Spine

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 …

Treatment of 213 Patients with Symptomatic Tarlov Cysts by CT-Guided Percutaneous Injection of Fibrin Sealant

Fellows’ Journal Club

Editor’s Comment

This cohort study assesses outcomes in patients who underwent CT-guided aspiration and injection of sacral Tarlov cysts at Johns Hopkins Hospital from 2003–2013. A total of 289 cysts were treated in 213 consecutive patients, with 83% followed for 3–6 years. One year postprocedure, excellent results were obtained in 104 patients (54.2% of patients followed), and good or satisfactory results were obtained in 53 patients (27.6%).

Abstract

BACKGROUND AND PURPOSE

There has been a steady progression of case reports and a small surgical series that report successful surgical treatment of Tarlov cysts with concomitant relief of patients’ symptoms and improvement in their neurological dysfunction, yet patients are still told that these lesions are asymptomatic by physicians. The purpose of this study was to analyze the efficacy and safety of intervention in 213 consecutive patients with symptomatic Tarlov cysts treated by CT-guided 2-needle cyst aspiration and fibrin sealing.

MATERIALS AND METHODS

This study was designed to assess outcomes in patients who underwent CT-guided aspiration and injection of ≥1 sacral Tarlov cyst at Johns Hopkins Hospital between 2003 and 2013. In all, 289 cysts were treated in 213 consecutive patients. All these patients were followed for at least 6 months, 90% were followed for 1 year, and 83% were followed for 3–6 years. The aspiration-injection procedure used 2 needles and was performed with the patients under local anesthesia and intravenous anesthesia. In the fibrin-injection stage of the procedure, a commercially available fibrin sealant was injected into the cyst through the deep needle (Tisseel VH).

RESULTS

One year postprocedure, excellent results were obtained in 104 patients (54.2% of patients followed), and good or satisfactory results were obtained in 53 patients (27.6%). Thus, 157 patients (81.8%) in all were initially satisfied with the outcome of treatment. At 3–6 years postprocedure,

Handbook of Spine Surgery

Baaj AA, Mummaneni PV, Uribe JS, Vaccaro AR, Greenberg MS, eds. Handbook of Spine Surgery. 2nd ed. Thieme; 2016; 558 pp; $99.99

baaj_spine-surgery_coverThe second edition of Handbook of Spine Surgery is edited by the same 5 orthopedic surgeons—who are from 4 different institutions—responsible for the first edition, which was published in 2012. This handbook is just under 100 pages longer (total of 558 pages) than the first edition and is divided into sections similar to the prior edition: Anatomy (6 chapters), Clinical Issues (11 chapters), Spine Pathology/Abnormalities (16 chapters), Surgical Techniques (39 chapters), and special short chapters on positioning, orthoses, and outcomes. Each chapter is written in a bulletpoint format, highlighting key points, concepts, specific items relative to the subject, tables (as needed), diagrams, radiology images (as warranted), a variable number of clinical questions with answers, and short reference lists.

For the radiologist, this is a good way to develop—by way of by diagrams, imaging, and descriptions—an understanding of many surgical techniques use in spine surgery. While radiologists easily recognize the imaging features of, for example, cervical laminoplasties, anterior cervical diskectomies, arthroplasties, Chiari decompressions, various osteotomies, pedicle instrumentation, and TLIFs/PLIFs, among others, few appreciate the actual steps required in achieving the end result. This handbook takes one through the major steps involved in these and many other procedures. Certainly, having some deeper understanding of what goes into each surgery makes the interpretation of the postoperative images more interesting and, potentially, more accurate.

