Sarcopenic visceral obesity is associated with increased post-liver transplant mortality in acutely ill patients with cirrhosis.

"Sarcopenic obesity" refers to a condition of low muscle mass in the context of obesity, though may be difficult to assess in patients with cirrhosis who are acutely ill. We aimed to define sarcopenic visceral obesity (SVO) using CT-based skeletal muscle index (SMI) and visceral-to-subcutaneous adipose tissue ratio (VSR) to examine its association with post-transplant mortality. We analyzed 116 adult inpatients with cirrhosis who were urgently listed and transplanted between 1/2005 and 12/2017 at 4 North American transplant centers. SVO was defined as patients with sarcopenia (SMI <50 cm2 /m2 in men and <39 cm2 /m2 in women) and visceral obesity (VSR ≥ 1.54 in men and ≥1.37 in women). The percentage who met criteria for sarcopenia, visceral obesity, and SVO were 45%, 42%, and 20%, respectively. Cumulative rates of post-transplant mortality were higher in patients with SVO compared to patients with sarcopenia or visceral obesity alone at 36 months (39% vs. 14% vs. 8%) [logrank p = .01]. In univariable regression, SVO was associated with post-transplant mortality (HR 2.92, 95%CI 1.04-8.23) and remained significant after adjusting for age, sex, diabetes, encephalopathy, hepatocellular carcinoma, and MELD-Na (HR 3.50, 95%CI 1.10-11.15). In conclusion, SVO is associated with increased post-transplant mortality in acutely ill patients with cirrhosis.

Visceral Adipose Tissue Inflammation and Radiographic Visceral-to-Subcutaneous Adipose Tissue Ratio in Patients with Cirrhosis.

BACKGROUND AND AIMS: Accumulation of visceral adipose tissue is associated with hepatic inflammation and fibrosis, suggestive of its metabolic and inflammatory properties. We aimed to examine the histologic findings of visceral and subcutaneous adipose tissue and to associate these findings with clinical and radiologic characteristics in patients with cirrhosis. METHODS: Included were 55 adults with cirrhosis who underwent liver transplantation from 3/2017-12/2018 and had an abdominal computed tomography (CT) scan within 6 months prior to transplant. Visceral-to-subcutaneous adipose tissue ratio (VSR) was calculated using visceral (VATI) and subcutaneous adipose tissue index (SATI) quantified by CT at the L3-vertebral level and normalized for height (cm2/m2). VAT (greater omentum), SAT (abdominal wall), and skeletal muscle (rectus abdominis) biopsies were collected at transplant. RESULTS: Majority of patients had VAT inflammation (71%); only one patient (2%) had SAT inflammation. Patients with VAT inflammation had similar median VATI (42 vs 41 cm2/m2), lower median SATI (64 vs 97 cm2/m2), and higher median VSR (0.63 vs 0.37, p = 0.002) than patients without inflammation. In univariable logistic regression, VSR was associated with VAT inflammation (OR 1.47, 95%CI 1.11-1.96); this association remained significant even after adjusting for age, sex, BMI, HCC, or MELD-Na on bivariable analyses. CONCLUSION: In patients with cirrhosis undergoing liver transplantation, histologic VAT inflammation was common, but SAT inflammation was not. Increased VSR was independently associated with VAT inflammation. Given the emerging data demonstrating the prognostic value of VSR, our findings support the value of CT-quantified VSR as a prognostic marker for adverse outcomes in the liver transplant setting.

Assessment of in-stent restenosis using 64-MDCT: analysis of the CORE-64 Multicenter International Trial.

OBJECTIVE: Evaluations of stents by MDCT from studies performed at single centers have yielded variable results with a high proportion of unassessable stents. The purpose of this study was to evaluate the accuracy of 64-MDCT angiography (MDCTA) in identifying in-stent restenosis in a multicenter trial. MATERIALS AND METHODS: The Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography Using 64 Detectors (CORE-64) Multicenter Trial and Registry evaluated the accuracy of 64-MDCTA in assessing 405 patients referred for coronary angiography. A total of 75 stents in 52 patients were assessed: 48 of 75 stents (64%) in 36 of 52 patients (69%) could be evaluated. The prevalence of in-stent restenosis by quantitative coronary angiography (QCA) in this subgroup was 23% (17/75). Eighty percent of the stents were or=50% stenosis by QCA was 0.25 (p=0.073). Quantitative assessment failed to improve the accuracy of MDCT over qualitative assessment. CONCLUSION: The results of our study showed that 64-MDCT has poor ability to detect in-stent restenosis in small-diameter stents. Evaluability and negative predictive value were better in large-diameter stents. Thus, 64-MDCT may be appropriate for stent assessment in only selected patients.

