Model-Informed Vancomycin Dosing Optimization to Address Delayed Renal Maturation in Infants and Young Children with Critical Congenital Heart Disease.

Ensuring safe and effective drug therapy in infants and young children often requires accounting for growth and organ development; however, data on organ function maturation are scarce for special populations, such as infants with congenital diseases. Children with critical congenital heart disease (CCHD) often require multiple staged surgeries depending on their age and disease severity. Vancomycin (VCM) is used to treat postoperative infections; however, the standard pediatric dose (60-80 mg/kg/day) frequently results in overexposure in children with CCHD. In this study, we characterized the maturation of VCM clearance in pediatric patients with CCHD and determined the appropriate dosing regimen using population pharmacokinetic (PK) modeling and simulations. We analyzed 1,254 VCM serum concentrations from 152 postoperative patients (3 days-13 years old) for population PK analysis. The PK model was developed using a two-compartment model with allometrically scaled body weight, estimated glomerular filtration rate (eGFR), and postmenstrual age as covariates. The observed clearance in patients aged ≤ 1 year and 1-2 years was 33% and 40% lower compared with that of non-CCHD patients, respectively, indicating delayed renal maturation in patients with CCHD. Simulation analyses suggested VCM doses of 25 mg/kg/day (age ≤ 3 months, eGFR 40 mL/min/1.73 m2 ) and 35 mg/kg/day (3 months < age ≤ 3 years, eGFR 60 mL/min/1.73 m2 ). In conclusion, this study revealed delayed renal maturation in children with CCHD, could be due to cyanosis and low cardiac output. Model-informed simulations identified the lower VCM doses for children with CCHD compared with standard pediatric guidelines.

Detectability of cold tumors by xSPECT bone technology compared with hot tumors: a supine phantom study.

Detecting cold as well as hot tumors is vital for interpreting bone tumors on single-photon emission computed tomography (SPECT) images. This study aimed to visually and quantitatively demonstrate the detectability of cold tumors using xSPECT technology compared with that of hot tumors in the phantom study. Five tumors of different sizes and normal bone contained a mixture of 99mTc and K2HPO4 in a spine phantom. We acquired SPECT data using an xSPECT protocol and transverse images were reconstructed using xSPECT Bone (xB) and xSPECT Quant (xQ). Mean standardized uptake values (SUVmean) in volumes of interest (VOI) were calculated. Recovery coefficients (RCs) for each tumor site were calculated with reference to radioactive concentrations. The SUVmeans of the whole vertebral body for hot tumor bone image in cortical bone phantom reconstructed by with xB and xQ were 5.77 and 4.86 respectively. The SUVmean of xB was similar to the true value. The SUVmeans for xB and xQ reconstructed images of cold tumors were both approximately 0.16. The RC of the cold tumor on xQ images increased as the tumor diameter decreased, whereas that of xB remained almost constant regardless of the tumor diameter. In conclusion, the quantitative accuracy of detecting hot and cold tumors was higher in the xB image than in the xQ image. Moreover, the visual detectability of cold tumors was also excellent in xB images.

Long-term outcomes of functional single ventricles associated with heterotaxy syndrome†.

OBJECTIVES: The goal of this study was to determine the long-term surgical outcomes of patients with functional single ventricles associated with heterotaxy syndrome, risk factors for mortality and factors associated with Fontan stage completion. METHODS: Overall, 279 patients with a functional single ventricle associated with heterotaxy syndrome who underwent an initial surgical procedure at our institute between 1978 and 2021 were grouped into 4 "eras" based on the surgical year during which the initial procedure was performed: era 1 (1978-1989, n = 71), era 2 (1990-1999, n = 98), era 3 (2000-2009, n = 64) and era 4 (2010-2021, n = 46). Neonatal surgery was more frequent in eras 3 and 4 than in eras 1 and 2. RESULTS: Overall, 228 patients had right atrial isomerism; 120 patients (43.0%) had a total anomalous pulmonary venous connection; and 58 patients (20.8%) underwent an initial procedure as neonates. Overall survival rates at 10, 20 and 30 years after the initial procedure were 47.1%, 40.6% and 36.1%, respectively. Neonatal surgery (P < 0.001), total anomalous pulmonary venous connection repair at the initial procedure (P < 0.001) and early era (P < 0.001) were identified as risk factors for mortality, with the last 2 variables being negatively associated with Fontan stage completion (P < 0.001 for both). CONCLUSIONS: Although era had a favourable effect on survival, total anomalous pulmonary venous connection with intrinsic pulmonary vein obstruction was associated with both mortality and Fontan stage completion. CLINICAL REGISTRATION NUMBER: R19092.

