Suzanne A. Gronemeyer

Accuracy of MR imaging for detecting epiphyseal extension of osteosarcoma

Background. Too few patients are receiving epiphyseal-sparing limb salvage procedures for osteosarcoma. Objective. To determine how magnetic resonance (MR) imaging can best predict the epiphyseal extension of osteosarcoma. Materials and methods. Forty children underwent complete pretreatment static and dynamic contrast-enhanced MR imaging (DEMRI). Static MR images [T1-weighted and short tau inversion recovery (STIR)] of the epiphyses were read in three ways: (1) for suspicion of any abnormality (tumor or edema), (2) for suspicion of tumor, excluding suspected edema, and (3) validating the second method by using a scale to rate the likelihood of tumor. Presentation imaging was compared to histopathologic findings after chemotherapy and resection. The receiver operating characteristic (ROC) method was used to analyze the scaled ratings of static MR and DEMRI values. Results. At delayed resection, 20 of 40 children with osteosarcoma had confirmed epiphyseal tumor; however, 32 epiphyses were abnormal on STIR and 28 abnormal on T1. Differentiating suspected tumor from edema increased the accuracy to an Az (area under the ROC curve) of 0.94 for both T1-weighted and STIR static sequences. T1-weighted MR had better specificity and STIR better sensitivity at any given rating. DEMRI was slightly less accurate (Az = 0.90). Conclusion. Static MR imaging most accurately detected epiphyseal extension of osteosarcoma when readers distinguished suspected tumor from edematous or normal tissue.

3D gadolinium-enhanced MRA: Evaluation of hepatic vasculature in children with hepatoblastoma

We used contrast‐enhanced three‐dimensional magnetic resonance angiography (3D MRA) modified for pediatric use to evaluate the hepatic vasculature prior to partial hepatectomy in five consecutive children with hepatoblastoma. Modifications included non‐breath‐hold technique in four of the five children who were sedated. The single breath‐hold technique was performed in only one awake child. Scan delay times were based on contrast infusion time rather than total infusion time. The hepatic artery, portal vein, and inferior vena cava were identified in all patients. MRA findings were confirmed by conventional angiography in one patient and by surgery in all. Contrast‐enhanced 3D MRA is a useful and rapid technique prior to partial hepatectomy in patients with hepatoblastoma. J. Magn. Reson. Imaging 2000;11:65–68.

Tumor volume or dynamic contrast-enhanced MRI for prediction of clinical outcome of Ewing sarcoma family of tumors.

Background. The identification of risk factors that predict poor clinical outcome at the time of diagnosis could lead to intensified early therapy and improved outcome for pediatric patients with Ewing sarcoma family of tumors (ESFT). Objective. To compare the effectiveness of static magnetic resonance (MR) imaging measurements of tumor volume with variables obtained by dynamic contrast-enhanced MR imaging (DEMRI) in predicting ESFT outcome. Methods. MR examinations that included DEMRI were retrospectively reviewed. The analyses included 45 examinations of 21 patients with ESFT (performed from 1992 to 1996). Tumor volumes were measured on the static MR images, and the regions of interest were selected for DEMRI analysis. The relationships of static MR imaging and DEMRI variables with the probability of progression-free survival (PFS) and disease-free survival (DFS) were determined. Results. Larger tumor volume at the time of diagnosis predicted poorer PFS and DFS estimates. No DEMRI variable predicted outcome. Conclusion. Determination of tumor volume by static MR imaging at the time of diagnosis is a simple and reliable method of predicting the clinical outcome of patients with ESFT. DEMRI is not as reliable a technique as static MR imaging for predicting the outcome of these patients.

Applications of 3D contrast-enhanced MR angiograpy in pediatric oncology

Abstract Contrast-enhanced 3D MR angiography can be used for imaging of children. This technique can improve the delineation of the vasculature that is more anatomically familiar to surgeons. Here we illustrate the usefulness of contrast-enhanced 3D MR angiography in the diagnosis and follow-up of pediatric oncology patients.

Subtraction technique for contrast-enhanced MR images of musculoskeletal tumors

Vascularized malignant tissue, fat and hemorrhage may have similar intensities on Gd-DTPA-enhanced, T1-weighted MRI performed to evaluate musculoskeletal tumors. We describe a simple, rapid post-processing subtraction technique which resulted in improved definition of these tissues in 33 of 42 examinations. While the subtraction process is susceptible to complex patient motion, the improved contrast can be obtained without modifying standard pulse sequences.

Pilot study of noninvasive detection of venous occlusions from central venous access devices in children treated for acute lymphoblastic leukemia.

Background. Survivors of childhood acute lymphocytic leukemia (ALL) are at risk of venous occlusion induced by central venous access devices (CVADs). A sensitive, noninvasive screening technique to identify the magnitude of this problem is needed. Ultrasound (US) cannot always adequately image the innominate veins or the superior vena cava. Magnetic resonance angiography (MRA) can be noninvasive and may be useful for screening these patients. Objective. We examined the suitability of US and MRA to identify venous occlusion. Materials and methods. We used MRA and ultrasound to examine 11 pediatric patients previously treated for ALL. CVADs had been in place a median of 2.5 years (range, 0.4–2.8 years) and removed a median of 2.1 years (range, 0.6–2.9 years) previously. We also performed 2D time-of-flight magnetic resonance angiography (TOF MRA) on two healthy young adult women with no history of venous abnormality or CVAD use. Results. MRA suggested central venous abnormalities in 8 of the 11 ALL survivors and in both healthy control subjects. US results were negative in all 11 survivors. Conclusion. Further investigation is warranted to develop a sensitive and specific noninvasive method for identifying venous occlusion caused by prior CVAD use. Such a method would allow prospective studies of this complication in pediatric ALL survivors.

