Body and Extremity MR Venography: Technique, Clinical Applications, and Advances.

Magnetic resonance venography (MRV) represents a distinct imaging approach that may be used to evaluate a wide spectrum of venous pathology. Despite duplex ultrasound and computed tomography venography representing the dominant imaging modalities in investigating suspected venous disease, MRV is increasingly used due to its lack of ionizing radiation, unique ability to be performed without administration of intravenous contrast, and recent technical improvements resulting in improved sensitivity, image quality, and faster acquisition times. In this review, the authors discuss commonly used body and extremity MRV techniques, different clinical applications, and future directions.

ACR Appropriateness Criteria® Chronic Chest Pain-High Probability of Coronary Artery Disease: 2021 Update.

Management of patients with chronic chest pain in the setting of high probability of coronary artery disease (CAD) relies heavily on imaging for determining or excluding presence and severity of myocardial ischemia, hibernation, scarring, and/or the presence, site, and severity of obstructive coronary lesions, as well as course of management and long-term prognosis. In patients with no known ischemic heart disease, imaging is valuable in determining and documenting the presence, extent, and severity of obstructive coronary narrowing and presence of myocardial ischemia. In patients with known ischemic heart disease, imaging findings are important in determining the management of patients with chronic myocardial ischemia and can serve as a decision-making tool for medical therapy, angioplasty, stenting, or surgery. This document summarizes the recent growing body of evidence on various imaging tests and makes recommendations for imaging based on the available data and expert opinion. This document is focused on epicardial CAD and does not discuss the microvascular disease as the cause for CAD. 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 include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Increasing Vaginal Chlamydia Trachomatis Testing in Adolescent and Young Adults.

OBJECTIVE: The Centers for Disease Control and Prevention recommend testing for Chlamydia trachomatis in sexually active female patients <25 years old using nucleic-acid amplification tests (NAAT) from a vaginal swab. Our providers were typically testing using the less sensitive urine NAATs. We aimed to increase the percentage of urogenital C trachomatis NAATs performed by using vaginal swabs in adolescent female patients ages 10 through 20 years from 1.4% to 25%. METHODS: We implemented 3 interventions at 3 pediatric practices over 12 months including education, process standardization, and cross-training. We used statistical process control to analyze the effect of interventions on our primary outcome: the percentage of urogenital C trachomatis tests performed with a vaginal swab. Our balance measure was the total number of urogenital C trachomatis tests. RESULTS: There were 818 urogenital C trachomatis tests performed: 289 before and 529 after the first intervention. Of urogenital C trachomatis tests in the preintervention time period, 1.4% were performed by using vaginal swabs. We surpassed our aim of 25% 6 weeks after the first intervention. We noted sustained improvement after the second intervention, with an average of 68.3% of tests performed by using vaginal swabs for the remaining postintervention period. There was no difference in the overall number of urogenital C trachomatis tests pre- and postintervention. CONCLUSIONS: Using quality improvement methodology and implementing easily replicable interventions, we significantly and sustainably increased use of vaginal swabs. The interventions standardizing processes were associated with a higher impact than the educational intervention.

Vascular magnetic resonance angiography techniques.

Magnetic resonance angiography (MRA) denotes a unique option for the evaluation of peripheral vasculature due to its noninvasive nature, lack of ionizing radiation exposure, potential for non-contrast examination, and ability for generating volumetric representations that showcase vascular pathology. The constant evolution of the available MRA techniques, however, makes understanding and determining an optimal imaging protocol difficult. Here we present a brief overview of the major MRA sequence options, their major weaknesses and strengths, and related imaging considerations. Understanding the technical underpinnings of the various MRA methods helps with recognition of common imaging issues and artifacts and rendering clinically relevant interpretations.

The Role of Contrast-Enhanced Cardiac Magnetic Resonance in the Assessment of Patients with Malignant Ventricular Arrhythmias.

Cardiac magnetic resonance (CMR) imaging has gained significant traction as an imaging modality of choice in the evaluation of individuals with, or at risk for, heart failure. Ventricular arrhythmias, often malignant, may be sequelae of heart failure and arise from fibrosis. Late gadolinium enhancement evaluation by CMR has become a preferred modality to assess individuals at risk for malignant ventricular arrhythmias. A spectrum of various pathologies that predispose individuals to malignant ventricular arrhythmias, as well as the usefulness of CMR in their identification and prognostication, are reviewed.

Diagnostic Accuracy of Advanced Imaging in Cardiac Sarcoidosis.

