Disease activity in large-vessel vasculitis (LVV) is traditionally assessed by clinical and serological variables rather than vascular imaging. This study determined the effect of treatment on ...18F-fluorodeoxyglucose positron emission tomography (FDG-PET) vascular activity in relation to clinical- and serologic-based assessments.
Patients with giant cell arteritis (GCA) or Takayasu arteritis (TA) were prospectively evaluated at 6-month intervals in an observational cohort. Treatment changes were made at least 3 months before the followup visit and categorized as increased, decreased, or unchanged. Imaging (FDG-PET qualitative analysis), clinical, and serologic (erythrocyte sedimentation rate, C-reactive protein) assessments were determined at each visit and compared over interval visits.
Serial assessments were performed in 52 patients with LVV (GCA = 31; TA = 21) over 156 visits. Increased, decreased, or unchanged therapy was recorded for 36-, 23-, and 32-visit intervals, respectively. When treatment was increased, there was significant reduction in disease activity by imaging, clinical, and inflammatory markers (p ≤ 0.01 for each). When treatment was unchanged, all 3 assessments of disease activity remained similarly unchanged over 6-month intervals. When treatment was reduced, PET activity significantly worsened (p = 0.02) but clinical and serologic activity did not significantly change. Treatment of GCA with tocilizumab and of TA with tumor necrosis factor inhibitors resulted in significant improvement in imaging and clinical assessments of disease activity, but only rarely did the assessments both become normal.
In addition to clinical and serologic assessments, vascular imaging has potential to monitor disease activity in LVV and should be tested as an outcome measure in randomized clinical trials.
Psoriasis, a chronic immune-mediated disease, is associated with an increased risk of cardiovascular events and mortality. Secukinumab selectively neutralizes IL-17A and has reported high efficacy ...with a favorable safety profile in various psoriatic disease manifestations. Subsequent to the 12-week randomized, placebo-controlled, double-blind treatment period, patients with moderate-to-severe psoriasis received secukinumab for 40 weeks. Vascular inflammation using 18F-2-fluorodeoxyglucose–positron emission tomography/computed tomography imaging and blood-based cardiometabolic was assessed at week 0, 12, and 52. The difference in change in aortic inflammation from baseline to week 12 for secukinumab (n = 46) versus placebo (n = 45) was –0.053 (95% confidence interval = –0.169 to 0.064; P= 0.37). Small increases in total cholesterol, low-density lipoprotein, and low-density lipoprotein particles, but no changes in markers of inflammation, adiposity, insulin resistance, or predictors of diabetes, were observed with secukinumab treatment compared with placebo. At week 52, reductions in TNF-α (P= 0.0063) and ferritin (P= 0.0354), and an increase in fetuin-A (P= 0.0024), were observed with secukinumab treatment compared with baseline. No significant changes in aortic inflammation or markers of advanced lipoprotein characterization, adiposity, or insulin resistance were observed with secukinumab treatment compared with baseline. Secukinumab exhibited a neutral impact on aortic vascular inflammation and biomarkers of cardiometabolic disease after 52 weeks of treatment.
To compare the presence of head, neck and upper extremity symptoms in patients with Takayasu's (TAK) and giant cell arteritis (GCA) and their association with vascular inflammation assessed by
...F-fluorodeoxyglucose positron emission tomography (FDG-PET) or arterial damage assessed by magnetic resonance angiography (MRA).
Patients with TAK and GCA underwent clinical and imaging assessments within 24 hours, blinded to each other. Vascular inflammation was defined as arterial FDG-PET uptake greater than liver by visual assessment. Arterial damage was defined as stenosis, occlusion, or aneurysm by MRA. Clinically reported symptoms were compared with corresponding imaging findings using generalised mixed model regression. Cranial symptoms were studied in association with burden of arterial disease in the neck using ordinal regression.
Participants with TAK (n=56) and GCA (n=54) contributed data from 270 visits. Carotidynia was reported only in patients with TAK (21%) and was associated with vascular inflammation (p<0.01) but not damage (p=0.33) in the corresponding carotid artery. Posterior headache was reported in TAK (16%) and GCA (20%) but was only associated with corresponding vertebral artery inflammation and damage in GCA (p<0.01). Arm claudication was associated with subclavian artery damage (p<0.01) and inflammation (p=0.04) in TAK and with damage in GCA (p<0.01). Patients with an increased burden of damaged neck arteries were more likely to experience positional lightheadedness (p<0.01) or a major central nervous system event (p=0.01).
The distribution of symptoms and association with imaging abnormalities differs in patients with TAK and GCA. These findings may help clinicians predict associated FDG-PET and MRA findings based on a specific clinical symptom.
NCT02257866.
Cardiac PET is a versatile imaging technique providing important diagnostic information about ischemic heart diseases. Respiratory and cardiac motion of the heart can strongly impair image quality ...and therefore diagnostic accuracy of cardiac PET scans. The aim of this study was to investigate a new cardiac PET/MR approach providing respiratory and cardiac motion-compensated MR and PET images in less than 5 min.
Free-breathing 3-dimensional MR data were acquired and retrospectively binned into multiple respiratory and cardiac motion states. Three-dimensional cardiac and respiratory motion fields were obtained with a nonrigid registration algorithm and used in motion-compensated MR and PET reconstructions to improve image quality. The improvement in image quality and diagnostic accuracy of the technique was assessed in simultaneous
F-FDG PET/MR scans of a canine model of myocardial infarct and was demonstrated in a human subject.
