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1.
Article in English | MEDLINE | ID: mdl-39297850

ABSTRACT

BACKGROUND: Myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) using stress cardiovascular magnetic resonance (CMR) have been shown to identify epicardial coronary artery disease. However, comparative analysis between quantitative perfusion and conventional qualitative assessment (QA) remains limited. OBJECTIVES: The aim of this multicenter study was to test the hypothesis that quantitative stress MBF (sMBF) and MPR analysis can identify obstructive coronary artery disease (obCAD) with comparable performance as QA of stress CMR performed by experienced physicians in interpretation. METHODS: The analysis included 127 individuals (mean age 62 ± 16 years, 84 men [67%]) who underwent stress CMR. obCAD was defined as the presence of stenosis ≥50% in the left main coronary artery or ≥70% in a major vessel. Each patient, coronary territory, and myocardial segment was categorized as having either obCAD or no obCAD (noCAD). Global, per coronary territory, and segmental MBF and MPR values were calculated. QA was performed by 4 CMR experts. RESULTS: At the patient level, global sMBF and MPR were significantly lower in subjects with obCAD than in those with noCAD, with median values of sMBF of 1.5 mL/g/min (Q1-Q3: 1.2-1.8 mL/g/min) vs 2.4 mL/g/min (Q1-Q3: 2.1-2.7 mL/g/min) (P < 0.001) and median values of MPR of 1.3 (Q1-Q3: 1.0-1.6) vs 2.1 (Q1-Q3: 1.6-2.7) (P < 0.001). At the coronary artery level, sMBF and MPR were also significantly lower in vessels with obCAD compared with those with noCAD. Global sMBF and MPR had areas under the curve (AUCs) of 0.90 (95% CI: 0.84-0.96) and 0.86 (95% CI: 0.80-0.93). The AUCs for QA by 4 physicians ranged between 0.69 and 0.88. The AUC for global sMBF and MPR was significantly better than the average AUC for QA. CONCLUSIONS: This study demonstrates that sMBF and MPR using dual-sequence stress CMR can identify obCAD more accurately than qualitative analysis by experienced CMR readers.

2.
Front Radiol ; 4: 1327406, 2024.
Article in English | MEDLINE | ID: mdl-39175870

ABSTRACT

Background: Cardiac magnetic resonance is a useful clinical tool to identify late gadolinium enhancement in heart failure patients with implantable electronic devices. Identification of LGE in patients with CIED is limited by artifact, which can be improved with a wide band radiofrequency pulse sequence. Objective: The authors hypothesize that image quality of LGE images produced using wide-band pulse sequence in patients with devices is comparable to image quality produced using standard LGE sequences in patients without devices. Methods: Two independent readers reviewed LGE images of 16 patients with CIED and 7 patients without intracardiac devices to assess for image quality, device-related artifact, and presence of LGE using the American Society of Echocardiography/American Heart Association 17 segment model of the heart on a 4-point Likert scale. The mean and standard deviation for image quality and artifact rating were determined. Inter-observer reliability was determined by calculating Cohen's kappa coefficient. Statistical significance was determined by T-test as a p {less than or equal to} 0.05 with a 95% confidence interval. Results: All patients underwent CMR without any adverse events. Overall IQ of WB LGE images was significantly better in patients with devices compared to standard LGE in patients without devices (p = 0.001) with reduction in overall artifact rating (p = 0.05). Conclusion: Our study suggests wide-band pulse sequence for LGE can be applied safely to heart failure patients with devices in detection of LV myocardial scar while maintaining image quality, reducing artifact, and following routine imaging protocol after intravenous gadolinium contrast administration.

3.
JACC Cardiovasc Imaging ; 17(7): 795-810, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38613553

ABSTRACT

Microvascular injury immediately following reperfusion therapy in acute myocardial infarction (MI) has emerged as a driving force behind major adverse cardiovascular events in the postinfarction period. Although postmortem investigations and animal models have aided in developing early understanding of microvascular injury following reperfusion, imaging, particularly serial noninvasive imaging, has played a central role in cultivating critical knowledge of progressive damage to the myocardium from the onset of microvascular injury to months and years after in acute MI patients. This review summarizes the pathophysiological features of microvascular injury and downstream consequences, and the contributions noninvasive imaging has imparted in the development of this understanding. It also highlights the interventional trials that aim to mitigate the adverse consequences of microvascular injury based on imaging, identifies potential future directions of investigations to enable improved detection of disease, and demonstrates how imaging stands to play a major role in the development of novel therapies for improved management of acute MI patients.


Subject(s)
Coronary Circulation , Hemorrhage , Microcirculation , Myocardial Infarction , Myocardium , Predictive Value of Tests , Humans , Myocardial Infarction/physiopathology , Myocardial Infarction/diagnostic imaging , Myocardial Infarction/therapy , Myocardial Infarction/complications , Animals , Hemorrhage/diagnostic imaging , Hemorrhage/physiopathology , Hemorrhage/therapy , Hemorrhage/etiology , Myocardium/pathology , Treatment Outcome , Myocardial Reperfusion Injury/physiopathology , Myocardial Reperfusion Injury/diagnostic imaging , Myocardial Reperfusion Injury/etiology , Prognosis , Coronary Vessels/physiopathology , Coronary Vessels/diagnostic imaging , Microvessels/physiopathology , Microvessels/diagnostic imaging , Risk Factors , Myocardial Reperfusion
4.
Magn Reson Med ; 91(5): 1936-1950, 2024 May.
Article in English | MEDLINE | ID: mdl-38174593

