A Novel Dual Energy Computed Tomography Score Correlates With Postoperative Outcomes in Chronic Thromboembolic Pulmonary Hypertension.

PURPOSE: To compare dual-energy computed tomography (DECT) based qualitative and quantitative parameters in chronic thromboembolic pulmonary hypertension with various postoperative primary and secondary endpoints. MATERIALS AND METHODS: This was a retrospective analysis of 64 patients with chronic thromboembolic pulmonary hypertension who underwent DECT. First, a clot score was calculated by assigning the following score: pulmonary trunk-5, each main pulmonary artery-4, each lobar-3, each segmental-2, and subsegmental-1 per lobe; the sum total was then calculated. The perfusion defect (PD) score was calculated by assigning 1 point to each segmental PD. The combined score was calculated by adding clot and PD scores. For quantitative evaluation, we calculated perfused blood volume (PBV) (%) of each lung and the sum of both lungs. Primary endpoints included testing association between combined score and total PBV with change in mean pulmonary arterial pressure ([mPAP], change calculated as preop minus postop values). Secondary endpoints included explorative analysis of the correlation between combined score and PBV with change in preoperative and postoperative pulmonary vascular resistance, change in preoperative 6-minute walk distance (6MWD), and immediate postoperative complications such as reperfusion edema, ECMO placement, stroke, death and mechanical ventilation for more than 48 hours, all within 1 month of surgery. RESULTS: Higher combined scores were associated with larger decreases in mPAP ( =0.27, P =0.036). On average, the decrease in mPAP (pre mPAP-post mPAP) increased by 2.2 mm Hg (95% CI: -0.6, 5.0) with each 10 unit increase in combined score. The correlation between total PBV and change in mPAP was small and not statistically significant. During an exploratory analysis, higher combined scores were associated with larger increases in 6MWD at 6 months postprocedure ( =0.55, P =0.002). CONCLUSION: Calculation of DECT-based combined score offers potential in the evaluation of hemodynamic response to surgery. This response can also be objectively quantified.

ACR Appropriateness Criteria® Congenital or Acquired Heart Disease.

Pediatric heart disease is a large and diverse field with an overall prevalence estimated at 6 to 13 per 1,000 live births. This document discusses appropriateness of advanced imaging for a broad range of variants. Diseases covered include tetralogy of Fallot, transposition of great arteries, congenital or acquired pediatric coronary artery abnormality, single ventricle, aortopathy, anomalous pulmonary venous return, aortopathy and aortic coarctation, with indications for advanced imaging spanning the entire natural history of the disease in children and adults, including initial diagnosis, treatment planning, treatment monitoring, and early detection of complications. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Preprocedural Planning for Transcatheter Aortic Valve Replacement: 2023 Update.

This document discusses preprocedural planning for transcatheter aortic valve replacement, evaluating the imaging modalities used in initial imaging for preprocedure planning under two variants 1) Preintervention planning for transcatheter aortic valve replacement: assessment of aortic root; and 2) Preintervention planning for transcatheter aortic valve replacement: assessment of supravalvular aorta and vascular access. US echocardiography transesophageal, MRI heart function and morphology without and with IV contrast, MRI heart function and morphology without IV contrast and CT heart function and morphology with IV contrast are usually appropriate for assessment of aortic root. CTA chest with IV contrast, CTA abdomen and pelvis with IV contrast, CTA chest abdomen pelvis with IV contrast are usually appropriate for assessment of supravalvular aorta and vascular access. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Novel Depiction of Collateral Flow in Chronic Thromboembolic Pulmonary Hypertension Using 4D Dynamic 82 Rb PET/CT.

ABSTRACT: CT pulmonary angiogram and ventilation-perfusion scintigraphy are the 2 primary imaging modalities for evaluating patients with CTEPH (chronic thromboembolic pulmonary hypertension). PET/CT and MRI currently have a limited role in the evaluation of acute or chronic pulmonary embolism. We present incidentally captured dynamic pulmonary perfusion images in a patient with history of CTEPH who underwent 82 Rb myocardial perfusion PET/CT for evaluation of chest pain. Analysis of the PET data revealed delayed perfusion of the affected lobes suggesting collateralization, highlighting a potentially new imaging paradigm for assessment of pulmonary perfusion.

Clinical Characteristics and Transplant-Free Survival Across the Spectrum of Pulmonary Vascular Disease.

