Editor’s Choices

Stent-Assisted Coiling of Complex Middle Cerebral Artery Aneurysms: Initial and Midterm Results • J.-F. Vendrell, V. Costalat, H. Brunel, C. Riquelme, and A. Bonafe
Complex middle cerebral artery aneurysms are difficult to treat surgically or via endovascular approaches. Here, the authors treated 52 such lesions (41 aneurysms were unruptured and 11 had previously bled) via a combined approach that included stenting and coil embolization. They were able to coil 50 aneurysms after stent deployment and the most common immediate complication was intra-stent clot formation. At 14 months, follow-up showed 7 recurrences and 5 of these were re-treated. No aneurysm bled during this period of time and no intra-stent stenoses developed. The authors concluded that their technique is feasible, safe, and durable.

Recovery of Ophthalmoplegia after Endovascular Treatment of Intracranial Aneurysms • V. Panagiotopoulos, S.C. Ladd, E. Gizewski, S. Asgari, E.I. Sandalcioglu, M. Forsting, and I. Wanke
Do patients with a cranial nerve palsy induced by the presence of a neighboring aneurysm recover after coiling? This is, of course, handy information to have when talking to patients. These authors assessed the parameters of aneurysms and their treatments that influence recovery of ophthalmoplegia. Ten of the patients studied had bled whereas 20 patients had unruptured aneurysms. The mean interval between onset of symptoms and coiling was 48 days. Fifty percent of patients recovered clinically but the others had some residual cranial nerve deficits. Patient age, neck size, and time of treatment did not influence prognosis but those with smaller aneurysms had a better outcome. Only the initial degree of symptoms was a significant prognostic factor.

Acute Hyperammonemic Encephalopathy in Adults: Imaging Findings • J.M. U-King-Im, E. Yu, E. Bartlett, R. Soobrah, and W. Kucharczyk
If you work in the hospital where organ transplants are done, you have probably seen this condition (even if you did not recognize it!). Unless identified and treated early, this encephalopathy has significant morbidity and mortality. In this short retrospective review, 4 patients with liver failure and plasma ammonia levels ranging from 55-168 umol/L were studied with MR imaging. The findings were significantly similar to those seen with anoxia, that is, diffuse gray and subcortical white matter involvement. The abnormalities were more pronounced in the insular cortex and cingulate gyri, a finding that helps distinguish acute hyperammonemic encephalopathy from other diseases.

Fellows’ Journal Club

CT Angiography for Differentiation between Intracerebral and Intra-Sylvian Hematoma in Patients with Ruptured Middle Cerebral Artery Aneurysms • J.J. van der Zande, J. Hendrikse, and G.J.E. Rinkel
Somewhere between 30–50% of patients with middle cerebral artery aneurysms will have intracerebral hematomas while others have intra-Sylvian hematomas (that is, in the subarachnoid space). Apparently the prognosis is different for each type of hematoma, and in patients with ICH it depends on the initial brain damage whereas in those with intra-Sylvian hematoma it is related to secondary ischemia. Thus, initial treatment may be different for each type of presentation. Here, the authors used CT angiography to differentiate between these hematomas and found that enhancing blood vessels clearly identified the hematoma as being intra-Sylvian, and absence of enhancing blood vessels placed it intra-axially.

MR Imaging of Partially Thrombosed Cerebral Aneurysms: Characteristics and Evolution • A.J. Martin, S.W. Hetts, W.P. Dillon, R.T. Higashida, V. Halbach, C.F. Dowd, M.T. Lawton, and D. Saloner
Noninvasive imaging of partially thrombosed aneurysm is important because it delineates the true lumen and provides information about the walls. The authors examined 9 patients twice each, separated by 4–22 months, and found thrombus in all MR imaging sequences. Thrombus was better seen on T1-weighted images whereas differentiation between lumen and thrombus was better depicted on the steady-state sequence. Peripheral high T1 signal in the clot was typical and all clots remained stable during the time period between imaging studies. Thus, MR imaging may be used to evaluate aneurysm size, thrombosed portions, and growth and may affect treatment decisions in these patients.

Evaluation of Image Quality of a 32-Channel versus a 12-Channel Head Coil at 1.5T for MR Imaging of the Brain • P.T. Parikh, G.S. Sandhu, K.A. Blackham, M.D. Coffey, D. Hsu, K. Liu, J. Jesberger, M. Griswold, and J.L. Sunshine
How much better is a 32-channel head coil at 1.5T when compared with a 12-channel coil? Does the higher spatial resolution and signal-to-noise ratio affect clinical interpretations? Here, 21 patients were consecutively imaged with both coils and the results in axial T2, T1, fluid-attenuated inversion recovery, and diffusion-weighted imaging sequences were assessed. Most of the improvement was seen in the FLAIR, DWI, and T2 sequences and to a lesser extent on T1 images. Artifacts were similar with both coils. Conclusion: Improvements in SNR and spatial resolution attributed to image acquisition with a 32-channel head coil are paralleled by perceived improvements in image quality.