Dilatation of the ascending aorta is associated with presence of aortic regurgitation in patients after repair of tetralogy of Fallot.

To evaluate the association between aortic morphology and elasticity with aortic regurgitation in surgically corrected of tetralogy of Fallot (TOF) patients. We retrospectively identified 72 consecutive patients with surgically corrected TOF and 27 healthy controls who underwent cardiac MRI evaluation. Velocity-encoded cine MRI was used to quantify degree of aortic regurgitation (AR) in TOF patients. Ascending aorta diameters were measured at standard levels on MRA images. Aortic pulse-wave velocity (PWV) was quantified with MRI. Morphological and functional MRI variables were compared between groups of TOF patients with and without clinically relevant AR and controls. The association between aortic morphology and elasticity with the presence of AR was evaluated using univariate and multivariate logistic regression. The majority of TOF patients had only trace AR. Nine TOF patients (12 %) had an AR fraction higher than 15 %. Indexed aorta diameter at the sinotubular junction (p = 0.007), at the RPA level (p = 0.006), and low left ventricular ejection fraction (LVEF) (p = 0.015) showed the strongest associations with the presence of at least mild AR, which persisted after controlling for age and gender. Increased ascending aorta dimension is associated with AR in patients after repair of TOF. LVEF was also low in the group of patients with relevant AR compared to those without, suggesting even mild to moderate AR may contribute to LV dysfunction in these patients. Enlarged ascending aorta may be an indication for precise quantification of regurgitant fraction with MRI, since symptomatic patients may need aortic valve repair when moderate regurgitation is present.

The Potential Impact of Risk-Based Screening Mammography in Women 40-49 Years Old.

OBJECTIVE: The purpose of this study was to determine the prevalence of very strong family history and extremely dense tissue in women 40-49 years old with breast cancer detected on screening mammography. MATERIALS AND METHODS: All cancers detected by screening mammography at our institution between January 1997 and November 2012 in 40- to 49-year-old women were retrospectively identified. Those with a personal history of breast cancer were excluded. Family history, breast density, type of malignancy, hormone receptor status, and lymph node status were recorded. RESULTS: One hundred thirty-six cases of breast cancer were identified on screening mammography in 40- to 49-year-old women; 50% were invasive cancers, and 50%, ductal carcinoma in situ. Very strong family history was absent in 88%, and extremely dense breast tissue was absent in 86%. Seventy-six percent of patients had neither very strong family history nor extremely dense breasts, including 79% of the cases of invasive cancers, of which 25% had axillary nodal involvement and 89% were estrogen receptor positive. CONCLUSION: Very strong family history and extremely dense breast tissue were absent in most 40- to 49-year-old women with breast cancer detected at screening mammography. These cancers were frequently invasive (often with nodal metastases) and treatable (hormone receptor positive). Reducing the number of women to be screened in this age group by using this risk-based approach would reduce the number of screen-detected cancers by more than 75%, thereby precluding the benefit of mortality reduction. Even using a risk-based strategy with an expanded definition of high risk that included any first-degree family history, extremely dense tissue, or both, 66% of malignancies would still be missed.

Left atrial transverse diameter on computed tomography angiography can accurately diagnose left atrial enlargement in patients with atrial fibrillation.

PURPOSE: Left atrial (LA) enlargement is associated with increased risk for adverse cardiovascular events. We assessed the accuracy of LA transverse and antero-posterior (AP) diameters obtained from chest computed tomography (CT) angiography in patients with atrial fibrillation. MATERIALS AND METHODS: Nongated contrast-enhanced 64-slice multidetector CT angiography (slice thickness of 0.625 to 1.25 mm) was used to measure the volume and transverse and AP diameters of the LA in 222 subjects. The internal contours of the LA and LA appendage were outlined in 1 of every 5 axial images, and the LA area was multiplied by 5 times the slice thickness. Maximum transverse and AP diameters of the LA were measured, excluding the appendage. Receiver operating characteristic curves were fitted to assess the accuracy of the diameters. A Wald test was used to compare the area under the curves. RESULTS: The mean age of patients was 60.0±10.6 years, and 71% were male. Median LA volume was 55.9±24.4 mL/m. LA enlargement was present in 83% of the patients. Transverse and AP LA diameters were accurate estimators of the LA enlargement. The transverse diameter demonstrated higher accuracy than the AP diameter, with area under the curves of 0.89 (0.84 to 0.94) and 0.81 (0.73 to 0.89), respectively (P<0.05). A transverse LA diameter of 7.3 cm had a sensitivity and specificity of 85% for detection of LA enlargement. At the same sensitivity level, an AP diameter of 4.3 cm had a specificity of 60.5%. CONCLUSIONS: Transverse LA diameter can accurately detect LA enlargement in patients with atrial fibrillation. This parameter can be used for detection of patients with possible LA enlargement on chest CT angiography.