BACKGROUND: PVDOMICS (Pulmonary Vascular Disease Phenomics) is a precision medicine initiative to characterize pulmonary vascular disease (PVD) using deep phenotyping. PVDOMICS tests the hypothesis that integration of clinical metrics with omic measures will enhance understanding of PVD and facilitate an updated PVD classification. OBJECTIVES: The purpose of this study was to describe clinical characteristics and transplant-free survival in the PVDOMICS cohort. METHODS: Subjects with World Symposium Pulmonary Hypertension (WSPH) group 1-5 PH, disease comparators with similar underlying diseases and mild or no PH and healthy control subjects enrolled in a cross-sectional study. PH groups, comparators were compared using standard statistical tests including log-rank tests for comparing time to transplant or death. RESULTS: A total of 1,193 subjects were included. Multiple WSPH groups were identified in 38.9% of PH subjects. Nocturnal desaturation was more frequently observed in groups 1, 3, and 4 PH vs comparators. A total of 50.2% of group 1 PH subjects had ground glass opacities on chest computed tomography. Diffusing capacity for carbon monoxide was significantly lower in groups 1-3 PH than their respective comparators. Right atrial volume index was higher in WSPH groups 1-4 than comparators. A total of 110 participants had a mean pulmonary artery pressure of 21-24 mm Hg. Transplant-free survival was poorest in group 3 PH. CONCLUSIONS: PVDOMICS enrolled subjects across the spectrum of PVD, including mild and mixed etiology PH. Novel findings include low diffusing capacity for carbon monoxide and enlarged right atrial volume index as shared features of groups 1-3 and 1-4 PH, respectively; unexpected, frequent presence of ground glass opacities on computed tomography; and sleep alterations in group 1 PH, and poorest survival in group 3 PH. PVDOMICS will facilitate a new understanding of PVD and refine the current PVD classification. (Pulmonary Vascular Disease Phenomics Program PVDOMICS [PVDOMICS]; NCT02980887).

Dual energy CT based scoring in chronic thromboembolic pulmonary hypertension and correlation with clinical and hemodynamic parameters: a retrospective cross-sectional study.

Background: We used a dual energy computed tomography (DECT) based scoring system in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and correlated it with functional and hemodynamic parameters. Methods: This was a retrospective study on 78 patients with CTEPH who underwent DECT. First, clot burden score was calculated by assigning a following score: pulmonary trunk-5, each main pulmonary artery-4, each lobar-3, each segmental-2, and subsegmental-1 per lobe; sum total was then calculated. Perfusion defect (PD) score was calculated by assigning 1 point to each segmental PD. Combined score was calculated by adding the clot burden and PD score. All three scores were correlated with clinical and hemodynamic parameters that included New York Heart Association (NYHA) functional class, 6-minute walk distance (6MWT) in feet, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), diffusing capacity of the lung for carbon monoxide (DLCO), pulmonary arterial pressure (PAP) [systolic PAP (sPAP), diastolic PAP (dPAP) and mean PAP (mPAP)], pulmonary vascular resistance (PVR), right atrial pressure, cardiac output, and cardiac index. Results: Clot burden score, PD score, and combined score all positively correlated with sPAP (0.25, 0.34, 0.34), PVR (0.27, 0.30, 0.34), and mPAP (0.28, 0.31, 0.36). There was no statistically significant correlation of clot burden score, PD score and combined score with 6MWT, % predicted 6MWT, FEV1, FEV1%, FVC, FVC%, DLCO% and NYHA functional class. Conclusions: DECT based scoring in CTEPH is feasible and correlates positively with sPAP, mPAP and PVR. Combined score has the highest magnitude of correlation.

Morphologic and Functional Dual-Energy CT Parameters in Patients With Chronic Thromboembolic Pulmonary Hypertension and Chronic Thromboembolic Disease.