Background The diagnostic yield of cardiac sarcoidosis (CS) by endomyocardial biopsy is limited. Fluorodeoxyglucose (FDG) positron emission tomography (PET) and cardiac magnetic resonance imaging (MRI) may facilitate noninvasive diagnosis, but the accuracy of this approach is not well defined. We aimed to correlate findings from FDG PET and cardiac MRI with histological findings from explanted hearts of patients who underwent cardiac transplantation. Methods We analyzed the explanted heart histology for all patients who underwent cardiac transplant at our center from April 2008 to July 2018 and had pretransplant FDG PET (n=18) or cardiac MRI (n=31). The likelihood of CS based on FDG PET or cardiac MRI was categorized in a blinded fashion using a previously published method. RESULTS: Using a CS probable cutoff for FDG PET resulted in a sensitivity of 100.0% (95% CI, 54.1%-100.0%) and a specificity of 33.3% (95% CI, 9.9%-65.1%). Three of the 9 CS probable by FDG PET cases were found to be arrhythmogenic cardiomyopathy. The test characteristics of cardiac MRI are more challenging to comment on using our data as there was only one confirmed case of CS on post-transplant histological assessment. Of the 8 CS highly probable or probable cases by cardiac MRI, 3 were found to be dilated cardiomyopathy, and 2 were found to be end-stage hypertrophic cardiomyopathy. Conclusions FDG PET and cardiac MRI can help facilitate the diagnosis of CS in patients with advanced heart failure with a high degree of sensitivity but lower specificity.

Subclinical Burden of Coronary Artery Calcium in Patients With Coarctation of the Aorta.

Coronary computed tomography (CT) angiography is often performed in adults with coarctation of the aorta (CoA) for anatomic assessment. As this population ages, assessment of atherosclerotic cardiovascular disease burden is important. Thus, quantitative and qualitative coronary artery calcium (CAC) scores were assessed for patients with CoA ≥16 years of age, who were seen at a referral center. CoA patients had either coronary CT angiography or chest CT with interpretable coronary information performed for clinical indications (follow-up, preoperative, or for symptoms) from 2004 to 2017. Qualitative CAC was determined based on low-dose CT and lung cancer screening protocols. Quantitative CAC scores were compared with an age- and gender-matched control cohort of patients chosen from an emergency department database of patients who received coronary CT angiography for chest pain evaluation. Atherosclerotic cardiovascular disease 10-year predicted risk scores were calculated for both cohorts. Out of 131 patients with CoA (mean age 46.1 ± 15.3 years), 22 patients (17%) had multivessel atherosclerotic disease on qualitative assessment. In the subgroup of patients ≥40 years, those with CoA were more likely to have a quantitative CAC score ≥400 compared with those without CoA (14% vs 4%, p = 0.02). Median atherosclerotic cardiovascular disease risk score was 8% (interquartile range 2% to 12%) for CoA patients ≥40 years, and 5% (interquartile range 2% to 9%) for patient without CoA ≥40 years. In conclusion, we determined that CoA patients have subclinical atherosclerosis identifiable on CT in high rates when compared with patients without CoA. Atherosclerotic cardiovascular disease should be assessed in these patients for prevention and treatment.

Ultrasmall superparamagnetic iron oxide nanoparticle uptake as noninvasive marker of aortic wall inflammation on MRI: proof of concept study.

OBJECTIVE:: Radiation therapy for cancer can lead to atherosclerosis by inducing inflammatory changes in the vascular wall. It is difficult to quantitatively measure inflammation on CT and MRI studies. The purpose of this study was to assess the use of ferumoxytol, an ultrasmall superparamagnetic iron oxide nanoparticle, as a noninvasive marker of vessel wall inflammation secondary to radiation therapy in pancreatic cancer patients in comparison with healthy volunteers. METHODS:: MRI of upper abdomen (T1, T2, multi echo T2* weighted imaging) was performed on 3 T magnet before and 48 h after intravenous administration of ferumoxytol in pancreatic cancer patients who underwent radiation therapy (n = 8) and in healthy volunteers (n = 8). R2* value was obtained by drawing regions of interest outlining the aortic wall directly on the T2* medic image and subsequently transposed to the R2* image using Amira software (v. 5.3.2, FEI, Bordeaux, France). The change in R2* values was analyzed by student's t-test. RESULTS:: The average change in R2* value of the pancreatic cancer patients was determined to be 216.1 ms-1. The average change R2* value of the control patients was determined to be 54.6 ms-1. Thus, pancreatic cancer patients following radiation therapy had a greater uptake of ferumoxytol (p = 0.0082) in their aortic wall as compared to healthy controls. CONCLUSION:: This proof of concept study suggests that greater uptake of ferumoxytol in the aortic wall in cancer patients without visible atherosclerosis may be the expression of increased inflammation. ADVANCES IN KNOWLEDGE:: Ultrasmall superparamagnetic iron oxide enhanced MRI can offer an imaging biomarker for quantitative estimation of aortic inflammation preceding atherosclerosis.

