Theodore R. Hall

Variable morbidity in Alagille syndrome : a review of 43 cases

BACKGROUND Alagille syndrome is one of the most common inherited disorders that cause chronic liver disease in children. Early reports suggested a benign course in these patients. Subsequent reports showed significant morbidity and mortality. This study was designed to analyze the long-term clinical course in Alagille syndrome. METHODS The records of children with Alagille syndrome seen during a 20-year period were reviewed. RESULTS Forty-three patients were identified. Liver disease was diagnosed before 12 months of age in 95%. The frequencies of renal anomalies (50%) and intracranial hemorrhage (12%) were significant. The high incidence of chronic otitis media (35%) has not been reported previously. One patient had a renal transplant. Vascular compromise as a pathologic mechanism for some characteristics of the syndrome is also suggested by the presence of small bowel stenosis and atresia, tracheal and bronchial stenosis, renal artery stenosis, middle aortic syndrome, and avascular necrosis of the humeral and femoral heads. Twenty (47%) patients underwent liver transplantation. Five of six who underwent Kasai procedure required liver transplantation. Twelve died (28%), five after liver transplantation. One patient died of intracranial bleeding. Sixteen (37%) without liver transplantation and 15 (35%) who underwent liver transplantation are alive. CONCLUSIONS Some patients with early-onset and more severe liver disease can benefit from liver transplantation. Careful and complete assessment should be made of infants with a cholestatic syndrome, to avoid misdiagnosis and unnecessary Kasai procedures. Our observation of vascular compromise in various organ systems suggests that notch signaling pathway defects affect angiogenesis in Alagille syndrome.

Pulmonary edema and fluid mobilization as determinants of the duration of ECMO support

The physiological variables that govern recovery of pulmonary function during neonatal extracorporeal membrane oxygenation (ECMO) remain poorly understood. We hypothesized that pulmonary hypertension (PHN) resolves soon after starting ECMO and that neonatal weight gain, pulmonary edema, and fluid mobilization are major determinants of recovery of pulmonary function and the ability to decrease ECMO support. To evaluate this, 17 consecutive neonates requiring ECMO for severe respiratory failure were reviewed. PHN was studied by daily echocardiography to assess the direction of ductal shunting. To evaluate fluid flux, pulmonary function, and edema during ECMO, we measured body weight, urine output, and ECMO flow every 12 hours. To evaluate pulmonary edema, serial chest radiographs obtained every 12 hours were randomly reviewed and scored by two radiologists with a semiquantitative chest radiograph index score (CRIS). By 25% of bypass time, PHN had resolved in all patients. However, at that time, weight had increased to 9.16% +/- 1.78% above birth weight, and the CRIS was 44% worse than the value just prior to ECMO. From 25% time on bypass, as urine output increased, patient weight and CRIS progressively decreased, allowing ECMO support to be weaned. At the time of discontinuation of ECMO support, weight had decreased to 2.0% +/- 1.3% above birth weight, and urine output remained steady at 3.0 +/- 0.3 mL/kg/h. Within 24 hours of stopping ECMO, the CRIS showed a 58% improvement compared to maximal scores during ECMO. We conclude that PHN decreases early in ECMO and that edema and its mobilization are important determinants of the improvement in pulmonary function and duration of ECMO.(ABSTRACT TRUNCATED AT 250 WORDS)

Implementation of a large-scale picture archiving and communication system

This paper describes the implementation of a large-scale picture archiving and communication system (PACS) in a clinical environment. The system consists of a PACS infrastructure, composed of a PACS controller, a database management system, communication networks, and optical disk archive. It connects to three MR units, four CT scanners, three computed radiography systems, and two laser film digitizers. Seven display stations are on line 24 h/day, 7 days/wk in genitourinary radiology (2K), pediatric radiology in-patient (1K and 2K) and outpatient (2K), neuroradiology (2K), pediatric ICU (1K), coronary care unit (1K), and one laser film printing station. The PACS is integrated with the hospital information system and the radiology information system. The system has been in operation since February 1992. We have integrated this PACS as a clinical component in daily radiology practice. It archives an average of 2.0-gigabyte image data per workday. A 3-mo system performance of various components are tabulated. The deployment of this large-scale PACS signifies a milestone in our PACS research and development effort. Radiologists, fellows, residents, and clinicians use it for case review, conferences, and occasionally for primary diagnosis. With this large-scale PACS in place, it will allow us to investigate the two critical issues raised when PACS research first started 10 yrs ago: system performance and cost effectiveness between a digital-based and a film-based system.

