Coronary Artery Vasculitis and Encasement: Multimodality Imaging Findings and Mimics.

Coronary artery vasculitis (CAV) and coronary artery encasement are rarely diagnosed conditions that are important diagnostic considerations, particularly in patients with acute coronary syndrome without traditional cardiovascular risk factors or systemic illness. Vasculitis refers to inflammation of the blood vessel walls, which can be primary or secondary. This process should be distinguished from neoplastic involvement of the coronary arteries, termed coronary artery encasement. Prospective diagnosis of these diseases is challenging, often requiring multidisciplinary workup with careful attention to clinical presentation and multiorgan findings. While CAV and coronary artery encasement can be indistinguishable at coronary CT angiography, certain imaging features help order the differential diagnosis. CAV should be considered when there is smooth wall thickening that is circumferential and/or continuous. A diagnosis of coronary artery encasement is favored when there is irregular or nodular wall thickening that is eccentric to the vessel lumen. Epicardial fat stranding may also appear more extensive compared with CAV. Potential mimics of CAV include atherosclerosis, acute plaque rupture, coronary artery aneurysm, and spontaneous coronary artery dissection. Detection and diagnosis of CAV may help avoid complications related to accelerated atherosclerosis and infarction. Radiologists should be familiar with the range of pathologic conditions that can affect the coronary arteries beyond atherosclerosis as they may be the first to raise such diagnostic possibilities, guiding next steps in patient workup and management. ©RSNA, 2024 Supplemental material is available for this article.

CT Fractional Flow Reserve: A Practical Guide to Application, Interpretation, and Problem Solving.

CT fractional flow reserve (FFRCT) is a physiologic simulation technique that models coronary flow from routine coronary CT angiography (CTA). To evaluate lesion-specific ischemia, FFRCT is measured 2 cm distal to a stenotic lesion. FFRCT greater than 0.8 is normal, 0.76-0.8 is borderline, and 0.75 or less is abnormal. FFRCT should always be interpreted in correlation with clinical and anatomic coronary CTA findings. FFRCT increases the specificity of coronary CTA in the evaluation of coronary artery disease, decreases the prevalence of nonobstructive disease in invasive coronary angiography (ICA), and helps with revascularization decisions and planning. Patients with intermediate-risk coronary anatomy at CTA and abnormal FFRCT can undergo ICA and revascularization, whereas those with normal FFRCT can be safely deferred from ICA. In borderline FFRCT values, management is decided in the context of the clinical scenario, but many cases could be safely managed with medical treatment. There are some limitations and pitfalls of FFRCT. Abnormal FFRCT values can be seen in mild stenosis, and normal FFRCTvalues can be seen in severe stenosis. Gradually decreasing or abnormal low FFRCT values at the distal vessel without a proximal focal lesion could be due to diffuse atherosclerosis. Coronary stents, bypass grafts, coronary anomalies, coronary dissection, transcatheter aortic valve replacement, unstable angina, and acute or recent myocardial infarction are situations in which FFRCT has not been validated and should not be used at this time. The authors provide a practical guide to the applications and interpretation of FFRCT, focusing on common pitfalls and challenges. Online supplemental material is available for this article. ©RSNA, 2022.

Performing chest computed tomography on pediatric patients on extracorporeal membrane oxygenation (ECMO): a stepwise approach.

Chest CT in pediatric patients on extracorporeal membrane oxygenation (ECMO) can be done safely and provide valuable high-quality diagnostic images to help guide patient management. An understanding of the basics of the ECMO circuit, cannula locations, where and how to inject contrast media, and how to time image acquisition is vital for the radiologist. Additionally, understanding the precautions associated with performing these exams is essential to ensure the safety of the child. This article provides a brief review of pediatric ECMO and its challenges and considerations, as well as a stepwise approach to perform and optimize these exams safely.

Imaging Features of Complications after Coronary Interventions and Surgical Procedures.

