Table of Contents
Review Article
- MR Thermometry during Transcranial MR Imaging–Guided Focused Ultrasound Procedures: A Review
Transcranial MR imaging-guided focused ultrasound enables precise delivery of energy through an intact skull for the treatment of various neurologic disorders. Real-time and noninvasive MR thermometry is critical to achieve precise and controlled transcranial focused ultrasound treatments. This article provides an updated review on clinically applicable considerations of proton resonance frequency MR thermometry, including pitfalls and limitations, to avoid complications during MRgFUS procedures.
State of Practice
General Contents
- The Choroid Plexus as an Alternative Locus for the Identification of the Arterial Input Function for Calculating Cerebral Perfusion Metrics Using MRI
MR imaging-based cerebral perfusion metrics can be obtained by tracing a contrast bolus through the brain microvasculature. The authors compared the calculated resting relative perfusion metrics obtained from the choroid plexus (CP) with those obtained from the middle cerebral artery (MCA) in healthy participants and patients with glioma. The findings of this study suggest that an arterial input function chosen from within the CP is comparable with one chosen from the MCA and may be an alternative, particularly when there is no suitable MCA location to interrogate.
- CTA and CTP for Detecting Distal Medium Vessel Occlusions: A Systematic Review and Meta-analysis
This systematic review and meta-analysis aimed to compare the diagnostic test accuracy for CTA and CTP in the detection of distal medium vessel occlusion. The study found consistent evidence for a higher sensitivity in detecting distal medium vessel occlusion, particularly in arteries beyond the M2 segment of MCA, with multiphase CTA or CTP compared with single-phase CTA.
- Central Vein Sign in Multiple Sclerosis: A Comparison Study of the Diagnostic Performance of 3T versus 7T MRI
The perivenular relationship of MS demyelinating plaque is thought to represent one of the most histologically specific features of MS. In this retrospective study, the authors directly compared the utility of 3T SWI, 7T SWI, and T2&WI in detecting central vein sign (CVS) and the ability of CVS to differentiate MS from nonspecific WM lesions in patients without MS (presumed vascular origin) in a large cohort of patients. They found that 7T SWI and T2* (73% and 87% of lesions, respectively) showed significantly more CVSs than 3T (31%). Both T2*WI and 7T SWI sequences were 100% accurate (AUC=1.0) for diagnosing MS from WM lesions of presumed vascular origin, which was superior to 3T (AUC=0.975).
- Temporal Characteristics of CSF-Venous Fistulas on Dynamic Decubitus CT Myelography: A Retrospective Multi-Institution Cohort Study
This retrospective multi-institution cohort study analyzed the temporal features of CSF-venous fistula (CVF) visualization on dynamic decubitus CT myelography (dCTM) in 48 patients. The results showed that most CVFs were visible on first or subsequent phases of dCTM, but approximately 1 in 8 were only visible on either the early or delayed phase. The authors conclude that acquiring greater than 1 phase of imaging increases the sensitivity of dCTM by increasing its temporal resolution.
- Frequency of Coexistent Spinal Segment Variants: Retrospective Analysis in Asymptomatic Young Adults
Spinal segment variants are highly prevalent and can potentially lead to incorrect spinal enumeration. The objective of this study was to assess the prevalence of spinal segment variants and to study the potential association among these variants in an asymptomatic population. The results showed that the spinal segment variants are highly prevalent, ranging from 4.2% (cervical rib) to 26.4% (LSTV), and that these variants are associated with each other. The authors recommend further imaging for spine enumeration before interventions or operations when a spinal segment variant is identified.