MR motion fields were successfully used to compensate for in vivo cardiac motion, leading to improvements in full width at half maximum of the canine myocardium of 13% ± 5%, similar to cardiac gating but with a 90% ± 57% higher contrast-to-noise ratio between myocardium and blood. Motion correction led to an improvement in MR image quality in all subjects, with an increase in sharpness of the canine coronary arteries of 85% ± 72%. A functional assessment showed good agreement with standard MR cine scans with a difference in ejection fraction of -2% ± 3%. MR-based respiratory and cardiac motion information was used to improve the PET image quality of a human in vivo scan.
The MR technique presented here provides both diagnostic and motion information that can be used to improve MR and PET image quality. Reliable respiratory and cardiac motion correction could make cardiac PET results more reproducible.
Dose-adjusted-EPOCH-R obviates the need for radiotherapy in most patients with primary mediastinal B-cell lymphoma. End-of-treatment PET, however, does not accurately identify patients at risk of ...treatment failure, thereby confounding clinical decision making. To define the role of PET in primary mediastinal B-cell lymphoma following dose-adjusted-EPOCH-R, we extended enrollment and follow up on our published phase II trial and independent series. Ninety-three patients received dose-adjusted-EPOCH-R without radiotherapy. End-of-treatment PET was performed in 80 patients, of whom 57 received 144 serial scans. One nuclear medicine physician from each institution blindly reviewed all scans from their respective institution. End-of-treatment PET was negative (Deauville 1-3) in 55 (69%) patients with one treatment failure (8-year event-free and overall survival of 96.0% and 97.7%). Among 25 (31%) patients with a positive (Deauville 4-5) end-of-treatment PET, there were 5 (20%) treatment failures (8-year event-free and overall survival of 71.1% and 84.3%). Linear regression analysis of serial scans showed a significant decrease in SUV
in positive end-of-treatment PET non-progressors compared to an increase in treatment failures. Among 6 treatment failures, the median end-of-treatment SUV
was 15.4 (range, 1.9-21.3), and 4 achieved long-term remission with salvage therapy. Virtually all patients with a negative end-of-treatment PET following dose-adjusted-EPOCH-R achieved durable remissions and should not receive radiotherapy. Among patients with a positive end-of-treatment PET, only 5/25 (20%) had treatment-failure. Serial PET imaging distinguished end-of-treatment PET positive patients without treatment failure, thereby reducing unnecessary radiotherapy by 80%, and should be considered in all patients with an initial positive PET following dose-adjusted-EPOCH-R (
).
The use of fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging to detect vascular inflammation is increasingly common in the clinical management of patients with large-vessel vasculitis ...(LVV). In this review, the role of FDG-PET imaging to diagnose and monitor vascular disease activity will be detailed. Suggestions on incorporation of FDG-PET imaging into a clinical workflow will be provided with emphasis on patient preparation, image acquisition, and image interpretation. If FDG-PET imaging is obtained, multimodal imaging assessment, whereby FDG-PET imaging and non-invasive angiography are obtained concurrently, and correlation of imaging findings with clinical assessment is generally advisable. Considering the clinical scenario and treatment status of the patient is important when interpreting vascular FDG-PET image findings.
Purpose To investigate whether photon-counting detector (PCD) technology can improve dose-reduced chest computed tomography (CT) image quality compared with that attained with conventional ...energy-integrating detector (EID) technology in vivo. Materials and Methods This was a HIPAA-compliant institutional review board-approved study, with informed consent from patients. Dose-reduced spiral unenhanced lung EID and PCD CT examinations were performed in 30 asymptomatic volunteers in accordance with manufacturer-recommended guidelines for CT lung cancer screening (120-kVp tube voltage, 20-mAs reference tube current-time product for both detectors). Quantitative analysis of images included measurement of mean attenuation, noise power spectrum (NPS), and lung nodule contrast-to-noise ratio (CNR). Images were qualitatively analyzed by three radiologists blinded to detector type. Reproducibility was assessed with the intraclass correlation coefficient (ICC). McNemar, paired t, and Wilcoxon signed-rank tests were used to compare image quality. Results Thirty study subjects were evaluated (mean age, 55.0 years ± 8.7 standard deviation; 14 men). Of these patients, 10 had a normal body mass index (BMI) (BMI range, 18.5-24.9 kg/m
; group 1), 10 were overweight (BMI range, 25.0-29.9 kg/m
; group 2), and 10 were obese (BMI ≥30.0 kg/m
, group 3). PCD diagnostic quality was higher than EID diagnostic quality (P = .016, P = .016, and P = .013 for readers 1, 2, and 3, respectively), with significantly better NPS and image quality scores for lung, soft tissue, and bone and with fewer beam-hardening artifacts (all P < .001). Image noise was significantly lower for PCD images in all BMI groups (P < .001 for groups 1 and 3, P < .01 for group 2), with higher CNR for lung nodule detection (12.1 ± 1.7 vs 10.0 ± 1.8, P < .001). Inter- and intrareader reproducibility were good (all ICC > 0.800). Conclusion Initial human experience with dose-reduced PCD chest CT demonstrated lower image noise compared with conventional EID CT, with better diagnostic quality and lung nodule CNR.
RSNA, 2017 Online supplemental material is available for this article.
PDF