Determinants of second-order bile duct visualization at CT cholangiography in potential living liver donors.

OBJECTIVE: The purpose of this article is to investigate the determinants of second-order bile duct visualization at CT cholangiography in living potential liver donors. MATERIALS AND METHODS: We retrospectively identified 143 potential living liver donors (83 men and 60 women; mean age, 37 years) evaluated with CT cholangiography, which included a slow infusion of iodipamide meglumine with CT acquisition 15 minutes after biliary contrast agent administration. Two readers independently scored the visualization of the second-order bile duct branches on a previously established 4-point scale (0 = not seen, 1 = faintly seen, 2 = well seen, and 3 = excellent visualization). Multivariate analysis was used to investigate the correlation between visualization scores and potential determinants of second-order bile duct opacification, specifically age, body mass index, creatinine level, total and direct bilirubin levels, alkaline phosphatase level, aspartate aminotransferase level, alanine aminotransferase level, patient maximum linear width, CT noise, and hepatosplenic attenuation difference at unenhanced CT. RESULTS: The mean (± SD) second-order bile duct visualization scores were 2.35 ± 0.66 and 2.55 ± 0.60 for readers 1 and 2, respectively. In the multivariate analysis, the only independent predictors of reduced second-order bile duct visualization were higher alkaline phosphatase level (p = 0.01) and higher CT noise (p = 0.02). CONCLUSION: Higher serum alkaline phosphatase level and higher CT noise in potential living liver donors indicate a higher risk of poor second-order bile duct visualization at CT cholangiography.

A pictorial essay of brain perfusion-CT: not every abnormality is a stroke!

Perfusion-CT (PCT) of the brain is a rapidly evolving imaging technique used to assess blood supply to the brain parenchyma. PCT is readily available at most imaging centers, resulting in steadily increasing use of this imaging technique. Though PCT was initially introduced and still most widely used to evaluate patients with acute ischemic stroke, a wide variety of other pathologic processes demonstrate abnormal perfusion maps. Therefore, it is important for the radiologist to recognize altered perfusion patterns observed in diseases other than typical ischemic stroke. The goal of this article is to show the perfusion maps and review the perfusion patterns observed in some subtypes of atypical stroke and in neurological entities other than stroke, so that they are recognized and not confused with the PCT patterns observed in patients with typical ischemic stroke.

Contrast delay on perfusion CT as a predictor of new, incident infarct: a retrospective cohort study.

BACKGROUND AND PURPOSE: The purpose of this study was to determine if the assessment of intracranial collateral circulation by CT angiography and/or perfusion CT (PCT) can predict the risk of future ischemic stroke in a large, retrospective cohort study. METHODS: We identified 135 consecutive patients who underwent CT angiography of the head and neck and PCT of the brain at baseline and with subsequent follow-up brain imaging. Clinical and demographic information and carotid wall features were collected. Collateral circulation was assessed anatomically at CT angiography and functionally by measuring the mean transit time delay at PCT. The clinical, carotid, CT angiography, and PCT variables were compared between those with and without new incident infarct at follow-up imaging using mixed effect logistic statistical models. RESULTS: During the follow-up period, 15 patients developed a new infarct and 120 patients did not. Clinical features associated with the stroke risk were age, hypertension, hyperlipidemia, and atrial fibrillation. The carotid features associated with stroke risk were wall thickness. Anatomic assessment of collaterals on CT angiography was not associated with stroke risk, whereas the functional assessment of collaterals (mean transit time delay on PCT) was associated with stroke risk. In a multivariate model, age, atrial fibrillation, and mean transit time delay (OR, 22.8; P<0.001) were the only covariates that were independent predictors of future ischemic stroke. CONCLUSIONS: The mean transit time delay on PCT contains important physiological information and should not be discarded. Along with age and atrial fibrillation, this functional assessment of intracranial collateral circulation predicts the risk of future hemispheric infarct.

