Prediction of voluntary movements of the upper extremities by resting state-brain regional glucose metabolism in patients with chronic severe brain injury: A pilot study.

Confirmation of the exact voluntary movements of patients with disorder of consciousness following severe traumatic brain injury (TBI) is difficult because of the associated communication disturbances. In this pilot study, we investigated whether regional brain glucose metabolism assessed by 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) at rest could predict voluntary movement in severe TBI patients, particularly those with sufficient upper limb capacity to use communication devices. We visually and verbally instructed patients to clasp or open their hands. After video capture, three independent rehabilitation therapists determined whether the patients' movements were voluntary or involuntary. The results were compared with the standardized uptake value in the primary motor cortex, referring to the Penfield's homunculus, by resting state by FDG-PET imaged 1 year prior. Results showed that glucose uptake in the left (p = 0.0015) and right (p = 0.0121) proximal limb of the primary motor cortex, based on Penfield's homunculus on cerebral cartography, may reflect contralateral voluntary movement. Receiver operating characteristic curve analysis showed that a mean cutoff standardized uptake value of 5.47 ± 0.08 provided the best sensitivity and specificity for differentiating between voluntary and involuntary movements in each area. FDG-PET may be a useful and robust biomarker for predicting long-term recovery of motor function in severe TBI patients with disorders of consciousness.

The role of optimal cut-off diagnosis in 11C-methionine PET for differentiation of intracranial brain tumor from non-neoplastic lesions before treatment.

PURPOSE: Amino acid positron emission tomography (PET) may provide additional information to computed tomography and magnetic resonance imaging for detecting the pretreatment diagnosis of intracranial lesions. The purpose of this study was to investigate the role of cutoff values of 11C-METPET, an amino acid PET tracer, in the differentiation of pretreatment brain tumors from non-neoplastic lesions. METHODS: This retrospective cohort study analyzed 101 pretreatment patients with a definitive diagnosis out of a total of 425 consecutive 11C-METPET imaging studies. The standardized uptake values (SUV) and the ratios of lesion to contralateral normal frontal-lobe gray matter uptake (L/N ratios) were measured. Cutoff values for the differential diagnosis of brain tumors from non-neoplastic lesions were determined using receiver operating characteristics curve (ROC) analysis. RESULTS: Based on the ROC analyses, the cutoffs were 3.33 for maximum SUV, 2.54 for mean SUV, 2.33 for peak SUV, 2.04 for Lmax/Nmean, and 2.23 for Lmax/Nmax. The sensitivity and specificity of these cutoffs were 69.2% and 82.6%, respectively, for maximum SUV, 64.1% and 91.3% for mean SUV, 69.2% and 91.3% for peak SUV, 70.5% and 91.3% for Lmax/Nmax and 75.6% and 82.6% for Lmax/Nmean. CONCLUSION: In differentiating intracranial brain tumor from non-neoplastic lesion with 11C-METPET, the use of optimal cutoff values indicates the high specificity, which means that positive result indicates the high likelihood of brain tumor. Considering the high specificity of 11C-METPET, more invasive examinations such as biopsy may be considered in positive cases.

Semi-quantitative Assessment Using [18F]FDG Tracer in Patients with Severe Brain Injury.

Patients with severe traumatic brain injury (sTBI) have difficulty knowing whether they are accurately expressing their thoughts and emotions because of disorders of consciousness, disrupted higher brain function, and verbal disturbances. As a consequence of an insufficient ability to communicate, objective evaluations are needed from family members, medical staff, and caregivers. One such evaluation is the assessment of functioning brain areas. Recently, multimodal brain imaging has been used to explore the function of damaged brain areas. [18F]-fluorodeoxyglucose positron emission tomography-computed tomography ([18F]FDG-PET/CT) is a successful tool for examining brain function. However, the assessment of brain glucose metabolism based on [18F]FDG-PET/CT is not standardized and depends on several varying parameters, as well as the patient's condition. Here, we describe a series of semiquantitative assessment protocols for a region-of-interest (ROI) image analysis using self-produced [18F]FDG tracers in patients with sTBI. The protocol focuses on screening the participants, preparing the [18F]FDG tracer in the hot lab, scheduling the acquisition of [18F]FDG-PET/CT brain images, and measuring glucose metabolism using the ROI analysis from a targeted brain area.

Increased brain glucose metabolism in chronic severe traumatic brain injury as determined by longitudinal 18F-FDG PET/CT.

Little is known about changes in glucose metabolism in patients with chronic severe traumatic brain injury (sTBI). It remains to be elucidated how neurological manifestations of sTBI are associated with brain glucose metabolism during longitudinal follow-up. We show here that neurological manifestations are associated with changes of brain glucose metabolism by using two serial 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) images. In this longitudinal observational study, two serial 18F-FDG PET/CT images from each of 45 patients were analyzed for whole-brain maximum standardized uptake values (SUVmax). For clinical assessment, we applied two different scales: the coma recovery scale-revised and the original Chiba score with additional information regarding nutrition, excretion, facial expression, and position change of the patient's relative immobility and bedridden state. As a result, the increased FDG uptake group was associated with a high level of wakefulness (first PET, p = 0.04; second PET, p = 0.01) and small ventricular size (first PET, p = 0.01; second PET, p = 0.01). In addition, anticonvulsant withdrawal (p = 0.001), improvement of total Chiba score (p = 0.01), language expression (p = 0.03), position change (p = 0.03), and communication (p = 0.03) were accelerated in the increased FDG uptake group. Spearman's rank correlation coefficients of change in SUVmax and language expression between the first and second PET were 0.4 (p = 0.01). Our results indicate that chronic severe traumatic head injury patients have changed brain glucose metabolism.

[Usefulness of FDG-PET for the diagnosis of copper deficiency at an early stage: a case report].

For the patients under long-term tube feeding, copper deficiency is known to be a cause of neutropenia and/or anemia. It is recognized as reversible myelodysplasia, since the condition improves by giving a copper supplementation. Myelodysplasia caused by copper deficiency is difficult to be diagnosed because it is not so common, and often it takes a long time to reach correct diagnosis. We reported usefulness of FDG-PET for the diagnosis of myelodysplasia caused by copper deficiency in early stage. The case was 46 y.o. male patient in vegetative state for 2 years after traumatic brain injury. Laboratory examination revealed slight leukopenia. PET/CT demonstrated high and diffuse FDG accumulation mainly in the vertebral bone marrow. Based on the lower levels of serum copper and ceruloprasmin, the patient was diagnosed as copper deficiency. After treatment of copper supplementation, FDG accumulation of the bone marrow disappeared, and the serum copper level has normalized. From the FDG-PET findings, even in the early stage of copper deficiency, high glucose metabolism of bone marrow was shown.