Spine

Analysis of 30 Spinal Angiograms Falsely Reported as Normal in 18 Patients with Subsequently Documented Spinal Vascular Malformations

Fellows’ Journal Club

Eighteen patients with 19 lesions underwent a total of 30 negative spinal angiograms. The lesions included 9 epidural arteriovenous fistulas, 8 dural arteriovenous fistulas, and 2 perimedullary arteriovenous fistulas. Seventeen patients underwent endovascular (11) or surgical (6) treatment, with a delay ranging between 1 week and 32 months; the Aminoff-Logue score improved in 76.5%. Causes of the inadequate results included: 1) lesion angiographically documented but not identified (55.6%); 2) region of interest not documented (29.6%); or 3) level investigated but injection technically inadequate (14.8%). All the angiograms falsely reported as normal were caused by correctible, operator-dependent factors.

Clinically Feasible Microstructural MRI to Quantify Cervical Spinal Cord Tissue Injury Using DTI, MT, and T2*-Weighted Imaging: Assessment of Normative Data and Reliability

Fellows’ Journal Club

Forty healthy subjects underwent T2WI, DTI, magnetization transfer, and T2*WI at 3T in <35 minutes using standard hardware and pulse sequences. Cross-sectional area, fractional anisotropy, magnetization transfer ratio, and T2*WI WM/GM signal intensity ratio were calculated. Reliable multiparametric assessment of spinal cord microstructure is possible by using clinically suitable methods. These results establish normalization procedures and pave the way for clinical studies.

Intraforaminal Location of Thoracolumbar Radicular Arteries Providing an Anterior Radiculomedullary Artery Using Flat Panel Catheter Angiotomography

Fellows’ Journal Club

Ninety-four flat panel catheter angiotomography acquisitions obtained during the selective injection of intersegmental arteries providing an anterior radiculomedullary artery were reviewed. The location of radicular arteries could be ascertained in 78/94 flat panel catheter angiotomography acquisitions. Fifty-three acquisitions (67.9%) were on the left side, and 25 (32.1%), on the right, between T2 and L3. The arteries were found in the anterosuperior quadrant in 75 cases (96.2%), in the posterosuperior quadrant in 2 (2.6%), and in the anteroinferior quadrant in 1(1.3%). Needle placement in the anterosuperior quadrant (subpedicular approach) should be avoided during transforaminal epidural steroid injection. The authors advocate the posterolateral approach that allows placing the needle tip away from the documented position of ARMA contributors within the neural foramen, reducing the risk of intra-arterial injection or injury to the spinal vascularization.

MRI Atlas-Based Measurement of Spinal Cord Injury Predicts Outcome in Acute Flaccid Myelitis

Editor’s Choice

Using the open source platform, the “Spinal Cord Toolbox,” the authors sought to correlate measures of GM, WM, and cross-sectional area pathology on T2 MR imaging with motor disability in 9 patients with acute flaccid myelitis. Proportion of GM metrics at the center axial section significantly correlated with measures of motor impairment upon admission and at 3-month follow-up. The proportion of GM extracted across the full lesion segment significantly correlated with initial motor impairment. This is the first atlas-based study to correlate clinical outcomes with segmented measures of T2 signal abnormality in the spinal cord.

Limited Dorsal Myeloschisis and Congenital Dermal Sinus: Comparison of Clinical and MR Imaging Features

Editor’s Choice

These investigators retrospectively reviewed the clinical and MR imaging findings of 12 patients with limited dorsal myeloschisis and 10 patients with congenital dermal sinus. A crater covered with pale epithelium was the most common skin lesion in limited dorsal myeloschisis (83%). Infectious complications were common in congenital dermal sinus (60%), but not found in limited dorsal myeloschisis. They show that limited dorsal myeloschisis has distinct MR imaging features including a visible intrathecal tract with dorsal tenting of the cord at the tract-cord union.

Cervical Spinal Cord DTI Is Improved by Reduced FOV with Specific Balance between the Number of Diffusion Gradient Directions and Averages

Fellows’ Journal Club

The authors evaluated multiple parameters of reduced-FOV DTI to optimize image quality. Fifteen healthy individuals underwent cervical spinal cord 3T MRI, including an anatomic 3D Multi-Echo Recombined Gradient Echo, high-resolution full-FOV DTI with a NEX of 3 and 20 diffusion gradient directions, and 5 sets of reduced-FOV DTIs differently balanced in terms of NEX/number of diffusion gradient directions. Qualitatively, reduced-FOV DTI sequences with a NEX of >5 were significantly better rated than the full-FOV DTI and the reduced-FOV DTI with low NEX (N=3) and a high number of diffusion gradient directions (D=20). Quantitatively, the best trade-off was reached by the reduced-FOV DTI with a NEX of 9 and 9 diffusion gradient directions. They conclude that the best compromise was obtained with a NEX of 9 and 9 diffusion gradient directions, which emphasizes the need for increasing the NEX at the expense of the number of diffusion gradient directions for spinal cord DTI, unlike brain imaging.

