Accuracy of Noncontrast T2 SPACE in Active MS Cord Lesion Detection.

BACKGROUND AND PURPOSE: The diagnosis of active MS lesions is often based on postgadolinium T1-weighted MR imaging. Recent studies suggest a risk of IV gadolinium to patients, predominantly based on gadolinium deposition in tissue. Noncontrast sequences have shown promise in MS diagnosis, but none differentiate acute from chronic MS lesions. We hypothesized that 3D T2 sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE) MR imaging can help detect and differentiate active-versus-chronic MS lesions without the need for IV contrast. MATERIALS AND METHODS: In this single-center retrospective study, 340 spinal MR imaging cases of MS were collected in a 24-month period. Two senior neuroradiologists blindly and independently reviewed postcontrast T1-weighted sagittal and T2-SPACE sagittal images for the presence of MS lesions, associated cord expansion/atrophy on T2-SPACE, and enhancement on postcontrast T1WI. Discrepancies were resolved by consensus between the readers. Sensitivity, specificity, and accuracy of T2-SPACE compared with postcontrast T1WI were computed, and interobserver agreement was calculated. RESULTS: The sensitivity of lesion detection on T2-SPACE was 85.71%, 95% CI, 63.66%-96.95%; with a specificity of 93.52%, 95% CI, 90.06%-96.05%; and an accuracy of 92.99%, 95% CI, 89.58%-95.56. Additionally, 16/21 (84.2%) acute enhancing cord lesions showed cord expansion on T2-SPACE. The interobserver agreement was 92%. CONCLUSIONS: Our study shows that T2-SPACE facilitates noncontrast detection of acute MS lesions with high accuracy compared with postcontrast T1WI and with high interobserver agreement. The lack of gadolinium use provides an advantage, bypassing any potential adverse effects of repetitive contrast administration.

Rate of Missed Intracranial Colloid Cysts on MRI and CT.

BACKGROUND AND PURPOSE: Intracranial colloid cysts of the third ventricle are rare; however, they may be symptomatic. They can create a mass effect on the foramina of Monro, resulting in acute hydrocephalus. Colloid cysts are detectable on CT and MRI but are commonly missed. In this paper, we investigate the rate of missed colloid cysts on MRI and/or CT imaging within our multihospital metropolitan medical group. MATERIALS AND METHODS: A retrospective, institutional review board-approved search of the network-wide picture archiving and communication system (PACS) from January 1, 2010, to October 31, 2020, was performed to identify reports including a "colloid cyst" in MRI brain or CT head imaging. Results without imaging and/or surgical confirmation of intracranial colloid cysts were excluded, rendering 229 cases. A PACS review of these cases was performed by two neuroradiologists to determine instances where the cyst had previously been imaged but not diagnosed on either CT or MRI. RESULTS: Two hundred twenty-nine subjects had confirmed colloid cysts through imaging and/or surgical reports. Of these, 46 had prior imaging depicting a colloid cyst either on CT and/or MRI without mention on the interpretative report, resulting in a non-detection rate of 20.1%. CONCLUSION: Intracranial colloid cysts can be missed at a considerably high rate, which is concerning given their clinically unpredictable nature and ability to cause significant morbidity and mortality. As such, it is important to take a proactive approach to searching for these cysts as part of a regular imaging search pattern and to continue to determine new methods of increasing detection sensitivity.

Spinal arachnoid webs in adults: Clinical and imaging features in a multicenter study.