Understanding the impact of 'cost' under MACRA: a neurointerventional imperative!

The cost of providing healthcare in the United States continues to rise. The Affordable Care Act created systems to test value-based alternative payments models. Traditionally, procedure-based specialists such as neurointerventionalists have largely functioned in, and are thus familiar with, the traditional Fee for Service system. Administrative charge data would suggest that neurointerventional surgery is an expensive specialty. The Medicare Access and CHIP Reauthorization Act consolidated pre-existing federal performance programs in the Merit-based Incentive Payments System (MIPS), including a performance category called 'cost'. Understanding cost as a dimension that contributes to the value of care delivered is critical for succeeding in MIPS and offers a meaningful route for favorably bending the cost curve.

Incidental pulmonary nodules in emergent coronary CT angiography for suspected acute coronary syndrome: Impact of revised 2017 Fleischner Society Guidelines.

BACKGROUND: Pulmonary nodules (PN) are frequently detected incidentally during coronary computed tomography angiography (CTA). We evaluated whether the 2017 Fleischner Society guidelines may result in a decrease of follow-up testing of incidental PN as compared to prior guidelines in patients undergoing coronary CTA. METHODS: We conducted a retrospective study of a registry of emergency department patients who underwent coronary CTA for acute coronary syndrome assessment between 2012 and 2017. Based on guidelines, patients <35 years, history of cancer, or prior exams showing stability of PN were excluded. Patients >60 years, history of smoking, irregular/spiculated PN morphology, or PN size >20 mm were classified as high-risk for lung cancer. Radiological findings pertaining to PN were identified (PN size, morphology, quantity) through review of radiology reports. PN follow-up recommendations were established using 2017 Fleischner Society Guidelines and compared with prior guidelines for solid (2005) and subsolid (2013) PN. Data were analyzed with Student's t-test. RESULTS: The registry included 2066 patients (female 45.1%, 52.9 ± 11.0 years), of which 578 (28.0%) reported PN. 438 of those (21.2%) were eligible for guideline-based follow-up evaluation. 205 (4 6.8%) were classified as high-risk for lung cancer. 2017 guidelines reduced the number of individuals requiring follow-up by 64.5%, from 264 (12.8%) to 94 patients (4.5%) when compared to prior guidelines (p < 0.001). The minimum number of follow-up chest CTs decreased by 55.8% from 430 to 190 (p < 0.001). CONCLUSION: Application of the 2017 Fleischner Society Guidelines resulted in a significant decrease of follow-up testing for incidental PN in patients undergoing coronary CTA for suspected acute coronary syndrome.

Safety of coronary CT angiography and functional testing for stable chest pain in the PROMISE trial: A randomized comparison of test complications, incidental findings, and radiation dose.

BACKGROUND: Coronary computed tomography angiography (CTA) and functional testing strategies for stable chest pain yield similar outcomes; one aspect that may guide test choice is safety. METHODS: We compared test safety (test complications, incidental findings, and effective radiation dose) between CTA and functional testing as-tested in PROMISE (PROspective Multicenter Imaging Study for Evaluation of Chest Pain). In the subgroup whose physicians intended nuclear stress over other functional tests if randomized to the functional arm, we compared radiation dose of CTA versus nuclear stress and identified characteristics associated with dose. RESULTS: Of 9470 patients, none had major and <1% had minor complications (CTA: 0.8% [37/4633] vs. functional: 0.6% [27/4837]). CTA identified more incidental findings (11.6% [539/4633] vs. 0.7% [34/4837], p < 0.001), most commonly pulmonary nodules (9.4%, 437/4633). CTA had similar 90-day cumulative radiation dose to functional testing. However, in the subgroup whose physicians intended nuclear stress (CTA 3147; nuclear 3203), CTA had lower median index test (8.8 vs. 12.6 mSv, p < 0.001) and 90-day cumulative (11.6 vs. 13.1 mSv, p < 0.001) dose, independent of patient characteristics. The lowest nuclear doses employed 1-day Tc-99m protocols (12.2 mSv). The lowest CTA doses were at sites performing ≥500 CTAs/year (6.9 mSv) and with advanced (latest available) CT scanners (5.5 mSv). CONCLUSION: Complications were negligibly rare for both CTA and functional testing. CTA detects more incidental findings. Compared to nuclear stress testing, CTA's lower radiation dose, independent of patient characteristics, makes it an attractive test choice. Radiation dose varies with imaging protocol, indicating opportunities to further reduce dose. (ClinicalTrials.gov number, NCT01174550).

