyp sensitivity was also calculated. RESULTS: Of 1398 studies considered for inclusion, 24 met our criteria. There were 4181 patients with a study prevalence of abnormality of 15%-72%. Meta-analysis of 2610 patients, 206 of whom had large polyps, showed high per-patient average sensitivity (93%; 95% confidence interval [CI]: 73%, 98%) and specificity (97%; 95% CI: 95%, 99%) for colonography; sensitivity and specificity decreased to 86% (95% CI: 75%, 93%) and 86% (95% CI: 76%, 93%), respectively, when the threshold was lowered to include medium polyps. When polyps of all sizes were included, studies were too heterogeneous in sensitivity (range, 45%-97%) and specificity (range, 26%-97%) to allow meaningful meta-analysis. Of 150 cancers, 144 were detected (sensitivity, 95.9%; 95% CI: 91.4%, 98.5%). Data reporting was frequently incomplete, with no generally accepted format. CONCLUSION: CT colonography seems sufficiently sensitive and specific in the detection of large and medium polyps; it is especially sensitive in the detection of symptomatic cancer. Studies are poorly reported, however, and the authors propose a minimum data set for study reporting