Computed tomography guided sizing for transcatheter pulmonary valve replacement.

OBJECTIVE: To evaluate the predictive value of Computed Tomography Angiography (CTA) measurements of the RVOT for transcatheter valve sizing. BACKGROUND: Transcatheter pulmonary valve replacement (TPVR) provides an alternative to surgery in patients with right ventricular outflow tract (RVOT) dysfunction. We studied 18 patients who underwent catheterization for potential TPVR to determine whether CT imaging can be used to accurately predict implant size. METHODS: Cases were grouped by RVOT characteristics: native or transannular patch (n = 8), conduit (n = 5) or bioprosthetic valve (n = 5). TPVR was undertaken in 14/18 cases, after balloon-sizing was used to confirm suitability and select implant size. Retrospective CT measurements of the RVOT (circumference-derived (Dcirc) and area-derived (Darea) diameters) were obtained at the level of the annulus, bioprosthesis or conduit. Using manufacturer sizing guidance, a valve size was generated and a predicted valve category assigned: (1) <18 mm, (2) 18-20 mm, (3) 22-23 mm, (4) 26-29 mm and (5) >29 mm. Predicted and implanted valves were compared for inter-rater agreement using Cohen's kappa coefficient. RESULTS: The median age of patients was 37 years old (IQR: 30-49); 55% were male. Diagnoses included: Tetralogy of Fallot (12/18), d-Transposition repair (3/18), congenital pulmonary stenosis (2/18) and carcinoid heart disease (1/18). Measurements of Darea (κ = 0.697, p < 0.01) and Dcirc (κ = 0.540, p < 0.01) were good predictors of implanted valve size. When patients with RVOT conduits were excluded, the predictive accuracy improved for Darea (κ = 0.882, p < 0.01) and Dcirc (κ = 0.882, p < 0.01). CONCLUSIONS: CT measurement of the RVOT, using Darea or Dcirc, can predict prosthetic valve sizing in TPVR. These measurements are less predictive in patients with conduits, compared to those with a native RVOT or pulmonic bioprosthesis. CONDENSED ABSTRACT: We studied 18 patients who underwent catheterization for TPVR to determine whether CT imaging could be used to accurately predict implant size. Retrospective RVOT measurements were used to generate a predicted valve size, which was compared with implanted valve size for inter-rater agreement. Measurements of Darea (κ = 0.697, p < 0.01) and Dcirc (κ = 0.540, p < 0.01) were good predictors of implanted valve size. When cases with RVOT conduits were excluded, the predictive accuracy improved for Darea (κ = 0.882, p < 0.01) and Dcirc (κ = 0.882, p < 0.01). CT measurement of the RVOT can accurately predict prosthetic valve sizing in TPVR. These measurements are less predictive in patients with conduits.

Sarcopenia Predicts Post-transplant Mortality in Acutely Ill Men Undergoing Urgent Evaluation and Liver Transplantation.

BACKGROUND: We examined the association between sarcopenia and post-transplant mortality in acutely ill inpatients with cirrhosis who underwent urgent liver transplantation. METHODS: Included were inpatients at 4 centers who were urgently listed as nonstatus 1 and transplanted from 2005 to 2017 with an abdominal computed tomography scan <90 days before transplantation. Skeletal muscle index (SMI) = total skeletal muscle cross-sectional area at the L3 vertebral level, normalized to height. Cox regression associated SMI with post-transplant mortality. Optimal search identified SMI cutoffs to detect survival. RESULTS: Of 126 inpatients, 63% were male patients, model for end-stage liver disease (MELDNa) was 32, and follow up was 5.1 years. Among men, 23% died. Median SMI was lower in men who died versus survived (45 versus 51 cm/m). SMI was associated with post-transplant mortality (hazard ratio [HR] = 0.96 per cm/m, 95% CI 0.92-0.99). Patients with SMI ≤ 48 cm/m versus >48 cm/m experienced higher rates of death at 1 year (86% versus 95%) and 3 years (73% versus 95%) (Log-rank P = 0.01). In MELD-adjusted analysis, sarcopenia was strongly associated with post-transplant mortality (HR = 4.39, 95% CI 1.49-12.97). Among women, 35% died. Median SMI was similar in women who died versus survived (45 versus 44 cm/m). SMI was not associated with post-transplant mortality (HR = 1.02, 95% CI 0.96-1.09). Optimal search did not identify any SMI cutoff that predicted post-transplant mortality. CONCLUSIONS: Among patients who underwent urgent inpatient evaluation and liver transplantation, we identified an SMI cutoff value of 48 cm/m to predict post-transplant mortality in men. Our data support the use of SMI as a tool to capture the impact of muscle depletion on post-transplant mortality in acutely ill men with cirrhosis undergoing urgent liver transplantation.