ACR Appropriateness Criteria® Chronic Chest Pain-High Probability of Coronary Artery Disease.

In patients with chronic chest pain in the setting of high probability of coronary artery disease (CAD), imaging has major and diverse roles. First, imaging is valuable in determining and documenting the presence, extent, and severity of myocardial ischemia, hibernation, scarring, and/or the presence, site, and severity of obstructive coronary lesions. Second, imaging findings are important in determining the course of management of patients with suspected chronic myocardial ischemia and better defining those patients best suited for medical therapy, angioplasty/stenting, or surgery. Third, imaging is also necessary to determine the long-term prognosis and likely benefit from various therapeutic options by evaluating ventricular function, diastolic relaxation, and end-systolic volume. Imaging studies are also required to demonstrate other abnormalities, such as congenital/acquired coronary anomalies and severe left ventricular hypertrophy, that can produce angina in the absence of symptomatic coronary obstructive disease due to atherosclerosis. Clinical risk assessment is necessary to determine the pretest probability of CAD. Multiple methods are available to categorize patients as low, medium, or high risk for developing CAD. 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 include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Coronary CT angiography in the emergency department utilizing second and third generation dual source CT.

BACKGROUND: Coronary computed tomography angiography (coronary CTA) allows efficient triage of low to intermediate risk patients with suspected acute coronary syndrome (ACS) in the emergency department (ED). Techniques for coronary CTA acquisition in the ED continue to evolve with the establishment of standardized scan protocols and the introduction of newer generations of CT hardware. OBJECTIVES: To evaluate qualitative and quantitative image quality and radiation dose exposure of coronary CTA acquired on 2nd versus 3rd generation dual source CT (DSCT) scanners using a standardized institutional scan protocol designed for the ED. METHODS: A retrospective observational case-control study was performed of 246 ED patients referred to coronary CTA with suspicion of ACS (56.5% male; mean age 53.3 ± 11.6 years) between October 2013 and August 2015.123 consecutive patients were scanned on 3rd generation DSCT, and a cohort of 123 patients matched by age, BMI and heart rate were identified who had undergone 2nd generation DSCT imaging utilizing the same standard clinical protocol. Qualitative and quantitative image quality parameters and radiation exposures were evaluated. RESULTS: Qualitative image quality was significantly higher using 3rd generation DSCT as compared to 2nd generation (p < 0.001). Mean attenuation in the proximal coronary arteries was also significantly higher on 3rd generation DSCT than for 2nd generation (586 HU vs. 426 HU in the left main coronary artery (LM), p < 0.001). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) values, however, were lower in 3rd generation DSCT than 2nd generation (SNR 11.2 [9.9-13.4] vs 13.5 [11.0-15.5] and CNR 12.4 [10.9-14.8] vs 15.2 [12.8-17.9] in the LM, p < 0.001). Median effective dose was also lower for 3rd generation DSCT than for 2nd generation (2.9 [2.3-5.0] mSv and 3.7 mSv [2.5-5.7], respectively) although this trend did not reach statistical significance (p = 0.065). CONCLUSION: Qualitative image quality and mean CT attenuation values of the assessed coronary segments were significantly higher using 3rd generation DSCT. SNR and CNR were lower on 3rd generation DSCT, however this was accompanied by a trend toward lower radiation dose exposure when using the same standard institutional protocol.

Non-diagnostic coronary artery calcification and stenosis: a correlation of coronary computed tomography angiography and invasive coronary angiography.

Background Heavy coronary artery calcification (CAC) impairs diagnostic accuracy of coronary computed tomography angiography (cCTA) and is considered to be a major limitation. Purpose To investigate the effect of non-evaluable CAC seen on cCTA on clinical decision-making by determining the degree of subsequent invasive testing and to assess the relationship between non-evaluable segments containing CAC and significant stenosis as seen in invasive coronary angiography (ICA). Material and Methods The study comprised of 356 patients who underwent cCTA and subsequent ICA within 2 months between 2005 and 2009. Clinical reports were reviewed to identify the indications for referral to ICA. In a subset of 68 patients where non-diagnostic CAC on cCTA and significant stenosis on ICA were present in the same segment, we correlated and analyzed the underlying stenosis severity of the lesion on ICA to the cCTA. Lesions with CAC were analyzed in a standardized fashion by application of reading rules. Results Non-diagnostic CAC on cCTA prompted ICA in 5.6% of patients. CAC occurred at the site of maximum stenosis in segments with stenosis <50% (95.9% [47/49]), 50-69% (82.4% [28/34]), 70-99% (64.5% [31/48]), and 100% (33.3% [1/3]). At the point of maximum calcium deposit, non-obstructive disease was present in 61.2%. Application of reading rules resulted in a 44% reduction in non-diagnostic cCTA reads. Conclusion Severe CAC may prompt further investigation with ICA. There is less CAC with increasing lesion severity at the point of maximum stenosis. Additional application of reading rules improved non-diagnostic cCTA reads.

