Ectopic gas in the fibular graft after anterior cervical corpectomy and fusion.

BACKGROUND: Ectopic gas in the graft is occasionally encountered upon follow-up computed tomography (CT) after anterior cervical corpectomy and fusion (ACCF). However, most cases lack inflammatory responses and manifestations of infection. Although the clinical significance of ectopic gas in the graft has not yet been established, to the best of our knowledge, no previous studies have described ectopic gas in the graft after ACCF. This study evaluated ectopic gas in the fibular graft upon follow-up CT after ACCF. METHODS: We reviewed 112 patients who underwent ACCF and follow-up CT, with a minimum follow-up period of 3 years. CT images were retrospectively reviewed to confirm the presence of ectopic gas in the graft and bone fusion. Bone fusion was defined as follows: mobility less than 2 mm between spinous processes on the flection-extension radiograph or a bone bridge on CT images. RESULTS: Of the 112 patients, 30 (27%) patients had ectopic gas in the fibular grafts. Among them, ectopic gas was initially observed 3 months after surgery (early onset) in 23 (77%) patients and 6 months after surgery (late-onset) in the remaining seven (23%) patients. Upon the latest follow-up CT, ectopic gas more frequently remained in late-onset (4/7, 57%) rather than in early-onset (3/23, 13%) cases (p = 0.033). Bone fusion was not observed when CT images exhibited ectopic gas in the graft, whereas ectopic gas was not observed when CT images exhibited bone fusion. CONCLUSION: Ectopic gas in the fibular graft was observed at both early and late-onset after ACCF; late-onset gas remained significantly. The remaining gas was strongly associated with pseudoarthrosis; therefore, pseudoarthrosis should be considered when ectopic gas in the graft is observed on CT images.

Glucose corrected standardized uptake value (SUVgluc) in the evaluation of brain lesions with 18F-FDG PET.

PURPOSE: To retrospectively assess the utility of (18)F fluorodeoxyglucose (FDG) positron emission tomography (PET) images of standardized uptake values corrected for blood glucose (SUV(gluc)), and to compare this to various quantitative methods to identify the presence or absence of high grade malignancy. METHODS: A retrospective review in 42 patients, found 81 central nervous system (CNS) lesions. Fifty one were malignant and 30 were benign or post treatment changes based on pathology (n = 32) and on clinical outcome (n = 49). Dynamic FDG PET scans were processed to generate parametric images of SUV(gluc), SUV, glucose metabolic rate (GMR), and lesion to cerebellum ratios (SUV(Rc)), and contralateral white matter ratios (SUV(Rw)). The SUV(gluc) was calculated from SUV(max) * BG/[100 mg/dl], where SUV(max) is the maximum SUV and BG is the blood glucose level (mg/dL). RESULTS: Using a malignant threshold for SUV(gluc) of 4.5 and GMR of 13.0 µmole/min/100 g, the accuracies were similar for the SUV(gluc) (80%) and GMR (81%) and were higher than the conventional SUV(max) (73%). The area under the receiver operating characteristic (ROC) curve for the SUV(gluc) (0.8661) was better than that for the SUV(max) (0.7955) (p < 0.02) and was similar to those of the GMR (0.8694), SUV(Rc) (0.8278), and SUV(Rw) (0.8559). CONCLUSION: These results suggest that the SUV(gluc) may assist in the interpretation of FDG PET brain images in patients with CNS lesions. The SUV(gluc) method avoids the complexity of kinetic modeling and the definition of a reference region.

Glucose-corrected standardized uptake value in the differentiation of high-grade glioma versus post-treatment changes.

BACKGROUND: Standardized uptake values (SUVs) of fluorine-18 fluorodeoxyglucose PET ((18)F-FDG PET) are used widely to differentiate residual or recurrent high-grade gliomas from post-treatment changes in patients with brain tumors. The aim of this study is to assess the accuracy of SUV corrected by blood glucose level (SUV(gluc)) compared with various quantitative methods in this role. MATERIALS AND METHODS: In 55 patients with dynamic F-FDG PET scans, there were 97 glioma lesions: glioblastoma (n=60), grade III gliomas (n=22), grade III or IV gliomas (n=6), grade I/II (n=7), and prebiopsy lesions (n=2). The final actual diagnosis was made on the basis of pathology (n=33) and clinical outcome (n=64). Dynamic F-FDG PET scans were processed to generate parametric images of SUV(gluc), SUV(max), and glucose metabolic rate (GMR). Lesion to cerebellum ratios (SUV(Rc)) and contralateral white matter ratios (SUV(Rw)) were also measured. The SUV(gluc) was calculated as SUV(max)×blood glucose level/100. RESULTS: Using the thresholds of SUV(max)>4.6, SUV(Rc)>0.9, SUV(Rw)>1.8, SUV(gluc)>4.3, and GMR>12.2 µmol/min/100 g to represent positivity for viable tumors, the accuracies were the same for the SUV(gluc) and SUV(Rw) (80%) and were higher than the conventional SUV(max) (72%). The area under the receiver operating characteristic curve for the SUV(gluc) (0.8933) was better than that for the SUV(max) (0.8266) (P<0.01) and was similar to those of the GMR (0.8622), SUV(Rc) (0.8606), and SUV(Rw) (0.8981). CONCLUSION: These results suggest that SUV(gluc) may aid in the differentiation of residual or recurrent high-grade tumor from post-treatment changes in patients with abnormal blood glucose levels. The simplicity of the SUV(gluc) avoids the complexity of kinetic analysis or the requirement of a reference tissue.

Portal shunt scintigraphy (PSS) in the evaluation of patients suspected of hereditary hemorrhagic telangiectasia.

Vascular malformations of the liver in hereditary hemorrhagic telangiectasia may develop high output cardiac failure. Currently, the treatment for refractory hepatic vascular shunts includes hepatic artery embolization. However, hepatic or biliary necrosis may occur if inadequate portal blood flow supplies the liver. In this study, we applied noninvasive portal shunt scintigraphy to determine the portal shunt index for their evaluation. We present a case of the patient with a high PSI value and another case with a normal PSI value (<10%).

Spontaneous disappearance of lumbar disk herniation within 3 months.

Although spontaneous regression of disk herniation is a well-known phenomenon, the time taken for the condition to resolve has not been detailed in previous studies. This article describes a case of vanishing lumbar disk herniation in a 33-year-old man. The patient experienced sudden severe lumbar pain while lifting a 240-kg weight while attempting a Donkey Calf Raise during muscle training. The pain persisted despite the use of a lumbar corset and nonsteroidal anti-inflammatory drugs. Twelve days after onset, sensory disturbance appeared in the right L5 dermatome, and a manual muscle test of the right anterior tibial muscle revealed level 3. The pain gradually spread over the right lower extremity and the indistinct lumbago changed to localized back pain at the L4/5 vertebral level. Magnetic resonance imaging (MRI) of the lumbar spine 12 days after onset revealed a large disk herniation at L4/5. T2-weighted images demonstrated the herniated disk with a sequestrated disk fragment, which compressed the right L5 nerve root. Over the following month, his pain gradually diminished and he was able to resume his muscle-building program. Follow-up MRI 3 months after the lumbar injury showed complete disappearance of the extruded disk material. This is the first reported case of disk herniation that disappeared within only 3 months, as previous reports have reported that a minimum 30-week period was needed. Clinical awareness of the possibility that disk herniation may resolve within a relatively short time may aid both correct informed consent and treatment.