Death, reoperation, and late cardiopulmonary function after truncus repair.

Objective: To identify the late surgical outcomes of truncus arteriosus. Methods: Fifty consecutive patients with truncus arteriosus who underwent surgery between 1978 and 2020 at our institute were enrolled in this retrospective, single institutional cohort study. The primary outcome was death and reoperation. The secondary outcome was late clinical status, including exercise capacity. The peak oxygen uptake was measured by a ramp-like progressive exercise test on a treadmill. Results: Nine patients underwent palliative surgery, which resulted in 2 deaths. Forty-eight patients went on to truncus arteriosus repair, including 17 neonates (35.4%). The median age and body weight at repair were 92.5 days (interquartile range, 10-272 days) and 3.85 kg (interquartile range, 2.9-6.5 kg), respectively. The survival rate at 30 years was 68.5%. Significant truncal valve regurgitation (P = .030) was a risk factor for survival. Survival rates were similar between in the early 25 and late 25 patients (P = .452). The freedom from death or reoperation rate at 15 years was 35.8%. Significant truncal valve regurgitation was a risk factor (P = .001). The mean follow-up period in hospital survivors was 15.4 ± 12 years (maximum, 43 years). The peak oxygen uptake, which was performed in 12 long-term survivors at a median duration from repair of 19.7 years (interquartile range, 16.8-30.9 years), was 70.2% of predicted normal (interquartile range, 64.5%-80.4%). Conclusions: Truncal valve regurgitation was a risk factor for both survival and reoperation, thus improvement of truncal valve surgery is essential for better life prognosis and quality of life. Slightly reduced exercise tolerance was common in long-term survivors.

A novel objective method for discriminating pathological and physiological colorectal uptake in the lower abdominal region using whole-body dynamic 18F-FDG-PET.

OBJECTIVES: To investigate whether the center-of-mass shift distance (CMSD) analysis on whole-body dynamic positron emission tomography (WBD-PET) with continuous bed motion is an objective index for discriminating pathological and physiological uptake in the lower abdominal colon. METHODS: We retrospectively analyzed the CMSD in 39 patients who underwent delayed imaging to detect incidental focal uptake that was difficult to determine as pathological and physiological on a conventional early-PET (early) image reconstructed by 5-phase WBD-PET images. The CMSD between each phase of WBD-PET images and between conventional early and delayed (two-phase) PET images were classified into pathological and physiological uptake groups based on endoscopic histology or other imaging diagnostics. The diagnostic performance of CMSD analysis on WBD-PET images was evaluated by receiver operator characteristic (ROC) analysis and compared to that of two-phase PET images. RESULTS: A total of 66 incidental focal uptake detected early image were classified into 19 and 47 pathological and physiological uptake groups, respectively. The CMSD on WBD-PET and two-phase PET images in the pathological uptake group was significantly lower than that in the physiological uptake group (p < 0.01), respectively. The sensitivity, specificity, and accuracy in CMSD analysis on WBD-PET images at the optimal cutoff of 5.2 mm estimated by the Youden index were 94.7%, 89.4%, and 89.4%, respectively, which were not significantly different (p = 0.74) from those of two-phase PET images. CONCLUSIONS: The CMSD analysis on WBD-PET was useful in discriminating pathological and physiological colorectal uptake in the lower abdominal region, and its diagnostic performance was comparable to that of two-phase PET images. We suggested that CMSD analysis on WBD-PET images would be a novel objective method to omit unnecessary additional delayed imaging.