There are other good features of this concise handbook, such as a short chapter on the essentials of spine biologics, where autographs, allographs, osteoconductives, osteoinductives, BMP, and fusion issues are outlined along with the risks/benefits of each, plus chapters on features of degenerative disease from a surgeon’s perspective; considerations given in the evaluation, workup, or potential corrections …

Spine Cryoablation: Pain Palliation and Local Tumor Control for Vertebral Metastases

Editor’s Choice

Editor’s Comment

This is a retrospective study of imaging-guided spine cryoablation that was performed on 31 vertebral metastases in 14 patients. The lesions were refractory to conventional chemoradiation therapy or analgesics and were ablated to achieve pain palliation and local tumor control. The procedures were performed with the patient under conscious sedation (13 patients) or general anesthesia in 1 case. Postcryoablation MR imaging and PET/CT imaging were available for all patients. Spinal nerve and soft-tissue thermal protection techniques were implemented in all ablations (epidural or neuroforaminal carbon dioxide or warmed 5% dextrose). There were statistically significant decreases in the median numeric pain rating scale score and analgesic usage at 1-week, 1-month, and 3-month time points. Local tumor control was achieved in 96.7% (30/31) of tumors.

Abstract

Figure from Tomasian et al -- Editor's Choice
A 69-year-old man with metastatic follicular thyroid carcinoma and painful right S1 metastasis. Transaxial iodine-131 SPECT CT image demonstrates increased radiopharmaceutical uptake in the right S1, compatible with metastasis (A). Transaxial intraprocedural CT images demonstrate coaxial placement of 2 Perc-17 Endocare cryoprobes within the right S1 lesion (B and C, short arrow). Thermal protection is performed by placement of a thermocouple and a spinal needle within the right S1 neuroforamen (B, long black arrow) and injection of carbon dioxide into the right S1 neuroforamen with epidural extension (B and C, white arrows). A 24-month postcryoablation FDG PET/CT demonstrates complete local tumor control with no evidence of metabolically active tumor (D, arrow).

BACKGROUND AND PURPOSE

Percutaneous cryoablation has emerged as a minimally invasive technique for the management of osseous metastases. The purpose of this study was to assess the safety and effectiveness of percutaneous imaging-guided spine cryoablation for pain palliation and local tumor control for vertebral metastases.

MATERIALS AND METHODS

Imaging-guided spine cryoablation was performed in 14 patients (31 tumors) with vertebral metastases

Thoracolumbar Spine Trauma, AOSpine Masters Series

Vialle LR, ed. Bellabarba C, Kandziora F, guest eds. Thoracolumbar Spine Trauma. AOSpine Masters Series. Vol. 6. Thieme; 2015; 190 pp; 207 ill; $115.81

Vialle_thoracolumabar-spine-trauma_coverThis book on spine trauma is a publication from AOSpine, which is a specialty group under the umbrella of the AO (Arbeitsgemeinschaft für Osteosynthesefragen) foundation. Founded in 1958 by a group of four Swiss surgeons, AO is a society focused on the treatment of trauma and disorders of the musculoskeletal system. One focus of AO is education, and this is book 6 in a series of 10 volumes dedicated to the spine. Further information can be found at https://aospine.aofoundation.org/.

The first chapter is a presentation of a new classification system for spine trauma, the “AOSpine Thoracolumbar Injury Classification.” Injury is divided into three types. Type A are compression fractures with further subclassification (minor, wedge, pincer, etc). Type B are tension band injuries, referring to injury to the anterior or posterior bony-ligamentous complexes, again with further subtyping. Type C are translation/displacement injuries with failure of all elements in the spine. Neurologic involvement further classifies the trauma and is a factor in clinical algorithims. One of the consistent features of this book is that all subsequent chapters refer to this classification system in regards to clinical decisions. This chapters includes radiographic examples of most of the subtyped injuries.

The second chapter is “Radiographic Assessment of Thoracolumbar Fractures,” with emphasis on applying this new classification system. The chapter includes all pertinent modalities (x-ray, CT, MRI); however, at 23 pages, it can only provide a general overview.

The remaining 11 chapters include:

  • Posteriorly Minimally Invasive Surgery in Thoracolumbar Fractures
  • Anteriorly Minimally Invasive Surgery in Thoraclumbar Fractures
  • Cervicothoracic Spine Injuries
  • Transpedicular and Costotransversectomy Approaches for Trauma
  • Short or Long Posterior Fusion: Determining Extent of Fixation
  • Brust Fracture Treatment
  • Differentiating