MR Neurography of Lumbosacral Plexus: Incremental Value Over XR, CT, and MRI of L Spine With Improved Outcomes in Patients With Radiculopathy and Failed Back Surgery Syndrome.

BACKGROUND: Lower back pain is often evaluated using magnetic resonance imaging (MRI) and conventional imaging, which provide incomplete information about the etiology of pain and lead to less than optimal management. HYPOTHESIS: MR neurography (MRN) of the lumbosacral (LS) plexus renders a more accurate diagnosis, alters the management strategy, and clinical outcomes of radiculopathy or failed back surgery Syndrome (FBSS) patients when compared to the conventional imaging modalities. STUDY TYPE: Retrospective, cross-sectional. POPULATION: A total of 356 patients (mean age 65.8 ± 12.3; 48.9% female) from single university hospital over 6 years with MRN of LS plexus were included from a cohort of 14,775 total patients with lumbar spine MR imaging. ASSESSMENT: Conventional imaging obtained before and after MRN of LS plexus was reevaluated and categorized into three levels based on extent of imaging findings' correlation to presenting clinical symptoms (contributory levels). Clinical notes were reviewed for changes in ordering provider's recommended management and subsequent patients' symptom level pre-MRN to post-MRN. FIELD STRENGTH/SEQUENCE: A 5 T and 3.0 T. T1-weighted (T1W), T2-weighted (T2W), short T1 inversion recovery (STIR), T1 turbo spin echo (T1 TSE), T2 spectral attenuated inversion recovery (T2 SPAIR). STATISTICAL TESTS: Chi-squared test. Statistical significance was set at P < 0.05. RESULTS: A total of 356 total patients (174 females) with mean age ± SD was 65.8 ± 12.3 years, 4.2% of patients imaged with lumbar spine MRI. Definitely contributory studies among X-rays, computed tomography, MRI, and MRN were 3 of the 129 (2.3%), 3 of the 48 (6.2%), 35 of the 184 (19.0%), and 283 of the 356 (79.8%), respectively. Pre-MRN vs. post-MRN led to change in recommendation in 219 of the 356 (61.5%) patients and 71 of the 99 (71.7%) patients had improved symptoms. CONCLUSION: MRN of the LS plexus can provide more corroborative image findings for symptom correlation compared to other imaging modalities for accurate diagnosis, effects patient management and leads to positive clinical outcomes in a small subset of patients with radiculopathy or FBSS. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 5.

Prospective pre-operative 3-T MR neurography peripheral nerve mapping of upper extremity amputations implanted with FAST-LIFE electrode interfaces of robotic hands: technical report.

BACKGROUND AND PURPOSE: Fascicular targeting of longitudinal intrafascicular electrode (FAST-LIFE) interface enables hand dexterity with exogenous electrical microstimulation for sensory restoration, custom neural recording hardware, and deep learning-based artificial intelligence for motor intent decoding. The purpose of this technical report from a prospective pilot study was to illustrate magnetic resonance neurography (MRN) mapping of hand and nerve anatomy in amputees and incremental value of MRN over electrophysiology findings in pre-surgical planning of FAST-LIFE interface (robotic hand) patients. MATERIALS AND METHODS: After obtaining informed consent, patients with upper extremity amputations underwent pre-operative 3-T MRN, X-rays, and electrophysiology. MRN findings were correlated with electrophysiology reports. Descriptive statistics were performed. RESULTS: Five patients of ages 21-59 years exhibited 3/5 partial hand amputations, and 2/5 transradial amputations on X-rays. The median and ulnar nerve end bulb neuromas measured 10.1 ± 3.04 mm (range: 5.5-14 mm, median: 10.5 mm) and 10.9 ± 7.64 mm (2-22 mm, 9.75 mm), respectively. The ADC of median and ulnar nerves were increased at 1.64 ± 0.1 × 10-3 mm2/s (range: 1.5-1.8, median: 1.64 × 10-3 mm2/s) and 1.70 ± 0.17 × 10-3 mm2/s (1.49-1.98 × 10-3 mm2/s, 1.65 × 10-3 mm2/s), respectively. Other identified lesions were neuromas of superficial branch of the radial nerve and anterior interosseous nerve. On electrophysiology, 2/5 reports were unremarkable, 2/5 showed mixed motor-sensory neuropathies of median and ulnar nerves along with radial sensory neuropathy, and 1/5 showed sensory neuropathy of lateral cutaneous nerve of the forearm. All patients regained naturalistic sensations and motor control of digits. CONCLUSION: 3-T MRN allows excellent demonstration of forearm and hand nerve anatomy, altered diffusion characteristics, and their neuromas despite unremarkable electrophysiology for pre-surgical planning of the FAST-LIFE (robotic hand) interfaces.