A 57-Year-Old Man With Insidious Dyspnea and Nonpleuritic Chest and Back Pain.

A 57-year-old man with a history of DVT and pulmonary embolism, transient ischemic attacks, prior 60 pack-year smoking history, and oxygen-dependent COPD presented with insidiously worsening dyspnea associated with new pleuritic chest and back pain.

Relationship Between Measures of Adiposity, Arterial Inflammation, and Subsequent Cardiovascular Events.

BACKGROUND: The objective of this study was to evaluate how different measures of adiposity are related to both arterial inflammation and the risk of subsequent cardiovascular events. METHODS AND RESULTS: We included individuals who underwent (18)F-fluorodeoxyglucose positron emission tomography/computed tomography imaging for oncological evaluation. Subcutaneous adipose tissue (SAT) volume, visceral adipose tissue (VAT) volume, and VAT/SAT ratio were determined. Additionally, body mass index, metabolic syndrome, and aortic (18)F-fluorodeoxyglucose uptake (a measure of arterial inflammation) were determined. Subsequent development of cardiovascular disease (CVD) events was adjudicated. The analysis included 415 patients with a median age of 55 (P25-P75: 45-65) and a median body mass index of 26.4 (P25-P75: 23.4-30.9) kg/m(2). VAT and SAT volume were significantly higher in obese individuals. VAT volume (r=0.290; P<0.001) and VAT/SAT ratio (r=0.208; P<0.001) were positively correlated with arterial inflammation. Thirty-two subjects experienced a CVD event during a median follow-up of 4 years. Cox proportional hazard models showed that VAT volume and VAT/SAT ratio were associated with CVD events (hazard ratio [95% confidence interval]: 1.15 [1.06-1.25]; P<0.001; 3.60 [1.88-6.92]; P<0.001, respectively). Body mass index, metabolic syndrome, and SAT were not predictive of CVD events. CONCLUSIONS: Measures of visceral fat are positively related to arterial inflammation and are independent predictors of subsequent CVD events. Individuals with higher measures of visceral fat as well as elevated arterial inflammation are at highest risk for subsequent CVD events. The findings suggest that arterial inflammation may explain some of the CVD risk associated with adiposity.

Anomalous Aortic Origin of a Coronary Artery: Surgical Repair With Anatomic- and Function-Based Follow-Up.

BACKGROUND: Anomalous aortic origin of the coronary artery (AAOCA) with an interarterial (IAC) course is an uncommon congenital anomaly. Surgical indications and repair techniques have evolved. We have managed 259 adult patients with AAOCA over 40 years. Our management strategy includes anatomic- and function-based surveillance to select surgical candidates. We reviewed our surgical cohort and analyzed anatomic and functional outcomes. METHODS: We queried our heart center databases to obtain the names of all patients with AAOCA managed at our institution between 1974 and 2014. We performed a retrospective chart review. RESULTS: Two hundred fifty-nine patients were managed for AAOCA. Sixty-one underwent surgical intervention. Twenty-six with associated coronary atherosclerosis were excluded. Thirty-one who underwent surgical repair were analyzed. Mean age was 42.5 ± 2.7 years. Twenty-four patients (77.4%) had right AAOCA. Six (19.4%) had left AAOCA. One (3.2%) had bilateral coronary anomalies. Repair techniques included 21 unroofing procedures (67.7%), 6 translocations (19.4%), and 4 coronary artery bypass grafting (CABG) procedures (12.9%). Mean follow-up was 3.8 ± 0.8 years. Thirteen patients underwent follow-up anatomic testing with computed tomography. Twelve of these patients had widely patent coronary arteries, and 1 patient had mild coronary artery stenosis. Seventeen patients underwent functional testing. Fifteen of these patients had no evidence of ischemia. One patient had reversible ischemia after CABG, and 1 had subclinical ischemia after unroofing. There was 1 late mortality from endocarditis. CONCLUSIONS: Our multidisciplinary program uses a treatment algorithm to select patients with AAOCA for surgical intervention. Only a small subset requires an operation, and we favor unroofing and translocation techniques. With this paradigm, outcomes are excellent, as validated with anatomic- and function-based testing.