Reduced cathartic bowel preparation for CT colonography: prospective comparison of 2-L polyethylene glycol and magnesium citrate.

PURPOSE: To prospectively compare adequacy of colonic cleansing, adequacy of solid stool and fluid tagging, and patient acceptance by using reduced-volume, 2-L polyethylene glycol (PEG) versus magnesium citrate bowel preparations for CT colonography. MATERIALS AND METHODS: This study was approved by the institutional Committee on Human Research and was compliant with HIPAA; all patients provided written consent. In this randomized, investigator-blinded study, 50 patients underwent oral preparation with either a 2-L PEG or a magnesium citrate solution, tagging with oral contrast agents, and subsequent CT colonography and segmentally unblinded colonoscopy. The residual stool (score 0 [best] to 3 [worst]) and fluid (score 0 [best] to 4 [worst]) burden and tagging adequacy were qualitatively assessed. Residual fluid attenuation was recorded as a quantitative measure of tagging adequacy. Patients completed a tolerance questionnaire within 2 weeks of scanning. Preparations were compared for residual stool and fluid by using generalized estimating equations; the Mann-Whitney test was used to compare the qualitative tagging score, mean residual fluid attenuation, and adverse effects assessed on the patient experience questionnaire. RESULTS: The mean residual stool (0.90 of three) and fluid burden (1.05 of four) scores for PEG were similar to those for magnesium citrate (0.96 [P = .58] and 0.98 [P = .48], respectively). However, the mean fecal and fluid tagging scores were significantly better for PEG (0.48 and 0.28, respectively) than for magnesium citrate (1.52 [P < .01] and 1.28 [P < .01], respectively). Mean residual fluid attenuation was higher for PEG (765 HU) than for magnesium citrate (443 HU, P = .01), and mean interpretation time was shorter for PEG (14.8 minutes) than for magnesium citrate (18.0 minutes, P = .04). Tolerance ratings were not significantly different between preparations. CONCLUSION: Reduced-volume PEG and magnesium citrate bowel preparations demonstrated adequate cleansing effectiveness for CT colonography, with better tagging and shorter interpretation time observed in the PEG group. Adequate polyp detection was maintained but requires further validation because of the small number of clinically important polyps.

Evaluation of potential outcome predictors in type II Endoleak: a retrospective study with CT angiography feature analysis.

OBJECTIVE: The purpose of this study is to investigate which CT features of type II endoleaks following abdominal aortic aneurysm (AAA) endoluminal stent-graft repair can be used to predict clinical outcome. MATERIALS AND METHODS: We retrospectively identified 59 patients with type II endoleak after endovascular repair of an AAA with CT of the abdomen and pelvis. Patients were stratified into two groups: those who did (n = 23) and those who did not (n = 35) require reintervention. CT characteristics of type II endoleaks were recorded and correlated with the clinical outcome. RESULTS: The CT features showing the strongest association with the clinical outcome were the transverse diameter of the endoleak cavity (mean, 1.13 cm in the nonreintervention group vs 1.85 cm in the reintervention group; p = 0.007) and the maximum diameter of the vessel communicating with the endoleak (0.34 vs 0.40 cm; p = 0.046). The transverse diameter of the endoleak cavity on arterial phase imaging had the greatest predictive capability, with an area under the receiver operating characteristic curve of 0.74. A transverse diameter greater than 1.42 cm had a positive predictive value of 0.71 and a negative predictive value of 0.82. The anteroposterior diameter, location, and heterogeneity of the endoleak cavity and the number of patent communicating vessels did not correlate well with clinical outcome. The correlation between endoleak cavity measurements and clinical outcome was independent of the aneurysm size. CONCLUSION: There are identifiable CT features associated with the clinical outcome of patients with type II endoleak that have moderate predictive capabilities.