OBJECTIVE. The objective of our study was to compare morphologic and functional dual-energy CT (DECT) parameters in patients with chronic thromboembolic disease (CTED) and chronic thromboembolic pulmonary hypertension (CTEPH). MATERIALS AND METHODS. Using the local CTEPH registry, we identified 28 patients with CTED and 72 patients with CTEPH. On each DECT examination, a clot burden score was calculated by assigning the following scores for chronic changes by location: pulmonary trunk, 5; each main pulmonary artery (MPA), 4; each lobar branch, 3; each segmental branch, 2; and each subsegmental branch, 1. The total clot burden score was calculated by adding the individual scores from both lungs. Functional parameters were assessed using perfused blood volume (PBV) maps and included lung enhancement (in Hounsfield units), percentage of PBV, MPA peak enhancement (in Hounsfield units), maximum enhancement corresponding to 100, and the ratio of MPA peak enhancement to lung enhancement. A perfusion defect (PD) score was calculated by assigning 1 point to each segmental PD. Patients with CTED and patients with CTEPH were matched using propensity score matching to account for potential confounders. RESULTS. After matching, the CTEPH group showed a higher PD score than the CTED group and unilateral disease was more common in the CTED group than in the CTEPH group. In the unmatched sample, patients with CTED showed increased percentages of PBV for both lungs (PBV total) and for the right lung as compared with the CTEPH group (adjusted p = 0.040 and 0.028, respectively); after adjustment for clot burden, the difference between groups was still noted but was not statistically significant. No statistically significant differences were noted in the various functional DECT parameters after propensity score matching. CONCLUSION. Patients with CTED show anatomic and functional changes in the pulmonary vasculature and lung parenchyma similar to those seen in patients with CTEPH. Functional DECT parameters support the observation that CTED is an intermediate clinical phenotype in the population with chronic pulmonary embolism.

CT-Based Biomarkers for Prediction of Chronic Thromboembolic Pulmonary Hypertension After an Acute Pulmonary Embolic Event.

OBJECTIVE. The purpose of this study is to assess CT-based markers predictive of the development of chronic thromboembolic pulmonary hypertension (CTEPH) after acute pulmonary embolism. MATERIALS AND METHODS. Identified from a search of local registries, 48 patients who had CTEPH develop were included in the study group, and 113 patients who had complete resolution of acute pulmonary embolism were included in the control group. Baseline CT scans obtained at the time of the initial pulmonary embolism event were evaluated for the degree of clot-induced vessel obstruction, the quantitative Walsh score, the ratio of the right ventricle diameter to the left ventricle diameter, the right atrium diameter, the pulmonary artery diameter, right heart thrombus, pericardial effusion, lung infarction, and mosaic attenuation. Classification and regression tree analysis was used to create a decision tree. The decision tree was externally validated on an anonymized cohort of 50 control subjects and 50 patients with CTEPH. RESULTS. During univariable analysis, an increase in the degree occlusive clot on initial imaging, a decrease in the Walsh score, absence of pericardial effusion, presence of lung infarction, and the presence of mosaic attenuation were associated with an increased probability of CTEPH development. In the final decision tree, the occlusive nature of the clot remained. Two patients in the cohort used for external validation had nondiagnostic findings and were excluded. The decision process correctly classified 33% (16/48) of patients who had CTEPH develop and 86% (43/50) of patients who did not have CTEPH develop, for an odds ratio of 3.1 (95% CI, 1.1-8.3). CONCLUSION. The presence of an occlusive clot on initial imaging is associated with an increased probability of CTEPH development. Presence of mosaic attenuation and lung infarction may also predict CTEPH development, although additional studies are needed.

Assessment of ventilation-perfusion scans in patients with chronic thromboembolic pulmonary hypertension before and after surgery and correlation with clinical parameters.

PURPOSE: We did a comparative analysis of matched and mismatched defects in pre- and post-operative V/Q scans in CTEPH patients. We correlated the number of these defects with pre-operative clinical and hemodynamic parameters. METHODS: This was a retrospective study on 27 patients with CTEPH who underwent surgery. Pre- and post-operative V/Q scans were graded for each lung segment as normal, matched or mismatched defect. Additional pre- and post-operative clinical and hemodynamic parameters that were collected include New York Heart Association functional class, six-minute walk distance in feet, N-terminal pro b-type natriuretic peptide, forced expiratory volume in one second/forced vital capacity, diffusing capacity of the lung for carbon monoxide, pulmonary arterial pressure (systolic, diastolic and mean), right atrial pressure, cardiac output and cardiac index. Pulmonary vascular resistance was then calculated. RESULTS: On a segmental basis, 176 mismatched defects were noted in 27 patients, of which 111 improved post-surgery (63%). 22 of the 34 matched defects improved following surgery (64%). 31 new mismatched defects were observed. The number of pre-operative matched defects per patient ranged from 0 to 6. No statistically significant associations were observed between the number of pre-operative matched defects and pre-operative clinical parameters. No statistically significant associations were observed between the number of improved matched defects and the change in clinical parameters (pre- to post-surgery). CONCLUSION: Both matched and mismatched defects on preoperative V/Q scans can show normalization post-surgery. The extent of matched defects on a preoperative V/Q scan does not correlate significantly with other clinical and hemodynamic parameters.