Coronary artery interventions and surgical procedures are used in the treatment of coronary artery disease and some congenital heart diseases. Cardiac and noncardiac complications can occur at variable times after these procedures, with the clinical presentation ranging from asymptomatic to devastating symptoms. Invasive coronary angiography is the reference standard modality used in the evaluation of coronary arteries, with intravascular US and optical coherence tomography providing high-resolution information regarding the vessel wall. CT is the mostly commonly used noninvasive imaging modality in the evaluation of coronary artery intervention complications and allows assessment of the stent, lumen of the stent, lumen of the coronary arteries, and extracoronary structures. MRI is limited to the evaluation of the proximal coronary arteries but allows comprehensive evaluation of the myocardium, including ischemia and infarction. The authors review the clinical symptoms and pathophysiologic and imaging features of various complications of coronary artery interventions and surgical procedures. Complications of percutaneous coronary interventions are discussed, including restenosis, thrombosis, dissection of coronary arteries or the aorta, coronary wall rupture or perforation, stent deployment failure, stent fracture, stent infection, stent migration or embolism, and reperfusion injury. Complications of several surgical procedures are reviewed, including coronary artery bypass grafting, coronary artery reimplantation procedure (for anomalous origin from opposite sinuses or the pulmonary artery or as part of surgical procedures such as arterial switching surgery and the Bentall and Cabrol procedures), coronary artery unroofing, and the Takeuchi procedure. Online supplemental material is available for this article. ©RSNA, 2021.

Ventriculotomy Decreases Agreement Between Assessment of Right Ventricular Function by Echocardiography and Cardiac Magnetic Resonance Imaging in Patients with Hypoplastic Left Heart Syndrome.

Accurate assessment of the right ventricular (RV) volume and function is important in patients with hypoplastic left heart syndrome (HLHS). We sought to investigate the effect of ventriculotomy on the correlation of RV functional assessments by two-dimensional echocardiography (2DE) to cardiac magnetic resonance (CMR)-derived RV ejection fraction (EF) in patients with HLHS. A retrospective re-analysis of CMR imaging with matched 2DE was performed from the institutional HLHS registry. Echocardiographic RV functional parameters were analyzed and correlated with CMR-derived EF. Intraclass correlation coefficient was used to determine interobserver reliability. A total of 58 matched echocardiograms and CMR imaging studies from 46 patients was evaluated. Median duration between CMR imaging and echocardiogram was 1 day (range 0-6 days). No significant difference was seen in CMR RV EF between patients with and without a ventriculotomy (EF - 43.6% vs 44.7%, p = 0.85). The presence of a ventriculotomy significantly decreased the correlation of biplane FAC (r = 0.86 vs 0.52; p = 0.02), triplane FAC (r = 0.84 vs 0.49; p = 0.03), and 2DE visually estimated EF (r = 0.83 vs 0.49; p = 0.02). The correlation of circumferential and longitudinal strains to CMR-derived EF was not significantly affected by the presence of a ventriculotomy. A prior ventriculotomy significantly affected correlation between 2DE FAC and visually estimated EF with CMR-derived EF. The dyskinetic myocardial segment due to ventriculotomy, which is often not visualized by 2DE, may be the reason for this discrepancy.

Negative Impact of the Left Ventricular Remnant Morphology on Systemic Right Ventricular Myocardial Deformation in Hypoplastic Left Heart Syndrome.

