High Resolution MR Angiography of the Posterior Cerebral Circulation: Variants, Incidence and Clinical Impact

Objective: In the embryonic period, several developmental anomalies of the posterior cerebral circulation might occur. Digital subtractive angiography used to be the imaging technique of choice for the illustration of such variations. Nowadays, the development of MR imaging has led to a new entry in the diagnostic archer’s quivery, the MR an- giography, with which most of these variations may be diagnosed. Purpose of this study is to illustrate these anatomic variants, their incidence and their potential clinical significance. Materials and Methods: We retrospectively reviewed 282 MR angiographies performed in our institution, in order to assess the posterior cerebral circulation. The imaging findings (including both normal development and variations) were depicted. Results: In our study 61/282 (21.63%) MR angiographies were positive for imaging findings concerning variations of the vertebrobasilar system. These variations included abnormal origin of the vertebral artery (0.7%), unilateral aplasia or hypoplasia (8.86%), unilateral aplasia or hypoplasia of the distal part of the vertebral artery (3.85%), and unilateral or bilateral fetal posterior cerebral artery (7.7%). These results show that anatomic variations of the posterior cerebral circulation are not very uncommon in the population. Conclusion: High resolution Magnetic Resonance Angiography provides excellent interpretation of the vertebral arteries, allowing depiction of all anatomic variations. Knowing these anatomic variations is important, espe- cially for clinicians and patients planning a surgical operation or an interventional radiology technique. Furthermore, it contributes to avoiding potential diagnostic pitfalls or to explaining unusual acute vascular cerebral events.

Percutaneous, computed tomography guided neurolysis using continuous radiofrequency for pain reduction in oncologic patients

Aim:This study evaluates the efficacy and safety of percutaneous computed tomography(CT)-guided neurolysis using continuous radiofrequency for pain reduction in oncologic patients.Methods:Over the course of 16 months,22 patients underwent radiofrequency neurolysis as palliative therapy for pain reduction in celiac and splachnic plexus(n=9),thoracic(n=1),lumbar(n=2)and superior hypogastric plexus(n=5),as well as stellate ganglion(n=5).Pain levels before treatment,one week after treatment,and at the last follow-up(average follow-up 6 months)were compared by means of a Numeric Visual Scale(NVS)questionnaire and a Brief Pain Inventory(Short Form)questionnaire.Results:Median procedure time was 44 min.Median number of CT scans,performed to control correct positioning of the cannula and precise electrode placement,was 8.Pain scores of questionnaires prior to treatment(mean value 9.50 NVS units,range 8-10 NVS units)and post treatment(mean value 3.27 NVS units,range 2-6 NVS units)showed a mean decrease of 6.23 NVS units in terms of pain reduction and life quality improvement(P<0.05).Overall mobility improved in 18/18(100%)patients.No complication was observed.Conclusion:This study concludes that CT-guided neurolysis by means of continuous radiofrequency ablation is a safe and efficient technique for pain palliation in oncologic patients.