Comparison of the detectability of hot lesions on bone SPECT using six state-of-the-art SPECT/CT systems: a multicenter phantom study to optimize reconstruction parameters.

Single-photon emission computed tomography with X-ray computed tomography (SPECT/CT) systems have diversified due to the remarkable developments made by each manufacturer. This study aimed to optimize the reconstruction parameters of six state-of-the-art SPECT/CT systems and compare their image quality of bone SPECT. SPECT images were acquired on SPECT/CT systems, including Symbia Intevo, Discovery NM/CT 670, Discovery NM/CT 870 CZT, Brightview XCT, and VERITON-CT. SIM2 bone phantom with tough lung phantoms on both sides of the spinal inserts that simulate the thorax was used for image quality assessment. SPECT images were obtained at individual workstations using an ordered subset expectation maximization method with three-dimensional resolution recovery, as well as CT attenuation and scatter correction, subset 2, iteration 12-84, and a full width at half maximum 10-mm Gaussian smooth filter. An automatic image analysis software dedicated to SIM2 bone phantom was used to assess the contrast-to-noise ratio (CNR), relative recovery coefficient, percentage of coefficient of variance, contrast, and detectability. The optimal parameters for each system were defined with superior detectability of spherical lesions and noise characteristics, as well as the highest CNR. All systems exhibited better image quality indexes using the optimal parameters than using the manufacturer's recommended parameters. The detectability of all systems was in agreement while using the optimal parameters. Detectability agreement can be achieved by optimizing the reconstruction parameters for different reconstruction algorithms, which can further improve the image quality. Therefore, future research should focus on optimal reconstruction parameters for SPECT alone.

Use of Donor Hearts ≥50 Years Old for Septuagenarians in Heart Transplantation.

BACKGROUND: The impact of using donors ≥50 years old on heart transplantation outcomes of septuagenarians is unknown, which may have a potential to expand the donor pool. METHODS: From January 2011 to December 2021, 817 septuagenarians received donor hearts <50 years old (DON<50) and 172 septuagenarians received donor hearts ≥50 years old (DON≥50) in the United Network for Organ Sharing database. Propensity score matching was performed using recipient characteristics (167 pairs). The Kaplan-Meier method and Cox proportional hazards model were used to analyze death and graft failure. RESULTS: The number of heart transplants in septuagenarians has been increasing (54 per year in 2011 to 137 per year in 2021). In a matched cohort, the donor age was 30 years in DON<50 and 54 years in DON≥50. In DON≥50, cerebrovascular disease was the main cause of death (43%), whereas head trauma (38%) and anoxia (37%) were the causes in DON<50 (P < .001). The median heart ischemia time was comparable (DON<50, 3.3 hours; DON≥50, 3.2 hours; P = .54). In matched patients, 1- and 5-year survival rates were 88.0% (DON<50) vs 87.2% (DON≥50) and 79.2% (DON<50) vs 72.3% (DON≥50), respectively (log-rank, P = .41). In the multivariable Cox proportional hazards models, donors ≥50 years old were not associated with death in matched (hazard ratio, 1.05; 95% CI, 0.67-1.65; P = .83) and nonmatched groups (hazard ratio, 1.11; 95% CI, 0.82-1.50; P = .49). CONCLUSIONS: The use of donor hearts older than 50 years can be an effective option for septuagenarians, thereby potentially increasing organ availability without compromising outcomes.

Feasibility of using counts-per-volume approach with a new SPECT phantom to optimize the relationship between administered dose and acquisition time.

