Fellows Journal Club:

A.T. Vertinsky, N.E. Schwartz, N.J. Fischbein, J. Rosenberg, G.W. Albers, and G. Zaharchuk
Comparison of Multidetector CT Angiography and MR Imaging of Cervical Artery Dissection
http://www.ajnr.org/cgi/content/full/29/9/1753

My impression is that most of us use either CTA or MRA for the diagnosis of acute cervical artery dissections initially but still believe that catheter angiography is the ‘gold standard’. In this retrospective study the authors analyzed images from 18 patients with 25 dissections imaged non-invasively and also rated each vessels on the basis of which imaging technique better displayed the abnormalities. In 11 instances both CTA and MRA were judged equal, in 13 CTA was better and only in one instance MRA was preferred. MR may be complementary to CTA particularly due to the fact that ischemia is better visualized with it.

S. Gultekin, H. Celik, S. Akpek, Y. Oner, T. Gumus, and N. Tokgoz
Vascular Loops at the Cerebellopontine Angle: Is There a Correlation with Tinnitus?
http://www.ajnr.org/cgi/content/full/29/9/1746

The discussion continues…do vascular loops resulting in compression of the 8th cranial nerves are the cause of tinnitus? In this prospective study, the authors studied 58 patients with unexplained tinnitus using high-resolution T2 images and compared their results with those in 44 age-matched controls. In addition, contrast enhanced imaging was done in all. The authors evaluated the anatomy of the vascular loops, their contact and the angulation of the nerves. There were no differences in any of these parameters in both groups.

F. Runck, R.P. Steiner, W.A. Bautz, and M.M. Lell
MR Imaging: Influence of Imaging Technique and Postprocessing on Measurement of Internal Carotid Artery Stenosis
http://www.ajnr.org/cgi/content/full/29/9/1736

The authors looked at the effects that different MRA techniques have on the measurement of carotid stenoses. They analyzed images obtained with three different post processing methods in 55 patients with symptomatic cervical carotid stenoses. Stenosis grading was found to be independent of the postprocessing technique except for comparison of CE-MPR with CE volume-rendering, with the volume-rendering technique resulting in higher stenosis values. MPR seems to be best-suited for measurement of ICA stenosis. Parameter setting is critical with volume-rendering, in which stenosis values were consistently higher compared with the other methods.

 
Editor’s Choices:

M.H. Lee, H.-J. Kim, I.H. Lee, S.T. Kim, P. Jeon, and K.H. Kim
Prevalence and Appearance of the Posterior Wall Defects of the Temporal Bone Caused by Presumed Arachnoid Granulations and Their Clinical Significance: CT Findings
http://www.ajnr.org/cgi/content/full/29/9/1704

Atypical arachnoid granulations are receiving attention in the literature as they are common, may be confused with other lesions and may occasionally cause symptoms. The authors retrospectively looked at 1255 studies to determine the prevalence and appearance of arachnoid granulations remodeling the posterior surface of the petrous pyramids. They found them 2.4% of patients, particularly older ones and in the lateral 1.3 of the petrous pyramid. The arachnoid granulations were the cause of CSF leaks in two instances.

R.P.H. Bokkers, P.J. van Laar, K.C.C. van de Ven, L.J. Kapelle, C.J.M. Klijn, and J. Hendrikse
Arterial Spin-Labeling MR Imaging Measurements of Timing Parameters in Patients with a Carotid Artery Occlusion
http://www.ajnr.org/cgi/content/full/29/9/1698

ASL techniques are becoming more robust and are being used more frequently because no exogenous contrast is needed. However, the operator may vary the results by altering its timing parameters. These investigators examined 15 patients with symptomatic carotid artery occlusions with ASL using multiple delay times to measure CBF. In them, frontal CBF was lower and trailing edge (end of labeled bolus) was longer in the ipsilateral hemisphere. In patients with leptomeningeal collaterals (as seen on DSA), the trailing edge was longer in the frontal region. It seems that the most impaired territory in these patients was the frontal lobe.

A.E. Rad and D.F. Kallmes
Pain Relief Following Vertebroplasty in Patients with and without Localizing Tenderness on Palpation
http://www.ajnr.org/cgi/content/full/29/9/1622

Is focal point pain a pre-requisite for performing percutaneous vertebroplasties? In this retrospective study the author evaluated pain and activity in three groups of patients: 534 with focal pain over treated fractures, 119 with pain beyond the fractured vertebra or over non-treated vertebrae, and 42 without focal pain but with pain over non-treated vertebrae. They concluded that presence of focal-point tenderness does not predict superior clinical response following vertebroplasty compared with the absence of focal tenderness and that even patients without focal tenderness may benefit from vertebroplasty.