Faculty Bibliography

BACKGROUND:Gout is the most common cause of inflammatory arthritis in adults. Gout predominantly affects the peripheral joints, but an increasing number of published cases report gout affecting the spine. We used dual-energy CT (DECT) to assess the prevalence of monosodium urate (MSU) deposition in the spine of gout patients compared to controls, and to investigate whether gout or spinal MSU deposition is associated with low back pain. METHODS:25 controls and 50 gout subjects (non-tophaceous and tophaceous) were enrolled. Demographics, gout history, Aberdeen back pain score, serum urate (sU), ESR and CRP were ascertained. Subjects underwent DECT of the lumbosacral spine, which was analyzed using manufacturer's default post-processing algorithm for MSU deposition as well as a maximally-specific algorithm to exclude potential artifact. FINDINGS/RESULTS:72 subjects were analyzed (25 control, 47 gout). Gout subjects had greater BMI, serum creatinine, sU, CRP, and ESR versus controls. Using the default algorithm, MSU-coded volumes in the lumbosacral spines were significantly higher among the gout subjects vs controls (p = 0.018). 34% of gout subjects vs 4% of controls had spinal MSU-coded deposition (p = 0.0036). Applying the maximally-specific DECT post-processing algorithm, 18% of gout patients vs 0% of controls continued to demonstrate spinal MSU-coded deposition (p = 0.04). Non-tophaceous and tophaceous subjects did not differ in spinal MSU-coded deposition or sU. Gout patients had more back pain than controls. INTERPRETATION/CONCLUSIONS:A significant subpopulation of gout patients have spinal MSU-coded lesions. Default and maximally-specific MSU post-processing algorithms yielded different absolute MSU-coded volumes, but similar patterns of results. Gout patients had more back pain than controls. Spinal MSU deposition in gout patients may have implications for clinical picture and treatment.

Background/Purpose: Axial gout involvement was first reported in 1950 (1). Over 100 cases have subsequently been published. Reported cases have presented as acute back pain, cord compression, and/or neurologic symptoms, with diagnosis made by invasive procedure (surgical excision or biopsy). However, the true extent of MSU deposition in the spine of gout patients, including asymptomatic patients or those with non-specific symptoms, is unknown and likely higher. We used DECT to determine the extent of MSU deposition in the lumbosacral spines of patients with gout, with and without tophi, compared to controls without gout.
Method(s): We recruited controls, nontophaceous, and tophaceous gout patients, age 45-80. Individuals with CPPD disease, RA, spondyloarthropathy, active spinal malignancy, or on urate lowering treatment (ULT) >= 6 months were excluded. Gout subjects met 2015 ACR gout classification criteria, with entry serum urate (sU) of >6.8 mg/dL ( >6.0 mg/dL if on ULT for < 6 months). Demographics, gout history, Aberdeen back pain scale, sU, ESR, and CRP were collected. Subjects underwent DECT of the lumbosacral spine (LS) to assess for MSU deposition.
Result(s): 75 subjects were enrolled, and 72 completed the study (1 nontophaceous gout patient lost to follow-up prior to DECT, 2 tophaceous excluded after sU at time of DECT found to be < 6.0mg/dL). All groups were similar in age in years (controls 61.8+/-3.8, nontophaceous 64.0+/-6.1, tophaceous 60.4+/-11.0, p=0.81) but differed in BMI (controls 28.3+/-6.5 kg/m², nontophaceous 34.1+/-7.2 kg/m², tophaceous 29.5+/-4.5 kg/m², p=0.03) and creatinine (controls 1.0+/-0.2 mg/dL, nontophaceous 1.4+/-0.7 mg/dL, tophaceous 1.4+/-0.6 mg/dL, p< 0.05). Mean sU and ESR were higher in gout subjects (sU-controls 5.3+/-1 mg/dL, nontophaceous 8.5+/-1.7 mg/dL, tophaceous 8.5+/-1.6 mg/dL, p< 0.05; ESR-controls 13.7+/-13.8 mm/h, nontophaceous 26.5+/-19.4 mm/h, tophaceous 25.1+/-15.7 mm/h, p< 0.05). Using standard DECT settings for MSU visualization, gout patients had larger MSU volumes than controls (controls 2.2+/-1.2 cm3, all gout 5.23+/-6.9 cm3; p =0.03). Tophaceous patients had numerically greater MSU deposition compared with nontophaceous (6.0+/-8.9 cm3, vs 4.4+/-4.3 cm3, ns). Reanalysis of a subset of scans using highly specific settings to eliminate artifact reduced the number of subjects with MSU signal but confirmed greater prevalence of deposition among gout patients (n=29; controls with deposition 0/9, nontophaceous with deposition 1/11, tophaceous with deposition 2/9). Back pain was also more common among gout patients. No subject had frank tophi on spinal DECT.
Conclusion(s): Gout patients have significantly greater intercritical inflammation and LS MSU deposition than controls, and trend toward greater deposition among patients with tophi. Preliminary results using the most stringent DECT threshold settings suggests MSU differences are not artifact. The complete data set is currently undergoing evaluation and the full results will be presented

