Vance T. Lehman

Visual assessment versus quantitative three-dimensional stereotactic surface projection fluorodeoxyglucose positron emission tomography for detection of mild cognitive impairment and Alzheimer disease.

Introduction We examined the clinical impact of commercially available quantitation software using 3-dimensional stereotactic surface projection (3D-SSP) on the diagnostic accuracy of 18F fluorodeoxyglucose positron emission tomography (18F FDG PET) in mild cognitive impairment (MCI) and Alzheimer disease (AD). Methods Enrollees underwent clinical evaluation to determine cognitive status and subsequent 18F FDG PET neuroimaging. Four blinded readers (2 novices and 2 experts) rated the images for degree of abnormality and interpretive confidence without and with 3D-SSP. Diagnostic accuracy was determined with area under the curve (area under the curve) of a receiver operating characteristic (receiver operating characteristic) curve analysis and change in confidence with model-based means (LSMeans). Results Twenty-three normal controls and 31 patients with cognitive impairment (18 MCI and 13 AD) were enrolled (28 female and 26 male; mean age 74 years). During follow-up (mean 3.6 years), all normal participants remained normal, 12 of 18 participants with MCI progressed to dementia, and all participants with baseline dementia progressed. The area under the curve with 3D-SSP (0.88; 95% CI: 0.76–0.95) was significantly higher than without it (0.72; 95% CI: 0.55–0.83). The specificity increased from 26% to 63% for novices and from 56% to 87% for experts with addition of 3D-SSP, whereas the sensitivity was essentially unchanged at 86% and 86% for the beginners and 81% and 79% for the experts. The interpretive confidence increased significantly from 3.3 to 4.0 (maximum value = 5, P = 0.048). Conclusion The use of commercially available 3D-SSP quantitation improved diagnostic accuracy for evaluation of MCI and AD with 18F FDG PET.

Cervical Spine MR Imaging Findings of Patients with Hirayama Disease in North America: A Multisite Study

The authors sought to determine if Hirayama disease in North America has the same imaging findings as it does in Asia. They assessed imaging studies in 21 patients and looked for loss of attachment of posterior dura, lower cord atrophy and high T2 signal, loss of cervical lordosis, and anterior dural shift in flexion. These 4 findings were able to discriminate patients from healthy controls. MR imaging findings in white North American patients with Hirayama disease include loss of attachment on neutral images and forward displacement of the dura with flexion. Findings are often present on neutral MR images and, in the appropriate clinical scenario, should prompt flexion MR imaging to evaluate anterior dural shift. BACKGROUND AND PURPOSE: Most studies of HD have been conducted in Asia, particularly Japan. To characterize the MR imaging findings of North American patients with HD, we reviewed neutral and flexion cervical MR imaging examinations performed for possible HD at 3 academic medical centers located in the Southeastern, Southwestern, and Midwestern regions of the United States. MATERIALS AND METHODS: Three neuroradiologists assessed the MR imaging examinations in a blinded fashion and reached a consensus rating for LOA of the posterior dura to the spine, lower spinal cord atrophy, spinal cord T2 hyperintensity, loss of cervical lordosis, anterior dural shift with flexion, and confidence of imaging diagnosis. Final reference diagnosis was established separately with a retrospective chart review by a neurologist. RESULTS: Twenty-one patients met the criteria for HD, all were North American males and all who reported their race were white. Seventeen patients did not meet the criteria and served as controls. Four imaging attributes, LOA, dural shift with flexion, consensus diagnosis of neutral images, and consensus diagnosis of combined neutral and flexion images were all able to discriminate the group with HD from the group without HD (P < .05 for each). Findings of HD were often present on neutral images, but the addition of flexion images increased diagnostic confidence. CONCLUSIONS: MR imaging findings in white North American patients with HD include LOA on neutral images and forward displacement of the dura with flexion. Findings are often present on neutral MR images and, in the appropriate clinical scenario, should prompt flexion MR imaging to evaluate anterior dural shift.

Position-related variability of CSF opening pressure measurements.