Imaging indications and findings in evaluation of lung transplant graft dysfunction and rejection.

Lung transplantation is a treatment option in end-stage lung disease. Complications can develop along a continuum in the immediate or longer post-transplant period, including surgical and technical complications, primary graft dysfunction, rejection, infections, post-transplant lymphoproliferative disorder, and recurrence of the primary disease. These complications have overlapping clinical and imaging features and often co-exist. Time of onset after transplant is helpful in narrowing the differential diagnosis. In the early post transplantation period, imaging findings are non-specific and need to be interpreted in the context of the clinical picture and other investigations. In contrast, imaging plays a key role in diagnosing and monitoring patients with chronic lung allograft dysfunction. The goal of this article is to review primary graft dysfunction, acute rejection, and chronic rejection with emphasis on the role of imaging, pathology findings, and differential diagnosis.

Imaging-Guided Therapies for Pericardial Diseases.

Frequently, multimodality imaging is indispensable in the care of patients with pericardial disease. With cardiac magnetic resonance imaging, pericardial inflammation can be characterized as acute, subacute, or chronic. This spectrum of inflammation is variably associated with reduced compliance of the pericardium, which may result in constrictive pathophysiology, typically well-defined with echocardiography. This interplay between inflammation and hemodynamics is often optimally characterized with multimodality imaging and has redefined the approach of pericardiologists to diagnose, prognosticate, and tailor individual therapies.

Impact of Multidisciplinary Pulmonary Embolism Response Team Availability on Management and Outcomes.

Treatment strategies for complex patients with pulmonary embolism (PE) are often debated given patient heterogeneity, multitude of available treatment modalities, and lack of consensus guidelines. Although multidisciplinary Pulmonary Embolism Response Teams (PERT) are emerging to address this lack of consensus, their impact on patient outcomes is not entirely clear. This analysis was conducted to compare outcomes of all patients with PE before and after PERT availability. We analyzed all adult patients admitted with acute PE diagnosed on computed tomography scans in the 18 months before and after the institution of PERT at a large tertiary care hospital. Among 769 consecutive inpatients with PE, PERT era patients had lower rates of major or clinically relevant nonmajor bleeding (17.0% vs 8.3%, p = 0.002), shorter time-to-therapeutic anticoagulation (16.3 hour vs 12.6 hour, p = 0.009) and decreased use of inferior vena cava filters (22.2% vs 16.4%, p = 0.004). There was an increase in the use of thrombolytics/catheter-based strategies, however, this did not achieve statistical significance (p = 0.07). There was a significant decrease in 30-day/inpatient mortality (8.5% vs 4.7%, p = 0.03). These differences in outcomes were more pronounced in intermediate and high-risk patients (mortality 10.0% vs 5.3%, p = 0.02). The availability of multidisciplinary PERT was associated with improved outcomes including 30-day mortality. Patients with higher severity of PE seemed to derive most benefit from PERT availability.

Evaluation of Vascular Parameters in Patients With Pulmonary Thromboembolic Disease Using Dual-energy Computed Tomography.

PURPOSE: The purpose of this study was to evaluate patterns of vascular and lung parenchymal enhancement in patients with suspected chronic thromboembolic pulmonary hypertension (CTEPH) and in those with acute pulmonary embolism (PE) and compare those two groups. MATERIALS AND METHODS: We retrospectively studied 186 thoracic DECT studies referred for evaluation of CTEPH or pulmonary hypertension. A total of 80 of these patients had a negative scan (control group), 13 had acute PE, and 53 had chronic thromboembolic disease (CTED)/CTEPH. Five different DECT-based parameters were evaluated that highlight patterns of vascular kinetics. Specifically, total DECT-based parenchymal attenuation in Hounsfield Unit (HU) (LungHU), percentage of perfused blood volume (PBV), peak enhancement of main pulmonary artery (PApeak in HU), maximum enhancement corresponding to 100 (PAmax), and the ratio of PApeak to LungHU were calculated. RESULTS: Compared with patients with negative CT, patients with CTED/CTEPH tended to have lower LungHU (median: 27 vs. 38, P<0.001), lower PBV (median: 39 vs. 51, P=0.003), and higher PApeak/LungHU ratio (median: 17 vs. 13, P=0.003). Compared with patients with acute PE, patients with CTED/CTEPH tended to have lower LungHU (median: 27 vs. 39, P=0.006), lower PBV (median: 39 vs. 62, P=0.023), and higher PApeak/LungHU ratio (median: 17 vs. 11, P=0.023). No statistically significant differences were observed between patients with acute PE and those with negative CT. CONCLUSIONS: DECT-based vascular parameters offer the potential to differentiate patients with acute versus chronic PE. These various anatomic and functional vascular DECT-based parameters might be reflective of the state of the underlying vascular bed.

