Corrigendum to "Erdheim-Chester disease with tendon and muscle involvement: Reports of a rare presentation" [Radiology Case Reports 19 (2024) 1866-1871].

[This corrects the article DOI: 10.1016/j.radcr.2024.02.009.].

Erdheim-Chester disease with tendon and muscle involvement: Reports of a rare presentation.

Erdheim-Chester disease (ECD) is a rare histiocytic disease that affects multiple systems in the body. While it typically targets long bones, cardiovascular structures, the retroperitoneum, and the central nervous system, reports of tendon and skeletal muscle involvement are scarce. This review presents 2 cases: a case of ECD involving the left Achilles tendon and left abductor hallucis, as well as an unusual manifestation of ECD in the thigh musculature. In Case 1, studies involved a 39-year-old man who initially presented with bone and pituitary involvement. An order for 18F-FDG PET/CT imaging was placed by marked swelling in the patient's left ankle and observed soft tissue fullness on foot radiographs, which revealed a soft tissue mass involving the left Achilles tendon, which arose along the tendon-muscle junction and involved the left abductor hallucis muscle. In Case 2, studies involved a 41-year-old man who initially presented with involvement of the cardiovascular system and retroperitoneum. 18F-FDG PET/CT scan showed an infiltrative right atrial mass and hypermetabolic lesion in the left external obturator muscle, extending to the left pectineus and right quadratus femoris muscle. Involvement of the Achilles tendon and skeletal muscle involvement, including left abductor hallucis muscle and medial thigh muscles, is one of the rare manifestations of ECD. Diagnostic delays were frequent due to the condition's rarity and nonspecific multisystemic symptoms. This should be considered in patients who present with myositis, tendinopathy, and bone pain and have other unexplained multisystemic problems.

Transient responses and significant toxicities of anti-CD30 CAR T cells for CD30+ lymphomas: results of a phase 1 trial.

ABSTRACT: New treatments are needed for relapsed and refractory CD30-expressing lymphomas. We developed a novel anti-CD30 chimeric antigen receptor (CAR), designated 5F11-28Z. Safety and feasibility of 5F11-28Z-transduced T cells (5F11-Ts) were evaluated in a phase 1 dose escalation clinical trial. Patients with CD30-expressing lymphomas received 300 mg/m2 or 500 mg/m2 of cyclophosphamide and 30 mg/m2 of fludarabine on days -5 to -3, followed by infusion of 5F11-Ts on day 0. Twenty-one patients received 5F11-T infusions. Twenty patients had classical Hodgkin lymphoma, and 1 had anaplastic large-cell lymphoma. Patients were heavily pretreated, with a median of 7 prior lines of therapy and substantial tumor burden, with a median metabolic tumor volume of 66.1 mL (range, 6.4-486.7 mL). The overall response rate was 43%; 1 patient achieved a complete remission. Median event-free survival was 13 weeks. Eleven patients had cytokine release syndrome (CRS; 52%). One patient had grade 3 CRS, and there was no grade 4/5 CRS. Neurologic toxicity was minimal. Nine patients (43%) had new-onset rashes. Two patients (9.5%) received extended courses of corticosteroids for prolonged severe rashes. Five patients (24%) had grade 3/4 cytopenias, with recovery time of ≥30 days, and 2 of these patients (9.5%) had prolonged cytopenias with courses complicated by life-threatening sepsis. The trial was halted early because of toxicity. Median peak blood CAR+ cells per µL was 26 (range, 1-513 cells per µL), but no infiltration of CAR+ cells was detected in lymph node biopsies. 5F11-Ts had low efficacy and substantial toxicities, which limit further development of 5F11-Ts. This trial was registered at www.clinicaltrials.gov as #NCT03049449.

Development of the Takayasu Arteritis Integrated Disease Activity Index.

