Importance of imaging-acquisition protocol and post-processing analysis for extracellular volume fraction assessment by computed tomography.

BACKGROUND: Computed tomography angiography (CTA) assessment of myocardial extracellular volume fraction (CT-ECV) is feasible, although the protocols for imaging acquisition and post-processing methodology have varied. We aimed to identify a pragmatic protocol for CT-ECV assessment encompassing both imaging acquisition and post-processing methodologies to facilitate its clinical implementation. METHODS: We evaluated consecutive patients with severe aortic stenosis undergoing evaluation for transcatheter aortic valve replacement (TAVR). Pre-contrast and 3-min-delayed CTA were obtained in systole using either helical prospective-ECG-triggered (high-pitch) or axial sequential-ECG-gated acquisition, adding to standard TAVR CTA protocol. Using a dedicated software for co-registration of CTA datasets, three methodologies for ECV measurement were evaluated: (1) mid-septum region of interest (Septal ECV), (2) averaged-global ECV (Global ECV) encompassing 16-AHA segments, and (3) average of septal and lateral segments (Averaged ECVsep and Averaged ECVlat). RESULTS: Among the 142 patients enrolled (median â€‹= â€‹81 years, 44% females), 8 were excluded due to significant imaging artifacts precluding Global ECV assessment. High-pitch scan mode was performed in 68 patients (48%). Suboptimal image quality for Global ECV assessment was associated with high-pitch scan mode (odds ratio: OR â€‹= â€‹2.26, p â€‹= â€‹0.036), along with the presence of intracardiac leads (OR â€‹= â€‹4.91, p â€‹= â€‹0.002), and BMI≥35 â€‹kg/m2 (OR â€‹= â€‹2.80, p â€‹= â€‹0.026). Septal ECV [median â€‹= â€‹29.4%] and Averaged ECVsep [29.0%] were similar (p â€‹= â€‹0.108), while Averaged ECVlat [27.5%] was lower than Averaged ECVsep (p â€‹< â€‹0.001), resulting in lower Global ECV [28.6%]. CONCLUSIONS: Myocardial CT-ECV assessment is feasible using a systolic sequential acquisition pre-contrast, and similar additional 3-min delayed scan. Septal ECV measurement provides similar values to Global ECV and is equally reproducible.

Outcomes of an inpatient medical nutritional rehabilitation protocol in children and adolescents with eating disorders.

BACKGROUND: Medical stabilization through inpatient nutritional rehabilitation is often necessary for patients with eating disorders (EDs) but includes the inherent risk of refeeding syndrome. Here we describe our experience of implementing and sustaining an inpatient nutritional rehabilitation protocol designed to strategically prepare patients with EDs and their families for discharge to a home setting in an efficient and effective manner from a general adolescent medicine unit. We report outcomes at admission, discharge, and 4-weeks follow-up. METHODS: Protocol development, implementation, and unique features of the protocol, are described. Data were collected retrospectively as part of a continuous quality improvement (QI) initiative. Safety outcomes were the clinical need for phosphorus, potassium, and magnesium supplementation, other evidence of refeeding syndrome, and unexpected readmissions within one month of discharge. The value outcome was length of stay (LOS). Treatment outcomes were the percentage median BMI (MBMI) change from admission to discharge, and from discharge to 4-weeks follow-up visit. RESULTS: A total of 215 patients (88% F, 12% M) were included. Patients averaged 15.3 years old (5.8-23.2y); 64% had AN, 18% had atypical anorexia (AtAN), 6% bulimia nervosa (BN), 5% purging disorder (PD), 4% avoidant-restrictive food intake disorder (ARFID), and 3% had an unspecified food and eating disorder (UFED). Average LOS was 11 days. Initial mean calorie level for patients at admission was 1466 and at discharge 3800 kcals/day. Phosphorus supplementation for refeeding hypophosphatemia (RH) was needed in 14% of inpatients; full-threshold refeeding syndrome did not occur. Only 3.8% were rehospitalized in the thirty days after discharge. Patients averaged 86.1% of a median MBMI for age and gender, 91.4% MBMI at discharge, and 100.9% MBMI at 4-weeks follow-up. Mean percentage MBMI differences between time points were significantly different (admission-discharge: 5.3%, p <0.001; discharge-follow-up: 9.2%, p <0.001). CONCLUSIONS: Implementation of the CHOP inpatient nutritional rehabilitation protocol aimed at rapid, efficient, and safe weight gain and integration of caregivers in treatment of patients with diverse ED diagnoses led to excellent QI outcomes in percentage MBMI at discharge and 4-weeks follow-up, while maintaining a short LOS and low rates of RH phosphorus supplementation.

Outcomes of an inpatient refeeding protocol in youth with Anorexia Nervosa and atypical Anorexia Nervosa at Children's Hospitals and Clinics of Minnesota.