Comparative assessment of qualitative and quantitative perfusion with dual-energy CT and planar and SPECT-CT V/Q scanning in patients with chronic thromboembolic pulmonary hypertension.

BACKGROUND: The purpose of this study was to compare the qualitative and quantitative assessment of perfusion on dual-energy CT (DECT) and planar and single photon emission computed tomography (SPECT)-CT V/Q scanning in patients with chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: Nineteen patients with known CTEPH underwent both DECT and SPECT-CT V/Q scanning. Sixteen of these patients underwent planar V/Q imaging concurrently. Two readers independently graded DECT-perfused blood volume (PBV) defects on a four-point scale (0= normal, 1= mild <25%, 2= moderate 25-50%, 3= severe >50%). A grade was given for each lung lobe and for each of 18 lung segments. One reader graded the SPECT-CT images similarly. Quantitative measurements of lung perfusion were calculated with DECT and planar V/Q scanning for 16 of these patients. RESULTS: The inter-reader agreement on DECT was strong with agreement in 85% (258/304) of segments (kappa =0.86) and 84% (80/95) of lobes (kappa =0.82). The inter-modality agreement between DECT and SPECT-CT was lower. Readers 1 and 3 agreed in only 34% (103/304) of segments (kappa =0.25) and 33% (31/94) of lobes (kappa =0.22). Agreement between readers 2 and 3 was similar. Correlation between quantitative measurements with DECT and planar V/Q imaging was poor and ranged from 0.01 to 0.45. CONCLUSIONS: Inter-observer agreement in subjective grading of PBV maps is excellent. However, inter-modality agreement between DECT and SPECT-CT is modest. Automated quantification values of PBV maps correlate poorly with established tools like planar V/Q imaging. These differences need to be kept in mind during clinical decision making.

A review of imaging modalities in pulmonary hypertension.

Pulmonary hypertension (PH) is defined as resting mean pulmonary artery pressure ≥25 mmHg measured by right heart catheterization. PH is a progressive, life-threatening disease with a variety of etiologies. Swift and accurate diagnosis of PH and appropriate classification in etiologic group will allow for earlier treatment and improved outcomes. A number of imaging tools are utilized in the evaluation of PH, such as chest X-ray, computed tomography (CT), ventilation/perfusion (V/Q) scan, and cardiac magnetic resonance imaging. Newer imaging tools such as dual-energy CT and single-photon emission computed tomography/computed tomography V/Q scanning have also emerged; however, their place in the diagnostic evaluation of PH remains to be determined. In general, each imaging technique provides incremental information, with varying degrees of sensitivity and specificity, which helps suspect the presence and identify the etiology of PH. The present study aims to provide a comprehensive review of the utility, advantages, and shortcomings of the imaging modalities that may be used to evaluate patients with PH.

Attenuation-based kV pair selection in dual source dual energy computed tomography angiography of the chest: impact on radiation dose and image quality.

OBJECTIVES: The purpose of this study was to evaluate the impact of attenuation-based kilovoltage (kV) pair selection in dual source dual energy (DSDE)-pulmonary embolism (PE) protocol examinations on radiation dose savings and image quality. METHODS: A prospective study was carried out on 118 patients with suspected PE. In patients in whom attenuation-based kV pair selection selected the 80/140Sn kV pair, the pre-scan 100/140Sn CTDIvol (computed tomography dose index volume) values were compared with the pre-scan 80/140Sn CTDIvol values. Subjective and objective image quality parameters were assessed. RESULTS: Attenuation-based kV pair selection switched to the 80/140Sn kV pair ("switched" cohort) in 63 out of 118 patients (53%). The mean 100/140Sn pre-scan CTDIvol was 8.8 mGy, while the mean 80/140Sn pre-scan CTDIvol was 7.5 mGy. The average estimated dose reduction for the "switched" cohort was 1.3 mGy (95% CI 1.2, 1.4; p < 0.001), representing a 15% reduction in dose. After adjusting for patient weight, mean attenuation was significantly higher in the "switched" vs. "non-switched" cohorts in all five pulmonary arteries and in all lobes on iodine maps. CONCLUSIONS: This study demonstrates that attenuation-based kV pair selection in DSDE examination is feasible and can offer radiation dose reduction without compromising image quality. KEY POINTS: • Attenuation-based kV pair selection in dual energy examination is feasible. • It can offer radiation dose reduction to approximately 50% of patients. • Approximate 15% reduction in radiation dose was achieved using this technique. • The image quality is not compromised by use of attenuation-based kV pair selection.