BACKGROUND AND PURPOSE: Spinal arachnoid webs (SAWs) are rare and can present with myelopathic symptoms. This study aims to add 85 more cases of SAWs to the literature so we can continue to analyze clinical and imaging trends of SAWs to better understand this entity and its natural history. METHODS: An institutional review board-approved retrospective review of SAW cases between 2016 and 2022 within a metropolitan, multihospital network was performed, searching for MR and CT reports that included "arachnoid web." Of 108 identified reports, 85 patients had imaging and/or pathologically proven arachnoid webs. Demographic and clinical data were collected. Images were analyzed for SAW level, point of maximum kyphosis, presence of cord expansion, and signal intensity. The electronic medical record (EMR) was reviewed for age, sex, symptom presentation and duration, management, and outcomes. RESULTS: Of 85 cases, the most common presenting chief complaint was back pain and weakness. All (100%) SAWs were in the dorsal thoracic subarachnoid space, with 87% (74/85) located from thoracic (T) 2 to T6. Spinal cord expansion and signal abnormality were present in 54.1% and 23.5%, respectively. Twenty-six underwent surgical resection with 20 showing improvement of at least one symptom. CONCLUSION: We present 85 additional cases of SAWs to the existing literature. Our cases all occurred in the dorsal thoracic subarachnoid space, predominantly from T2 to T6. Patients present with symptoms like other causes of cord compression, and spinal MR studies should be evaluated routinely for the findings of SAWs. Further research could focus on understanding SAW prevalence, risk factors, and pathophysiology.

Enhancing the REMBRANDT MRI collection with expert segmentation labels and quantitative radiomic features.

Malignancy of the brain and CNS is unfortunately a common diagnosis. A large subset of these lesions tends to be high grade tumors which portend poor prognoses and low survival rates, and are estimated to be the tenth leading cause of death worldwide. The complex nature of the brain tissue environment in which these lesions arise offers a rich opportunity for translational research. Magnetic Resonance Imaging (MRI) can provide a comprehensive view of the abnormal regions in the brain, therefore, its applications in the translational brain cancer research is considered essential for the diagnosis and monitoring of disease. Recent years has seen rapid growth in the field of radiogenomics, especially in cancer, and scientists have been able to successfully integrate the quantitative data extracted from medical images (also known as radiomics) with genomics to answer new and clinically relevant questions. In this paper, we took raw MRI scans from the REMBRANDT data collection from public domain, and performed volumetric segmentation to identify subregions of the brain. Radiomic features were then extracted to represent the MRIs in a quantitative yet summarized format. This resulting dataset now enables further biomedical and integrative data analysis, and is being made public via the NeuroImaging Tools & Resources Collaboratory (NITRC) repository ( https://www.nitrc.org/projects/rembrandt_brain/ ).

Lateral versus prone robot-assisted percutaneous pedicle screw placement: a CT-based comparative assessment of accuracy.

OBJECTIVE: Single-position lateral lumbar interbody fusion (SP-LLIF) has recently gained significant popularity due to increased operative efficiency, but it remains technically challenging. Robot-assisted percutaneous pedicle screw (RA-PPS) placement can facilitate screw placement in the lateral position. The authors have reported their initial experience with SP-LLIF with RA-PPS placement in the lateral position, and they have compared this accuracy with that of RA-PPS placement in the prone position. METHODS: The authors reviewed prospectively collected data from their first 100 lateral-position RA-PPSs. The authors graded screw accuracy on CT and compared it to the accuracy of all prone-position RA-PPS procedures during the same time period. The authors analyzed the effect of several demographic and perioperative metrics, as a whole and specifically for lateral-position RA-PPS placement. RESULTS: The authors placed 99 lateral-position RA-PPSs by using the ExcelsiusGPS robotic platform in the first 18 consecutive patients who underwent SP-LLIF with postoperative CT imaging; these patients were compared with 346 prone-position RA-PPSs that were placed in the first consecutive 64 patients during the same time period. All screws were placed at L1 to S1. Overall, the lateral group had 14 breaches (14.1%) and the prone group had 25 breaches (7.2%) (p = 0.032). The lateral group had 5 breaches (5.1%) greater than 2 mm (grade C or worse), and the prone group had 4 (1.2%) (p = 0.015). The operative level had an effect on the breach rate, with breach rates (grade C or worse) of 7.1% at L3 and 2.8% at L4. Most breaches were grade B (< 2 mm) and lateral, and no breach had clinical sequelae or required revision. Within the lateral group, multivariate regression analysis demonstrated that BMI and number of levels affected accuracy, but the side that was positioned up or down did not. CONCLUSIONS: RA-PPSs can improve the feasibility of SP-LLIF. Spine surgeons should be cautious and selective with this technique owing to decreased accuracy in the lateral position, particularly in obese patients. Further studies should compare SP-LLIF techniques performed while the patient is in the prone and lateral positions.