Incidental paranasal sinus imaging abnormalities and the normal Lund score in children.

OBJECTIVES: Our goal was to determine the incidental Lund score for pediatric patients without chronic rhinosinusitis (CRS). METHODS: Pediatric patients with computed tomography scans of the orbit or brain were identified. Patients with a clinical history of sinonasal disorders or skeletal facial trauma were excluded. The remaining scans were scored according to the Lund-MacKay system. Pneumatization of the frontal and sphenoid sinuses was also recorded. A scaled Lund score was computed, and the mean Lund score for this normal population was determined. RESULTS: One hundred ninety-two computed tomography scans were examined (mean age, 9.0 years). The frontal sinuses and sphenoid sinuses were absent in 40.1% and 1.6% of cases, respectively. The mean scaled Lund score in this pediatric population without CRS was 2.81 (95% confidence interval, 2.40 to 3.22). This result differed statistically from a score of 0 (P < 0.001). Only 37 (19.3%) patients had completely radiographically normal sinuses. CONCLUSIONS: The mean incidental Lund score in the absence of CRS approaches 3, and this should be considered when determining the diagnostic likelihood of CRS in pediatric patients.

Mycotic Aneurysm of the Thoracic Aorta Due to Aspergillus terreus: Case Report and Review

Mycotic aneurysms of the aorta caused by fungi are uncommon. We describe an unusual case of aortic aneurysm infection caused by Aspergillus terreus, which most likely spread from an adjacent pulmonary focus. Successful treatment included partial pneumonectomy, resection of the aneurysm with graft repair, and prolonged sequential administration of amphotericin B and itraconazole. A review of the published experience with aortic aneurysms caused by Aspergillus species is also presented. When invasive aspergillosis is suspected in proximity to areas with major vascular structures in immunocompromised patients, further investigation to rule out vascular invasion may be warranted. If the diagnosis is confirmed, aggressive and prompt treatment with antifungal agents combined with surgical debridement is essential to improve outcome.

Failure of duplex sonography to diagnose hepatic artery thrombosis in a high-risk group of pediatric liver transplant recipients

Excellent correlation between angiographic findings and duplex sonography has been previously reported in the diagnosis of hepatic artery thrombosis (HAT), the most common technical complication of pediatric orthotopic liver transplantation (OLT). We now report a significant incidence of false-negative sonograms, ie, hepatic artery reported as patent but thrombosed on subsequent angiography. HAT was diagnosed in 10 of 57 pediatric OLT recipients evaluated prospectively by duplex sonography. In 5 patients HAT was diagnosed only by angiography even though arterial wave forms were observed on duplex sonography. Selective angiography demonstrated extensive collateral vessel formation arising from the superior mesenteric artery, the celiac axis, or both. The 5 patients shared very similar clinical courses marked by relapsing bacteremias with multiple enteric organisms, associated with focal infarctions of the liver. Four of the grafts had difficult arterial reconstructions and 3 of 5 had segmental bile duct dilation. We conclude that duplex sonography has proven to be a valuable screening tool in evaluating hepatic artery patency but must be correlated with angiography studies in a high-risk group of pediatric transplant patients characterized clinically by relapsing bacteremia and radiographically by false-negative duplex examinations.