We developed a phantom for single-photon emission computed tomography (SPECT), with the objective of assessing image quality to optimize administered dose and acquisition time. We investigated whether the concept of counts-per-volume (CPV), which is used as a predictor of visual image quality in positron emission tomography, can be used to estimate the acquisition time required for each SPECT image. QIRE phantoms for the head (QIRE-h) and torso (QIRE-t) were developed to measure four physical indicators of image quality in a single scan: uniformity, contrast of both hot and defective lesions with respect to the background, and linearity between radioactivity concentration and count density. The target organ's CPV (TCPV), sharpness index (SI), and contrast-to-noise ratio (CNR) were measured for QIRE-h and QIRE-t phantoms, and for anthropomorphic brain and torso phantoms. The SPECT image quality of the four phantoms was visually assessed on a 5-point scale. The acquisition time and TCPV were correlated for all four phantoms. The SI and CNR values were nearly identical for the QIRE and anthropomorphic phantoms with comparable TCPV. The agreement between the visual scores of QIRE-h and brain phantoms, as well as QIRE-t and torso phantoms, was moderate and substantial, respectively. Comparison of SPECT image quality between QIRE and anthropomorphic phantoms revealed close agreement in terms of physical indicators and visual assessments. Therefore, the TCPV concept can also be applied to SPECT images of QIRE phantoms, and optimization of imaging parameters for nuclear medicine examinations may be possible using QIRE phantoms alone.

Characteristics and long-term outcome for congenital left main coronary artery atresia.

The prevalence of congenital left main coronary artery atresia is very low. We report the characteristics and long-term outcomes of four children with left main coronary artery atresia. Three patients had heart murmurs due to mitral regurgitation at less than 1 year old. Their myocardial ischaemia worsened on exercise with aging. In the fourth patient, hypertrophic cardiomyopathy and Noonan syndrome were suspected at 1 year old. The development of communicating arteries between the conus branch and the left anterior descending artery was detected at 7 years old. The left main coronary artery atresia was confirmed by a selective coronary angiogram at 15 years old. Congenital left main coronary artery atresia could not be diagnosed by two-dimensional echocardiography; however, the left coronary arteries were small. Two patients underwent coronary artery bypass grafting of the left anterior descending artery using the left internal thoracic artery at 3 years and 6 years old, respectively. Two patients had an angioplasty with a cut back at the orifice of the left coronary artery at 2 years old and 17 years old, respectively. Two patients had no cardiac events without medication for more than 30 years after the operation. We must differentiate the diagnosis of left main coronary artery atresia in the small left coronary arteries with mitral regurgitation during the first year. Coronary artery revascularisation and mitral annuloplasty are needed. The long-term outcome of both coronary artery bypass grafting and angioplasty were good. The degree of mitral regurgitation after surgery may affect the prognosis.

Patient-Prosthesis Mismatch Associated With Somatic Growth After Mechanical Mitral Valve Replacement in Small Children: Metrics for Reoperation and Outcomes.

Reoperation after pediatric mitral valve replacement (MVR) is inevitable due to patient-prosthesis mismatch (PPM) associated with somatic growth. We analyzed potential metrics for PPM and outcomes of redo MVR for valve upsizing. Between 1999 and 2018, 15 children without obstructive left heart lesions other than mitral stenosis underwent initial MVR with a 16-mm ATS-Advanced Performance valve. We analyzed hemodynamic data from 28 postoperative catheterizations and concomitant echocardiograms. The median age and body weight at initial MVR were 4.9 months (25th, 75th percentile: 3.6, 6.6) and 5.9 kg (5.0, 7.3). Redo MVR was planned when patients had congestive heart failure and postcapillary pulmonary hypertension (PH) due to PPM: systolic pulmonary arterial pressure (SPAP) >35 mm Hg and pulmonary capillary wedge pressure (PCWP) >15 mm Hg on catheterization. Indexed effective orifice area (iEOA) and mean transmitral pressure gradient (TMPG) were strongly correlated with SPAP (r = -0.72, P < 0.001 and r = 0.75, P < 0.001) and PCWP (r = -082, P < 0.001 and r = 0.84, P < 0.001). Cut-off values for detecting postcapillary PH due to PPM were 1.0 cm2/m2 for iEOA and 18 mm Hg for mean TMPG. Nine patients underwent redo MVR for postcapillary PH due to PPM at a median postoperative interval of 10 years (9.2, 11.9). All the patients survived, and PH was improved one year after surgery. iEOA and mean TMPG can be metrics for PPM in children after MVR. Careful follow-up is required to confirm the improvement of preoperatively existing PH after redo MVR for valve upsizing.