The black rim susceptibility sign in the MRI evaluation of intracranial colloid cysts.

BACKGROUND AND PURPOSE: Colloid cysts are relatively rare intracranial lesions located in the rostral aspect of third ventricle. They may produce acute hydrocephalus, brain herniation, and death. On conventional MRI, the appearance of a colloid cyst varies depending on its composition. Small isointense cysts can be missed. The purpose of this study is to introduce a new sign, "black rim susceptibility" sign for the accurate diagnosis of colloid cyst on susceptibility weighted imaging (SWI). METHODS: A retrospective case-control study consisted of 100 MRI brain scans (19 cases and 81 controls) performed from January 2012 to September 2018. Two fellowship trained neuroradiologists individually interpreted SWI sequences for the presence of the "black rim susceptibility" sign (thin rim of dark signal along the periphery of a rounded, hyperintense focus). RESULTS: The sample was 43% male and 57% female, with an average age of 51.8 ± 17.7. Out of 19 cases, 9 had undergone surgery in which pathology had confirmed colloid cyst. Sensitivity, specificity, and accuracy for reader 1 was 94.8%, 98.8%, and 98% and for reader 2 was 89.5%, 100%, and 98%, respectively. Positive predictive value and negative predictive value for reader 1 was 94.7% and 98.8% and for reader 2 was 100% and 97.6%, respectively. Interrater correlation between the two readers was calculated with kappa of 0.93. CONCLUSION: The black rim susceptibility appearance of colloid cyst on SWI is a novel description and an effective sign that can be used by radiologists for accurate diagnosis.

Normal range of clivoaxial angle in adults using flexion and extension cervical magnetic resonance imaging scans.

OBJECTIVE: An abnormally decreased clivoaxial angle (CXA) is used during the clinical evaluation for corrective skull base surgery. Published normal ranges of CXA using x-ray, computed tomography, or magnetic resonance imaging (MRI) vary dramatically, especially with neck flexion or extension. The aim of this study was to use high-resolution MRI to determine the normal range of CXA in various neck positions using a reproducible measurement technique. METHODS: The CXA was measured in 10 healthy volunteers on sagittal T2 SPACE c-spine MRI in supine and prone positions and with the neck both neck and extended. CXA is strictly defined as the angle between a line along the inferior third of the dorsal clival cortex and a line from the superior/posterior cortex of the dens to the posterior/inferior corner of the C2 body. Statistical analysis was performed in all positions and included mean CXA, range, standard deviation (SD), inter-reader agreement, and group comparisons. RESULTS: The mean CXA overall was 156.92° (SD=4.23°; range 134-179°). The mean value for extension CXA was 169.20° (SD=5.81°), and the mean value for flexion CXA was 144.73° (SD=5.71°), the difference being statistically significant (p<0.0001) regardless of supine or prone position. Concordant correlations of reader measurements showed substantial agreement in the supine position at 0.96, with lower agreement in the prone position at 0.87. CONCLUSIONS: We report normal ranges for CXA in various neck positions based on 3D T2-weighted MRI, using a reproducible measurement method. There was a significant difference in the CXA values between neck extended and neck flexed positions but not between supine and prone positions.

Robot-Assisted Percutaneous Pedicle Screw Placement: Evaluation of Accuracy of the First 100 Screws and Comparison with Cohort of Fluoroscopy-guided Screws.