Left ventricular (LV) morphology may affect right ventricular (RV) function before and after Fontan palliation in patients with hypoplastic left heart syndrome (HLHS). We sought to assess the potential impact of LV morphology on RV function in patients with HLHS using cardiac magnetic resonance (CMR) imaging. A retrospective analysis of available CMR scans from all patients with HLHS was performed. LV morphology was categorized as absent/slit-like or globular/miniaturized. Volumetric analysis was performed using manual disc-summation method on steady-state free precession (SSFP) stack obtained in short-axis orientation of the ventricles. 4-chamber and short-axis SSFP images were used to measure strain on a semi-automated feature-tracking (FT) module. Two sample t-test was used to compare the groups. A total of 48 CMR scans were analyzed. Of those, 12 patients had absent/slit-like and 36 had globular/miniaturized LV morphology. Averaged 4-chamber longitudinal RV strain was significantly higher for absent/slit-like (- 17.6 ± 4.7%) than globular/miniaturized (- 13.4 ± 3.5; P = 0.002). Averaged 4-chamber radial RV strain was also significantly higher for absent/slit-like (33.1 ± 14.9%) than globular/miniaturized (21.6 ± 7.1; P = 0.001). For globular/miniaturized LV morphology, the decreases of 4-chamber longitudinal and radial strains were mainly attributable to the septal basilar and septal mid-ventricular segments. No differences were found in short-axis RV global circumferential strain between the morphologic subtypes (absent/slit-like - 15.0 ± 6.5, globular/miniaturized - 15.7 ± 4.7; P = 0.68). Larger LV remnants, with globular/miniaturized LV morphology, demonstrated diminished strain in the septal base and mid-ventricle segments. Patients with globular/miniaturized LV morphology may benefit with closer monitoring and lower threshold to start heart failure medications. These results exemplify the utility of including both septal and regional deformation in systemic RV strain analysis.

Guiding peripheral arterial disease management with magnetic resonance imaging.

Peripheral arterial disease (PAD) management is exceptionally challenging. Despite advances in diagnostic and therapeutic technologies, long-term vessel patency and limb salvage rates are limited. Patients with PAD frequently require extensive workup with noninvasive tests and imaging to delineate their disease and help guide appropriate management. Ultrasound and computed tomography are commonly ordered in the workup of PAD. Magnetic resonance imaging (MRI), on the other hand, is less often acknowledged as a useful tool in this disease. Nevertheless, MRI is an important test that can effectively characterize atherosclerotic plaque, assess vessel patency in highly calcified disease, and measure lower extremity perfusion.

Time-resolved contrast-enhanced MR angiography with single-echo Dixon fat suppression.

PURPOSE: Dixon-based fat suppression has recently gained interest for dynamic contrast-enhanced MRI, but multi-echo techniques require longer scan times and reduce temporal resolution compared to single-echo alternatives without fat suppression. The purpose of this work is to demonstrate accelerated single-echo Dixon imaging with high spatial and temporal resolution. THEORY AND METHODS: Real-valued water and fat images can be obtained from a single measurement if the shared initial phase and that due to ΔB0 are assumed known a priori. An expression for simultaneous sensitivity encoding (SENSE) unfolding and fat-water separation is derived for the general undersampling case, and simplified under the special case of uniform Cartesian undersampling. In vivo experiments were performed in extremities and brain with SENSE acceleration factors of up to R = 8. RESULTS: Single-echo Dixon reconstruction of highly undersampled data was successfully demonstrated. Dynamic contrast-enhanced water and fat images provided high spatial and temporal resolution dynamic images with image update times shorter than previous single-echo Dixon work. CONCLUSION: Time-resolved contrast-enhanced MRI with single-echo Dixon fat suppression shows high image quality, improved vessel delineation, and reduced sensitivity to motion when compared to time-subtraction methods.

Cardiac MR elastography using reduced-FOV, single-shot, spin-echo EPI.

