Predictors of 6-minute walk test and 12-minute walk/run test in obese children and adolescents

The purpose of this study was to identify predictors of the distance achieved during a 6-minute walk test and a 12-minute walk/run test (Cooper test) in obese children and adolescents and to evaluate the influence of a residential treatment on the association of these predictors with the distance. A search of the Revalidation Centre Zeepreventorium (De Haan, Belgium) medical records database of all children and adolescents (age 10 to 18 yrs) treated for obesity between September 2003 and February 2006, revealed 65 charts with all relevant data (anthropometrical, maximal graded exercise, lung function, 6-minute walk test and 12-minute walk/run test) at admission as well as after 3 months treatment. The multidisciplinary treatment has a positive influence on anthropometrical variables, endurance capacity, vital capacity, and residual volume (p < 0.05). The distance covered during the 6-minute walk test and the 12-minute walk/run test is correlated with all anthropometrical data and peak VO₂ (p < 0.05). After 3 months of treatment, bivariate correlation was stronger for almost every parameter compared to admission. Following a stepwise regression, BMI z-score is a dominant predictor of both field tests at admission and after 3 months treatment. VO₂peak contributes only significantly in the 12-minute walk/run test at admission. Conclusion: In obese children and adolescents BMI z-score is the most dominant predictor of the variability in performances on the 6-minute walk test and the 12-minute walk/run test at admission as well as after 3 months of treatment.     

Magnetization transfer‐based 3D visualization of foot peripheral nerves

Purpose:

To investigate magnetization transfer (MT) effects as a new source of contrast for imaging and tracking of peripheral foot nerves.

Materials and Methods:

Two sets of 3D spoiled gradient‐echo images acquired with and without a saturation pulse were used to generate MT ratio (MTR) maps of 260 μm in‐plane resolution for eight volunteers at 3T. Scan parameters were adjusted to minimize signal loss due to T2 dephasing, and a dedicated coil was used to improve the inherently low signal‐to‐noise ratio of small voxels. Resulting MTR values in foot nerves were compared with those in surrounding muscle tissue.

Results:

Average MTR values for muscle (45.5 ± 1.4%) and nerve (21.4 ± 3.1%) were significantly different (P < 0.0001). In general, the difference in MTR values was sufficiently large to allow for intensity‐based segmentation and tracking of foot nerves in individual subjects. This procedure was termed MT‐based 3D visualization.

Conclusion:

The MTR serves as a new source of contrast for imaging of peripheral foot nerves and provides a means for high spatial resolution tracking of these structures. The proposed methodology is directly applicable on standard clinical MR scanners and could be applied to systemic pathologies, such as diabetes. J. Magn. Reson. Imaging 2013;37:1234–1237. © 2012 Wiley Periodicals, Inc.     

FDG-PET, 99mTc-HMPAO white blood cell SPET and bone scintigraphy in the evaluation of painful total knee arthroplasties

Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET), technetium-99m hexamethylpropylene amine oxime (HMPAO)-labelled white blood cell (WBC) scintigraphy and bone scintigraphy were used in the evaluation of total knee arthroplasties (TKAs). We prospectively included 21 patients who had a three-phase bone scan for exclusion of infection of TKAs. Four hours after injection of 185 MBq ^99mTc-HMPAO-labelled WBCs, planar and single-photon emission tomographic (SPET) imaging was performed. Planar imaging was repeated at 24 h p.i. Consecutively images of the knees were obtained with a dedicated PET system 60 min following the injection of 370 MBq of FDG. Focal tracer uptake was scored on SPET and PET visually (0=no uptake, 4=intense uptake). In addition, SUV (standardised uptake value) per voxel was calculated from attenuation-corrected PET images using the MLAA algorithm. Focal uptake at the bone-prosthesis interface was used as the criterion for infection before and after correlation with the third phase of the bone scan. Final diagnosis was based on operative findings, culture and clinical outcome. In the infected TKAs, the WBC scan showed focal activity of grade 2 (n=2), 3 (n=1) or 4 (n=2). PET scan revealed focal activity of grade 4 (n=5) or 3 (n=1). WBC scan alone had a specificity for infection of 53% [positive predictive value (PPV) 42%, sensitivity 100%], compared with 73% for PET scan (PPV 60%, sensitivity 100%). Considering only lesions at the bone-prosthesis interface that were also present on the third phase of the bone scan, we found a specificity of 93% (PPV 83%) for WBC scan. Using these criteria, a specificity of 80% (PPV 67%) was obtained for PET scan. Two out of three false-positive PET scans were due to loosening of the TKA. It is concluded that WBC scintigraphy in combination with bone scintigraphy has a high specificity in the detection of infected TKAs. FDG-PET seems to offer no additional benefit.     

Hematopoietic stem cell transplantation for CD40 ligand deficiency: Results from an EBMT/ESID-IEWP-SCETIDE-PIDTC study

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Cutaneous involvement in children with acute lymphoblastic leukemia or lymphoblastic lymphoma. The Children's Leukemia Cooperative Group of the European Organization of Research and Treatment of Cancer (EORTC)

OBJECTIVE: Skin involvement in children with acute monocytic leukemia or CD30-positive anaplastic large-cell lymphoma is well-known. In contrast, very little is known about the malignant cutaneous infiltrates in children with acute lymphoblatic leukemia (ALL) or lymphoblastic lymphoma (LBL). This study was designed to determine the frequency of these specific lesions in childhood ALL or LBL and the characteristics of such patients. DESIGN: We studied the clinical and biological findings of children with cutaneous involvement at initial diagnosis of ALL or LBL enrolled between August 1989 and March 1995 in the multicentric trial 58881 of the Children's Leukemia Cooperative Group of the European Organization of Research and Treatment of Cancer (EORTC). RESULTS: Among the 1359 children enrolled in the multicenter trial EORTC 58881, 24 presented with skin involvement at diagnosis. ALL was diagnosed in 15 patients and LBL in 9. In 15 cases, skin lesions were observed within a median time of 6 weeks (range, a few days to 8 months) before the diagnosis of the hematologic disease. Twenty-one children had at least one skin lesion located on the head. Diffuse cutaneous lesions were observed in 7 infants with high-risk ALL. Seventeen of the 24 children remain in the first complete remission (median follow-up of 3 years; range 2 months to 5 years) and 3 are in the second remission with a follow-up of 14 to 24 months. CONCLUSION: The present study demonstrates that cutaneous involvement can be an early manifestation of ALL or LBL. Cutaneous leukemic infiltrates can be observed in children with standard risk as well as in high-risk ALL. Cutaneous involvement in children with LBL is mainly associated with a B-cell precursor immunophenotype of the lymphomatous cells. The most frequent location of skin lesions in children with ALL or LBL is on the head. Further studies are needed to evaluate the prognosis of children with such involvement at diagnosis.     

The cartilaginous Eustachian tube: Reliable CT measurement and impact of the length

Purpose

Balloon dilation of the Eustachian tube is a treatment option for obstructive Eustachian tube dysfunction. The desired balloon position is in the cartilaginous portion. However, the balloon catheter may slide into the bony portion without the surgeon's knowledge. Knowing the length of the cartilaginous portion may improve catheter positioning, but there is no published research on measuring this portion selectively or on whether the length has an impact on development of disease or treatment outcome.To evaluate whether a measurement obtained from CT images is valuable and accurate, to standardize the manner of which the length is measured, and to compare our radiologic measurements to procedural findings, we designed a combined study. Further, we tested the length's influence on development of disease and treatment outcome.