OBJECTIVE: Percutaneous pedicle screws (PPS) are used to stabilize the spine after interbody fusion in minimally invasive approaches. Recently, robotic assistance has been developed to improve the accuracy of PPS. We report our initial experience with ExcelsiusGPS and compare its accuracy with our historical cohort of fluoroscopy-guided PPS. METHODS: We reviewed prospectively collected data from our first 100 robot-assisted PPS. We graded accuracy of screws on computed tomography imaging and compared it with a previous cohort of 90 PPS placed using fluoroscopy. We also analyzed the effect of various demographic and perioperative metrics on accuracy. RESULTS: We placed 103 PPS in the first 20 consecutive patients with postoperative computed tomography imaging using ExcelsiusGPS. All screws were placed at L2 to S1. Our robot-assisted cohort had 6 breaches, with only 2 breaches >2 mm, yielding an overall breach rate of 5.8% and a significant breach rate of 1.9%. In comparison, our fluoroscopy-guided cohort had a breach rate of 3.3% and a significant breach rate of 1.1%, which was not significantly different. More breaches occurred in the first half of cases, suggesting a learning curve with robotic assistance. No demographic or perioperative metrics had a significant effect on accuracy. CONCLUSIONS: Our breach rates with ExcelsiusGPS were low and consistent with others reported in the literature, as well as with other robotic systems. Our series shows equivalent accuracy of placement of PPS with this robotic platform compared with fluoroscopic guidance and suggests a relatively short learning curve.

Cervical intradural disc herniation, case report and reflection on preoperative imaging.

Intradural disc herniation in the cervical spine is a rare condition that requires identification and modification of surgical technique to avoid postoperative complications. A 55-year-old male with a C4-5 intradural disc herniation who presented with radicular symptoms was treated via anterior cervical discectomy and fusion. The dural defect was identified at the time of surgery. On retrospective review of the patient's preoperative MRI, there were subtle findings of the intradural disc location, including a surrounding ring of hyperintensity on T2 and less deformation of the spinal cord than would be expected given its size.

Mobile Schwannoma of the Lumbar Spine: A Case Report and Review of the Literature.

Mobile schwannomas of the spine have been sparsely documented in the literature. In cases referred to in existing literature, the migratory schwannoma was documented to occur in the lumbar spine. We added another case to the small available literature. In our case report, the patient had a previously known lumbar schwannoma that was being managed conservatively. Due to an acute change in clinical symptoms, repeat imaging was performed. A magnetic resonance imaging (MRI) of his spine revealed migration of the schwannoma two levels rostral to his recent imaging from six weeks earlier. The patient underwent surgical resection of his lesion. During the operation, the ultrasound was utilized to confirm the lesion prior to dural opening. In this report, we attempt to provide further evidence of the utility of an intraoperative ultrasound for intradural lesions and intend to add to the published literature of mobile schwannomas of the spine.

Effectiveness of a Rapid Lumbar Spine MRI Protocol Using 3D T2-Weighted SPACE Imaging Versus a Standard Protocol for Evaluation of Degenerative Changes of the Lumbar Spine.