Background: Gout affecting the spine is reported as a rare event presenting with neuropathy, spinal compression and acute back pain (1). Cases are often diagnosed by tissue confirmation of monosodium urate (MSU) deposition. The frequency of gout involving the spine asymptomatically or with milder, non-specific symptoms is likely higher than reported.
Objective(s): Using dual-energy CT (DECT), we are determining prevalence/ extent of MSU deposition in the lumbosacral spines of patients with gout and tophaceous gout, compared to non-gout controls.
Method(s): We are recruiting 25 controls, 25 non-tophaceous and 25 tophaceous gout patients, 45-80 years old. Exclusion criteria include CPPD disease, RA, spondyloarthropathy or spinal malignancy. All gout subjects meet ACR gout classification criteria with entry serum urate (sU) of >6.8 mg/dL, or sU >6.0 mg/dL on ULT for <6 months. Demographics, gout history, Aberdeen back pain scale, sU, ESR, and CRP are collected. DECT of the lumbosacral spine is used to assess MSU deposition and osteoarthritic changes.
Result(s): 63 subjects are enrolled and analyzed to date (25 control, 23 non-tophaceous and 15 tophaceous gout). Control, non-tophaceous gout, and tophaceous gout subjects have similar mean age in years (controls 61.8+/-3.8, non-tophaceous 64.0+/-6.2, tophaceous 63.5+/-9.2, p=0.45), but differ in BMI (controls 28.3+/-6.5 kg/ m2, non-tophaceous 32.1+/-6.7 kg/m², tophaceous 29.1+/-4.3 kg/m², p=0.01) and creatinine (controls 1.0+/-0.2 mg/dL, non-tophaceous 1.4+/-0.6 mg/dL, tophaceous 1.7+/-0.9 mg/dL, p=0.048). Mean sU and ESR are higher in gout subjects (sU-controls 5.3+/-1 mg/dL, non-tophaceous 8.3+/-1.4 mg/dL, tophaceous 8.4+/-2.0 mg/ dL, p<0.05; ESR-controls 13.7+/-13.8 mm/h, non-tophaceous 25.2+/-18.7 mm/h, tophaceous 22.5+/-15.1 mm/h, p<0.05). Using default threshold settings for MSU visualization, greater MSU deposition is observed in the spine of gout patients (controls 2.2+/-1.2 cm³, non-tophaceous 4.5+/-4.3 cm³, tophaceous 8.5+/-12.5 cm³, p<0.05; Table 1). Reanalysis of several scans using narrower threshold settings to limit possible artifact confirms increased MSU signal among gout patients. Although many subjects in each group do not have excessive MSU deposition, deposition is more common in both gout groups. No subject demonstrated a frank spinal tophus.
Conclusion(s): Based on preliminary results, gout patients have higher inflammatory markers and greater spinal MSU deposition than controls. Preliminary analyes with more stringent DECT threshold settings suggests these differences are not artifact, but analysis is ongoing. These data suggest that MSU deposition in the spine occurs in a subset of gout patients

