Comparison of [18F] FDG-PET/MRI and Clinical Findings for Assessment of Suspected Lumbar Facet Joint Pain: A Prospective Study to Characterize Candidate Nonanatomic Imaging Biomarkers and Potential Impact on Management.

BACKGROUND AND PURPOSE: Prior retrospective studies have suggested that both T2 hyperintensity and gadolinium enhancement on fat-suppressed MR imaging are associated with lumbar facet joint pain, but prospective evaluation of FDG-PET/MR imaging with a standardized protocol and correlation to clinical findings are lacking. The primary aim was to prospectively assess a standardized FDG-PET/MRI protocol in patients with suspected facetogenic low back pain, with determination of the concordance of imaging and clinical findings. MATERIALS AND METHODS: Ten patients with clinically suspected facetogenic low back pain were prospectively recruited with a designation of specific facet joints implicated clinically. Subsequently, patients underwent an FDG-PET/MR imaging examination with gadolinium. Each facet joint was graded for perifacet signal change on MR imaging and FDG activity. The frequency and correlation of MR imaging, FDG-PET, and clinical findings were determined. RESULTS: FDG activity showed high concordance with high overall MR imaging scores (concordance correlation coefficient = 0.79). There was concordance of the clinical side of pain with the side of high overall MR imaging scores and increased FDG activity on 12/20 (60%) sides. Both a high overall MR imaging score (concordance correlation coefficient = 0.12) and FDG-PET findings positive for increased activity (concordance correlation coefficient = 0.10) had low concordance with the specific clinically implicated facet joints. Increased FDG activity or high MR imaging scores or both were present in only 10/29 (34%) facet joints that had been clinically selected for percutaneous intervention. Eleven (11%) facet joints that had not been selected for treatment demonstrated these imaging findings. CONCLUSIONS: There was low concordance of perifacet signal change and FDG activity with clinically implicated facet joints. This could indicate either the potential to change patient management or a lack of biomarker accuracy. Therefore, additional larger randomized studies with the use of comparative medial branch blocks would be useful to further investigate the clinical utility of these findings.

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.

The posterior ligamentous complex inflammatory syndrome: spread of fluid and inflammation in the retrodural space of Okada.

The retrodural space of Okada is situated dorsal to the ligamentum flavum in the interlaminar space, and provides communication between contralateral facet joints. MRI will often demonstrate heterogeneous signal abnormality with contrast enhancement in this space and several communicating compartments of the posterior ligamentous complex: bilateral facet joints, adventitial interspinous bursae, or retrodural cysts penetrating the ligamentum flavum. Pars interarticularis defects are frequently present. This imaging pattern may be associated with axial low back pain and/or radicular pain. Recognition of this pattern at MRI has distinct implications for image interpretation, unifying prior reports of involvement of individual components of the posterior ligamentous complex. Its recognition will also affect planning for therapeutic interventional pain procedures. We refer to this constellation of imaging and clinical findings as posterior ligamentous complex inflammatory syndrome (PLCIS).

Correlation of the Patient Reported Outcomes Measurement Information System with legacy outcomes measures in assessment of response to lumbar transforaminal epidural steroid injections.

BACKGROUND AND PURPOSE: The Patient Reported Outcomes Measurement Information System is a newly developed outcomes measure promulgated by the National Institutes of Health. This study compares changes in pain and physical function-related measures of this system with changes on the Numeric Rating Pain Scale, Roland Morris Disability Index, and the European Quality of Life scale 5D questionnaire in patients undergoing transformational epidural steroid injections for radicular pain. MATERIALS AND METHODS: One hundred ninety-nine patients undergoing transforaminal epidural steroid injections for radicular pain were enrolled in the study. Before the procedure, they rated the intensity of their pain by using the 0-10 Numeric Rating Pain Scale, Roland Morris Disability Index, and European Quality of Life scale 5D questionnaire. Patients completed the Patient Reported Outcomes Measurement Information System Physical Function, Pain Behavior, and Pain Interference short forms before transforaminal epidural steroid injections and at 3 and 6 months. Seventy and 43 subjects replied at 3- and 6-month follow-up. Spearman rank correlations were used to assess the correlation between the instruments. The minimally important differences were calculated for each measurement tool as an indicator of meaningful change. RESULTS: All instruments were responsive in detecting changes at 3- and 6-month follow-up (P < .0001). There was significant correlation between changes in Patient Reported Outcomes Measurement Information System scores and legacy questionnaires from baseline to 3 months (P < .05). There were, however, no significant correlations in changes from 3 to 6 months with any of the instruments. CONCLUSIONS: The studied Patient Reported Outcomes Measurement Information System domains offered responsive and correlative psychometric properties compared with legacy instruments in a population of patients undergoing transforaminal epidural steroid injections for radicular pain.