OBJECTIVE: Accurate clinical assessment of disease activity in Takayasu arteritis (TAK) can be challenging. 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) can directly measure vascular inflammation. This study details the development of a new type of disease activity index called the Takayasu's Arteritis Integrated Disease Activity Index (TAIDAI). METHODS: Clinical symptoms for TAIDAI were identified from a literature review. Each symptom was paired with FDG-PET findings in corresponding arterial territories. Constitutional symptoms were paired with acute phase reactant levels. One point was given for each clinical symptom paired with supporting FDG-PET or laboratory abnormalities and summed into the TAIDAI score. A TAIDAI of ≥1 defined active disease. To assess performance of TAIDAI, face validity, content validity, and sensitivity to change were evaluated within a prospective observational cohort study of patients with TAK. RESULTS: Seventeen clinical symptoms were paired with imaging or laboratory abnormalities. In a cohort of 96 patients contributing 204 study visits, TAIDAI showed excellent sensitivity (96.3%) and good specificity (79.2%) compared to physician's clinical assessment. TAIDAI significantly correlated with physician global assessment, PET Vascular Activity Score, patient global assessment, and acute phase reactant levels. In patients treated with either tumor necrosis factor inhibitors or tocilizumab, a TAIDAI of 0 was achieved in 21 (91%) of 23 patients who met a predefined definition of clinical response. CONCLUSION: TAIDAI is new type of disease activity index in TAK in which clinical symptoms are integrated with specific laboratory and imaging findings. TAIDAI should be validated in future randomized controlled trials in TAK.

Skeletal involvement in Erdheim-Chester disease: Multimodality imaging features and association with the BRAFV600E mutation.

OBJECTIVE: The aim of this study was to characterize the distribution of skeletal involvement in Erdheim-Chester disease (ECD) by using radiography, computed tomography (CT), 18F-FDG positron emission tomography/computed tomography (PET/CT), and bone scans, as well as looking for associations with the BRAFV600E mutation. MATERIAL AND METHODS: Prospective study of 50 consecutive patients with biopsy-confirmed ECD who had radiographs, CT, 18F-FDG PET/CT, and Tc-99m MDP bone scans. At least two experienced radiologists with expertise in the relevant imaging studies analyzed the images. Summary statistics were expressed as the frequency with percentages for categorical data. Fisher's exact test, as well as odds ratios (OR) with 95 % confidence intervals (CI), were used to link imaging findings to BRAFV600E mutation. The probability for co-occurrence of bone involvement at different locations was calculated and graphed as a heat map. RESULTS: All 50 cases revealed skeletal involvement at different regions of the skeleton. The BRAFV600E mutation, which was found in 24 patients, was correlated with femoral and tibial involvement on 18F-FDG PET/CT and bone scan. The appearance of changes on the femoral, tibial, fibular, and humeral involvement showed correlation with each other based on heat maps of skeletal involvement on CT. CONCLUSION: This study reports the distribution of skeletal involvement in a cohort of patients with ECD. CT is able to detect the majority of ECD skeletal involvement. Considering the complementary nature of information from different modalities, imaging of ECD skeletal involvement is optimized by using a multi-modality strategy.

Advanced molecular imaging in large-vessel vasculitis: Adopting FDG-PET into a clinical workflow.

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.

Micronutrient Supplementation and Bone Health After Prophylactic Total Gastrectomy in Patients With CDH1 Variants.