OBJECTIVE: Reducing lumbar spine MRI scanning time while retaining diagnostic accuracy can benefit patients and reduce health care costs. This study compares the effectiveness of a rapid lumbar MRI protocol using 3D T2-weighted sampling perfection with application-optimized contrast with different flip-angle evolutions (SPACE) sequences with a standard MRI protocol for evaluation of lumbar spondylosis. MATERIALS AND METHODS: Two hundred fifty consecutive unenhanced lumbar MRI examinations performed at 1.5 T were retrospectively reviewed. Full, rapid, and complete versions of each examination were interpreted for spondylotic changes at each lumbar level, including herniations and neural compromise. The full examination consisted of sagittal T1-weighted, T2-weighted turbo spin-echo (TSE), and STIR sequences; and axial T1- and T2-weighted TSE sequences (time, 18 minutes 40 seconds). The rapid examination consisted of sagittal T1- and T2-weighted SPACE sequences, with axial SPACE reformations (time, 8 minutes 46 seconds). The complete examination consisted of the full examination plus the T2-weighted SPACE sequence. Sensitivities and specificities of the full and rapid examinations were calculated using the complete study as the reference standard. RESULTS: The rapid and full studies had sensitivities of 76.0% and 69.3%, with specificities of 97.2% and 97.9%, respectively, for all degenerative processes. Rapid and full sensitivities were 68.7% and 66.3% for disk herniation, 85.2% and 81.5% for canal compromise, 82.9% and 69.1% for lateral recess compromise, and 76.9% and 69.7% for foraminal compromise, respectively. CONCLUSION: Isotropic SPACE T2-weighted imaging provides high-quality imaging of lumbar spondylosis, with multiplanar reformatting capability. Our SPACE-based rapid protocol had sensitivities and specificities for herniations and neural compromise comparable to those of the protocol without SPACE. This protocol fits within a 15-minute slot, potentially reducing costs and discomfort for a large subgroup of patients.

Multifocal hemangioendothelioma of the lumbar spine and response to surgical resection and radiation.

BACKGROUND CONTEXT: Epithelioid hemangioendothelioma rarely occurs in the lumbosacral spine, with very few case reports of spinal hemangioendothelioma in the literature. There is variability in aggressiveness of these lesions without established treatment guidelines. PURPOSE: The aim was to present a case of epithelioid hemangioendothelioma in the lumbar spine, including magnetic resonance imaging (MRI) findings, which rapidly progressed over a 2-month period as regional multifocal lumbosacral spinal lesions with epidural extension causing severe spinal canal stenosis. STUDY DESIGN/SETTING: This was a case report in a university hospital setting. PATIENT SAMPLE: The sample included an otherwise healthy adult male with low back pain. METHODS: Multimodality imaging was performed to help with diagnosis and management including computed tomography, MRI, and positron emission tomography (PET). The patient was treated by embolization, L5 corpectomy and L4-S1 stabilization, and radiation therapy. The diagnosis was confirmed by tissue biopsy. RESULTS: The patient initially presented with severe back and leg pain after a vertebroplasty for an L5 compression fracture at an outside hospital where biopsy was negative for malignancy. Magnetic resonance imaging showed diffuse abnormality of L5 with several smaller lesions in the sacrum. Due to progressive pain 2 weeks after the vertebroplasty, the patient underwent an L5 laminectomy, L4-S1 instrumented posterior fusion, and attempted partial corpectomy for stenosis. At this surgery, the L5 corpectomy was aborted owing to profound bleeding. Pathology was again negative for malignancy. Presumed to be an atypical hemangioma, the lesion was embolized before repeat surgery where the thecal sac was decompressed by partial L5 corpectomy. Biopsy at this time revealed a vascular neoplasm, with hemangioendothelioma not excluded. Approximately 2 months after the stabilization procedure, the patient had increasing pain and bilateral lower extremity weakness. Magnetic resonance imaging was performed and demonstrated marked local progression of disease with new multifocal lesions involving L4 through S2 vertebrae and new severe spinal canal stenosis. These lesions were subsequently treated with localized radiation therapy. Magnetic resonance imaging 2 months after radiation therapy showed significant regression of the epidural tumor although a new metastatic lesion was discovered at T6 vertebra. CONCLUSIONS: Spinal hemangioendothelioma is a rare disease and can present in variable forms, including as a multifocal regional process--which may be mistaken for infection. Additionally, there are no standard treatment protocols for this entity. We present the extensive imaging and treatment of a single case of rapidly progressive lumbar epithelioid hemangioendothelioma, which to our knowledge has not been described with this multifocal appearance in the lumbar spine.