Computed tomography-based 3D modeling to provide custom 3D-printed glasses for children with craniofacial abnormalities.

Children with craniofacial malformations frequently require spectacles but have difficulty finding an acceptable fit with current offerings of pediatric spectacle frames. We describe a novel method for creating custom 3D-printed spectacle frames based on a 3D reconstruction of a prior computed tomography scan. This method offers the ability to create better-fitting spectacles to children who are not served by "off the rack" frames.

Measuring noncalcified coronary atherosclerotic plaque using voxel analysis with MDCT angiography: a pilot clinical study.

OBJECTIVE: The purpose of our study was to evaluate a new method using voxel analysis for quantifying noncalcified plaque in coronary arteries using MDCT angiography (MDCTA) compared with luminal stenosis by catheter coronary arteriography. MATERIALS AND METHODS: Forty-one normal and eight abnormal arterial cross sections with noncalcified plaque selected from 40 patients undergoing MDCTA were analyzed for percentage of stenosis and plaque volume using a voxel analysis technique. RESULTS: Using voxel analysis, the normal arterial wall thickness was determined to be 0.8 +/- 0.4 mm. Attenuation values (in Hounsfield units) for normal segments ranged between 30 and 175 H and for abnormal (plaque-containing) segments ranged from -49 to 139 H (p < 0.05). Plaque volume measurements varied from 0.90 to 156 mm(3) with good interobserver correlation (R(2) = 0.9671). Percentage of stenosis correlated with quantitative coronary arteriography measurement (R(2) = 0.55). Voxel analysis underestimated the percentage of stenosis (Pearson's correlation coefficient, 1.2; p = 0.03). CONCLUSION: The study shows that the voxel analysis technique appears to be an accurate and reproducible method to measure arterial wall thickness, noncalcified plaque, and degree of arterial stenosis using density values measured in Hounsfield units. The technique may be useful on further correlative studies.

Cine CT during coughing for assessment of tracheomalacia: preliminary experience with 64-MDCT.

OBJECTIVE: 64-MDCT is advantageous for functional imaging because of its high spatial and temporal resolution combined with its length of coverage. Our purpose is to describe the technical aspects of using 64-MDCT for cine CT during coughing and to share our preliminary clinical experience using this method. CONCLUSION: This method is technically feasible and offers a promising alternative to previous cine CT methods for diagnosing tracheomalacia.

CT perfusion for determination of pharmacologically mediated blood flow changes in an animal tumor model.

PURPOSE: To prospectively compare single- and multisection computed tomographic (CT) perfusion for tumor blood flow determination in an animal model. MATERIALS AND METHODS: All animal protocols and experiments were approved by the institutional animal care and use committee before the study was initiated. R3230 mammary adenocarcinoma was implanted in 11 rats. Tumors (18-20 mm) were scanned with dynamic 16-section CT at baseline and after administration of arsenic trioxide, which is known to cause acute reduction in blood flow. The concentration of arsenic was titrated (0-6 mg of arsenic per kilogram of body weight) to achieve a defined blood flow reduction (0%-75%) from baseline levels at 60 minutes, as determined with correlative laser Doppler flowmetry. The mean blood flow was calculated for each of four 5-mm sections that covered the entire tumor, as well as for the entire tumor after multiple sections were processed. Measurements obtained with both methods were correlated with laser Doppler flowmetry measurements. Interobserver agreement was determined for two blinded radiologists, who calculated the percentage of blood flow reduction for the "most representative" single sections at baseline and after arsenic administration. These results were compared with the interobserver variability of the same radiologists obtained by summing blood flow changes for the entire tumor volume. RESULTS: Overall correlations for acute blood flow reduction were demonstrated between laser Doppler flowmetry and the two CT perfusion approaches (single-section CT, r=0.85 and r(2)=0.73; multisection CT, r=0.93 and r(2)=0.87; pooled data, P=.01). CT perfusion disclosed marked heterogeneity of blood flow, with variations of 36% +/- 13 between adjacent 5-mm sections. Given these marked differences, interobserver agreement was much lower for single-section CT (standard deviation, 0.22) than for multisection CT (standard deviation, 0.10; P=.01). CONCLUSION: Multisection CT perfusion techniques may provide an accurate and more reproducible method of tumor perfusion surveillance than comparison of single representative tumor sections.