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.

Immediate pain response does not predict long-term outcome of CT-guided cervical transforaminal epidural steroid injections.

BACKGROUND AND PURPOSE: Imaging-guided cervical transforaminal epidural steroid injections have been shown to decrease verbal numerical pain scores and improve functionality (Roland Morris Disability Index). These injections are often administered in combination with local anesthetic. The purpose of this study was to determine if the immediate postprocedure VNPS predicts the long-term effectiveness of the injection. MATERIALS AND METHODS: A quality assurance data base review of 247 patient records was used to document the VNPS and RMDI of patients undergoing a single CT-guided CTESI. Pain scores were recorded before the procedure, immediately after the procedure, at 2 weeks, and at 2 months. The RMDI was recorded before the procedure, at 2 weeks, and at 2 months. Spearman rank correlation analysis and logistic regression models were used to determine if the immediate postprocedure or 2-week VNPS correlated with or predicted the longer-term VNPS and RMDI as measured at 2 weeks and 2 months. RESULTS: There was not a strong correlation between the pain score obtained immediately after the procedure and the 2-month outcome of the VNPS or RMDI. The pain scores at 2 weeks did correlate with the 2-month outcomes. The 2-week VNPS also was a significant predictor of patients who would achieve a >50% improvement in VNPS or RMDI at 2 months. CONCLUSIONS: Pain scores obtained immediately after completion of a single CT-guided CTESI do not predict the long-term effectiveness of this procedure. However, patient response at 2 weeks does correlate with the long-term effectiveness of these injections as measured by the VNPS and the RMDI.

Safety and efficacy of CT-guided transforaminal cervical epidural steroid injections using a posterior approach.

BACKGROUND AND PURPOSE: Image-guided cervical transforaminal epidural injections play an important role in the management of cervical radicular pain syndromes. The safety and efficacy of these injections via an anterolateral approach has been well-studied. The goal of this retrospective review was to determine the safety and efficacy of CT-guided transforaminal epidural injections by using a posterior approach. MATERIALS AND METHODS: Retrospective review of patient records was used to define VNPS and RMDI of patients undergoing CT-guided transforaminal cervical epidural injections between 2006 and 2010. Pain scores were recorded preprocedure, immediately postprocedure, at 2 weeks, and at 2 months. The RMDI was recorded preprocedure, at 2 weeks, and at 2 months. Data analysis of 247 patients was completed. Differences in VNPS scores and the RMDI were then compared on the basis of a CT-guided approach (anterolateral versus posterior). RESULTS: There was no statistical difference in the degree of pain relief and improvement in the RMDI between the CT-guided transforaminal anterolateral approach and the posterior approach at 2 weeks and at 2 months. Both groups demonstrated a statistically significant improvement in pain scores and the RMDI. Approximately 35% of patients in both groups demonstrated >50% pain relief at 2 months. There were no serious complications in either group. CONCLUSIONS: CT-guided transforaminal cervical epidural injections by using a posterior approach are safe and effective.

Acute pulmonary embolism: assessment of helical CT for diagnosis.

PURPOSE: To determine the sensitivity and specificity of helical computed tomography (CT) for the diagnosis of acute pulmonary embolism. MATERIALS AND METHODS: This prospective study included 47 patients who underwent pulmonary arteriography for evaluation for possible acute pulmonary embolism. Tailored helical CT and pulmonary arteriography were performed within 24 hours of each other. Each CT scan was interpreted by two chest radiologists, blinded to arteriographic results, at two institutions. CT scan interpretations were compared with findings on bilateral selective pulmonary arteriograms interpreted by two vascular radiologists at one institution. RESULTS: Fifteen (32%) of 47 patients had angiographically proved pulmonary embolism. For the readers at the first institution, helical CT had 60% sensitivity, 81% specificity, 60% positive predictive value, 81% negative predictive value, and 75% overall accuracy. For the readers at the second institution, helical CT had 53% sensitivity, 97% specificity, 89% positive predictive value, 82% negative predictive value, and 83% accuracy. CONCLUSION: Detection of pulmonary embolism with helical CT may be less accurate than previously reported. Given its high specificity but relatively low sensitivity, helical CT may not have the ideal attributes of a first-line imaging study for the diagnosis of pulmonary embolism.

Fast CT for pulmonary embolus.