Comparison of long-term outcomes of atrial switch with Rastelli and physiological repair using left ventricle-to-pulmonary artery conduit for levo-transposition of the great arteries.

OBJECTIVES: The objectives of this study was to compare the long-term outcomes of anatomic repair using atrial switch with the Rastelli procedure versus physiological repair with left ventricle-to-pulmonary artery conduit for patients with levo-transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction. METHODS: Of patients with levo-transposition of the great arteries who underwent biventricular repair between 1978 and 2001, 31 hospital survivors after anatomic repair of atrial switch and the Rastelli (anatomic group) and 14 hospital survivors after physiological repair with left ventricle-to-pulmonary artery conduit (physiological group) were enrolled. Survival rates, reoperation rates, and most recent conditions were compared. RESULTS: The overall survival rate at 20 years was 79.7% (95% CI, 66.4%-95.6%) in the anatomic group and 85.1% (95% CI, 68.0%-100%) in the physiological group (P = .87). The reoperation rate at 10 years was 19.8% (95% CI, 5.6%-34.0%) in the anatomic group and 52.0% (95% CI, 25.0%-79.1%) in the physiological group (P = .067). Only patients in the physiological group underwent systemic tricuspid valve replacement. The anatomic group showed a better cardiac index at catheterization (2.79 ± 0.75 L/min/m2 vs 2.30 ± 0.54 L/min/m2; P = .035), lower serum brain natriuretic peptide (73 ± 86 pg/mL vs 163 ± 171 pg/mL; P = .024), and better maximal oxygen uptake in the treadmill test (64.1 ± 16.5% vs 52.7 ± 17.8% of predicted normal; P = .036), although the period until most recent catheterization, blood inspection, and treadmill testing were earlier in the anatomic group. CONCLUSIONS: Preservation of the left ventricle as the systemic ventricle using anatomic repair contributes to better cardiopulmonary condition compared with physiological repair.

Long-Term Influence of Atrial Switch Operation on Hemodynamics After the Rastelli Procedure.

The study aimed to investigate the long-term influence of atrial switch on post-Rastelli hemodynamic condition. Of 112 patients with transposition of the great arteries (TGA) or TGA-type double outlet right ventricle, ventricular septal defect (VSD), and pulmonary stenosis (PS) who underwent intra-cardiac repair between 1979 and 2018, 50 patients with levo-TGA underwent atrial switch and Rastelli as an anatomic repair and 62 patients with dextro-TGA underwent Rastelli. Postoperative outcomes were retrospectively compared. The median follow-up durations were 20.1 years (interquartile range: 4.3, 32.4) in the Rastelli group and 15.3 years (7.1, 23.0) in the atrial switch plus Rastelli group (p = 0.19). Sex, age, and weight at operation were similar in both groups. Overall survival rates at 30 years were 69.8% in the Rastelli group and 80.1% in the atrial switch plus Rastelli group (p = 0.18). The atrial switch plus Rastelli group required more frequent catheter interventions (p < 0.001), mainly for caval obstruction (n = 8) and atrial arrhythmia (n = 6). Medication was more frequent in the atrial switch plus Rastelli group (p = 0.009). Exercise capacity was similarly reduced in two groups. Protein-losing enteropathy (PLE) occurred in three long-term survivors in the atrial switch plus Rastelli group (p = 0.07). Concomitantly performed atrial switch operation did not affect long-term survival and exercise capacity after Rastelli procedure. However, the occurrence of PLE, a frequent need for medication, and catheter interventions after atrial switch plus Rastelli may result from atrial switch under the post-Rastelli condition.

New index to assess the extent of bone disease in patients with prostate cancer using SPECT/CT.