Background/Purpose: Spinal gout is reported as a rare event, presenting as acute back pain, neuropathy, and spinal compression. Diagnosis is commonly based on identification of a mass, followed by tissue confirmation of monosodium urate (MSU) deposition. It is likely that many more cases of gout involve the spine asymptomatically or with non-specific or under-recognized symptoms.
Method(s): Using dual-energy CT (DECT), we are determining the prevalence/extent of MSU deposition in the lumbosacral spines of patients with gout vs without gout, and with tophaceous vs non-tophaceous gout. We are recruiting 25 controls, 25 non-tophaceous and 25 tophaceous gout patients, 50-80 years old. Exclusion criteria include known CPPD disease, RA, spondyloarthropathy or active spinal malignancy. All gout subjects meet ACR classification criteria and have entry serum urate (sU) of >6.8 mg/dL, or sU >6.0 mg/dL on ULT for < 6 months. Demographics, gout history, Aberdeen back pain scale, sU, ESR, and CRP are collected. Subjects undergo DECT of the lumbosacral spine to assess for MSU deposition and osteoarthritic changes.
Result(s): 61 subjects are enrolled to date (25 control, 24 non-tophaceous and 12 tophaceous gout). Control and gout (all pooled) subjects have similar mean age in years (controls, 61.8+/-3.8 vs gout, 64.1+/-7.32, p=0.15), but differ in BMI (controls, 28.3+/-6.5 kg/m 2 vs gout, 32.35+/-6.9 kg/m 2, p=0.02) and creatinine (controls, 1.0+/-0.2 mg/dL vs gout, 1.5+/-0.7 mg/dL, p< 0.05). Mean sU and ESR are higher in gout subjects (sU-controls, 5.3+/-1 mg/dL vs gout, 8.7+/-1.7 mg/dL, p< 0.05; ESR-controls, 13.7+/-13.8 mm/h vs gout, 25.3+/-18.3 mm/h, p< 0.05). Using default threshold settings for MSU visualization, greater MSU deposition is observed in the spine of gout patients (controls, 2.2+/-1.2 cm 3 vs gout, 10.8+/-32.2 cm 3, p=0.18; Fig 1). When a single gout outlier with excessively high sU and spinal MSU is excluded, spinal MSU deposition between controls and gout patients becomes significant (controls, 2.2+/-1.2 cm 3 vs gout, 5.6+/-7.8 cm 3, p=0.04). Reanalysis of several scans using narrower threshold settings to limit possible artifact confirms increased MSU signal among gout patients. Although many subjects in each group do not have excessive MSU deposition, deposition is more common in both gout groups (Fig 2). Thus far, MSU deposition is not different between non-tophaceous and tophaceous gout patients (non-tophaceous, 12.3+/-2.92 cm 3 vs tophaceous, 7.9+/-3.2 cm 3, p = 0.7). No subject demonstrated a frank spinal tophus. Gout patients report higher back pain scores (controls, 5.7+/-8.3, vs gout, 11.8+/-14.3, p=0.06). Across all groups deposition is greater in patients with higher sU.
Conclusion(s): Based on preliminary results, gout patients have higher inflammatory markers, more spinal MSU deposition, and increased back pain versus controls. Preliminary results with more stringent DECT threshold settings suggests these differences are not artifact, but analysis is ongoing. These data suggest that non-tophaceous MSU deposition in the spine occurs in a subset of gout patients, is associated with sU level, and may be associated with low back pain

