Physical therapy assessment and whole-body magnetic resonance imaging findings in children with glycogen storage disease type IIIa: A clinical study and review of the literature.

INTRODUCTION: Early recognized manifestations of GSD III include hypoglycemia, hepatomegaly, and elevated liver enzymes. Motor symptoms such as fatigue, muscle weakness, functional impairments, and muscle wasting are typically reported in the 3rd to 4th decade of life. OBJECTIVE: In this study, we investigated the early musculoskeletal findings in children with GSD IIIa, compared to a cohort of adults with GSD IIIa. METHODS: We utilized a comprehensive number of physical therapy outcome measures to cross-sectionally assess strength and gross motor function including the modified Medical Research Council (mMRC) scale, grip and lateral/key pinch, Gross Motor Function Measure (GMFM), Gait, Stairs, Gowers, Chair (GSGC) test, 6 Minute Walk Test (6MWT), and Bruininks-Oseretsky Test of Motor Proficiency Ed. 2 (BOT-2). We also assessed laboratory biomarkers (AST, ALT, CK and urine Glc4) and conducted whole-body magnetic resonance imaging (WBMRI) to evaluate for proton density fat fraction (PDFF) in children with GSD IIIa. Nerve Conduction Studies and Electromyography results were analyzed where available and a thorough literature review was conducted. RESULTS: There were a total of 22 individuals with GSD IIIa evaluated in our study, 17 pediatric patients and 5 adult patients. These pediatric patients demonstrated weakness on manual muscle testing, decreased grip and lateral/key pinch strength, and decreased functional ability compared to non-disease peers on the GMFM, 6MWT, BOT-2, and GSGC. Additionally, all laboratory biomarkers analyzed and PDFF obtained from WBMRI were increased in comparison to non-diseased peers. In comparison to the pediatric cohort, adults demonstrated worse overall performance on functional assessments demonstrating the expected progression of disease phenotype with age. CONCLUSION: These results demonstrate the presence of early musculoskeletal involvement in children with GSD IIIa, most evident on physical therapy assessments, in addition to the more commonly reported hepatic symptoms. Muscular weakness in both children and adults was most significant in proximal and trunk musculature, and intrinsic musculature of the hands. These findings indicate the importance of early assessment of patients with GSD IIIa for detection of muscular weakness and development of treatment approaches that target both the liver and muscle.

Assessment of EchoMRI-AH versus dual-energy X-ray absorptiometry by iDXA to measure human body composition.

Comparison of percent fat mass across different body composition analysis devices is important given variation in technology accuracy and precision, as well as the growing need for cross-validation of devices often applied across longitudinal studies. We compared EchoMRI-AH and Lunar iDXA quantification of percent body fat (PBF) in 84 adults (43M, 41F), with the mean age 39.7±15.9 years and body mass index (BMI) 26.2±5.3 kg/m2. PBF correlated strongly between devices (r>0.95, P<0.0001). A prediction equation was derived in half of the subjects, and the other half were used to cross-validate the proposed equation (EchoMRI-AH PBF=[(0.94 × iDXA PBF)+(0.14 × Age)+(3.3 × Female)-8.83). The mean PBF difference (predicted-measured) in the validation group was not different from 0 (diff=0.27%, 95% confidence interval: -0.42-0.96, P=0.430). Bland-Altman plots showed a bias with higher measured PBF on EchoMRI-AH versus iDXA in all 84 subjects (ß=0.13, P<0.0001). The proposed prediction equation was valid in our cross-validation sample, and it has the potential to be applied across multicenter studies.

Whole-body computed tomography in the initial assessment of trauma patients: is there optimal criteria for patient selection?

OBJECTIVE: To describe the use of whole-body computed tomography (WBCT) at this Major Trauma Centre; to determine independent predictors of multi-region injury; and to evaluate the accuracy of the decision to perform WBCT in detecting multi-region injury. METHODS: A prospective cohort study was performed at a single Major Trauma Centre in New South Wales, Australia. All adult patients who triggered trauma team activation and required an initial CT scan were studied. Primary outcome was the presence of multi-region injury. Logistic regression with stepwise selection was used to derive a prediction model for the need for WBCT based on our primary outcome. Receiver operator characteristic (ROC) analysis was used to compare the accuracy of the derived model and the clinical decision to perform WBCT. RESULTS: Six hundred and sixty patients were studied. WBCT scanning rate was 9.3% of all trauma activations. Of the patients who underwent WBCT, 31/98 (32.0%) had multi-region injury compared with 31/562 (5.5%) who underwent selective CT scanning (P < 0.001). Predictors of multi-region injuries were GCS <9 (OR 3.0, 95% CI 1.3-7.0, P = 0.01), full trauma activation (OR 2.9, 95% CI 1.5-5.3, P = 0.001), fall >5 m (OR 4.8, 95% CI 1.8-13.4, P = 0.003) and pedal cyclist (OR 3.0, 95% CI 1.2-7.5, P = 0.02). Area under ROC curve for the clinical decision to perform WBCT was 0.70 (95% CI 0.63-0.76) compared with 0.74 (95% CI 0.67-0.80) for the prediction model. CONCLUSION: The decision to perform WBCT scans in trauma should be at the discretion of the treating clinician. Applying a prediction rule would increase the number of WBCT scans performed without improving overall accuracy.