OBJECTIVE: Assessing the extent of bone metastases in patients with prostate cancer is very important to predict patient prognosis. Therefore, the bone scan index (BSI), which is easy to use, has been used; however, the accuracy is not that high. In this study, we proposed a new index for the extent of bone disease using single-photon emission computed tomography with computed tomography (SPECT/CT) images and assessed the accuracy of calculation. METHODS: In this study, a total of 46 bone scans from 12 patients with prostate cancer treated for bone metastases with Radium-223 were included. Whole-body planar images were obtained 150-180 min after an intravenous injection of 99mTc-methylene diphosphonate, and cervical-to-pelvic SPECT/CT was immediately obtained. The total bone volume (TBV) and regional metabolic bone volume (MBV) were defined as Hounsfield unit of > 120, standardized uptake value (SUV) of > 0.5, and SUV of > 5-8 in four levels, respectively. Bone metabolism volumetric index (BMVI) was calculated as the percentage of the total MBV divided by TBV. The variability of the TBV measurement was evaluated by the percentage coefficient of variance (%CV) of TBV within individual patients. We evaluated the correlation of TBV with age, height, weight, and body mass index and the correlation and agreement between BSI and BMVI. RESULTS: The mean and %CV of TBV were 4661.7 cm3 and 2.8%, respectively, and TBV was strongly correlated with body weight. BMVI was significantly higher than BSI and correlated with alkaline phosphatase. For patients with progressive bone metastases, BSI was clearly underestimated, whereas BMVI was elevated. CONCLUSIONS: Although assessed in a small number of cases, the new index for assessing the extent of bone disease using SPECT/CT imaging was highly value than BSI and was significantly correlated with alkaline phosphatase. Therefore, this study suggests that BMVI could improve the low sensitivity of BSI in patients with low extent of disease grade.

Impact of right ventriculotomy for tetralogy of Fallot repair with a pulmonary valve-sparing procedure.

Objectives: The study objectives were to reconfirm the superiority of the pulmonary valve-sparing procedure versus the transannular patch procedure for repair of tetralogy of Fallot and to evaluate the influence of a right ventriculotomy in the pulmonary valve-sparing procedure. Methods: Between 1978 and 2003, 440 patients (aged <10 years) underwent tetralogy of Fallot repair. Of these patients, 242 (55.0%) underwent the transannular patch procedure, 106 (24.1%) underwent the pulmonary valve-sparing procedure without right ventriculotomy, and 92 (20.9%) underwent the pulmonary valve-sparing procedure with right ventriculotomy. End points focused on adverse events and included all-cause mortality, reoperation, catheter intervention, and symptomatic arrhythmias. To compare the outcomes of pulmonary valve sparing with and without right ventriculotomy, inverse probability weighting was applied to adjust for potential confounding factors. Results: The median follow-up period was 20.3 years (interquartile range, 10.7-27.6). In all cohorts, the pulmonary valve-sparing procedure was the independent factor that reduced adverse events after tetralogy of Fallot repair (hazard ratio, 0.47; 95% confidence interval, 0.23-0.94; P = .033). After weighting, there was no difference in overall survival or event-free survival in the pulmonary valve-sparing with and without right ventriculotomy group. However, the pulmonary valve-sparing with right ventriculotomy group exhibited a larger cardiothoracic ratio (beta: 6.01; 95% confidence interval, 2.36-9.66; P = .001), lower medication-free rate (odds ratio, 0.29; 95% confidence interval, 0.098-0.79; P = .019), and higher New York Heart Association functional classification (odds ratio, 2.99; 95% confidence interval, 1.36-6.80; P = .007) at the latest follow-up. Conclusions: Right ventriculotomy for tetralogy of Fallot repair with pulmonary valve-sparing did not increase major adverse events. However, negative impacts on current status cannot be ignored.

[Evaluation of Detectability for Patient's Movement in Portable Chest Radiography: Comparison of Visual Detection and Motion Detection Software].