Abstract

Figure 2 from paper
Examples of MR images available for qualitative analysis. All the images came from the same subject. Cervical levels are located on 3D T2-MERGE and sagittal T2-spin echo. Fusion of FA − 3D MERGE clearly shows that f-FOV DTI and r-FOV 3N/20D are more distorted and more blurred with less anatomic precision than the other r-FOV images.

BACKGROUND AND PURPOSE

Reduced-FOV DTI is promising for exploring the cervical spinal cord, but the optimal set of parameters needs to be clarified. We hypothesized that the number of excitations should be favored over the number of diffusion gradient directions regarding the strong orientation of the cord in a single rostrocaudal axis.

MATERIALS AND METHODS

Fifteen healthy individuals underwent cervical spinal cord MR imaging at 3T, including an anatomic 3D-Multi-Echo Recombined Gradient Echo, high-resolution full-FOV DTI with a NEX of 3 and 20 diffusion gradient

Evaluation of Focal Cervical Spinal Cord Lesions in Multiple Sclerosis: Comparison of White Matter–Suppressed T1 Inversion Recovery Sequence versus Conventional STIR and Proton Density–Weighted Turbo Spin-Echo Sequences

Fellows’ Journal Club

The authors performed a retrospective blinded analysis of cervical cord MR imaging examinations of 50 patients with MS. In each patient, 2 neuroradiologists measured the number of focal lesions and overall lesion conspicuity in the STIR/proton density–weighted TSE and WM-suppressed T1 inversion recovery sequence groups. Substantial interreader agreement was noted on the WM-suppressed T1 inversion recovery sequence compared with STIR/proton density–weighted TSE. Average lesion conspicuity was better on the WM-suppressed T1 inversion recovery sequence. Additionally, spurious lesions were more common on STIR/proton density–weighted TSE than on the WM-suppressed T1 inversion recovery sequence. They conclude that the WM-suppressed T1 inversion recovery sequence could potentially be substituted for either STIR or proton density–weighted TSE sequences in routine clinical protocols.

Abstract

Figure 2 from paper
Example of improved lesion conspicuity in a 45-year-old woman with a relapsing-remitting subtype of multiple sclerosis. Sagittal STIR (A) and PDWTSE (B) images show a focal lesion in the dorsum of the cord at the lower C2 level (arrow). Anterior to this lesion, there is linear hyperintensity in the center of the cord usually noted on the STIR/PDWTSE sequence group (arrowhead). The central canal is more homogeneous in signal intensity on sagittal WMS image (C); this feature improves the definition of the superior margin of the dorsal lesion. An additional focal lesion is noted in the ventral cord at the upper C2 level (open arrow), better identified on the WMS sequence (C).

BACKGROUND AND PURPOSE

Conventional MR imaging of the cervical spinal cord in MS is challenged by numerous artifacts and interreader variability in lesion counts. This study compares the relatively novel WM-suppressed T1 inversion recovery sequence with STIR and proton density–weighted TSE sequences in the evaluation of cervical cord lesions in patients with MS.

MATERIALS AND METHODS

Retrospective blinded analysis of cervical cord MR imaging examinations of 50

Synopsis of Spine Surgery

An HS, Sing K, eds. Synopsis of Spine Surgery. 3rd ed. Thieme; 2016; 384 pp; 313 ill; $89.99

an_singh_synopsis-spin-surg_coverSynopsis of Spine Surgery by Drs. An and Singh is a short, 384-page softcover that highlights key concepts in spine surgery. Material is covered in a bullet-like format and accompanied by drawings and some imaging (CT, MR, plain radiographs). Twenty six chapters cover subjects from the craniovertebral junction to the sacral region. Cartoons also accompany many of the surgical descriptions, making the approaches to the spine, in all areas, more understandable.

Probably of greatest interest to a radiologist would be the chapters on pediatric and adult spine deformities. Here we gain an appreciation of what is felt to be of greatest importance to the surgeon from an imaging point of view. Concepts and measurements of balance lines, pelvic incidence/tilt, and other metrics are shown and discussed. How instrumentation is positioned and the effect of hardware and biologics is instructive.