Comparison of traditional methods with 3D computer models in the instruction of hepatobiliary anatomy.

This study was designed to determine whether an interactive three-dimensional presentation depicting liver and biliary anatomy is more effective for teaching medical students than a traditional textbook format presentation of the same material. Forty-six medical students volunteered for participation in this study. Baseline demographic information, spatial ability, and knowledge of relevant anatomy were measured. Participants were randomized into two groups and presented with a computer-based interactive learning module comprised of animations and still images to highlight various anatomical structures (3D group), or a computer-based text document containing the same images and text without animation or interactive features (2D group). Following each teaching module, students completed a satisfaction survey and nine-item anatomic knowledge post-test. The 3D group scored higher on the post-test than the 2D group, with a mean score of 74% and 64%, respectively; however, when baseline differences in pretest scores were accounted for, this difference was not statistically significant (P = 0.33). Spatial ability did not statistically significantly correlate with post-test scores for the 3D group or the 2D group. In the post-test satisfaction survey the 3D group expressed a statistically significantly higher overall satisfaction rating compared to students in the 2D control group (4.5 versus 3.7 out of 5, P = 0.02). While the interactive 3D multimedia module received higher satisfaction ratings from students, it neither enhanced nor inhibited learning of complex hepatobiliary anatomy compared to an informationally equivalent traditional textbook style approach. .

Diagnosis of cirrhosis by spiral computed tomography: a case-control study with feature analysis and assessment of interobserver agreement.

PURPOSE: To determine the accuracy and interobserver agreement of spiral computed tomography (CT) in the diagnosis of cirrhosis. MATERIALS AND METHODS: We retrospectively identified 126 patients who underwent spiral CT at our institution and who had a contemporaneous histopathologic confirmation of cirrhosis (n = 67) or clinical and biochemical evidence of a normal liver (n = 59). Two experienced readers independently recorded the overall likelihood of cirrhosis and the presence or absence of hepatic and extrahepatic findings of cirrhosis and portal hypertension on a 5-point scale from 1 (definitely absent) to 5 (definitely present/severe). RESULTS: Receiver operating characteristic curve and kappa statistic analyses showed that the overall likelihood of cirrhosis was the most accurate and objective observation, with an area under the curve (AUC) of 0.97 for reader 1 and 0.90 for reader 2 and a kappa value of 0.70. Individual findings that were accurate and objective were diaphragmatic surface nodularity (AUC = 0.95 and 0.88 for readers 1 and 2, respectively, kappa = 0.75), global or segmental volume loss (AUC = 0.95 and 0.87 for readers 1 and 2, respectively, kappa = 0.70), and superior diaphragmatic adenopathy (AUC = 0.85 for both readers, kappa = 0.78). Of note, portal vein diameter was not significantly different between normal and cirrhotic patients as measured by either reader (P = 0.54 and 0.65). CONCLUSION: Spiral CT demonstrates high accuracy and interobserver agreement in the diagnosis of cirrhosis, suggesting CT may be a supplementary diagnostic test in patients who have contraindications to biopsy or have equivocal biopsy findings.

An overview of intracranial aneurysms.

Intracranial aneurysms are relatively common, with a prevalence of approximately 4%. Unruptured aneurysms may cause symptoms mainly due to a mass effect, but the real danger is when an aneurysm ruptures, leading to a subarachnoid hemorrhage. Most aneurysms are asymptomatic and will not rupture, but they grow unpredictably and even small aneurysms carry a risk of rupture. Intracranial aneurysms are diagnosed and monitored with imaging including intra-arterial digital subtraction angiography, computed tomography angiography, magnetic resonance angiography, and recently transcranial Doppler ultrasonograpy has been proposed as a potential modality. Treatment options include observation, endovascular coiling, and surgical clipping. This paper will review the epidemiology, pathogenesis, clinical presentation, diagnosis, natural history, and management of unruptured saccular intracranial aneurysms.