Magnetic resonance imaging for evaluation of childhood aplastic anemia.

Purpose We prospectively evaluated the ability of magnetic resonance imaging (MRI) of the thoraco-lumbar vertebrae to determine the relative amount of red and fatty marrow in children with aplastic anemia. Patients and Methods Twenty pediatric patients (ages 1–19 years) with aplastic anemia underwent T1-weighted (T1W, n = 31) and short T1 inversion recovery (STIR, n = 30) MRI of the midline sagittal thoraco-lumbar spine. Bone marrow (BM) biopsies from the posterior iliac crest (n = 29) were also performed. All studies were evaluated by blinded observers; MR grading was based on visual inspection of signal intensity. Biopsy-estimated cellularity was compared with T1W and STIR grading when these were performed within 14 days of each other (n = 16). All studies were compared to a simultaneous absolute neutrophil count (ANC), absolute reticulocyte count (ARC), and platelet count. Results BM cellularity estimated by BM biopsy was significantly associated with STIR grading (p = 0.032, Jonckheere-Terpstra test), as were peripheral ANC (p = 0.044), ARC (p = 0.007), and platelet count (p = 0.003). T1W grade was significantly associated with ANC (P = 0.011) but not ARC (p = 0.053) or platelet count (p = 0.377). Biopsy-estimated cellularity was associated with ANC (p = 0.032) and ARC (p = 0.036), but not platelet count (p = 0.282). Conclusion In childhood aplastic anemia patients, STIR (and, to a lesser extent, T1W) MRI of the thoraco-lumbar spine reflects BM activity, as measured by peripheral blood ANC, ARC, and platelet count, and BM cellularity, as measured by BM biopsy. MRI may thus provide a noninvasive measure of hematopoietic status.

Creating synergy: Essential components of a successful R25E cancer education program.

For an R25E cancer research program to be a resounding success for both participating students and faculty, and to maintain federal funding, many synergistic elements are necessary. Essential components of the R25E Pediatric Oncology Education Program at St. Jude Childrens Research Hospital include (1) a unique focus, (2) a program director who is passionate about the program and who is enthusiastically supported by the institution, (3) committed and involved faculty mentors, (4) a current and complete program website with an online application process, (5) a large external network referring top students to the program, (6) an extensive, diverse, and highly qualified applicant pool with rigorous application requirements, (7) meticulous matching of faculty mentors with mentees, (8) adequate financial support for participants (stipend and housing), (9) an outstanding basic science and clinical research infrastructure, (10) training in the protection of human subjects, the responsible conduct of research, and research with vertebrate animals, (11) a comprehensive lunch and learn seminar series, (12) oral and written participant presentations of their research results, (13) ongoing internal and external program evaluation, (14) long-term tracking of participants, and (15) continuing program innovation.

Hepatic arterial resistance index - An indicator of diffuse liver disease in children treated with bone marrow transplantation

AIM To describe the relationship between the resistance index of the common hepatic artery and liver function tests in children undergoing bone marrow transplantation. MATERIALS AND METHODS We analysed prospectively the results of 106 Doppler ultrasound examinations of the common hepatic artery from 31 bone marrow transplant patients, 16 of whom had normal liver function. The aetiology of the liver dysfunction in the other 15 patients was veno-occlusive disease (n = 7), unknown (n = 3), hepatic graft-versus-host disease (n = 2), hepatitis (n = 2), or cholestasis (n = 1). We assessed the relationships between the hepatic arterial resistance index (HART) and the results of the serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic-pyruvic transaminase (SGPT), alkaline phosphatase (ALK), lactate dehydrogenase (LDH) and serum albumin (ALB) assays and calculated HARI break-point values that might distinguish patients with liver disease from patients with the normal liver function. RESULTS The significant break point (P < 0.05) of the HARI was 0.55 for SGOT, SGPT and ALK. LDH was associated with a break point of 0.53. Resistance indices for the common hepatic artery below the break-point values predicted liver dysfunction with specificities of 81%, 80%, 92% and 93%, respectively. There was no significant relationship between liver function tests and ALB levels. CONCLUSION If below 0.55, the hepatic arterial resistance index is a non-invasive indicator of liver dysfunction in children undergoing bone marrow transplantation.

Vaginal occlusion induced by cancer therapy

Two adolescent girls with acquired vaginal occlusion and resultant hematometracolpos are presented. Both are long-term survivors of childhood malignancies, who prior to multiagent chemotherapy and pelvic irradiation had normal uteri by imaging. Both were amenorrheic post therapy. Routine follow-up computed tomography (CT) scans to monitor their malignancies demonstrated unexpected cystic pelvic masses, subsequently diagnosed as hematometracolpos.