INTRODUCTION: Patients with germline variants in CDH1 who undergo prophylactic total gastrectomy (TG) are at risk of altered nutrient and drug absorption due to modified gastrointestinal anatomy. Bone mineral density loss and micronutrient deficiencies have not been described previously in this patient population. METHODS: In this study we included 94 patients with germline CDH1 variants who underwent prophylactic TG between October 2017 and February 2022. We examined pre- and post-gastrectomy bone mineral density (BMD); serum biomarkers including calcium, phosphorus, alkaline phosphatase, and 25 (OH)-vitamin D; and postoperative adherence to calcium and multivitamin supplementation. RESULTS: Almost all patients (92/94, 98%) lost a substantial amount of weight post-TG, with an average weight loss of 26.5% at 12 months post-surgery. Serum biomarkers of mineral metabolism, namely calcium and phosphorus, did not change significantly after TG. However, average BMD was decreased in all patients at 12 months post-TG. Nonadherence to calcium supplementation was associated with a decrease in BMD. Nonadherence to multivitamin supplementation was associated with greater percent BMD loss in the femoral neck and total hip. CONCLUSIONS: Appropriate micronutrient supplementation and nutritional counseling pre- and postoperatively in patients undergoing prophylactic TG are important to mitigate the long-term effects of gastrectomy on bone health.

Association of 18 F-Fluorodeoxyglucose-Positron Emission Tomography Activity With Angiographic Progression of Disease in Large Vessel Vasculitis.

OBJECTIVE: To assess whether vascular activity seen on 18 F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scan is associated with angiographic change in large vessel vasculitis (LVV). METHODS: Patients with LVV were recruited into a prospective cohort. All patients underwent magnetic resonance angiography or computed tomography angiography and FDG-PET imaging. Follow-up imaging using the same imaging modalities was obtained ≥6 months later per a standardized imaging protocol. Arterial damage, defined as stenosis, occlusion, or aneurysm, and corresponding FDG uptake were evaluated in 17 arterial territories. On follow-up, development of new lesions was recorded, and existing lesions were characterized as improved, worsened, or unchanged. RESULTS: A total of 1,091 arterial territories from 70 patients with LVV (38 patients with Takayasu arteritis, 32 patients with giant cell arteritis) were evaluated. Over a median 1.6 years of follow-up, new lesions developed only in 8 arterial territories in 5 patients with Takayasu arteritis. Arterial lesions improved in 16 territories and worsened in 6 territories. Most arterial territories that did not have vascular activity on FDG-PET scan at baseline had no angiographic change over the follow-up period (787 [99%] of 793). Few territories with baseline FDG-PET activity had angiographic change over time (24 [8%] of 298), but of the territories that developed angiographic change, 80% had FDG-PET activity at baseline. Within the same patient, an arterial territory with baseline FDG-PET activity had significantly increased risk for angiographic change compared to a paired arterial territory without FDG-PET activity (odds ratio 19.49 [95% confidence interval 2.44-156.02]; P < 0.01). Concomitant edema and wall thickening further increased risk for angiographic change. CONCLUSION: Development of angiographic change was infrequent in this cohort of patients with LVV. A lack of baseline FDG-PET activity was strongly associated with stable angiographic disease. In cases of angiographic progression, change was preceded by the presence of FDG-PET activity.

Longitudinal Characterization of Vascular Inflammation and Disease Activity in Takayasu Arteritis and Giant Cell Arteritis: A Single-Center Prospective Study.

OBJECTIVE: To examine and compare disease activity over time in giant cell arteritis (GCA) and Takayasu arteritis (TAK) using multimodal assessment combining clinical, laboratory, and imaging-based testing. METHODS: Patients with GCA or TAK were enrolled into a single-center prospective, observational cohort at any point in the disease course. Patients underwent standardized assessment, including 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) at enrollment and follow-up visits. Each FDG-PET finding was subjectively interpreted as active or inactive vasculitis. Global arterial FDG uptake was quantified by the PET Vascular Activity Score (PETVAS). Patients were stratified by disease duration at enrollment (0-2 years; 2-5 years; >5 years). Fisher exact and Mann-Whitney U tests, Spearman's correlation, and linear regression were used for statistical analyses. RESULTS: A total of 126 patients with large vessel vasculitis (GCA = 50; TAK = 76) were evaluated across 319 visits. Clinical disease activity was present in 33% of patients in the second to fifth year of disease and in 24% of patients evaluated >5 years after diagnosis. Active vasculitis by PET was observed in 66% of patients in years 2 to 5 after diagnosis and in 50% of patients enrolled >5 years into disease. PETVASs were consistently higher in GCA than TAK in the early and later phases of disease and significantly decreased over time in GCA but not TAK. Correlations between clinical, laboratory, and imaging findings were complex and varied with disease duration. CONCLUSION: Disease activity in GCA and TAK is common throughout the disease course. Patterns of vascular PET activity at diagnosis and later in disease differ between GCA and TAK.