BACKGROUND AND PURPOSE: Normative data for CSF OP have previously been established with patients in the LD position. During fluoroscopically guided LP procedures, radiologists frequently obtain these OP measurements with patients prone. In this prospective study, our goal was to determine the variability of OP measurements as a function of patient positioning and to assess whether there is a relationship with patient BMI. MATERIALS AND METHODS: Consecutive patients reporting for fluoroscopically guided LP or myelography were enrolled. OP was measured with the patient in 3 positions, with the order of the technique randomized: prone with table flat, prone with table tilted until the hub of the needle was at the level of the right atrium, and LD with the needle hub at the level of the spinal canal. The BMI of each patient was calculated. The Wilcoxon signed-rank test and linear regression analysis with bivariate fit of difference were used for analysis. RESULTS: OP measurements with the patient in the prone position were significantly elevated compared with those in the LD position, with mean differences of 2.7 (P < .001) and 1.6 cm H2O, (P = .017) for prone flat and prone tilted, respectively. There was no significant difference in OP measurements for the prone flat versus prone tilted positions (P = .20). There was no correlation between BMI and observed differences (LD-flat: R2 = 0.00028; LD-tilt: R2 = 0.00038; prone-tilt: R2 = 0.00000020). CONCLUSIONS: Measuring OP with the patient in the prone position may result in overestimation of CSF pressure. Table tilt did not significantly impact mean prone OP. Radiologists should specify exact patient positioning when reporting OP measurements.

Frequency of discordance between facet joint activity on technetium Tc99m methylene diphosphonate SPECT/CT and selection for percutaneous treatment at a large multispecialty institution

BACKGROUND AND PURPOSE: The clinical impact of facet joint bone scan activity is not fully understood. The hypothesis of this study is that facet joints targeted for percutaneous treatment in clinical practice differ from those with reported activity on technetium Tc99m methylene diphosphonate SPECT/CT. MATERIALS AND METHODS: All patients with a technetium Tc99m methylene diphosphonate SPECT/CT scan of the lumbar or cervical spine who underwent subsequent percutaneous facet joint steroid injection or comparative medial branch blocks at our institution between January 1, 2008, and February 19, 2013, were identified. Facet joints with increased activity were compared with those treated. A chart review characterized the clinical reasons for treatment discrepancies. RESULTS: Of 74 patients meeting inclusion criteria, 52 (70%) had discrepant imaging findings and treatment selection of at least 1 facet joint, whereas 34 patients (46%) had a side (right vs left) discrepancy. Only 92 (70%) of 132 facet joints with increased activity were treated, whereas 103 (53%) of 195 of treated facet joints did not have increased activity. The most commonly documented clinical rationale for discrepancy was facet joint activity that was not thought to correlate with clinical findings, cited in 18 (35%) of 52 patients. CONCLUSIONS: Facet joints undergoing targeted percutaneous treatment were frequently discordant with those demonstrating increased technetium Tc99m methylene diphosphonate activity identified by SPECT/CT at our institution, in many cases because the active facet joint(s) did not correlate with clinical findings. Further prospective double-blinded investigations of the clinical significance of facet joint activity by use of technetium Tc99m methylene diphosphonate SPECT/CT and comparative medial branch blocks are needed.

99mTc-MDP SPECT/CT of the spine and sacrum at a multispecialty institution: clinical use, findings, and impact on patient management.

