Surrogates of Muscle Mass on Cardiac MRI Correlate with Exercise Capacity in Patients with Fontan Circulation.

BACKGROUND: Sarcopenia is an increasingly recognized marker of frailty in cardiac patients. Patients with a history of congenital heart disease and Fontan procedure have a higher risk of developing progressive muscle wasting. Our objective was to determine if we could use routine cardiac MRI (CMR) for the surveillance of muscle wasting. METHODS: A retrospective study of all Fontan patients (n = 75) was conducted at our institution, with CMR performed from 2010 to 2022 and exercise stress testing performed within 12 months (4.3 ± 4.2 months). The skeletal muscle area (SMA) for the posterior paraspinal and anterior thoracic muscles were traced and indexed for body surface area (BSA). Patients were stratified by percentile into the upper and lower quartiles, and the two groups were compared. Multivariable regression was performed to control for sex and age. RESULTS: There was a significant positive association of both anterior (r = 0.34, p = 0.039) and paraspinal (r = 0.43, p = 0.007) SMA to peak VO2. Similarly, paraspinal but not anterior SMA was negatively associated with the VE/VCO2 (r = -0.45, p = 0.006). The upper quartile group had significantly more males (18/19 vs. 8/20; p = 0.0003) and demonstrated a significantly higher peak VO2 (32.2 ± 8.5 vs. 23.8 ± 4.7, p = 0.009), a higher peak RER (1.2 ± 0.1 vs. 1.1 ± 0.04, p = 0.007), and a significantly lower VE/VCO2 (32.9 ± 3.6 vs. 40.2 ± 6.2, p = 0.006) compared to the lowest quartile. The association of SMA to VO2 peak and VE/VCO2 was redemonstrated after controlling for sex and age. CONCLUSION: Thoracic skeletal muscle area may be an effective surrogate of muscle mass and is correlated to several measures of cardiorespiratory fitness post-Fontan. CMR would be an effective tool for the surveillance of sarcopenia in post-Fontan patients given its accessibility and routine use in these patients.

Pediatric mediastinal masses.

Mediastinal masses are categorized based on the International Thymic Malignancy Interest Group (ITMIG) classification into prevascular, visceral and paravertebral compartments. The schema is based on cross-sectional imaging, mainly CT, and helps with generating a differential diagnosis based on location of the mass. Up to half of all pediatric mediastinal tumors are malignant. In this review we describe mediastinal masses that are relevant to the pediatric population, as well as the role of MR imaging of mediastinal masses and its advantages.

Pediatric neuroendocrine carcinoid tumors: Management, pathology, and imaging findings in a pediatric referral center.

BACKGROUND: While neuroendocrine (carcinoid) tumors are increasingly recognized in the adult population, they are often not suspected in children. PROCEDURE: Retrospective review of all well-differentiated neuroendocrine (carcinoid) tumors was performed based on pathology reports from a quaternary pediatric medical center between January 2003 and June 2016. Clinical presentations, treatment approaches, imaging findings, and outcomes were reviewed and analyzed. RESULTS: A total of 45 cases of pathology-proven carcinoid tumor were reported with an average age of 14.1 years (range: 7-21 years, SD: 2.8 years). Of these cases, 80% (36) were appendiceal, 11% (5) bronchial, 2% (1) colonic, 2% (1) gastric, 2% (1) enteric, and 2% (1) testicular. Metastases were observed in one (3%) appendiceal, one (100%) enteric, and two (40%) bronchial cases. No recurrence was demonstrated in any appendiceal carcinoid cases. Recurrence was seen in one of three extra-appendiceal gastrointestinal tumors. Tumor site and size significantly correlated with metastases and recurrence. CONCLUSIONS: Contrary to recent epidemiological investigations in adults, appendiceal carcinoid tumors remain the most common site for pediatric carcinoid tumors. Appendiceal carcinoid tumors exhibited benign clinical courses without recurrence during short-term follow-up. Extra-appendiceal gastrointestinal carcinoid tumors exhibited much more aggressive behavior with greater metastases and recurrence. Bronchial carcinoid tumors demonstrated good clinical response to resection even in cases with mediastinal lymph node involvement. While increased use of urine 5-HIAA levels and somatostatin receptor-specific imaging might improve detection and guide management of extra-appendiceal carcinoid tumors, longer-term follow-up is needed.

Pediatric Neuroendocrine Carcinoid Tumors: Review of Diagnostic Imaging Findings and Recent Advances.

OBJECTIVE: Although rare, pediatric neuroendocrine tumors including carcinoid tumor have increased in incidence over the past few decades. Despite increased recognition, survival rates have not significantly improved. Earlier detection of these tumors is necessary to improve clinical outcomes. This article discusses imaging approaches for detecting pediatric carcinoid tumors including anatomic imaging methods such as CT and MRI as well as functional imaging methods targeting the somatostatin receptor including 111In-labeled octreotide and newer 68Ga-based radiotracers that may hold promise in hybrid PET/CT or PET/MRI. CONCLUSION: Improvements in functional imaging with novel somatostatin receptor-specific radiotracers along with fused functional and anatomic imaging have substantially improved the clinical detection of carcinoid tumors. Although rare, these tumors are encountered in children, and an awareness of the appropriate use of various imaging methods is essential for pediatric specialists. Further research is needed to ascertain the diagnostic value of newer imaging methods and radiotracer-based treatment approaches, especially in the pediatric population.

Single coronary artery anomaly: classification and evaluation using multidetector computed tomography and magnetic resonance angiography.