Use of 18F-fluorodeoxyglucose positron emission tomography to standardize clinical trial recruitment in Takayasu's arteritis.

OBJECTIVES: To assess whether data from 18F-fluorodeoxyglucose (FDG) PET should be incorporated into eligibility criteria for clinical trials in Takayasu's arteritis (TAK). METHODS: The study was conducted in two parts. Part one was an international online survey among physicians with experience managing TAK to determine, using clinical vignettes, whether FDG-PET data influence decisions about enrolment in trials. Part two used patient data from an observational cohort study in TAK to assess agreement regarding decisions about enrolment into trials, based on clinical assessment with and without incorporation of FDG-PET data. RESULTS: In part one, 68 physicians responded to the survey. Most physicians had used FDG-PET to diagnose TAK (82%) or monitor disease activity (66%). In vignettes representing active clinical disease, FDG-PET findings increased physician confidence in disease assessment and reduced outlier assessments. The greatest variability in decisions regarding enrolment into trials was observed in vignettes representing constitutional symptoms alone and elevated acute-phase reactants. In these cases, FDG-PET findings influenced decisions about enrolment and improved physician confidence. In multivariable models, FDG-PET findings were 1.29 times more strongly associated with enrolment decisions compared with levels of acute-phase reactants. In part two, incorporation of FDG-PET data significantly improved agreement about enrolment decisions between raters [inter-rater reliability (IRR) = 0.68 (95% CI 0.67, 0.69) to IRR = 0.88 (95% CI 0.87, 0.89); P < 0.01]. CONCLUSIONS: Incorporation of FDG-PET data into assessment of TAK influences decisions about enrolment of patients into trials, improves physician confidence about clinical assessment and could help reduce variability in study populations. Future trials in TAK should consider incorporating FDG-PET data into eligibility criteria.

Osteogenesis Imperfecta: The Impact of Genotype and Clinical Phenotype on Adiposity and Resting Energy Expenditure.

CONTEXT: Mutations in type I collagen or collagen-related proteins cause osteogenesis imperfecta (OI). Energy expenditure and body composition in OI could reflect reduced mobility or intrinsic defects in osteoblast differentiation increasing adipocyte development. OBJECTIVE: This study compares adiposity and resting energy expenditure (REE) in OI and healthy controls (HC), for OI genotype- and Type-associated differences. METHODS: We studied 90 participants, 30 with OI (11 COL1A1 Gly, 8 COL1A2 Gly, 4 COL1A1 non-Gly, 1 COL1A2 non-Gly, 6 non-COL; 8 Type III, 16 Type IV, 4 Type VI, 1 Type VII, 1 Type XIV) and 60 HC with sociodemographic characteristics/BMI/BMIz similar to the OI group. Participants underwent dual-energy x-ray absorptiometry to determine lean mass and fat mass percentage (FM%) and REE. FM% and REE were compared, adjusting for covariates, to examine the relationship of OI genotypes and phenotypic Types. RESULTS: FM% did not differ significantly in all patients with OI vs HC (OI: 36.6% ± 1.9%; HC: 32.7% ± 1.2%; P = 0.088). FM% was, however, greater than HC for those with non-COL variants (P = 0.016). FM% did not differ from HC among OI Types (P values > 0.05).Overall, covariate-adjusted REE did not differ significantly between OI and HC (OI: 1376.5 ± 44.7 kcal/d; HC: 1377.0 ± 96 kcal/d; P = 0.345). However, those with non-COL variants (P = 0.016) and Type VI OI (P = 0.04) had significantly lower REE than HC. CONCLUSION: Overall, patients with OI did not significantly differ in either extra-marrow adiposity or REE from BMI-similar HC. However, reduced REE among those with non-COL variants may contribute to greater adiposity.