ObjectiveThe use of technetium-99m methylene diphosphonate single-photon emission tomography/computed tomography (99mTc-MDP SPECT/CT) of the spine and sacrum has increased over the past years; however, there is little information about the optimal clinical role and true clinical impact of this modality. MethodsAll 99mTc-MDP SPECT/CT examinations of the spine and sacrum performed at our large multispecialty institution between 1 January 2008 and 12 April 2012 were identified. The indications, findings, clinical context, and impact on patient management were identified through a retrospective chart review. ResultsOf the 212 99mTc-MDP SPECT/CT examinations of the spine and sacrum identified, 191 (90%) were for pain evaluation, 14 (7%) were to assess infection, and seven (3%) were to evaluate a potential malignancy. The most common specific indication was evaluation of facet joint pain in 70/191 (37%) patients, and the most common finding was facet joint activity in 106/212 (50%) patients. Several findings were reported, although facet joint activity was the most frequent. The other findings included costovertebral joint activity, pars interarticularis defects, an osteoid osteoma, a lumbosacral pseudoarticulation, and a postoperative pseudoarthrosis. A resultant change in clinical management was documented in 168/212 (79%) patients. Ninety-two of the 212 (44%) patients had undergone an MRI of the same region for any indication within ±6 months. Conclusion99mTc-MDP SPECT/CT of the spine and sacrum is most frequently used for the diagnosis and management of pain. It helps identify several potential pain generators, is often used in patients who have a near-contemporaneous MRI, and has an impact on the procedural and/or conservative management in most patients. In addition, several areas in need of future research to establish the optimal clinical role of this modality were identified.

Facet Joint Signal Change on MRI at Levels of Acute/Subacute Lumbar Compression Fractures

BACKGROUND AND PURPOSE: The prevalence of facet joint signal change in acute/subacute lumbar vertebral body compression fractures is unknown. We hypothesized that facet joint signal change on MR imaging is more common in facet joints associated with an acute/subacute lumbar compression fracture than those associated with normal vertebral bodies or ones that have a chronic compression fracture. MATERIALS AND METHODS: Three neuroradiologists and a neuroradiology fellow retrospectively graded facet joint inflammatory change on MR imaging in 900 facet joints in 75 patients with at least 1 painful osteoporotic lumbar compression fracture. Facet joint signal change was assessed on T2-weighted images with chemical fat-saturation, STIR images, and/or gadolinium-enhanced T1-weighted images with chemical fat-saturation. Each facet joint from the T12/L1 to L5/S1 level was assessed individually. An overall facet joint signal-change score, which is a composite measure of the grade of signal change for all 4 facet joints associated with a given lumbar vertebral level, was devised, and statistical significance was assessed via Wilcoxon rank sum tests. RESULTS: The overall facet joint signal-change scores were significantly higher at vertebral body levels affected by an acute/subacute compression fracture compared with control levels, which were associated with either normal bodies or chronic compression fractures. CONCLUSIONS: Our findings suggest an association between facet joint signal change on MR imaging and acute/subacute lumbar vertebral body compression fractures.

The Effectiveness of Repeat Lumbar Transforaminal Epidural Steroid Injections

OBJECTIVE The aim of this study was to determine 1) if repeat lumbar transforaminal epidural steroid injections (TFESIs) resulted in recovery of pain relief, which has waned since an index injection, and 2) if cumulative benefit could be achieved by repeat injections within 3 months of the index injection. DESIGN Retrospective observational study with statistical modeling of the response to repeat TFESI. SETTING Academic radiology practice. PATIENTS Two thousand eighty-seven single-level TFESIs were performed for radicular pain on 933 subjects. Subjects received repeat TFESIs >2 weeks and <1 year from the index injection. METHODS Hierarchical linear modeling was performed to evaluate changes in continuous and categorical pain relief outcomes after repeat TFESI. Subgroup analyses were performed on patients with <3 months duration of pain (acute pain), patients receiving repeat injections within 3 months (clustered injections), and in patients with both acute pain and clustered injections. RESULTS Repeat TFESIs achieved pain relief in both continuous and categorical outcomes. Relative to the index injection, there was a minimal but statistically significant decrease in pain relief in modeled continuous outcome measures with subsequent injections. Acute pain patients recovered all prior benefit with a statistically significant cumulative benefit. Patients receiving clustered injections achieved statistically significant cumulative benefit, of greater magnitude in acute pain patients. CONCLUSION Repeat TFESI may be performed for recurrence of radicular pain with the expectation of recovery of most or all previously achieved benefit; acute pain patients will likely recover all prior benefit. Repeat TFESIs within 3 months of the index injection can provide cumulative benefit.

