Editor’s Choices
Differentiating between true neoplasms and lesions that look like neoplasms is difficult with conventional imaging methods. In this study, the authors investigated the clinical utility of MR spectroscopy in this setting. They examined 68 glial brain tumors and 16 pseudotumoral lesions (mostly demyelinating and infarctions). On short echo-time MR spectroscopy, pseudotumors showed higher myo-inositol than tumors, and on long echo-time MRS, tumors showed higher levels of choline but lower levels of N-acetylaspartate and glutamine/glutamate. All these results were statistically significant; thus, MRS improves accuracy and confidence in this situation.
Clot burden and degree of collateral flow are important determinants in the outcome of stroke patients. These authors created 2 new scales to take into consideration clot burden score and collateral score. They reviewed imaging studies in 121 patients with anterior circulation infarcts presenting within 3 hours of ictus. Not surprisingly, patients with higher scores on these 2 scales had smaller pretreatment perfusion defects, smaller final infarct volume, and better outcome. The role collaterals play in the final outcome of stroke patients is finally receiving the attention it deserves.
Results of the treatment of dural arteriovenous fistulas can be very good. In this article, the authors evaluated their experience in treating these lesions using Onyx. Presentation, angiographic features, treatment, and outcome were reviewed in 40 patients. Total lesion obliteration was achieved in 25 patients and residual shunts remained in 15. Complications occurred in 9 patients; all were nonfatal, but some were serious. Complete cure cannot be achieved in all patients by using Onyx and the potential for serious complications exists.
Fellows’ Journal Club
I chose this article because it is my impression that most lumbar punctures in training programs are done by residents and/or fellows. In this retrospective analysis, the authors aimed to determine if patient age, gender, gauge of needle, and level of puncture were associated with increased incidence of traumatic LPs. The overall rate of traumatic LPs was 13.3%; associated factors were patients older than 80 years and procedure done at the L4-5 level. Needle gauge and gender were not associated with an increased incidence of a bloody tap.
Here is one more article on the utility of diffusion-weighted imaging in the diagnosis of head and neck lesions, this time primary parotid tumors. In a large prospective study, the investigators assessed 149 consecutive parotid lesions with DWI and then obtained histologic diagnosis. Of these, 139 were proven parotid tumors and pleomorphic adenomas showing significantly higher apparent diffusion coefficient than all other entities except myoepithelial adenomas, lipomas, and salivary duct carcinomas. Other carcinomas could not be differentiated from Warthin tumors. The authors remind us the diagnosis of parotid masses should not be based solely on DWI features.
Residents and fellows are often the first to make the diagnosis of acute cerebral infarction. One of the most common MR imaging findings in acute infarction is intra-arterial hyperintensity on fluid-attenuated inversion recovery. Because there is no clear explanation for this finding, the authors studied the pathophysiologic and hemodynamic correlates on MR imaging and angiography in 74 patients. The hyperintensity on FLAIR correlated mostly with the presence of collateral circulation and was seen proximal or distal to a stenosis or occlusion.