Three-Dimensional Isotropic Versus Conventional Multisequence 2-Dimensional Magnetic Resonance Imaging of Sacroiliac Joints in Suspected Axial Spondyloarthritis.

OBJECTIVES: The aims of the study were to systematically evaluate the sacroiliac joints of a consecutive series of patients with clinically suspected axial spondyloarthritis and to compare the diagnostic efficacy of 3-dimensional (3D) imaging versus conventional multisequence 2D techniques for sacroiliitis. METHODS: In this cross-sectional multireader validation study, imaging studies of 104 consecutive patients with clinically suspected axial spondyloarthritis obtained with a rheumatology lumbosacral magnetic resonance imaging protocol were evaluated. Three-dimensional coronal oblique reconstructions parallel to the long axis of the sacrum were created. Two blinded readers evaluated 2D and 3D images separately for each study, and findings were compared with the reference standard for the final diagnosis and disease activity. Cohen κ and diagnostic performance measures on 2D and 3D imaging were evaluated and compared. RESULTS: With 2D versus 3D imaging, respectively, the sensitivity for detecting inflammatory cases was 57% versus 62% ( P = 0.1007), the sensitivity for detecting mechanical cases was 89% versus 76% ( P = 0.0312), the sensitivity for detecting active sacroiliitis was 49% versus 64% ( P = 0.0014), and the specificity for detecting active sacroiliitis was 87% versus 76% ( P = 0.0016). Interreader agreement of 2D imaging showed an overall range of κ = 0.27-0.85, and it was best for evaluation of bony ankylosis (κ = 0.85). Interreader agreement of 3D imaging was in an overall range of κ = 0.15-0.64. CONCLUSIONS: Single 3D isotropic magnetic resonance imaging provided adequate assessment of sacroiliac joints in this study and demonstrated significantly higher sensitivity and lower specificity for detecting active sacroiliitis. The initial results indicate that 3D imaging could be used for future works for screening sacroiliitis and abdominopelvic enthesopathy.

Hand and Wrist Neuropathies: High-resolution Ultrasonography and MR Neurography.

High-resolution ultrasonography (US) and magnetic resonance neurography (MRN) have followed parallel paths for peripheral nerve imaging with little comparison of the two modalities. They seem equally effective to study a variety of neuropathies affecting large and small nerves in the wrist and hand. This article outlines the technical considerations of US and MRN and discusses normal and abnormal imaging appearances of hand and wrist nerves from etiologies such as entrapment, injury, tumor, and proximal and diffuse neuropathy, with specific case illustrations.

Progression of coronary artery calcium predicts all-cause mortality.

OBJECTIVES: This study examined a large cohort to assess whether progression of coronary artery calcium (CAC) was associated with all-cause mortality, and which among 3 different methods to assess CAC progression provided the best estimate of risk. BACKGROUND: Serial assessment of CAC scores has been proposed as a method to follow progression of coronary artery disease, and it has been suggested that excessive CAC progression may be a useful noninvasive predictor of the patient's risk of future events. However, the optimal method to measure calcium progression has not been well established. METHODS: The study sample consisted of 4,609 consecutive asymptomatic individuals referred by primary physicians for CAC measurement with electron beam tomography, who underwent repeat screening. Three general statistical approaches were taken: 1) the absolute difference between follow-up and baseline CAC score; 2) percent annualized differences between follow-up and baseline CAC score; and 3) difference between square root of baseline and square root of follow-up CAC score >2.5 (the "SQRT method"). RESULTS: The average interscan time was 3.1 years, and there were 288 deaths. Progression of CAC was significantly associated with mortality regardless of the method used to assess progression (p < 0.0001). After adjusting for baseline score, age, sex, and time between scans, the best CAC progression model to predict mortality was the SQRT method (hazard ratio [HR]: 3.34; 95% confidence interval [CI]: 2.65 to 4.21; p < 0.0001), followed by a >15% yearly increase (HR: 2.98; 95% CI: 2.20 to 4.95; p < 0.0001). Progression was very limited and did not predict mortality in patients with baseline CAC = 0. CONCLUSIONS: The CAC progression added incremental value in predicting all-cause mortality over baseline score, time between scans, demographics, and cardiovascular risk factors. Serial assessment may have clinical value in assessing plaque progression and future cardiovascular risk.