This book is intended for surgical trainees in orthopedics and has limited utility for neuroradiologists.…

Imaging Psoas Sign in Lumbar Spinal Infections: Evaluation of Diagnostic Accuracy and Comparison with Established Imaging Characteristics

Fellows’ Journal Club

In this retrospective case-control study, the authors evaluated lumbar spine MR imagings during a 30-month period that were requested for the evaluation of discitis-osteomyelitis. Fifty age-matched control patients were compared with 51 biopsy-proved or clinically diagnosed patients with discitis-osteomyelitis. The investigators assessed the randomly organized MR imaging examinations for abnormalities of the psoas musculature, vertebral bodies, discs, and epidural space. Psoas T2 hyperintensity demonstrated high sensitivity (92%), specificity (92%), and positive likelihood ratio (11.5). They conclude that psoas T2 hyperintensity, the imaging psoas sign, is highly correlated with discitis-osteomyelitis.

Abstract

Figure 1 from Ledbetter et al. Imaging Psoas Sign in Lumbar Spinal Infections: Evaluation of Diagnostic Accuracy and Comparison with Established Imaging Characteristics
Click image to enlarge

BACKGROUND AND PURPOSE

Lumbar discitis-osteomyelitis has imaging characteristics than can overlap with noninfectious causes of back pain. Our aim was to determine the added accuracy of psoas musculature T2 hyperintensity (imaging psoas sign) in the MR imaging diagnosis of lumbar discitis-osteomyelitis.

MATERIALS AND METHODS

This retrospective case-control study evaluated lumbar spine MR imaging examinations, during a 30-month period, that were requested for the evaluation of discitis-osteomyelitis. Of this pool, 50 age-matched control patients were compared with 51 biopsy-proved or clinically diagnosed patients with discitis-osteomyelitis. Two reviewers, blinded to the clinical information, assessed the randomly organized MR imaging examinations for abnormalities of the psoas musculature, vertebral bodies, discs, and epidural space.

RESULTS

Psoas T2 hyperintensity demonstrated a high sensitivity (92.1%; 95% CI, 80%–97.4%) and specificity (92%; 95% CI, 80%–97.4%), high positive likelihood ratio (11.5; 95% CI, 4.5–29.6), low negative likelihood ratio (0.09; 95% CI, 0.03–0.20), and individual area under the receiver operating characteristic curve of 0.92; 95% CI, 0.87–0.97. Identification of psoas T2 abnormality significantly improved (P = .02) the diagnostic accuracy of discitis-osteomyelitis in noncontrast examinations from an area under the receiver operator characteristic curve of the established variables (vertebral body T2 and T1 signal, endplate integrity, disc T2 signal, and disc

ASSR 2016 Gold Medal: Wade H. M. Wong

PRESS RELEASE

The American Society of Spine Radiology Presents 2016 Gold Medal to Wade H. M. Wong, D.O., FACR, FAOCR During 2016 Annual Symposium

wade_wong
Wade H. M. Wong, DO, FACR, FAOCR

The American Society of Spine Radiology (ASSR) presented the Society’s 2016 Gold Medal to Wade H. M. Wong, D.O., FACR, FAOCR on February 20 during the ASSR 2016 Annual Symposium, February 18-21 at the Hyatt Regency Coconut Point Resort & Spa in Bonita Springs, Florida. Dr. Wong is the fourth recipient of the ASSR Gold Medal, which was established in 2013.  The ASSR Gold Medal is awarded annually in recognition of outstanding contributions to the Society and to spine radiology.

Dr. Wong is a Past President of the American Society of Spine Radiology. He is also a Past President of the Western Neuroradiological Society (WNRS) and of the American Osteopathic College of Radiology (AOCR.)  Dr. Wong is a Fellow of the American College of Radiology (ACR) and a Fellow of the AOCR.  He is a Senior Member of the American Society of Neuroradiology (ASNR), WNRS, and the Society for Interventional Surgery (SNIS.)

Early in his involvement the ASSR, Dr. Wong initiated the hands-on training courses for the ASSR starting in 1999 at the Annual Symposium.  About the same time he also introduced similar hands-on spine interventional courses for the RSNA, which led to his becoming the Chairman of the How-to and Hands-On Refresher Courses.

Dr. Wong is Professor Emeritus of Radiology at the University of California, San Diego. His involvement in teaching has been his hallmark. He is a three-time recipient of the Silver Spoon and two-time recipient of the Teacher of the Year Award for Neurosciences at UCSD.  He is the recipient of the Trenery Medal for outstanding Lecturing. For 2015, Dr. Wong was selected to be the …