Technical challenges and opportunities of whole-body magnetic resonance imaging at 3T.

An increasing number of magnetic resonance whole-body units operating at field strengths of 3T and beyond are currently installed in research institutions as well as clinical facilities. This review wants to describe the changes in physical properties at higher field strength and the resulting implications for clinical and experimental examinations of the whole body. An overview is provided on the resulting advantages and disadvantages for anatomical, functional and biochemical MR examinations in different regions of the body (except the brain). It is demonstrated that susceptibility and chemical shift effects increase linearly with field strengths and provide clearly higher sensitivity of most spectroscopic or blood oxygen level dependent (BOLD) techniques. On the other hand, homogeneity of the radiofrequency (RF) field is reduced in the body trunk at higher field strength due to the shorter wavelength. Examinations of the head or extremities provide sufficient homogeneity of the RF field for common examination techniques in most cases, whereas abdominal and pelvic examinations are still sometimes hampered by undesired dielectric effects. Nearly quadratic increase of RF energy deposition with increasing field strengths results in clear limitations for some common sequence types which work without any problems at 1.5 T. New strategies with multi-channel RF excitation have the potential to overcome limitations due to RF inhomogeneities, but a few years of further technological development seem necessary. Many problems have to be solved in the near future regarding the variety of MR techniques and applications in all parts of the human body.

[Cost considerations for whole-body MRI and PET/CT as part of oncologic staging]. / Kostenüberlegungen zur Ganzkörper-MRT und PET-CT im Rahmen des onkologischen Stagings.

PURPOSE: The aim of this study was to evaluate and discuss economic aspects of whole-body MRI and PET/CT in oncologic staging. Considerations from the perspective of the health care system, the radiologist, and the patients are presented. MATERIALS AND METHODS: Costs of both whole-body techniques are compared with the conventional radiologic diagnostic recommendations of the AWFM (Arbeitsgemeinschaft Wissenschaftlich Medizinischer Fachgesellschaften) in oncologic staging of the five most frequent tumor entities. Temporal and monetary aspects are calculated. Invasive, endoscopic, and endosonographic techniques are regarded as essential and cannot be replaced by other techniques. Thus only the minimal potential for cost reduction is quantified. RESULTS: In the German system there is no cipher to correctly balance whole-body MRI and PET/CT. Using the frequently applied ciphers 5700-5730 and 5378, 5489 (factor 1.0) total costs were 440.45 euros, and adding the cipher for additional series 545.37 euros (60 min examination time) for whole-body MRI and 774.74 euros (879.66 euros) (60/90 min examination time) for whole-body PET/CT. Using the common factor 1.8 costs were 981.66 and 1583.38 euros. On the basis of a simple full cost analysis total costs of whole-body PET/CT were higher than of whole-body MRI by a factor of about 2.0 (about 1123 vs 575 euros). There were substantial monetary and temporal differences between tumor entities. In extended bronchial carcinoma 375.32 euros and 55 min can be saved using whole-body MRI in comparison to conventional recommended techniques and using whole-body PET/CT 88.14 euros and 45 min. In tumor entities of lower stages with thus less essential radiologic diagnostics the potential for cost reduction is substantially lower. CONCLUSION: Whole-body imaging techniques make it possible to reduce the number of necessary separate radiologic examinations and thus time in oncologic staging. A substantial reduction of health care costs seems to be possible in many tumor entities but differences between different tumor entities are decisive.

Professional resource cost of body CT examinations: analysis of interpretation costs in different patient populations.

PURPOSE: To study professional cost and cost drivers in body computed tomography (CT), and to compare the professional cost associated with similar CT studies performed on patients with dissimilar diseases. METHODS: A time and motion study was undertaken to measure the allocation of physician time in body CT. The hourly cost of radiologists' clinical practice was calculated. The physician cost associated with individual CT patients was then calculated according to the amount of time radiologists devoted to each patient. Technical costs and hospital overhead were not included. RESULTS: The hourly cost of the clinical practice of attending radiologists, cross-sectional imaging fellows, and senior radiology residents was $293, $35, and $35 respectively. The average professional cost for CT examination of an abdominal pain patient with abdominal and pelvic imaging was $63. The average professional cost for CT examination of an oncology patient with abdominal and pelvic imaging was $90. The cost per relative value unit (RVU) was $25 for abdominal pain patients and $35 for oncology patients. CONCLUSION: Similar CT studies performed on patients with dissimilar diseases result in differing professional costs.