Purpose:Fibrin sheaths may develop around long-term indwelling central venous catheters (CVCs) and remain in place after the catheters are removed. We evaluated the prevalence, computed tomographic (CT) appearance, and clinical associations of retained fibrin sheaths after CVC removal.Materials and Methods:We retrospectively identified 147 adults (77 men and 70 women; mean age 58 y) who underwent CT after CVC removal. The prevalence of fibrin sheath remnants was calculated. Bivariate and multivariate analyses were performed to assess for associations between sheath remnants and underlying diagnoses leading to CVC placement; patients' age and sex; venous stenosis, occlusion, and collaterals; CVC infection; and pulmonary embolism.Results:Retained fibrin sheaths were present in 13.6% (20/147) of cases, of which 45% (9/20) were calcified. Bivariate analysis revealed sheath remnants to be more common in women than in men [23% (16/70) vs. 5% (4/77), P=0.0018] and to be more commonly associated with venous occlusion and collaterals [30% (6/20) vs. 5% (6/127), P=0.0001 and 30% (6/20) vs. 6% (7/127), P=0.0003, respectively]. Other variables were not associated. Multivariate analysis confirmed the relationship between fibrin sheaths and both female sex (P=0.005) and venous occlusion (P=0.01).Conclusions:Retained fibrin sheaths were seen on CT in a substantial minority of patients after CVC removal; nearly half of them were calcified. They were more common in women and associated with venous occlusion.

OBJECTIVE:To evaluate qualitative and simple quantitative measures of all 4 cardiac chamber sizes on computed tomography (CT) in comparison with transthoracic echocardiography (TTE).METHODS:We retrospectively identified 104 adults with electrocardiographically gated cardiac CT and TTE within 3 months. Axial early diastolic (75% R-R) CT images were reviewed for qualitative chamber enlargement, and each chamber was measured linearly. Transthoracic echocardiography was reviewed for linear, area, and volume measurements. Interrater agreement was calculated using Cohen κ and Pearson correlation.RESULTS:There were significant correlations between linear left atrium and left ventricle sizes by CT and TTE (r = 0.686 and r = 0.709, respectively). Correlations for right atrium and right ventricle measurements were lower (r = 0.447 and r = 0.492, respectively). Agreement between CT and TTE for qualitative chamber enlargement was poor (highest κ = 0.35). Computed tomography sensitivity was ≤ 62% for enlargement of all chambers.CONCLUSIONS:Linear CT measurements of left-sided chamber sizes correlate well with TTE. Right heart measurements and qualitative assessments agreed poorly with TTE.

BACKGROUND: Computed tomography (CT) of the heart is increasingly used to characterize not only the coronary arteries but also cardiac structure and function. The performance of CT in depicting myocardial perfusion is under active investigation.OBJECTIVE: We describe the pattern of normal myocardial perfusion on resting 64-detector cardiac CT.METHODS: Patients (n = 33; 20 women, 13 men; mean age, 52 years) with normal radio nuclide myocardial perfusion imaging and normal coronary arteries on CT angiography (120 kVp) comprised the study population. Segmental myocardial perfusion on CT was measured in Hounsfield units (HU) with manual and semiautomated methods for the 17-segment American Heart Association model in both systole and diastole. Segments were aggregated into coronary artery territories, from apex to base and by myocardial wall. The relationships between myocardial perfusion and various patient factors were evaluated.RESULTS: Overall mean myocardial perfusion was 98 HU in systole and 94 HU in diastole with the manual method (P = .011) and 92 HU in systole and 95 HU in diastole with the automated method (P = .001). The septum showed significantly higher mean attenuation values than the other walls in systole and diastole with both methods. Generally, attenuation values were lower in the left circumflex artery territory and in the apex. Bivariate analysis showed higher mean myocardial attenuation values for women than men, although this difference did not persist on multivariate analysis adjusted for patient size.CONCLUSION: Normal mean resting myocardial perfusion correlates with CT attenuation values of approximately 92-98 HU on CT angiography in the coronary arterial phase. The septum consistently shows greater attenuation values than the other walls. (C) 2011 Society of Cardiovascular Computed Tomography. All rights reserved.

OBJECTIVEPET cannot distinguish between bronchogenic carcinoma and granuloma, but positive scans may prompt surgery. We systematically evaluated the CT appearance of resected carcinomas and granulomas to identify features that could be used to reduce granuloma resections.MATERIALS AND METHODSWe retrospectively identified 93 consecutive patients between January 2005 and November 2008 who had resection of a pulmonary nodule pathologically diagnosed as bronchogenic carcinoma or granuloma and preoperative imaging with CT and PET. Each nodule was evaluated on CT for size, doubling time, location, borders, shape, internal characteristics, calcification, clustering, air bronchograms, and cavitation. A diagnostic impression was rendered. Bivariate and logistic regression analyses were performed. Pre-PET data regarding the proportion of resected granulomas and carcinomas between January 1995 and December 1996 were reviewed.RESULTSSixty-eight percent (65/96) of nodules were carcinomas and 32% (31/96) were granulomas. The CT impression was benign in 65% (20/31) of granulomas and 5% (3/65) of carcinomas (p < 0.0001; negative predictive value [NPV], 87% [20/23]). Specific CT features significantly associated with granuloma were clustering, cavitation, irregular shape, lack of pleural tags, and solid attenuation. The combination of nonspiculated borders, irregular shape, and solid attenuation had an NPV of 86% (12/14). Granulomas represented 18% (9/50) of resected nodules in 1995 and 1996 (p = 0.066).CONCLUSIONCT findings reduce but cannot eliminate the possibility that a nodule is malignant. Outcomes-based clinical trials are needed to determine whether CT features of benignity can guide less-invasive initial management and reverse a concerning trend in granuloma resection.

Purpose: Left ventricular ejection fraction (LVEF) determines patient management and is a standard part of cardiac imaging evaluation. Inter-modality comparisons are useful in determining whether modalities are interchangeable. Multidetector Computed tomography (CT) and single photon emission CT (SPECT) myocardial perfusion imaging (MPI) have been compared in only a few cohorts. We compared these modalities in a sex-balanced group.Materials and Methods: Sixty outpatients (30 women 30 men) referred for MPI underwent CT on the same day. We calculated LVEF, end-diastolic volume (EDV), and end-systolic volume (ESV) from CT and MPI datasets using a commercially available, semi-automated routine and quantitative gated SPECT (QGS) respectively. Correlations, t-tests and Bland-Altman plots were performed for ESV, EDV, and LVEF. Bivariate and multiple regression analyses for LVEF were performed for both modalities. The subgroups for men and women were analyzed.Results: Computed tomography showed moderate to high correlations with SPECT for LVEF (0.62), EDV (0.70), and ESV (0.63). End-diastolic volume and LVEF were significantly higher on CT as compared to SPECT (P < 0.001 each). Multiple regression analysis showed a significant relationship between sex and LVEF (P < 0.0001) on SPECT but not on CT. In men, there were significantly higher EDV (P = 0.014) and LVEF (P < 0.001) on CT compared with SPECT, but there was no difference in ESV For women, there were significantly higher EDV and ESV on CT (P < 0.001 each), but no difference in LVEF.Conclusions: Left ventricular volumes and LVEF differed significantly on CT compared with SPECT and varied according to sex. Therefore, left ventricular volumes and LVEF values on CT and SPECT are not interchangeable.