Imaging in Chronic Thromboembolic Pulmonary Hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is one of the potentially curable causes of pulmonary hypertension and is definitively treated with pulmonary thromboendartectomy. CTEPH can be overlooked, as its symptoms are nonspecific and can be mimicked by a wide range of diseases that can cause pulmonary hypertension. Early diagnosis of CTEPH and prompt evaluation for surgical candidacy are paramount factors in determining future outcomes. Imaging plays a central role in the diagnosis of CTEPH and patient selection for pulmonary thromboendartectomy and balloon pulmonary angioplasty. Currently, various imaging tools are used in concert, with techniques such as computed tomography (CT) and conventional pulmonary angiography providing detailed structural information, tests such as ventilation-perfusion (V/Q) scanning providing functional data, and magnetic resonance imaging providing a combination of morphologic and functional information. Emerging techniques such as dual-energy CT and single photon emission computed tomography-CT V/Q scanning promise to provide both anatomic and functional information in a single test and may change the way we image these patients in the near future. In this review, we discuss the roles of various imaging techniques and discuss their merits, limitations, and relative strengths in depicting the structural and functional changes of CTEPH. We also explore newer imaging techniques and the potential value they may offer.

Spectrum of Imaging Findings Following Bronchoscopic Intervention.

Interventional pulmonology (IP) is a relatively new field that uses endoscopy and other technologies for both the diagnosis and treatment of pulmonary and thoracic conditions. IP is a continually developing field driven by clinical need as well as technological and therapeutic innovation. Developments in IP have increased both the efficacy and breadth of procedures that may be encountered by radiologists on periprocedural and postprocedural imaging. In this article, we will describe commonly performed IP procedures, with a focus on relevant imaging implications for radiologists.

Screening CT Angiography of the Aorta, Visceral Branch Vessels, and Pelvic Arteries in Fibromuscular Dysplasia.

OBJECTIVES: This study sought to evaluate the diagnostic yield of a dedicated computed tomography angiography (CTA) protocol of the chest, abdomen, and pelvis in patients with fibromuscular dysplasia (FMD). BACKGROUND: FMD is an uncommon vascular disease that may result in stenosis, dissection, or aneurysm of nearly all arterial distributions, typically affecting medium-sized arteries. Findings from the United States Registry for Fibromuscular Dysplasia have suggested the potential need to perform screening imaging of the aorta and medium branch vessels. METHODS: A total of 113 consecutive patients enrolled in our institutional FMD registry who received a tailored CTA protocol at our institution between March 2013 and June 2015 were included in this study. Arterial phase contrast-enhanced images were obtained on a dual-source scanner using high pitch and electrocardiogram trigger. Images were analyzed by 2 readers. RESULTS: Abnormalities including beading, aneurysm, dissection, and stenosis/occlusion were noted in aortic, renal, mesenteric, and iliac distributions. The most commonly affected vessels were the renal arteries (n = 76 [67%]), followed by the lower extremity/iliac arteries (n = 37 [32%]). Aortic abnormalities were less frequently encountered (n = 3 [3%]), including 1 case with mild dilation (4.2 cm) of the ascending aorta and 2 cases of dissection involving the descending aorta, 1 with mild dilation (4.4 cm). Incremental findings beyond those known at patient intake were commonly noted, including new areas of arterial beading (n = 55 [49%]), new aneurysms (n = 21 [19%]), and new dissections (n = 3 [3%]). Reformatted images were crucial, affecting final assessment in 56% of cases evaluated by reader 1 and 36% evaluated by reader 2. CONCLUSIONS: Screening chest, abdomen, and pelvis CTA in patients with FMD showed substantial and incremental diagnostic yield. Reformatted images should routinely be included in imaging analysis. Abnormalities in the aorta were not common, so screening of the thoracic aorta may not be indicated.