Comparing Semiquantitative and Qualitative Methods of Vascular 18F-FDG PET Activity Measurement in Large-Vessel Vasculitis.

The study rationale was to assess the performance of qualitative and semiquantitative scoring methods for 18F-FDG PET assessment in large-vessel vasculitis. Methods: Patients with giant cell arteritis or Takayasu arteritis underwent independent clinical and imaging assessments within a prospective observational cohort. 18F-FDG PET/CT scans were interpreted for active vasculitis by central reader assessment. Arterial 18F-FDG uptake was scored by qualitative visual assessment using the PET vascular activity score (PETVAS) and by semiquantitative assessment using SUVs and target-to-background ratios (TBRs) relative to liver or blood activity. The performance of each scoring method was assessed by intrarater reliability using the intraclass correlation coefficient (ICC) and areas under the receiver-operating-characteristic curve, applying physician assessment of clinical disease activity and reader interpretation of vascular PET activity as independent reference standards. The Wilcoxon signed-rank test was used to analyze change in arterial 18F-FDG uptake over time. Results: Ninety-five patients (giant cell arteritis, 52; Takayasu arteritis, 43) contributed 212 18F-FDG PET studies. The ICC for semiquantitative evaluation (0.99 [range, 0.98-1.00]) was greater than the ICC for qualitative evaluation (0.82 [range, 0.56-0.93]). PETVAS and target-to-background ratio metrics were more strongly associated with reader interpretation of PET activity than SUV metrics. All assessment methods were significantly associated with physician assessment of clinical disease activity, but the semiquantitative metric liver tissue-to-background ratio (TBRLiver) achieved the highest area under the receiver-operating-characteristic curve (0.66). Significant but weak correlations with C-reactive protein were observed for SUV metrics (r = 0.19, P < 0.01) and TBRLiver (r = 0.20, P < 0.01) but not for PETVAS. In response to increased treatment in 56 patients, arterial 18F-FDG uptake was significantly reduced when measured by semiquantitative (TBRLiver, 1.31-1.23; 6.1% change; P < 0.0001) or qualitative (PETVAS, 22-18; P < 0.0001) methods. Semiquantitative metrics provided information complementary to qualitative evaluation in cases of severe vascular inflammation. Conclusion: Both qualitative and semiquantitative methods of measuring arterial 18F-FDG uptake are useful in assessing and monitoring vascular inflammation in large-vessel vasculitis. Compared with qualitative metrics, semiquantitative methods have superior reliability and better discriminate treatment response in cases of severe inflammation.

Characterization of extramedullary disease in B-ALL and response to CAR T-cell therapy.