PURPOSE: To implement a reduced field of view (rFOV) technique for cardiac MR elastography (MRE) and to demonstrate the improvement in image quality of both magnitude images and post-processed MRE stiffness maps compared to the conventional full field of view (full-FOV) acquisition. METHODS: With Institutional Review Board approval, 17 healthy volunteers underwent both full-FOV and rFOV cardiac MRE scans using 140-Hz vibrations. Two cardiac radiologists blindly compared the magnitude images and stiffness maps and graded the images based on several image quality attributes using a 5-point ordinal scale. Fisher's combined probability test was performed to assess the overall evaluation. The octahedral shear strain-based signal-to-noise ratio (OSS-SNR) and median stiffness over the left ventricular myocardium were also compared. RESULTS: One volunteer was excluded because of an inconsistent imaging resolution during the exam. In the remaining 16 volunteers (9 males, 7 females), the rFOV scans outperformed the full-FOV scans in terms of subjective image quality and ghosting artifacts in the magnitude images and stiffness maps, as well as the overall preference. The quantitative measurements showed that rFOV had significantly higher OSS-SNR (median: 1.4 [95% confidence interval (CI): 1.2-1.5] vs. 2.1 [95% CI: 1.8-2.4]), P < 0.05) compared to full-FOV. Although no significant change was found in the median myocardial stiffness between the 2 scans, we observed a decrease in the stiffness variation within the myocardium from 2.1 kPa (95% CI: [1.9, 2.3]) to 1.9 kPa (95% CI: [1.7, 2.0]) for full-FOV and rFOV, respectively (P < 0.05) in a subgroup of 7 subjects with ghosting present in the myocardium. CONCLUSION: This pilot volunteer study demonstrated that rFOV cardiac MRE has the capability to reduce ghosting and to improve image quality in both MRE magnitude images and stiffness maps. Magn Reson Med 80:231-238, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Evaluating Muscle Mass by Using Markers of Kidney Function: Development of the Sarcopenia Index.

OBJECTIVES: Sarcopenia is associated with a poor prognosis in the ICU. The purpose of this study was to describe a simple sarcopenia index using routinely available renal biomarkers and evaluate its association with muscle mass and patient outcomes. DESIGN: A retrospective cohort study. SETTING: A tertiary-care medical center. PATIENTS: High-risk adult ICU patients from October 2008 to December 2010. INTERVENTIONS: The gold standard for muscle mass was quantified with the paraspinal muscle surface area at the L4 vertebrae in the subset of individuals with an abdominal CT scan. Using Pearson's correlation coefficient, serum creatinine-to-serum cystatin C ratio was found to be the best performer in the estimation of muscle mass. The relationship between sarcopenia index and hospital and 90-day mortality, and the length of mechanical ventilation was evaluated. MEASUREMENTS AND MAIN RESULTS: Out of 226 enrolled patients, 123 (54%) were female, and 198 (87%) were white. Median (interquartile range) age, body mass index, and body surface area were 68 (57-77) years, 28 (24-34) kg/m, and 1.9 (1.7-2.2) m, respectively. The mean (± SD) Acute Physiology and Chronic Health Evaluation III was 70 (± 22). ICU, hospital, and 90-day mortality rates were 5%, 12%, and 20%, respectively. The correlation (r) between sarcopenia index and muscle mass was 0.62 and coefficient of determination (r) was 0.27 (p < 0.0001). After adjustment for Acute Physiology and Chronic Health Evaluation III, body surface area, and age, sarcopenia index was independently predictive of both hospital (p = 0.001) and 90-day mortality (p < 0.0001). Among the 131 patients on mechanical ventilator, the duration of mechanical ventilation was significantly lower on those with higher sarcopenia index (-1 d for each 10 unit of sarcopenia index [95% CI, -1.4 to -0.2; p = 0.006]). CONCLUSIONS: The sarcopenia index is a fair measure for muscle mass estimation among ICU patients and can modestly predict hospital and 90-day mortality among patients who do not have acute kidney injury at the time of measurement.

Evaluation of liver stiffness with magnetic resonance elastography in patients with constrictive pericarditis: Preliminary findings.