BACKGROUND: Historically, inpatient protocols have adopted relatively conservative approaches to refeeding in Anorexia Nervosa (AN) in order to reduce the risk of refeeding syndrome, a potentially fatal constellation of symptoms. However, increasing evidence suggests that patients with AN can tolerate higher caloric prescriptions during treatment, which may result in prevention of initial weight loss, shorter hospital stays, and less exposure to the effects of severe malnutrition. Therefore the present study sought to examine the effectiveness of a more accelerated refeeding protocol in an inpatient AN and atypical AN sample. METHODS: Participants were youth (ages 10-22) with AN (n = 113) and atypical AN (n = 16) who were hospitalized for medical stabilization. A retrospective chart review was conducted to assess changes in calories, weight status (percentage of median BMI, %mBMI), and indicators of refeeding syndrome, specifically hypophosphatemia, during hospitalization. Weight was assessed again approximately 4 weeks after discharge. RESULTS: No cases of refeeding syndrome were observed, though 47.3 % of participants evidenced hypophosphatemia during treatment. Phosphorous levels were monitored in all participants, and 77.5 % were prescribed supplemental phosphorous at the time of discharge. Higher rates of caloric changes were predictive of greater changes in %mBMI during hospitalization. Rates of caloric and weight change were not related to an increased likelihood of re-admission. CONCLUSIONS: Results suggest that a more accelerated approach to inpatient refeeding in youth with AN and atypical AN can be safely implemented and is not associated with refeeding syndrome, provided there is close monitoring and correction of electrolytes. These findings suggest that this approach has the potential to decrease length of stay and burden associated with inpatient hospitalization, while supporting continued progress after hospitalization.

Radiation dose and image quality of 70 kVp functional cardiovascular computed tomography imaging in congenital heart disease.

BACKGROUND: The use of cardiac computed tomography (CT) for quantification of ventricular function is limited by relatively high radiation dose. OBJECTIVES: The goal of this study was to describe the radiation exposure and image quality of 70 kVp functional cardiac CT in patients with congenital heart disease (CHD). METHODS: A retrospective review of 70 kVp ECG gated functional CT scans using tube current modulation was performed in CHD patients at a single institution. Quantitative and qualitative (assessed by myocardial segment, 1-4; 1 = optimal) image quality was determined. Per segment image quality was compared between thin (1.5 mm) and thick (8 mm) reconstructions and by patient age and size. Scan DLP was used to estimate radiation dose. RESULTS: 72 scans were performed during the time of review (7/2013-6/2015). Median patient age was 19.5 years (8.0, 27.1) and BMI was 20.1 (16.6, 24.5) kg/m(2). Median functional scan DLP was 78.8 (45.5, 98) and unadjusted and adjusted procedural mSv were 1.10 (0.64, 1.37) and 1.13 (0.90, 1.37). Image quality of 1 was achieved in all myocardial segments in >75% of scans. Patients with a weight ≥75 kg were more likely to have a scan achieve optimal image when using thick reconstructions compared to thin (81.3% vs. 43.8%; p = 0.028). CONCLUSIONS: Imaging of ventricular function with 70 kVp in CHD patients can be done with low radiation doses and provides diagnostic image quality, particularly for patients <75 kg. In larger patients, thicker slice reconstruction improved image quality.

Coronary computed tomographic angiographic findings in patients with Kawasaki disease.

Kawasaki disease (KD) is the leading cause of acquired coronary disease in children and may lead to subsequent myocardial ischemia and infarction. Because coronary computed tomographic angiography (CTA) is the most sensitive noninvasive test in patients with atherosclerosis, the aim of this study was to retrospectively evaluate coronary CTA performed in patients with KD for aneurysm, stenosis, and calcified and noncalcified coronary artery disease (CAD). Clinical histories and prior stress and imaging test results were reviewed. Thirty-two patients underwent coronary CTA for KD, and 385 coronary segments were evaluated. Twenty-three of 32 patients had ≥1 diseased coronary segment. There were 20 aneurysms, 7 lesions, and 75 segments (20%) with nonobstructive CAD (16% noncalcified, 2% calcified, and 2% mixed). All nonobstructive and obstructive CAD was in patients with histories of acute-phase coronary artery dilatation or aneurysm (echocardiographic z score 4 to 44), and were almost always associated with normal stress imaging test results on follow-up. No lesion or CAD was found in coronary computed tomographic angiographic studies performed in a control group referred for other indications (n = 32, 422 segments evaluated). The median coronary computed tomographic angiographic dose-length product was 59 mGy cm (interquartile range 32 to 131), the median unadjusted radiation dose was 0.8 mSv (interquartile range 0.4 to 1.8), and the median age- and size-adjusted radiation dose was 1.3 mSv (interquartile range 0.7 to 2.3). In conclusion, high-risk patients with histories of KD had nonobstructive and obstructive CAD not visualized by other noninvasive imaging tests. In properly selected high-risk patients with KD, coronary CTA may identify a subset at increased risk for future coronary pathology who may benefit from medical therapy.

