Vanishing bone metastases: a pitfall in contrast-enhanced CT in patients with venous thrombosis.

Enhancement patterns of visceral venous collaterals are well documented in cases of superior vena cava obstruction. Only recently has intraosseous venous collateral enhancement been described. We describe an unusual case of vertebral marrow enhancement in the lower thoracic spine related to venous collateral circulation caused by an incidental hemiazygos thrombus. Misinterpretation of this finding can lead to the erroneous interpretation of sclerotic bone metastases.

Glucose uptake of the spinal cord in patients with multiple sclerosis detected by ¹8F-fluorodeoxyglucose PET/CT after walking.

STUDY DESIGN: Case report. OBJECTIVES: To determine [(18)F]-fluorodeoxyglucose ([(18)F]-FDG) uptake in the spinal cord of patients with multiple sclerosis (MS) was compared with healthy controls after treadmill walking. SETTING: Colorado Translational Research Imaging Center, University of Colorado School of Medicine, Aurora, CO, USA. METHODS: Eight mildly disabled patients with MS and eight healthy subjects performed 15 min of treadmill walking at a self-selected pace. Two minutes after walking began, each participant was injected with ≈8 mCi of [(18)F]-FDG into a catheter inserted into an antecubital vein. Immediately after walking positron emission tomography/computed tomography (PET/CT) imaging was performed on each participant. Images were analyzed to determine [(18)F]-FDG uptake within the spinal cord. RESULTS: Total spinal cord [(18)F]-FDG uptake was lower in patients with MS (1.48±0.36 and 1.55±0.33, P=0.04), specifically within the thoracic (1.32±0.27 and 1.41±0.24, P<0.01) and the lumbar (1.58±0.40 and 1.89±0.43, P=0.04) spinal cord regions. CONCLUSION: This is the first report of [(18)F]-FDG uptake in the spinal cord of patients with MS. The decreased [(18)F]-FDG uptake within the thoracic and lumbar spinal cord regions could be associated with autonomic nervous system and walking/motor dysfunctions that are often seen in patients with MS. PET/CT imaging with [(18)F]-FDG is highly useful for the demonstration of impaired glucose metabolism in the spinal cord of patients with MS.

Asymmetric glucose uptake in leg muscles of patients with Multiple Sclerosis during walking detected by [18F]-FDG PET/CT.

BACKGROUND: In patients with Multiple Sclerosis (MS), comparative leg muscle strength asymmetries are common and typically accompanied by walking difficulties. Underlying mechanisms for these asymmetries are not completely known, but altered muscle energetics may play a role. OBJECTIVE: To investigate glucose uptake asymmetries in leg muscles of patients with mild MS during walking. METHODS: Eight MS and 8 healthy control (CON) participants performed a 15-min treadmill walking test at self-selected speed. They were injected with a glucose tracer (18F-FDG) two minutes into the test and immediately upon completion, underwent Positron Emission Tomography/Computed Tomography (PET/CT) imaging. RESULTS: MS group walked at a lower speed than the healthy control group (P < 0.01), however it was found that: 1) ([18F]-FDG) uptake in knee and hip flexors was higher compared to the CON group (P = 0.02); 2) the MS group exhibited asymmetrical strength of the knee flexors (P = 0.03); 3) [18F]-FDG uptake was significantly lower in the weaker knee flexors of patients with MS (P < 0.01). CONCLUSIONS: [18F]-FDG uptake and strength asymmetries in the legs of patients with MS indicate greater metabolic costs during activity, which may play a major role in premature muscle fatigability and subsequent impaired walking capacity.

Antibiotic prophylaxis in surgical procedures. A critical analysis of the literature.

The use of prophylactic antibiotics in surgery is widespread and often inappropriate. The lack of well-designed clinical studies partially explains the present confusion regarding the subject. We reviewed the literature in English on antibiotic prophylaxis through June 1982. Antibiotic prophylaxis reduces the incidence of wound infection after colorectal surgery, vaginal hysterectomy, and laryngeal and oropharyngeal resection for carcinoma, and in high-risk patients undergoing gastroduodenal or biliary surgery. In clean operations such as cardiac surgery, vascular procedures, and orthopedic surgery with placement of prostheses, the high morbidity associated with an infection justifies the use of antibiotics even though the risk of infection is small. There are conflicting data on the usefulness of prophylaxis in abdominal hysterectomy, cesarean section, noncardiac thoracic procedures, and urologic surgery. The effectiveness of prophylaxis in neurosurgery cannot be evaluated at the present time.