Comparison between 2D and 3D MEDIC for human cervical spinal cord MRI at 3T

Diagnostic utility of 3D MRI sequences in the assessment of central, recess and foraminal stenoses of the spine: a systematic review

OBJECTIVE

To perform a systematic literature review on the diagnostic utility of 3D MRI sequences in the assessment of central canal, recess and foraminal stenosis in the spine.

METHODS

The databases PubMed, MEDLINE (via OVID) and The Cochrane Central Register of Controlled Trials, were searched for studies that investigated the diagnostic use of 3D MRI to evaluate stenoses in various parts of the spine in humans. Three reviewers examined the literature and conducted systematic review according to PRISMA 2020 guidelines.

RESULTS

Thirty studies were retrieved from 2 595 publications for this systematic review. The overall diagnostic performance of 3D MRI outperformed the conventional 2D MRI with reported sensitivities ranging from 79 to 100% and specificities ranging from 86 to 100% regarding the evaluation of central, recess and foraminal stenoses. In general, high level of agreement (both intra- and interrater) regarding visibility and pathology on 3D sequences was reported. Studies show that well-optimized 3D sequences allow the use of higher spatial resolution, similar scan time and increased SNR and CNR when compared to corresponding 2D sequences. However, the benefit of 3D sequences is in the additional information provided by them and in the possibility to save total protocol scan times.

CONCLUSION

The literature on the spine 3D MRI assessment of stenoses is heterogeneous with varying MRI protocols and diagnostic results. However, the 3D sequences offer similar or superior detection of stenoses with high reliability. Especially, the advantage of 3D MRI seems to be the better evaluation of recess stenoses.

Focal Spinal Nondisjunctional Disorders: Including a Discussion on the Embryogenesis of Cranial Focal Nondisjunctional Lesions

The publication of a comprehensive report on limited dorsal myeloschisis by the senior author (DP) in 2010 has brought full attention to the concept of limited myeloschisis that he first formulated in 1992 and ignited interests in the whole spectrum of focal spinal nondisjunctional disorders. Now that focal nondisjunctional disorders have become well known, new clinical reports on these conditions or relevant subjects are frequently seen. Here we present an updated review on the full spectrum of focal spinal nondisjunctional disorders and extend the scope to include a discussion on the embryogenesis of cranial focal nondisjunctional malformations.

Optimized multi-echo gradient-echo magnetic resonance imaging for gray and white matter segmentation in the lumbosacral cord at 3 T

Atrophy in the spinal cord (SC), gray (GM) and white matter (WM) is typically measured in-vivo by image segmentation on multi-echo gradient-echo magnetic resonance images. The aim of this study was to establish an acquisition and analysis protocol for optimal SC and GM segmentation in the lumbosacral cord at 3 T. Ten healthy volunteers underwent imaging of the lumbosacral cord using a 3D spoiled multi-echo gradient-echo sequence (Siemens FLASH, with 5 echoes and 8 repetitions) on a Siemens Prisma 3 T scanner. Optimal numbers of successive echoes and signal averages were investigated comparing signal-to-noise (SNR) and contrast-to-noise ratio (CNR) values as well as qualitative ratings for segmentability by experts. The combination of 5 successive echoes yielded the highest CNR between WM and cerebrospinal fluid and the highest rating for SC segmentability. The combination of 3 and 4 successive echoes yielded the highest CNR between GM and WM and the highest rating for GM segmentability in the lumbosacral enlargement and conus medullaris, respectively. For segmenting the SC and GM in the same image, we suggest combining 3 successive echoes. For SC or GM segmentation only, we recommend combining 5 or 3 successive echoes, respectively. Six signal averages yielded good contrast for reliable SC and GM segmentation in all subjects. Clinical applications could benefit from these recommendations as they allow for accurate SC and GM segmentation in the lumbosacral cord.

Vitamin B12 deficiency in the setting of nitrous oxide abuse: diagnostic challenges and treatment options in patients presenting with subacute neurological complications

OBJECTIVE

It is well recognized that nitrous oxide abuse can lead to vitamin B₁₂ deficiency presenting with neurological complications. Nevertheless, establishing this diagnosis can be challenging, and treatment guidelines are lacking.

METHODS

In this paper, we present a case series of eight patients and discuss the diagnostic challenges and treatment options for vitamin B₁₂ deficiency due to nitrous oxide abuse presenting with neurologic complications.

RESULTS

Biochemical findings are not always straightforward and complementary testing is often necessary. Magnetic Resonance Imaging (MRI) revealed a longitudinally myelopathy extending over a long segment typically involving the dorsal columns of the cervical cord. To increase the lesion conspicuity, dedicated MRI sequences are needed. In our practice, we recommend the use of T2-weighted images (WI) with fat suppression (FS). Treatment consists of cessation of nitrous oxide abuse and supplementation with intramuscular injections of cobalamin. Due to a lack of treatment guidelines, we also describe the treatment schedule used in our neurology clinic and give a brief overview of treatment options suggested in the literature.

CONCLUSION

We described diagnostic steps en treatment plans in patients presenting with subacute neurological complications due to nitrous oxide abuse.

ABBREVIATIONS

crea: creatinine; HCy: homocysteine; MCA: 2-methylcitric acid; MMA: methylmalonic acid; MRI: magnetic resonance imaging; SEP: somatosensory evoked potentials.

3D MRI of the Spine

Three-dimensional (3D) magnetic resonance imaging of the spine is now clinically feasible due to technological advancements. Its advantages over two-dimensional imaging include higher in-plane spatial resolution and the ability for reformation in any plane that enables time savings in image acquisition and aids more accurate interpretation. Multispectral 3D techniques for imaging around metal are sometimes useful for evaluating anatomy adjacent to spinal fixation hardware. 3D gradient-recalled echo sequences, including ultrashort or zero time to echo sequences, can provide osseous detail similar to conventional computed tomography.