Clinical Utility of Diffusion-Weighted Imaging in Spinal Infections.

PURPOSE: Both laboratory markers and radiographic findings in the setting of spinal infections can be nonspecific in determining the presence or absence of active infection, and can lag behind both clinical symptoms and antibiotic response. Magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) has been shown to be helpful in evaluating brain abscesses but has not been commonly used in evaluating spinal infections. We aimed to correlate findings on DWI of the spine to results of microbiological sampling in patients with suspected spinal infections. METHODS: Patients who underwent MRI with DWI for suspicion of spinal infections and microbiological sampling from 2002 to 2010 were identified and reviewed retrospectively in this institutional review board approved study. In addition to DWI, scans included sagittal and axial T1, fast-spin echo (FSE) T2, and post-gadolinium T1 with fat saturation. Regions of interest were drawn on apparent diffusion coefficient (ADC) maps in the area of suspected infections, and ADC values were correlated with microbiological sampling. RESULTS: Of 38 patients with suspected spinal infections, 29 (76%) had positive microbiological sampling, and 9 (24%) had negative results. The median ADC value was 740â€¯× 10-6 mm2/s for patients with positive microbiological sampling and 1980â€¯× 10-6 mm2/s for patients with negative microbiological sampling (p < 0.001). Using an ADC value of 1250â€¯× 10-6 mm2/s or less as the cut-off value for a positive result for spinal infection, sensitivity was 66%, specificity was 88%, positive predictive value was 95%, negative predictive value was 41% and accuracy was 70%. CONCLUSION: In patients with suspected spine infection, ADC values on DWI are significantly reduced in those patients with positive microbiological sampling compared to patients with negative microbiological sampling. The DWI of the spine correlates well with the presence or absence of spinal infection and may complement conventional magnetic resonance imaging (MRI).

Screening multidetector computed tomography angiography in the evaluation on blunt neck injuries: an evidence-based approach.

Blunt cerebrovascular injuries (BCVI) can cause ischemic stroke and are associated with high mortality rates. These injuries may have an initial silent course and if recognized in a timely fashion can be treated before neurologic deficit occurs. This has led to the growing implementation of aggressive screening programs to detect and thereby treat BCVI early, before onset of symptoms. Digital subtraction angiography is the diagnostic reference standard for diagnosing BCVI. However, in recent years, there has been a renewed interest in the use of noninvasive techniques, such as multidetector computed tomography angiography (MDCTA) for the evaluation of these patients. The accuracy of MDCTA with respect to digital subtraction angiography is not completely elucidated; however, MDCTA shows a level of accuracy sufficient to serve as an initial screening examination for blunt cerebrovascular injuries.

Imaging for spine tumors and new applications.

OBJECTIVES: Discuss intramedullary, intradural/extramedullary, and extradural spinal tumors including imaging characteristics with emphasis on MR and advances in treatment. METHODS: Literature and institutional review. RESULTS: Spinal tumors: intramedullary, intradural/extramedullary, and extradural, comprise a wide range of histological tumors with an even wider range of clinical symptoms and prognostic features. They are relatively rare and if left untreated, can cause serious neurological deficits and disability. An accurate diagnosis is therefore crucial in determining prognosis and directing therapy. Magnetic resonance imaging (MRI) has revolutionized the diagnosis of intraspinal tumors, allowing for early detection and improved anatomical localization. Magnetic resonance has also become an integral part in staging of both primary and metastatic neoplasms of the spine for guiding therapy and is an excellent modality for follow-up. Advances in MRI (perfusion and molecular imaging) may help refine and describe these neoplasms for accurate treatment and prognosis in the future. Surveillance protocols and role of magnetic resonance are not well established. CONCLUSIONS: Magnetic resonance plays an integral role in evaluation of spinal tumors with increasing role in staging and treatment.

Magnetic resonance detects brainstem changes in chronic, active heavy drinkers.

Neuropathological and neuroimaging studies show cortical and subcortical volume loss in alcohol-dependent individuals. Using quantitative magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopic imaging ((1)H MRSI), we studied the size and potential cellular injury of the brainstem in untreated heavy alcohol drinkers. The brainstem is considered critical in the development and maintenance of drug and alcohol dependence. Two methods of brainstem size determination were compared: standard volumetry vs. midsagittal MR image area measurement. Heavy drinkers (n=12) and light drinkers (n=10) were compared with MRI; (1)H MRSI brainstem data were obtained from a subset of this cohort. Chronic heavy drinking was associated with significantly smaller midsagittal areas of the brainstem, midbrain, and pons, and with significantly smaller overall brainstem volume. Heavy drinking was also associated with significantly lower ratios of N-acetyl-aspartate and choline-containing metabolites compared with creatine-containing compounds in the brainstem, independent of brainstem atrophy. Additionally, brainstem volume and midsagittal brainstem area were correlated (r=0.78). These structural and metabolite findings are consistent with neuronal injury in the brainstem of untreated chronic heavy drinkers. The results also indicate that the midsagittal MRI brainstem area is an easily determined and reliable indicator of brainstem volume.

Cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) expression in human pituitary macroadenomas.

Macroadenomas are tumors of the pituitary gland and are considered almost to be always benign and curable. The clinical manifestations of a pituitary tumor depend on the hormone secreted by the tumor as well as on the pattern of tumor growth within the sella turcica. Current trends attempt to target new molecular markers that also may serve as potential therapeutic targets. Cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) are upregulated in a number of epithelial tumors. No published reports exist about expression of COX-2 in pituitary macroadenomas, and only a few reports with differing results exist concerning EGFR expression in pituitary macroadenomas. This study sought to determine whether a relationship exists between COX-2 and EGFR expression and pituitary macroadenomas. Thirty specimens of pituitary macroadenomas were evaluated after being identified in the surgical pathology database of Thomas Jefferson University Hospital. The hematoxylin and eosin-stained slides were reviewed, and the representative paraffin blocks containing the index case were chosen and immunohistochemically stained for COX-2 and EGFR expression. The COX-2 and EGFR-stained slides were reviewed and an immunohistochemical score was calculated and analyzed. The pituitary macroadenomas were classified on the basis of hormone expression: none (nonsecreting), minor (nondominant, plurihormonal), single (dominant nonplurihormonal), or plurihormonal (dominant plurihormonal). The hormonal classification was then analyzed for association with COX-2 expression. COX-2 expression was significantly associated with plurihormonal pituitary macroadenomas (p value 0.03). COX-2 expression was significantly associated with expression of luteinizing hormone (p value 0.007) and with expression of thyroid-stimulating hormone (TSH) (p value 0.04). Additionally, COX-2 expression was significantly associated with single-hormone of pituitary adenoma (p value 0.049). The expression of COX-2 in 100% of the normal autopsy pituitary glands establishes an additional central nervous system location of COX-2 expression. EGFR was not expressed in any of the pituitary macroadenomas. The expression of COX-2 in plurihormonal pituitary macroadenomas, particularly those secreting TSH, may be a potential target for treatment in addition to surgical and/or radiotherapy treatment in these benign but clinically significant tumors. COX-2 is expressed in normal autopsy pituitary tissue.