PURPOSE: To evaluate with magnetic resonance elastography (MRE) whether patients with constrictive pericarditis (CP) have increased hepatic stiffness. CP results in reduced pericardial compliance, ventricular interdependence, and right heart failure. Patients with untreated CP may develop liver fibrosis and ultimately cirrhosis due to chronic venous congestion. Chronic venous congestion ± fibrosis may lead to increased liver stiffness. MATERIALS AND METHODS: Prospectively, patients with suspected CP underwent 2D transthoracic echocardiography, cardiac MRI, and liver MRE. An automated method was used to draw regions of interest (ROIs) on the stiffness maps to calculate the mean liver stiffness in kilopascals (kPa). A t-test with α = 0.05 was performed between stiffness values of patients with positive and negative CP findings based on previously published echocardiography criteria. RESULTS: Nineteen patients met inclusion criteria with a mean ± standard deviation (SD) age of 51 ± 16 years. Nine patients (47%) had CP. Mean liver stiffness trended higher in patients with CP compared to those without CP (4.04 kPa vs. 2.46; P = 0.045). Liver stiffness correlated with MRI septal bounce (P = 0.04), inferior vena cava size (P = 0.003), echo abnormal septal motion (P = 0.04), and echo mitral inflow variation >25% (P = 0.02). Only MRI septal bounce predicted CP by echocardiography (P < 0.001). CONCLUSION: CP was associated with increased liver stiffness. The increased stiffness is most likely secondary to chronic hepatic venous congestion and/or fibrosis. MRE may be useful for noninvasive liver stiffness assessment in CP. J. Magn. Reson. Imaging 2016;44:81-88.

Muscle composition measured by CT scan is a measurable predictor of overall survival in advanced ovarian cancer.

OBJECTIVES: To assess the impact of muscle composition and sarcopenia on overall survival in advanced epithelial ovarian cancer (EOC) after primary debulking surgery (PDS). METHODS: Women with stage IIIC/IV EOC who underwent PDS with curative intent between 1/1/2006 and 12/31/2012 were included. Patient variables and vital status were abstracted. Body composition was evaluated in a semi-automated process using Slice-O-Matic software v4.3 (TomoVision). Skeletal muscle area and mean skeletal muscle attenuation were recorded. Associations with overall survival were evaluated using Cox proportional hazards models and recursive partitioning. RESULTS: We identified 296 patients and 132 (44.6%) were classified as sarcopenic. The average mean skeletal muscle attenuation of the entire cohort was 33.4 Hounsfield units (HU). A multivariate model of overall risk of death included histology, residual disease, and mean skeletal attenuation. Among patients without residual disease, overall survival, but not progression free survival was significantly different between patients with low versus high mean skeletal attenuation (median survival, 2.8 vs. 3.3years). Among patients with residual disease, overall survival was significantly different between patients with low versus high mean skeletal attenuation ≥36.40 vs. <36.40 HU (median survival, 2.0 vs. 3.3years). CONCLUSIONS: Sarcopenia and low mean skeletal muscle attenuation are common in women undergoing PDS for advanced EOC. These factors are associated with poorer outcomes, and can be used in preoperative risk stratification and patient counseling. Further research into body composition and whether this risk factor can be altered via nutrition or fitness in this population is warranted.

Imaging Findings of Congestive Hepatopathy.

Congestive hepatopathy (CH) refers to hepatic abnormalities that result from passive hepatic venous congestion. Prolonged exposure to elevated hepatic venous pressure may lead to liver fibrosis and cirrhosis. Liver dysfunction and corresponding clinical signs and symptoms typically manifest late in the disease process. Recognition of CH at imaging is critical because advanced liver fibrosis may develop before the condition is suspected clinically. Characteristic findings of CH on conventional images include dilatation of the inferior vena cava and hepatic veins; retrograde hepatic venous opacification during the early bolus phase of intravenous contrast material injection; and a predominantly peripheral heterogeneous pattern of hepatic enhancement due to stagnant blood flow. Extensive fibrosis can be seen in chronic or severe cases. Hyperenhancing regenerative nodules that may retain hepatobiliary contrast agents are often present. Magnetic resonance (MR) elastography can show elevated liver stiffness and may be useful in evaluation of fibrosis in CH because it can be incorporated easily into routine cardiac MR imaging. Preliminary experience with MR elastography suggests its future use in initial evaluation of patients suspected of having CH, for monitoring of disease, and for assessment after therapy. To facilitate appropriate workup and treatment, radiologists should be familiar with findings suggestive of CH at radiography, ultrasonography, computed tomography, MR imaging, and MR elastography. In addition, knowledge of underlying pathophysiology, comparative histologic abnormalities, and extrahepatic manifestations is useful to avoid diagnostic pitfalls and suggest appropriate additional diagnostic testing. (©)RSNA, 2016.