Chimeric antigen receptor (CAR) T cells effectively eradicate medullary B-cell acute lymphoblastic leukemia (B-ALL) and can traffic to and clear central nervous system (CNS) involvement. CAR T-cell activity in non-CNS extramedullary disease (EMD) has not been well characterized. We systematically evaluated CAR T-cell kinetics, associated toxicities, and efficacy in B-ALL non-CNS EMD. We conducted a retrospective review of B-ALL patients with non-CNS EMD who were screened for/enrolled on one of three CAR trials (CD19, CD22, and CD19/22) at our institution. Non-CNS EMD was identified according to histology or radiographic imaging at extramedullary sites excluding the cerebrospinal fluid and CNS parenchyma. Of ∼180 patients with relapsed/refractory B-ALL screened across multiple early-phase trials over an 8-year period, 38 (21.1%) presented with isolated non-CNS EMD (n = 5) or combined medullary/non-CNS EMD (n = 33) on 18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging. A subset receiving CAR T cells (18 infusions) obtained FDG PET/CT scans preinfusion and postinfusion to monitor response. At best response, 72.2% (13 of 18) of patients showed a medullary minimal residual disease-negative complete remission and complete (n = 7) or partial (n = 6) non-CNS EMD response. Non-CNS EMD responses to CAR T cells were delayed (n = 3), and residual non-CNS EMD was substantial; rarely, discrepant outcomes (marrow response without EMD response) were observed (n = 2). Unique CAR-associated toxicities at non-CNS EMD sites were seen in select patients. CAR T cells are active in B-ALL non-CNS EMD. Still, non-CNS EMD response to CAR T cells may be delayed and suboptimal, particularly with multifocal disease. Serial FDG PET/CT scans are necessary for identifying and monitoring non-CNS EMD.

First Somatic PRKAR1A Defect Associated With Mosaicism for Another PRKAR1A Mutation in a Patient With Cushing Syndrome.

CONTEXT: Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of ACTH-independent Cushing syndrome (CS) associated mostly with Carney complex (CNC), a rare autosomal dominant multiple neoplasia syndrome. More than two-thirds of familial cases and approximately one-third of sporadic cases of CNC harbor germline inactivating PRKAR1A defects. Increasingly sensitive technologies for the detection of genetic defects such as next-generation sequencing (NGS) have further highlighted the importance of mosaicism in human disease. CASE DESCRIPTION: A 33-year-old woman was diagnosed with ACTH-independent CS with abdominal computed tomography showing bilateral micronodular adrenal hyperplasia with a left adrenal adenoma. She underwent left adrenalectomy with pathology demonstrating PPNAD with a 1.5-cm pigmented adenoma. DNA analysis by Sanger sequencing revealed 2 different PRKAR1A variants in the adenoma that were absent from DNA extracted from blood and saliva: c.682C > T and c.974-2A > G. "Deep" NGS revealed that 0.31% of DNA copies extracted from blood and saliva did in fact carry the c.682C > T variant, suggesting low-level mosaicism for this defect. CONCLUSIONS: We present a case of PPNAD due to low-level mosaicism for a PRKAR1A defect which led to the formation of an adenoma due to a second, adrenal-specific, somatic PRKAR1A mutation. The identification of mosaicism for PRKAR1A, depending on the number and distribution of cells affected has implications for genetic counseling and tumor surveillance. This is the first recorded case of a patient with PRKAR1A mosaicism, PPNAD, and an adenoma forming due to complete inactivation of PRKAR1A in adrenal tissue from a second, somatic-only, PRKAR1A coding sequence mutation.

18Fluorodeoxyglucose-positron emission tomography/computed tomography for differentiation of renal tumors in hereditary kidney cancer syndromes.

PURPOSE: To assess differences in FDG-PET/CT uptake among four subtypes of renal tumors: clear cell RCC (ccRCC), papillary type I and II RCC (pRCC), and oncocytoma. METHODS: This retrospective study investigated 33 patients with 98 hereditary renal tumors. Lesions greater than 1 cm and patients with a timeframe of less than 18 months between preoperative imaging and surgery were considered. FDG-PET/CT images were independently reviewed by two nuclear medicine physicians, blinded to clinical information. Volumetric lesion SUVmean was measured and used to calculate a target-to-background ratio respective to liver (TBR). The Shrout-Fleiss intra-class correlation coefficient was used to assess reliability between readers. A linear mixed effects model, accounting for within-patient correlations, was used to compare TBR values of primary renal lesions with and without distant metastasis. RESULTS: The time interval between imaging and surgery for all tumors had a median of 77 (Mean: 139; Range: 1-512) days. Intra-class reliability of mean TBR resulted in a mean κ score of 0.93, indicating strong agreement between the readers. The mixed model showed a significant difference in mean TBR among the subtypes (p < 0.0001). Pairwise comparison showed significant differences between pRCC type II and ccRCC (p < 0.0001), pRCC type II and pRCC type I (p = 0.0001), and pRCC type II and oncocytoma (p = 0.0016). Furthermore, a significant difference in FDG uptake was present between primary pRCC type II renal lesions with and without distant metastasis (p = 0.023). CONCLUSION: pRCC type II lesions demonstrated significantly higher FDG activity than ccRCC, pRCC type I, or oncocytoma. These findings indicate that FDG may prove useful in studying the metabolic activity of renal neoplasms, identifying lesions of highest clinical concern, and ultimately optimizing active surveillance, and personalizing management plans.