Balloon aortic valvuloplasty in high risk aortic stenosis patients with left ventricular ejection fractions <20%.

OBJECTIVES: To determine outcomes following balloon aortic valvuloplasty (BAV) in aortic stenosis (AS) patients with a left ventricular ejection fraction (LVEF) <20%. BACKGROUND: Severe AS patients with a LVEF <20% are excluded from United States (U.S.) transcatheter aortic valve replacement (TAVR) trials and often surgical aortic valve replacement (AVR). The role for BAV to enhance LVEF is unclear. METHODS: Our BAV database of 270 consecutive patients extending from 2005 through 2010 was queried for a preoperative LVEF <20%. Demographics, echocardiograms, procedural technique, and outcomes were analyzed. Pre- and postoperative echocardiograms were used to determine improvement in aortic valve area (AVA) and LVEF. RESULTS: Sixteen patients were identified with a median age of 82 years. The composite Society of Thoracic Surgeons' (STS) mortality risk was 16.4%. The median preoperative AVA and LVEF were 0.60 cm(2) and 16%, respectively, and postoperative AVA and LVEF were 0.77 cm(2) and LVEF 19%, respectively. About 15 of the 16 patients had postoperative echocardiograms available for comparison. And 7 of these 15 (47%) demonstrated improvement in LVEF to ≥20% (median LVEF 25%). The absence of coronary disease and improvement in AVA of ≥0.2 cm(2) was associated with postoperative LVEF of ≥20%. Procedural mortality was 0%. The 30-day, 6-month, and 1-year survival was 69%, 56%, and 29%. STS's mortality risk score ≥15% was associated with short-term mortality. CONCLUSION: With appropriate technique, BAV can be reasonably safe in patients with LVEF <20%. Roughly half of these patients demonstrated improvement in LVEF to ≥20%.

Cardiovascular imaging trends in congenital heart disease: a single center experience.

BACKGROUND: Cardiac magnetic resonance imaging (MRI) and CT are available in the recent era at many pediatric cardiac centers. OBJECTIVE: The aim was to provide a contemporary description of diagnostic imaging trends for definition of congenital heart disease (CHD). METHODS: Echocardiography, cardiac catheterization, cardiac MRI, and cardiac CT use in patients with congenital heart disease at a single institution was retrospectively recorded (2005-2012). Surgical procedures were recorded. Total and modality-specific rates were estimated by Poisson regression and compared. The median age, studies in patients aged >17 years, and referral diagnosis were tabulated for the last year of review. RESULTS: An average of 11,940 cardiovascular diagnostic tests was performed annually. The number of total studies, echocardiograms, catheterizations, and surgical procedures, did not change significantly across time. Echocardiography comprised 95% to 97% of all studies performed during each year of review. The use of cardiac MRI (2%) and cardiac CT (1%) increased linearly (P < .001), and the use of diagnostic catheterization decreased (0.7%; P = .0005). The median age was 3 years for echocardiography, 15 years for MRI, 11 years for CT, and 3 years for catheterization. The percentage of patients aged >17 years was 9% for echocardiography, 33% for cardiac MRI, 29% for cardiac CT, and 8% for catheterization. Most patients undergoing CT, MRI, and diagnostic catheterization had moderate or complex CHD. CONCLUSION: Cardiac CT is used increasingly in the recent era for evaluation of CHD. The increased use of both cardiac CT and cardiac MRI are temporally associated with a decrease in diagnostic cardiac catheterization.

Comparative genome analyses of Arabidopsis spp.: inferring chromosomal rearrangement events in the evolutionary history of A. thaliana.

Comparative genome analysis is a powerful tool that can facilitate the reconstruction of the evolutionary history of the genomes of modern-day species. The model plant Arabidopsis thaliana with its n = 5 genome is thought to be derived from an ancestral n = 8 genome. Pairwise comparative genome analyses of A. thaliana with polyploid and diploid Brassicaceae species have suggested that rapid genome evolution, manifested by chromosomal rearrangements and duplications, characterizes the polyploid, but not the diploid, lineages of this family. In this study, we constructed a low-density genetic linkage map of Arabidopsis lyrata ssp. lyrata (A. l. lyrata; n = 8, diploid), the closest known relative of A. thaliana (MRCA approximately 5 Mya), using A. thaliana-specific markers that resolve into the expected eight linkage groups. We then performed comparative Bayesian analyses using raw mapping data from this study and from a Capsella study to infer the number and nature of rearrangements that distinguish the n = 8 genomes of A. l. lyrata and Capsella from the n = 5 genome of A. thaliana. We conclude that there is strong statistical support in favor of the parsimony scenarios of 10 major chromosomal rearrangements separating these n = 8 genomes from A. thaliana. These chromosomal rearrangement events contribute to a rate of chromosomal evolution higher than previously reported in this lineage. We infer that at least seven of these events, common to both sets of data, are responsible for the change in karyotype and underlie genome reduction in A. thaliana.