Recent advances in 3D time-resolved contrast-enhanced MR angiography.

Contrast-enhanced magnetic resonance angiography (CE-MRA) was first introduced for clinical studies approximately 20 years ago. Early work provided 3-4 mm spatial resolution with acquisition times in the 30-second range. Since that time there has been continuing effort to provide improved spatial resolution with reduced acquisition time, allowing high resolution 3D time-resolved studies. The purpose of this work is to describe how this has been accomplished. Specific technical enablers have been: improved gradients allowing reduced repetition times, improved k-space sampling and reconstruction methods, parallel acquisition, particularly in two directions, and improved and higher count receiver coil arrays. These have collectively made high-resolution time-resolved studies readily available for many anatomic regions. Depending on the application, ∼1 mm isotropic resolution is now possible with frame times of several seconds. Clinical applications of time-resolved CE-MRA are briefly reviewed.

Three-station three-dimensional bolus-chase MR angiography with real-time fluoroscopic tracking.

PURPOSE: To determine the feasibility of using real-time fluoroscopic tracking for bolus-chase magnetic resonance (MR) angiography of peripheral vasculature to image three stations from the aortoiliac bifurcation to the pedal arteries. MATERIALS AND METHODS: This prospective study was institutional review board approved and HIPAA compliant. Eight healthy volunteers (three men; mean age, 48 years; age range, 30-81 years) and 13 patients suspected of having peripheral arterial disease (five men; mean age, 67 years; age range, 47-81 years) were enrolled and provided informed consent. All subjects were imaged with the fluoroscopic tracking MR angiographic protocol. Ten patients also underwent a clinical computed tomographic (CT) angiographic runoff examination. Two readers scored the MR angiographic studies for vessel signal intensity and sharpness and presence of confounding artifacts and venous contamination at 35 arterial segments. Mean aggregate scores were assessed. The paired MR angiographic and CT angiographic studies also were scored for visualization of disease, reader confidence, and overall diagnostic quality and were compared by using a Wilcoxon signed rank test. RESULTS: Real-time fluoroscopic tracking performed well technically in all studies. Vessel segments were scored good to excellent in all but the following categories: For vessel signal intensity and sharpness, the abdominal aorta, iliac arteries, distal plantar arteries, and plantar arch were scored as fair to good; and for presence of confounding artifacts, the abdominal aorta and iliac arteries were scored as fair. The MR angiograms and CT angiograms did not differ significantly in any scoring category (reader 1: P = .50, .39, and .39; reader 2: P = .41, .61, and .33, respectively). CT scores were substantially better in 20% (four of 20) and 25% (five of 20) of the pooled evaluations for the visualization of disease and overall image quality categories, respectively, versus 5% (one of 20) for MR scores in both categories. CONCLUSION: Three-station bolus-chase MR angiography with real-time fluoroscopic tracking provided high-spatial-resolution arteriograms of the peripheral vasculature, enabled precise triggering of table motion, and compared well with CT angiograms.

Vascular masking for improved unfolding in 2D SENSE-accelerated 3D contrast-enhanced MR angiography.

PURPOSE: To describe and evaluate the method we refer to as "vascular masking" for improving signal-to-noise ratio (SNR) retention in sensitivity encoding (SENSE)-accelerated contrast-enhanced magnetic resonance angiography (CE-MRA). MATERIALS AND METHODS: Vascular masking is a technique that restricts the SENSE unfolding of an accelerated subtraction angiogram to the voxels within the field of view known to have enhancing signal. This is a more restricted voxel set than that identified with conventional masking, which excludes only voxels in the air around the object. Thus, improved retention of SNR is expected. Evaluation was done in phantom and in vivo studies by comparing SNR and the g-factor in results reconstructed using vascular versus conventional masking. A radiological evaluation was also performed comparing conventional and vascular masking in R = 8 accelerated CE-MRA studies of the thighs (n = 21) and calves (n = 13). RESULTS: Images reconstructed with vascular masking showed a significant reduction in g-factor and improved retention of SNR versus those reconstructed with conventional masking. In the radiological evaluation, vascular masking consistently provided reduced background noise, improved luminal signal smoothness, and better small vessel conspicuity. CONCLUSION: Vascular masking provides improved SNR retention and improved depiction of the vasculature in accelerated, subtraction 3D CE-MRA of the thighs and calves.