Purpose: To demonstrate the appearance of osseous pathologies other than traumatic bone marrow edema using DECT with virtual noncalcium application for bone marrow edema and color overlay in patients presenting acutely to the emergency department with atraumatic musculoskeletal pain. Materials and Methods: This study was IRB approved and informed consent was waived. 166 consecutive patients presenting to the emergency department from 2/1/2017 - 7/1/2017 who underwent DECT (Somatom Force, Siemens) for musculoskeletal indications were retrospectively identified. CTs performed for the indication of trauma (n=113) were excluded. Post-processing was performed offline using a virtual noncalcium algorithm with color overlay (syngo.via; Siemans). Demographics were extracted from the electronic medical record. Descriptive statistics were performed. Results: In the study period, 20 females and 31 males, average age 59 years (range 20-92) underwent 53 CTs. Indications for imaging were infection (n=28), postoperative pain (n=2), and atraumatic pain (n=23). 34 (64%) had only soft tissue findings or were negative. 19 (36%) demonstrated atraumatic osseous etiologies of pain including metastasis, primary bone tumor, osteomyelitis, and inflammatory or infectious arthropathy. The appearance of these etiologies with color overlay is illustrated. 15 (28%) underwent subsequent imaging with MRI, bone scan, or PET with concordant results and these correlates are shown. Conclusion: DECT has emerged as a technology for detecting traumatic bone marrow edema. Bone marrow edema related to other, atraumatic etiologies including inflammatory arthropathy, tumor, and infection are also visually highlighted by this technique. In the emergent setting, DECT with virtual noncalcium subtraction and color overlay may be a useful adjunct to provide a visual aid for the detection or exclusion of marrow edema or amarrow infiltrating process in patients presenting with atraumatic musculoskeletal pain

OBJECTIVE:Radiologic technologists may repeat images within a radiographic examination because of perceived suboptimal image quality, excluding these original images from submission to a PACS. This study assesses the appropriateness of technologists' decisions to repeat musculoskeletal and chest radiographs as well as the utility of repeat radiographs in addressing examinations' clinical indication. MATERIALS AND METHODS/METHODS:We included 95 musculoskeletal and 87 chest radiographic examinations in which the technologist repeated one or more images because of perceived image quality issues, rejecting original images from PACS submission. Rejected images were retrieved from the radiograph unit and uploaded for viewing on a dedicated server. Musculoskeletal and chest radiologists reviewed rejected and repeat images in their timed sequence, in addition to the studies' remaining images. Radiologists answered questions regarding the added value of repeat images. RESULTS:The reviewing radiologist agreed with the reason for rejection for 64.2% of musculoskeletal and 60.9% of chest radiographs. For 77.9% and 93.1% of rejected radiographs, the clinical inquiry could have been satisfied without repeating the image. For 75.8% and 64.4%, the repeated images showed improved image quality. Only 28.4% and 3.4% of repeated images were considered to provide additional information that was helpful in addressing the clinical question. CONCLUSION/CONCLUSIONS:Most repeated radiographs (chest more so than musculoskeletal radiographs) did not add significant clinical information or alter diagnosis, although they did increase radiation exposure. The decision to repeat images should be made after viewing the questionable image in context with all images in a study and might best be made by a radiologist rather than the performing technologist.

STUDY DESIGN: Patients with preoperative spine magnetic resonance imaging (MRI) studies from a prospective multicenter study of operative adolescent Scheuermann kyphosis (SK). OBJECTIVES: To investigate the usefulness of MRI screening in operative planning for SK surgeries. SUMMARY OF BACKGROUND DATA: Neural axis abnormalities in operative SK have not been previously studied with MRI screening, despite its use. METHODS: One orthopedic surgeon and two radiologists evaluated all images retrospectively. Radiographs were evaluated for kyphosis apex and magnitude. MRIs were evaluated for spinal cord abnormalities, epidural lipomatosis, location and number of vertebral wedging, Schmorl nodes and posterior disc herniations, frequency of spondylolysis, etc. The relationship of these pathologies to the kyphosis apex was explored. This group was compared to a surgical SK group without preoperative MRIs. RESULTS: Eighty-six patients with MRIs, mean age 16.3 years, 64% male, and a mean preoperative kyphosis of 75.9 degrees were evaluated. There were 17 spinal cord abnormalities. Low-lying conus was found in 2 patients, and syrinx in 15 (no Chiari malformations). Epidural lipomatosis was found in 49 patients, average of 5.7 levels. Anterior vertebral wedging occurred in all (mean 4.7 levels). Posterior disc herniations averaged 5.2 levels/patient and 1.8 levels caudad to the apex. Spondylolysis was reported in 8.1%. Four cases (4.7%) had the operative plan changed as a result of the preoperative MRI: two due to neural compression, one due to disc herniation and one due to a spinal cord draped over the apex. Thirty-one patients did not receive an MRI; there were no significant differences between the two groups. The rate of postoperative neurologic change was 3.5% in the MRI group and 3.2% in the no-MRI group. CONCLUSIONS: Based on 4.7% of cases requiring a change in the operative plan as a result of preoperative MRI, the authors recommend considering performing screening MRI in operative SK patients.