The aim of this study was to use multidetector computed tomography (MDCT) and magnetic resonance (MRA) angiography to illustrate the classification and clinical characteristics of single coronary artery anomaly (SCAA). Retrospective evaluation of 22 adult and pediatric patients with SCAA by way of a medical archiving system was performed between June 2001 and August 2012. Imaging modalities used for coronary artery evaluation included MRA and MDCT angiography. Of the 22 patients, the majority (n = 8; 36%) showed an interarterial course, the subtype having the worst prognosis. The retroaortic course (n = 3; 14%) and course anterior to the pulmonary trunk (n = 3; 14%) were the next most frequent patterns. Additional types (n = 8; 36%) included the following: L-I, R-III, septal, and combined. Four patients (18%) showed atherosclerotic involvement. SCAA anomaly was diagnosed as an incidental finding in the majority of patients evaluated initially for cardiovascular diseases (n = 19; 86%). Two patients (9%) required surgical interventions solely for their anomaly. Nine patients (41%) were found to have coexisting congenital heart disease. Although conventional catheter angiography is responsible for the current classification of SCAA, advanced imaging modalities are useful in the evaluation of morphological and clinical characteristics of single coronary arteries.

Isolated intramuscular fibrous band masquerading antral web in a premature neonate. A case report.

Isolated fibrous gastric antral band in a neonate causing partial gastric obstruction and mimicking prepyloric antral web is not reported in the English literature, and we would like to report the first case. A premature neonate with feeding difficulties and bilious aspirate underwent upper gastrointestinal contrast examination. The upper gastrointestinal series showed a thin, radiolucent, circumferential band in the antrum with delayed gastric emptying. Radiographic diagnosis of prepyloric antral web with partial gastric obstruction was made. Intraoperatively, a circumferential fibrous cord was found in the muscle layer (tunica muscularis) of the antrum, which was completely divided. Clinically and radiographically, the 2 conditions could not be differentiated but require 2 separate surgical techniques for their management.

Noncompaction cardiomyopathy in children with congenital heart disease: evaluation using cardiovascular magnetic resonance imaging.

Noncompaction of the left ventricle, a genetic cardiomyopathy with a reported incidence of 0.05% to 0.24%, can lead to sudden cardiac death, particularly among children, if left undetected. Because the diagnosis of isolated noncompaction cardiomyopathy (NCM) can be overlooked, its association with other congenital heart diseases (CHDs) makes the diagnosis of NCM even more difficult. This study aimed to assess the impact of NCM on the cardiovascular physiology of children with coexisting CHDs evaluated by cardiovascular magnetic resonance imaging. A case-control study was performed with 12 children (6 patients with combined NCM and CHD and 6 control subjects with isolated CHD). The mean left ventricular end-diastolic and end-systolic volume indices were significantly higher in the CHD patients presenting with NCM than in the CHD patients with no NCM (P = 0.028). However, no differences were observed for right ventricular end-diastolic and end-systolic volume indices, biventricular ejection fractions, stroke volumes and indices, left ventricular wall thickness, left ventricular fractional shortening, cardiac output, or cardiac index. This study suggests that NCM in children with CHDs increases left ventricular volumes, and larger studies are required to demonstrate other changes (e.g., ejection fraction, stroke volume) that were close to being significant.

Reducing abdominal CT radiation dose with the adaptive statistical iterative reconstruction technique in children: a feasibility study.

BACKGROUND: The use of the adaptive statistical iterative reconstruction (ASIR) algorithm has been shown to reduce radiation doses in adults undergoing abdominal CT studies while preserving image quality. To our knowledge, no studies have been done to validate the use of ASIR in children. OBJECTIVE: To retrospectively evaluate differences in radiation dose and image quality in pediatric CT abdominal studies utilizing 40% ASIR compared with filtered-back projection (FBP). MATERIALS AND METHODS: Eleven patients (mean age 8.5 years, range 2-17 years) had separate 40% ASIR and FBP enhanced abdominal CT studies on different days between July 2009 and October 2010. The ASIR studies utilized a 38% mA reduction in addition to our pediatric protocol mAs. Study volume CT dose indexes (CTDI(vol)) and dose-length products (DLP) were recorded. A consistent representative image was obtained from each study. The images were independently evaluated by two radiologists in a blinded manner for diagnostic utility, image sharpness and image noise. RESULTS: The average CTDI(vol) and DLP for the 40% ASIR studies were 4.25 mGy and 185.04 mGy-cm, compared with 6.75 mGy and 275.79 mGy-cm for the FBP studies, representing 37% and 33% reductions in both, respectively. The radiologists' assessments of subjective image quality did not demonstrate any significant differences between the ASIR and FBP images. CONCLUSION: In our experience, the use of 40% ASIR with a 38% decrease in mA lowers the radiation dose for children undergoing enhanced abdominal examinations by an average of 33%, while maintaining diagnostically acceptable images.

Left ventricular non-compaction on MRI in a patient with 22q11.2 distal deletion.

We report on a 22-year-old male carrying a presumptive clinical diagnosis of Dubowitz-like phenotype who has been followed-up by cardiology for bicuspid aortic valve with ascending aorta and aortic root dilatation. Cardiac magnetic resonance imaging (CMRI) confirmed these findings, along with an incidental finding of left ventricular non-compaction (LVNC). Genetic workup revealed the diagnosis of 22q11.2 distal deletion encompassing the BCR gene. This is the first time LVNC has been reported in a patient with 22q11.2 distal deletion.