NASCI case of the month: extensive ascending aortic graft infection with underlying chronic sternal osteomyelitis-a rare and high-risk complication.

Thoracic aortic graft infections are infrequent yet grave complications of cardiovascular surgery. Risk factors include prolonged operative time, postoperative wound infections, and patient-specific risk factors like diabetes or malnutrition (Van Hemelrijck et al., Vessel Plus 6:47, 2022). In postoperative vascular scenarios, it is critical to utilize cross-sectional imaging to detect the presence of a complication, followed by describing the morphology, extent, and ancillary features. FDG-PET/CT can help differentiate between expected postoperative changes and worrisome infection by metabolic activity (FDG uptake). We present an extensive case of ascending aortic graft infection in the setting of ongoing sternal osteomyelitis. CT and PET/CT reveal chronic sternal osteomyelitic changes spreading into the retrosternal soft tissues, and a large intraluminal thrombus in the ascending aortic graft. Small mobile strands propagate toward the right brachiocephalic origin, posing a significant stroke risk. PET/CT confirmed postoperative infection by demonstrating increased FDG uptake.

Buildup of image quality in view-shared time-resolved 3D CE-MRA.

Time-resolved three-dimensional contrast-enhanced MR angiography often relies on view sharing of peripheral k-space data to enable acquisition of angiograms with both high spatial resolution and a rapid frame rate. It is typically assumed that k-space will be fully sampled during passage of the contrast bolus arterial phase. However, this is not the case when view sharing is incomplete, for example, at the leading edge of an enhancing vessel or if acquisition time is limited as in fluoroscopic tracking for multistation bolus chase MR angiography. Incomplete view sharing will degrade image quality, for example, by reducing vessel signal and sharpness and increasing undersampling artifacts. In this work, the evolution of angiogram quality with view sharing is quantitatively assessed in phantom experiments and in vivo contrast-enhanced MR angiography calf studies. It is demonstrated that there are multiple sets of sequence parameters that can yield a target image update time, but the choice of parameters can profoundly affect how image quality evolves with view sharing. A fundamental tradeoff between vessel signal and sharpness and its relationship to the sequence temporal footprint is investigated and discussed.

Nutritional status, CT body composition measures and survival in ovarian cancer.

OBJECTIVE: Body composition measures (BCMs) are an important predictor of nutritional status in patients with cancer. Poor nutritional status is common in ovarian cancer (OC) and is a well-known variable that influences cancer treatment and outcome. We aim to establish the role of BCMs measured by computed tomography (CT) in predicting outcomes in patients with OC. METHODS: We retrospectively searched our institutional database for patients with stage IIIC/IV OC who underwent surgery as primary treatment at Mayo Clinic between 1996 and 2005 and had adequate presurgical CT images available. For each patient, 1 axial CT image at the level of the 3rd lumbar vertebra was evaluated. Adipose and lean tissues were discriminated using commercially available software. Cox models were fit to evaluate the relationship between patient factors and overall survival (OS). Associations were summarized using hazard ratios (HRs) and corresponding 95% CIs. RESULTS: A total of 82 patients were identified, with a median age of 68.4 years. OS at 1 and 5 years was 84.1% and 24.1%, respectively. Older age (P=.01), stage IV disease (P<.001), and subcutaneous and muscular fat<77.21cm(2) (P<.001) were independently associated with poor OS. Longer hospital stay was independently predicted by albumin≤3g/dL (P=.03), suboptimal surgery (P=.02), and subcutaneous and muscular fat<77.21cm(2) (P<.001). Surgical complications were independently predicted only by albumin≤3g/dL (P<.01). CONCLUSIONS: CT BCMs, as indicators of nutritional status, are independent predictors of longer hospital stay and poor OS in patients with OC.