PURPOSE: The purpose of this study was to evaluate the detectability of the observers and motion detection software for blurred portable chest radiographies. METHODS: The chest phantom radiographies of various blur sizes were obtained by moving the phantom using 4° slope. The phantom was moved in two directions, vertical (the upper and lower parts of the chest phantom were parallel to rails) and horizontal (the left and right parts of the chest phantom were parallel to rails). Six observers performed receiver operating characteristic (ROC) studies on blurred images. We used the results to compare detectability for vertical and horizontal blur by ROC analysis, and calculated sensitivity and specificity. In addition, the motion detection software was enabled during image acquisition, and the detectability was compared with that of the observers. RESULTS: The average of the area under the ROC curve for the detection of blur in the vertical and horizontal directions for the observers were 0.918 and 0.943, respectively, and no significant difference was found depending on the direction. The motion detection software performed better than the observers in most of the sensitivity and specificity scores. CONCLUSION: The motion detection software could be a useful support tool for motion detection in portable chest radiography.

Beads phantom for evaluating heterogeneity of SUV on 18F-FDG PET images.

PURPOSE: This study aimed to develop a dedicated phantom using acrylic beads for texture analysis and to represent heterogeneous 18F-fluorodeoxyglucose (FDG) distributions in various acquisition periods. METHODS: Images of acrylic spherical beads with or without diameters of 5- and 10-mm representing heterogeneous and homogeneous 18F-FDG distribution in phantoms, respectively, were collected for 20 min in list mode. Phantom data were reconstructed using three-dimensional ordered subset expectation maximization with attenuation and scatter corrections, and the time-of-flight algorithm. The beads phantom images were acquired twice to evaluate the robustness of texture features. Thirty-one texture features were extracted, and the robustness of texture feature values was evaluated by calculating the percentage of coefficient of variation (%COV) and intraclass coefficient of correlation (ICC). Cross-correlation coefficients among texture feature values were clustered to classify the characteristics of these features. RESULTS: Heterogeneous 18F-FDG distribution was represented by the beads phantom images. The agreements of %COV between two measurements were acceptable (ICC ≥ 0.71). All texture features were classified into four groups. Among 31 texture features, 24 exhibited significant different values between phantoms with and without beads in 1-, 2-, 3-, 4-, 5-, 20-min image acquisitions. Whereas, the homogeneous and heterogeneous 18F-FDG distribution could not be discriminated by seven texture features: low gray-level run emphasis, high gray-level run emphasis, short-run low gray-level emphasis, low gray-level zone emphasis, high gray-level zone emphasis, short-zone low gray-level emphasis, and coarseness. CONCLUSIONS: We have developed the acrylic beads phantom for texture analysis that could represent heterogeneous 18F-FDG distributions in various acquisition periods. Most texture features could discriminate homogeneous and heterogeneous 18F-FDG distributions in the beads phantom images.

Short-term outcomes of EXCOR Paediatric implantation.

OBJECTIVES: The aim of this study was to review a single institution's experience with EXCOR Paediatric implantation. METHODS: Patients <15 years old who underwent EXCOR implantation as a bridge to transplantation between 2015 and 2021 were enrolled. Major adverse events included death, cerebrovascular event resulting in sequelae, major infection (sepsis or surgical site infection requiring open sternal irrigation or device removal) and device malfunction requiring surgical treatment. RESULTS: Overall median age and weight for all 20 children at implantation were 10.8 (interquartile range, 7.9-33.2) months and 6.3 (4.6-10.2) kg. Ten patients (50%) weighed <5 kg. Primary diagnoses were dilated cardiomyopathy in 13 patients, fulminant myocarditis in 3, restrictive cardiomyopathy in 2 and congenital heart disease in 2. Two patients required biventricular assist support. The median support time was 365 (241-636) days. Six patients (30%) were supported for >20 months. One patient died. Seven patients underwent heart transplant. Heart transplant has not been performed in the last 1.5 years. Five patients were weaned from EXCOR support after native myocardial recovery, including a patient with dilated cardiomyopathy who recovered after 24 months of EXCOR support. Major complication-free survival at 6, 12 and 18 months were 79.3%, 49.6% and 38.6%, respectively. Body weight <5 kg at implantation was a risk factor for decreased major complication-free survival. CONCLUSIONS: Survival during EXCOR Paediatric support was good, but it prolonged the wait time for a heart transplant. The number of major complications increased over time and was not negligible, especially in small children.