PURPOSE: To evaluate the performance of diffusion tensor imaging (DTI) in the evaluation of chronic exertional compartment syndrome (CECS) as compared to T(2) -weighted (T2w) imaging. MATERIALS AND METHODS: Using an Institutional Review Board (IRB)-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant protocol, spectral adiabatic inversion recovery (SPAIR) T2w imaging and stimulated echo DTI were applied to eight healthy volunteers and 14 suspected CECS patients before and after exertion. Longitudinal and transverse diffusion eigenvalues, mean diffusivity (MD), and fractional anisotropy (FA) were measured in seven calf muscle compartments, which in patients were classified by their response on T2w: normal (<20% change), and CECS (>20% change). Mixed model analysis of variance compared subject groups and compartments in terms of response factors (post/pre-exercise ratios) of DTI parameters. RESULTS: All diffusivities significantly increased (P < 0.0001) and FA decreased (P = 0.0014) with exercise. Longitudinal diffusion responses were significantly smaller than transversal diffusion responses (P < 0.0001). Nineteen of 98 patient compartments were classified as CECS on T2w. MD increased by 3.8 +/- 3.4% (volunteer), 7.4 +/- 4.2% (normal), and 9.1 +/- 7.0% (CECS) with exercise. CONCLUSION: DTI shows promise as an ancillary imaging method in the diagnosis and understanding of the pathophysiology in CECS. Future studies may explore its utility in predicting response to treatment. J. Magn. Reson. Imaging 2013;. (c) 2013 Wiley Periodicals, Inc.

INTRODUCTION: It has been shown that the asymptomatic, dominant elbow of professional baseball pitchers can demonstrate magnetic resonance (MR) imaging signal abnormalities of the ulnar collateral ligament (UCL) consistent with a strain. The purpose of this study was to determine if younger, asymptomatic, adolescent baseball pitchers exhibit similar signal abnormalities in the UCL. METHODS: Magnetic resonance images of both elbows of 14 asymptomatic, young male baseball pitchers (ranging in age from 12 to 20 years) were performed on an outpatient basis using a 1.5-T Sigma MRI unit with a dedicated extremity coil to obtain T1 and T2 coronal and axial images which were subsequently evaluated by a musculoskeletal radiologist. Chronic tears of the UCL were suspected if the signal was attenuated or absent. Magnetic resonance images of the UCL were also evaluated for high-intensity signal or thinning. Morphologic changes such as complete tears, avulsions or thickening were identified. The images were classified into 4 grades from 0 to 3 depending on the degree of signal abnormality. RESULTS: No discrete tears were found in any of the subjects. For the dominant pitching arm, 4 of 14 subjects had increased thickness of the ulnar collateral ligament, 3 of 14 demonstrated Grade 1 changes, and 11 of 14 demonstrated no abnormal signal within the ligament. No focal tears were present in any of the subjects. Contralateral elbows in 13 of 14 patients demonstrated Grade 0 signals with 1 patient demonstrating morphological thickening of the ligament without increased signal. DISCUSSION: Signal abnormalities in the throwing elbow of asymptomatic, adolescent pitchers were uncommon. These pitchers may not have experienced sufficient pitching time to develop changes in the UCL