Benign fibrous dysplasia on [11C]choline PET: a potential mimicker of disease in patients with biochemical recurrence of prostate cancer

We present the case of a 74-year-old male with biochemical recurrence of prostate cancer who underwent [11C]choline PET/CT. The PET/CT demonstrated an intense focus of uptake within the skull base that was initially felt to potentially represent metastatic disease. Subsequent evaluation with MRI and dedicated thin-section CT revealed this area to be benign fibrous dysplasia of the bone. The focal uptake on PET/CT with [11C]choline in benign fibrous dysplasia represents a potential mimicker of metastatic disease. Due to recognizing this benign process, our patient was able to avoid systemic treatment and/or focal radiation and was treated with cryotherapy for biopsy-proven local recurrence within the prostate bed. While benign fibrous dysplasia can demonstrate increased radiotracer uptake on other modalities (i.e., bone scintigraphy, FDG PET/CT), its appearance on [11C]choline PET/CT has been largely overlooked in the literature. With the increasing use of [11C]choline PET/CT for biochemical recurrent prostate cancer evaluation, it is important to understand this potential mimicker of disease.

Fluoroscopically guided transforaminal epidural steroid injections at a quaternary-care teaching institution: effect of trainee involvement and patient body mass index on fluoroscopy time and patient dose

AIM To investigate whether there are differences in fluoroscopy time and patient dose for fluoroscopically guided lumbar transforaminal epidural steroid injections (TFESIs) performed by staff radiologists versus with trainees and to evaluate the effect of patient body mass index (BMI) on fluoroscopy time and patient dose, including their interactions with other variables. MATERIALS AND METHODS Single-level lumbar TFESIs (n=1844) between 1 January 2011 and 31 December 2013 were reviewed. Fluoroscopy time, reference point air kerma (Ka,r), and kerma area product (KAP) were recorded. BMI and trainee involvement were examined as predictors of fluoroscopy time, Ka,r, and KAP in models adjusted for age and gender in multivariable linear models. Stratified models of BMI groups by trainee presence were performed. RESULTS Increased age was the only significant predictor of increased fluoroscopy time (p<0.0001). Ka,r and KAP were significantly higher in patients with a higher BMI (p<0.0001 and p=0.0009). When stratified by BMI, longer fluoroscopy time predicted increased Ka,r and KAP in all groups (p<0.0001). Trainee involvement was not a statistically significant predictor of fluoroscopy time or Ka,r in any BMI category. KAP was lower with trainees in the overweight group (p=0.0009) and higher in male patients for all BMI categories (p<0.02). CONCLUSION Trainee involvement did not result in increased fluoroscopy time or patient dose. BMI did not affect fluoroscopy time; however, overweight and obese patients received significantly higher Ka,r and KAP. Male patients received a higher KAP in all BMI categories. Limiting fluoroscopy time and good collimation practices should be reinforced in these patients.

Percutaneous vertebroplasty for painful compression fractures in a small cohort of patients with a decreased expectation-related placebo effect due to dementia

BACKGROUND AND PURPOSE: Although abundant literature has reported success with vertebroplasty for the treatment of painful compression fractures, none has accounted for a potential expectation-related placebo effect. We report the results of vertebroplasty for painful vertebral body compression fractures in a small cohort of patients with dementia with the assumption that this patient subgroup is subjected to a decreased placebo effect. MATERIALS AND METHODS: All patients with objective evidence of dementia (N = 10) who had undergone vertebroplasty at our institution were identified from a comprehensive prospectively constructed vertebroplasty data base. The patients’ pain at rest and activity, mobility, and pain-medication use were analyzed at 2 hours postprocedure, 1 week, 1 month, 6 months, and 1 year. RESULTS: Pain with activity decreased or resolved in 80%–100% of patients at each time point, whereas pain at rest decreased or resolved in 78%–100% of all patients at each time point. Improved mobility was reported in 80%–100% of patients at all time points. Pain medication was decreased or stopped in 67% of patients at 1 week and in 100% of patients at 6 months and 1 year. CONCLUSION: Treatment of painful compression fractures in patients with dementia demonstrates a high rate of success regarding pain relief and mobility. This study offers additional evidence that vertebroplasty has true benefit.