Cerebral Aneurysm Imaging at 7 T with Use of Compressed Sensing.

Abstract

HomeRadiologyVol. 306, No. 3 PreviousNext Reviews and CommentaryFree AccessImages in RadiologyCerebral Aneurysm Imaging at 7 T with Use of Compressed SensingAmit Desai, Erik H. Middlebrooks Amit Desai, Erik H. Middlebrooks Author AffiliationsFrom the Department of Radiology, Mayo Clinic College of Medicine and Science, 4500 San Pablo Rd, Jacksonville, FL 32224.Address correspondence to E.H.M. (email: [email protected]).Amit DesaiErik H. Middlebrooks Published Online:Oct 18 2022https://doi.org/10.1148/radiol.221277MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Online supplemental material is available for this articleA 51-year-old woman was diagnosed with hypertension and found to have stage IV chronic kidney disease (estimated glomerular filtration rate = 24). Her family history was significant for a father with end-stage renal disease and dialysis starting at age 54 years. She was subsequently diagnosed with autosomal dominant polycystic kidney disease. Screening for intracranial aneurysms with intracranial time-of-flight (TOF) MR angiogram (MRA) (Figure) showed a superiorly projecting left ophthalmic artery aneurysm measuring 4 mm from neck to dome (Figure).Images in a 51-year-old woman with autosomal dominant polycystic kidney disease undergoing screening for intracranial aneurysm. Images are (A) cinematic rendering of 1.5-T time-of-flight (TOF) MR angiogram (MRA) versus (B) 7-T TOF MRA. The 7-T MRA better illustrates the complexity of the aneurysm sac, as well as the relationship to the ophthalmic artery origin (arrow).Download as PowerPointOpen in Image Viewer To better characterize the aneurysm, ultra-high resolution TOF MRA was repeated with a 7-T Siemens Terra MRI (Siemens Healthineers) with use of a 32-channel receive and eight-channel transmit head coil (Nova Medical) (Figure, Movie [online], Figure S1 [online]). Relevant imaging parameters include: repetition time of 51 msec, echo time of 5.61 msec, section thickness of 0.3 mm, flip angle of 20°, field of view of 220 × 174 mm, matrix of 704 × 552, and voxel size of 0.3 × 0.3 × 0.3 mm. Image acceleration was performed with compressed sensing with an acceleration factor of 7.2, resulting in an acquisition time of 8 minutes 16 seconds. The combination of ultra-high field strength scanner and compressed sensing allows for a voxel more than 90% smaller than standard clinical TOF MRA at 1.5 T (1).Get the Flash Player to see this video.Movie: Rotational video of cinematic rendered 7T time-of-flight MR angiogram.Download Original Video (2.2 MB)MRA is highly advantageous at 7 T due to the longer T1 relaxation time and increases in the signal-to-noise and contrast-to-noise ratios. The benefits of 7-T MRA have been shown previously, such as an alteration of diagnosis in 66% of cases scanned at 7 T versus 3 T (2). In this case, we have shown the utility of compressed sensing acceleration in 7-T TOF MRA, allowing a nearly 50% reduction in voxel volume over such previously published 7-T MRA cases (2).Disclosures of conflicts of interest: A.D. No relevant relationships. E.H.M. Grants or contracts from clinical trial sponsor by Varian Medical Systems; consultant for unrelated work from Varian Medical Systems and Boston Scientific; paid honorarium for educational lectures from Varian Medical Systems.