Use of 18F-fluorodeoxyglucose positron emission tomography to monitor tocilizumab effect on vascular inflammation in giant cell arteritis.

OBJECTIVES: To evaluate the time-dependent effects of tocilizumab on vascular inflammation as measured by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in GCA. METHODS: Patients with GCA treated with tocilizumab were selected from a prospective, observational cohort. Patients underwent FDG-PET at the baseline visit prior to initiation of tocilizumab and at subsequent follow-up visits performed at 6-month intervals. All imaging findings were interpreted blinded to clinical data. The PET vascular activity score (PETVAS) was used to quantify arterial FDG uptake. Wilcoxon signed rank test was used to compare change in PETVAS between visits. Linear regression was used to determine change in PETVAS over multiple timepoints. RESULTS: Twenty-five patients with GCA were included. All patients had physician-determined active vasculitis at the baseline visit by clinical assessment and FDG-PET interpretation. PETVAS was significantly reduced in association with tocilizumab treatment from the baseline to the most recent follow-up visit [24.0 (IQR 22.3-27.0) vs 18.5 (IQR 15.3-23.8); P <0.01]. A significant reduction in PETVAS was observed over a two-year treatment period (P <0.01 for linear trend), with a similar degree of improvement in both the first and second years of treatment. Repeat FDG-PET scans after tocilizumab discontinuation showed worsening PET activity in five out of six patients, with two patients subsequently experiencing clinical relapse. CONCLUSION: Treatment of patients with GCA with tocilizumab was associated with both clinical improvement and reduction of vascular inflammation as measured by serial FDG-PET. Future clinical trials in GCA should study direct treatment effect on vascular inflammation as an outcome measure.

Coronary CT Angiography and Carotid MRI Improve Phenotyping of Disease Extent Compared with ACC/AHA Risk Score Alone.

PURPOSE: To determine the relationship between the American College of Cardiology/American Heart Association (ACC/AHA) risk score and plaque phenotype of the coronary and carotid arteries assessed directly using CT angiography and MRI. MATERIALS AND METHODS: Asymptomatic subjects eligible for statin therapy by risk score were enrolled in a prospective study of disease burden using coronary artery calcium (CAC) scoring, coronary CT angiography, and MRI of the carotid arteries. Quartiles were calculated for noncalcified plaque, CAC, and average carotid wall volume and were compared with ACC/AHA risk quartiles. RESULTS: Two hundred three subjects were studied (60% men; mean age, 65 years). There were weak correlations between risk and carotid wall volume (Kendall tau = 0.29), noncalcified plaque (tau = 0.16), and CAC (tau = 0.33). ACC/AHA risk alone misclassified plaque extent compared with measurement by carotid wall volume, CAC, and noncalcified plaque in 22.1%, 24.1%, and 29.6% of subjects, respectively. On average, 13% of the subjects were underclassified, and 12.5% were overclassified. CONCLUSION: Approximately 25% of subjects had large discrepancies between ACC/AHA risk and plaque burden at imaging. These results suggest that clinical risk score models alone do not fully reflect the amount of atherosclerotic disease present.© RSNA, 2020See also the commentary by Truong and Villines in this issue.