Bow hunter's syndrome: the use of dynamic magnetic resonance angiography and intraoperative fluorescent angiography.

Bow hunter's syndrome is a diagnosis typically made using dynamic digital subtraction angiography. The authors present the case of a 68-year-old woman who presented with symptoms consistent with bow hunter's syndrome that was accurately diagnosed utilizing noninvasive dynamic MR angiography. The dynamic MR angiogram clearly illustrated unilateral vertebral artery compression upon turning of the head. A subsequent CT of the cervical spine showed a ventral C-1 osteophyte within the foramen. The patient underwent posterior surgical decompression of the left vertebral artery. Sufficient decompression was confirmed using intraoperative fluorescent angiography with the patient's head turned. This case report is the first to illustrate that dynamic MR angiography can be a reliable and less invasive diagnostic tool. It can also be used to confirm sufficient postoperative decompression and monitor for recurrence. Intraoperative fluorescent angiography has been previously used in the evaluation of intracranial and extracranial vascular patency. This report is the first to show that fluorescent angiography can offer rapid and reliable intraoperative evaluation of vertebral artery decompression in bow hunter's syndrome.

Rheumatoid arthritis: a review of the cutaneous manifestations.

Rheumatoid arthritis is a chronic inflammatory arthritis with significant extra-articular manifestations. Of note are unique cutaneous manifestations that the dermatologist may encounter. This article will make the dermatologist more cognizant of these skin findings in patients with this systemic inflammatory disorder. It examines rheumatoid arthritis, focusing on the general nonspecific and disease-specific rheumatoid arthritic skin changes. Classic rheumatoid nodules, accelerated rheumatoid nodulosis, rheumatoid nodulosis, rheumatoid vasculitis, Felty syndrome, pyoderma gangrenosum, interstitial granulomatosus dermatitis with arthritis, palisaded neutrophilic and granulomatosis dermatitis, rheumatoid neutrophilic dermatitis, juvenile rheumatoid arthritis, and adult-onset Still disease are reviewed. Understanding the cutaneous expressions of rheumatoid arthritis may lead to early diagnosis, prompt treatment, and lower morbidity and mortality for the affected persons. Learning objective At the completion of this learning activity, participants should be able to describe rheumatoid arthritis in terms of its epidemiology, etiology, pathogenesis, and general and specific cutaneous manifestations.

T-cell lymphoma as a model for the use of histone deacetylase inhibitors in cancer therapy: impact of depsipeptide on molecular markers, therapeutic targets, and mechanisms of resistance.

Depsipeptide (FK228) is a novel histone deacetylase inhibitor currently in clinical trials and the first to demonstrate clinical activity in patients. Responses have been observed in patients with T-cell lymphomas, despite prior treatment with multiple chemotherapeutic agents. To better understand the effects of histone deacetylase inhibitors on T-cell lymphoma, the human T-cell lymphoma cell line HUT78 was tested for sensitivity and molecular response to depsipeptide. Treatment with depsipeptide, as well as other histone deacetylase inhibitors, caused induction of histone acetylation, induction of p21 expression, and substantial apoptosis without significant cell cycle arrest. Treatment with the caspase inhibitor z-VAD-fmk significantly inhibited depsipeptide-induced apoptosis, enabling detection of cell cycle arrest. Treatment with depsipeptide increased expression of the interleukin-2 (IL-2) receptor, and combination with the IL-2 toxin conjugate denileukin diftitox resulted in more than additive toxicity. Cells selected for resistance to depsipeptide overexpressed the multidrug resistance pump, P-glycoprotein (Pgp). However, cells selected for resistance to depsipeptide in the presence of a Pgp inhibitor had a Pgp-independent mechanism of resistance. These studies confirm the activity of depsipeptide in a T-cell lymphoma model and suggest a general sensitivity of T-cell lymphoma to histone deacetylase inhibitors, an emerging new class of anticancer agents.