Recent technical advances in CT have led to the ability to scan a volume in a shorter period with optimal contrast opacification of blood vessels, including the pulmonary arteries. Initially, there were isolated instances of an accidental detection of a filling defect because of pulmonary embolus in the pulmonary arteries. Gradually, directed examinations were introduced to diagnose or exclude pulmonary embolus. These examinations were successful. Radiologists and clinicians now are turning to fast CT for this purpose for a variety of reasons, including the proven accuracy and reliability of the method and the relative deficiencies of traditional noninvasive methods. Accurate interpretation of CT scans for possible pulmonary embolus depends on the ability to conduct a high-quality examination and to recognize the spectrum of findings for both acute and chronic emboli. This article reviews the history of fast CT pulmonary angiography, and it presents both technical and diagnostic information germaine to the performance of this technique.

Pulmonary embolism: diagnosis with contrast-enhanced electron-beam CT and comparison with pulmonary angiography.

PURPOSE: To determine the sensitivity and specificity of contrast material-enhanced electron-beam computed tomography (CT) in the diagnosis of pulmonary embolism (PE). MATERIALS AND METHODS: Sixty patients suspected of having PE were prospectively evaluated with pulmonary angiography and contrast-enhanced electron-beam CT. Thirty-eight patients underwent ventilation-perfusion (V-P [also known as V/Q]) scanning. The pulmonary vasculature was divided into 12 anatomic zones. CT and angiographic findings were correlated on a patient-by-patient basis and for each vascular zone. RESULTS: Both studies were negative for PE in 36 patients. Both studies were positive in 15 patients, with the site of the emboli correlating well. Prospective sensitivity of CT was 65%; specificity, 97%; positive predictive value, 94%; and negative predictive value, 82%. After review of the nine discordant cases, sensitivity and specificity approached 100% for clinically important acute PE. CT depicted central and peripheral emboli equally well. CT was more sensitive and specific than V-P scanning. CONCLUSION: Electron-beam CT is a sensitive and specific noninvasive method for the diagnosis of PE. It has the potential to replace V-P scanning as the primary screening examination for PE.

Management of inferior pancreaticoduodenal artery aneurysms: a 4-year, single center experience.

Inferior pancreaticoduodenal artery aneurysms are uncommon visceral artery aneurysms usually difficult to resect, and, if untreated, have a propensity to rupture with catastrophic results. We reviewed the clinical and treatment records of four patients encountered in our institution within the last 4 years. Three patients presented as bleeding emergencies from single aneurysms and were successfully treated by transcatheter embolization using coaxial technique and a variety of embolic agents. One nonemergent, asymptomatic patient had surgical resection of two inferior pancreaticoduodenal artery aneurysms due to unfavorable anatomy for embolization. Embolization therapy appears to be the treatment of choice in the emergency setting. Patients with unsuitable anatomy for embolization may still require surgical intervention.

Popliteal artery aneurysms: the risk of nonoperative management.

To evaluate the risk of nonoperative management of popliteal artery aneurysms (PAAs), a retrospective cohort study of 106 consecutive patients (103 males and 3 females) with PAAs seen between January 1, 1980, and December 31, 1985, was performed. The mean age was 70.5 years (range 50 to 90 years). The 106 patients with 161 PAAs were followed for a mean of 6.7 years (range 3 days to 12.1 years). Follow-up was complete in 91.5% (97/106) of the patients. PAA was confirmed by ultrasonography in 124 limbs (77%), arteriography only in 7 (4.3%), and physical examination only in 32 (19.9%). Fifteen limbs presented with acute symptoms, 52 with chronic symptoms, and 94 were asymptomatic. Five of the 15 limbs with acute symptoms (33%) underwent amputation (4 primary, 1 secondary). PAAs in 23 of the 52 limbs with chronic symptoms were repaired; 2 limbs required amputation (8.7%). Twenty-seven of the 94 asymptomatic limbs were repaired initially; 1 required amputation (3.7%). The remaining 67 asymptomatic limbs were initially managed nonoperatively. Amputation was required in 3 of 67 limbs (4.4%), 1 with acute symptoms and 2 with chronic symptoms, all of which had undergone attempted repair. Symptoms (3 acute, 9 chronic) eventually developed in 12 (17.9%). At least one of three risk factors (size > 2 cm, thrombus, and poor runoff) was initially present in 11 of 12 limbs (91.7%) compared with 9 of 24 control limbs (37.5%) that remained asymptomatic (p < 0.05). Amputation rates in symptomatic patients with PAAs continues to be high. In patients with asymptomatic PAAs, aneurysm size > 2 cm, thrombus, or poor runoff predicted the development of symptoms. PAA patients with any of these factors should undergo elective repair, even asymptomatic patients who have a reasonable chance for long-term survival.