Radionuclide evaluation of liver transplants

Orthotopic liver transplantation is now an established technique for treating patients with various forms of end stage liver disease. The number of centers performing the procedure is increasing and, as the number of transplant recipients in the population increases, many institutions performing nuclear medicine studies will be confronted with requests to evaluate these patients. While a variety of radionuclides are proving useful in this evaluation, the 99mTc iminodiacetic acid (IDA) compounds, particularly 99mTc diisopropyl IDA (DISIDA), will probably account for the majority of radionuclide evaluations of these patients because they are well suited to monitor both structural and functional changes of the graft. The primary application of radionuclide studies is focused in the postoperative period, when problems with the vascular and biliary anastomoses, rejection, infections, and bile leaks all produce alterations in radionuclide hepatobiliary studies. Abnormalities such as rejection and infection produce primarily functional, rather than structural changes and are not easily differentiated based upon the kinetics of 99mTc-DISIDA extraction and excretion by the liver, serial imaging and correlation with clinical data is necessary in such situations. Quantitative analyses of kinetic 99mTc IDA (DISIDA) studies and quantitative approaches with other compounds such as 99mTc galactosyl-neoglycoalbumin (NGA) may permit better assessments of relatively subtle changes in liver function in the posttransplant period.

Post-transplant multiple myeloma in a pediatric renal transplant patient

Post‐transplant lymphoproliferative disease (PTLD) is a well‐recognized complication of the intense immunosuppression required in solid organ and bone marrow transplant recipients. The clinical presentation is varied and can range from a benign infectious mononucleosis‐like syndrome to malignant lymphoma. PTLD manifesting as multiple myeloma occurs rarely. We report the unique occurrence of Epstein–Barr virus (EBV)‐associated post‐transplant multiple myeloma in a 16‐year‐old male. In contrast to previously described cases of PTLD‐myeloma type, this patient was very young, had a clear association with EBV, and an indolent clinical course.

Is there a need for dedicated bone imaging in addition to 18F-FDG PET/CT imaging in pediatric sarcoma patients?

Purpose: Many children with sarcomas undergo whole body 2-deoxy-2-(18F)fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) and technetium methylene diphosphonate (99Tc-MDP) studies. It is unknown whether the combination of both tests results in more accurate detection of bone lesions than 18F-FDG- PET/CT alone. Methods: 99Tc-MDP bone and 18F-FDG PET/CT scans were each read by 2 “blinded” observers and then reviewed side-by-side by 3 readers. Bone lesions were graded qualitatively on a 5-point scale (from benign to malignant). Clinical and imaging follow-up (n=21) and bone biopsy results (n=8) served as reference standard. Results: A total of 39 paired 99Tc-MDP and 18F-FDG-PET/CT studies (cases) performed at a mean interval 4±7 days, were performed on 29 patients (mean age 12±5 y). Of these, 21 patients (72%) had bone sarcoma, whereas 8 patients (28%) had soft tissue sarcoma. By patient and case-based analysis, 18F-FDG PET/CT had an accuracy of 100%. 99Tc-MDP had accuracies of 90% and 82% by patient and case-based analysis. The combined interpretation had an accuracy of 97%. Conclusions: In this study, 99Tc-MDP bone imaging does not provide an added diagnostic value for bone involvement over 18F-FDG-PET/CT.

Knowledge-based Segmentation of Pediatric Kidneys in Ct for Measurement of Parenchymal Volume

Purpose The purpose of this work was to develop an automated method for segmenting pediatric kidneys in helical CT images and measuring their volume. Method An automated system was developed to segment the kidneys. Parametric features of anatomic structures were used to guide segmentation and labeling of image regions. Kidney volumes were calculated by summing included voxels. For validation, the kidney volumes of four swine were calculated using our approach and compared with the “true” volumes measured after harvesting the kidneys. Automated volume calculations were also performed in a cohort of nine children. Results The mean difference between the calculated and measured values in the swine kidneys was 1.38 ml. For the pediatric cases, calculated volumes ranged from 41.7 to 252.1 ml/kidney, and the mean ratio of right to left kidney volume was 0.96. Conclusion These results demonstrate the accuracy of a volumetric technique that may in the future provide an objective assessment of renal damage.