Pulmonary embolism: diagnosis with electron-beam CT.

Contrast material-enhanced electron-beam computed tomography (CT) (100-msec scan time) was performed to image the pulmonary vasculature in 86 patients, each suspected of having a pulmonary embolism (PE). Thromboembolic material was demonstrated in 39 patients; no emboli were demonstrated in 47. In 25 patients, angiographic or pathologic proof was available. There were 19 proved positive CT scans, four proved negative scans, one false-negative scan, and one false-positive scan. In the 21 patients with CT and angiographic correlation, evidence of thromboembolic disease was seen in 88 vascular zones. Fifty-three zones were positive for PE at both CT and angiography. Eighteen zones were positive for PE at angiography alone, and 17 zones were positive at CT alone. Electron-beam CT is a potentially effective noninvasive means of diagnosing PE.

Diagnostic features and clinical outcome of ischemic-type biliary complications after liver transplantation.

The clinical significance and outcome of nonanastomotic strictures and dilatations involving only the biliary tree of the graft with a radiological appearance of biliary ischemia is unknown. Therefore we analyzed the grafts of 128 patients to evaluate the biochemical, radiological and histological features that prompted the diagnosis of ischemic-type biliary stricture and the clinical outcome of this complication. Ischemic-type biliary strictures were diagnosed in 25 patients (19%). Initial graft function was similar in all patients, whether or not this complication developed. Most ischemic-type biliary strictures occurred between 1 and 4 mo after orthotopic liver transplantation. However, the appearance of ischemic-type biliary stricture in the month after transplantation was predictive for a poor outcome in all six grafts with early onset of ischemic-type biliary strictures. Eighteen patients (72%) were treated with biliary stents and repeated dilatations. Long-term patency was achieved in 88% of these patients. Repeat transplantation was performed in six patients (24%); five survived. Finally, patients with ischemic-type biliary strictures spent more time in the hospital during the first year after orthotopic liver transplantation than did patients without the complication (62 +/- 27 days vs. 37 +/- 20 days; p < or = 0.001). This was due to repeated hospitalizations and a higher incidence of retransplantation. One-year graft survival was lower in patients with ischemic-type biliary strictures than in patients without ischemic-type biliary strictures (69% vs. 88%; p = 0.006). However, 1-yr patient survival was similar in the two groups (91% vs. 89%). In conclusion, early appearance of ischemic-type biliary stricture features is associated with poor graft prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Ischemic-type biliary complications after orthotopic liver transplantation.

Nonanastomotic biliary strictures that involve only the biliary tree of the graft occur after orthotopic liver transplantation in patients with hepatic artery thrombosis, chronic ductopenic rejection and ABO blood group incompatibility. This complication may also occur in the absence of these known risk factors. The major focus of our study was to evaluate the risk factors for nonanastomotic biliary stricturing of unknown cause after orthotopic liver transplantation. Results demonstrate that the development of biliary strictures is strongly associated with the duration of cold ischemic storage of allografts in both Euro-Collins solution and University of Wisconsin solution. Results also demonstrate that strictures are not associated with the type of biliary reconstruction, the primary liver disease, cytomegalovirus infection, allograft rejection or the presence of a positive lymphocytotoxic crossmatch. More recently, we have markedly reduced the occurrence of nonanastomotic biliary stricturing by decreasing the ischemia time of our allografts. Thus nonanastomotic biliary strictures appear to be the result of the ischemia/reperfusion-induced tissue injury associated with the harvest and implantation of allografts.

Hilar biliary strictures after liver transplantation: cholangiography and percutaneous treatment.

Nonanastomotic hilar bile duct strictures developed in 16 of 152 patients who underwent liver transplantation. The type of pretransplantation liver disease did not significantly affect the likelihood of hilar stricture formation. Possible causes of hilar biliary strictures include hepatic artery occlusion, ductopenic arteriopathic rejection, and cytomegalovirus infection; however, five of the 16 patients had hilar strictures without these complications. Hilar strictures developed within 3 months after transplantation in 11 of the 16 patients. Strictures began as a slight common hepatic duct irregularity and progressed to mucosal cast formation and later to firm strictures. Fifteen of the 16 patients underwent percutaneous stricture dilation. Of 12 patients who no longer have stents, four have had no stricture recurrence for 12-30 months. Eight patients have had to undergo retransplantation or have died. Percutaneous dilations were most likely to result in patient bile ducts if strictures developed within 3 months after transplantation and in the absence of pretransplantation primary sclerosing cholangitis, ductopenic arteriopathic rejection, cytomegalovirus infection, or hepatic artery thrombosis.