ABSTRACT

PURPOSE: Widely used conventional 2D T2 * approaches that are based on breath-held, electrocardiogram (ECG)-gated, multi-gradient-echo sequences are prone to motion artifacts in the presence of incomplete breath holding or arrhythmias, which is common in cardiac patients. To address these limitations, a 3D, non-ECG-gated, free-breathing T2 * technique that enables rapid whole-heart coverage was developed and validated. METHODS: A continuous random Gaussian 3D k-space sampling was implemented using a low-rank tensor framework for motion-resolved 3D T2 * imaging. This approach was tested in healthy human volunteers and in swine before and after intravenous administration of ferumoxytol. RESULTS: Spatial-resolution matched T2 * images were acquired with 2-3-fold reduction in scan time using the proposed T2 * mapping approach relative to conventional T2 * mapping. Compared with the conventional approach, T2 * images acquired with the proposed method demonstrated reduced off-resonance and flow artifacts, leading to higher image quality and lower coefficient of variation in T2 *-weighted images of the myocardium of swine and humans. Mean myocardial T2 * values determined using the proposed and conventional approaches were highly correlated and showed minimal bias. CONCLUSION: The proposed non-ECG-gated, free-breathing, 3D T2 * imaging approach can be performed within 5 min or less. It can overcome critical image artifacts from undesirable cardiac and respiratory motion and bulk off-resonance shifts at the heart-lung interface. The proposed approach is expected to facilitate faster and improved cardiac T2 * mapping in those with limited breath-holding capacity or arrhythmias.


Subject(s)
Heart , Myocardium , Humans , Animals , Swine , Heart/diagnostic imaging , Respiration , Breath Holding , Magnetic Resonance Imaging, Cine/methods , Magnetic Resonance Imaging , Imaging, Three-Dimensional/methods
5.
FASEB J ; 37(9): e23122, 2023 09.
Article in English | MEDLINE | ID: mdl-37606555

ABSTRACT

There is emerging evidence that the cardiac interatrial septum has an important role as a thromboembolic source for ischemic strokes. There is little consensus on treatment of patients with different cardiac interatrial morphologies or pathologies who have had stroke. In this paper, we summarize the important background, diagnostic, and treatment considerations for this patient population as presented during the Federation of American Societies for Experimental Biology (FASEB) Virtual Catalytic Conference on the Cardiac Interatrial Septum and Stroke Risk, held on December 7, 2022. During this conference, many aspects of the cardiac interatrial septum were discussed. Among these were the embryogenesis of the interatrial septum and development of anatomic variants such as patent foramen ovale and left atrial septal pouch. Also addressed were various mechanisms of injury such as shunting physiologies and the consequences that can result from anatomic variants, as well as imaging considerations in echocardiography, computed tomography, and magnetic resonance imaging. Treatment options including anticoagulation and closure were addressed, as well as an in-depth discussion on whether the left atrial septal pouch is a stroke risk factor. These issues were discussed and debated by multiple experts from neurology, cardiology, and radiology.


Subject(s)
Cardiology , Heart Septal Defects, Atrial , Humans , Heart Septal Defects, Atrial/diagnostic imaging , Catalysis , Echocardiography , Embryonic Development
6.
Clin Imaging ; 101: 150-155, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37364365

ABSTRACT

PURPOSE: The objective is to show that TR-MRA is a useful non-invasive technique without ionizing radiation of traditional angiography in evaluating VMs. MATERIALS AND METHODS: Retrospective search utilizing M-Power for MRA studies done at 3 T (Trio, Siemens) with both 3D contrast enhanced TR-MRA and 3D CE-MRA sequences from 2009 to 2018 were obtained after IRB approval. The images were blindly reviewed by two experienced cardiovascular radiologists for informations regarding vascular malformations with the ability to separate arteries and veins without any overlay or contamination in real time. Both TR-MRA and 3D CE-MRA images were carefully evaluated. The following characteristics: flow rate, size, type, feeding vessels, draining vessels and clots were evaluated. The findings were then compared to the Catheter Angiography for the patients that had catheter angiography study. RESULTS: The M-Power search resulted a total of 69 patients (24 males, 45 females, age range 11 days to 74 years). Of those 69, there were 25 patients with confirmatory Catheter Angiography study. The radiologists characterized VMs as 19 high flow VMs, 47 slow flow VMs, 2 lymphatic malformations and 1 no flow VM. Of those with Cath, there was 100% concordance with the TR-MRA. CONCLUSION: TR-MRA provides functional characterization of a VM that cannot be determined with CE-MRA alone. This is critical in treatment planning with high-flow VMs.


Subject(s)
Magnetic Resonance Angiography , Vascular Malformations , Male , Female , Humans , Infant, Newborn , Magnetic Resonance Angiography/methods , Retrospective Studies , Angiography, Digital Subtraction/methods , Vascular Malformations/diagnostic imaging , Veins , Contrast Media
7.
Nat Commun ; 13(1): 6394, 2022 10 27.
Article in English | MEDLINE | ID: mdl-36302906

ABSTRACT

Sudden blockage of arteries supplying the heart muscle contributes to millions of heart attacks (myocardial infarction, MI) around the world. Although re-opening these arteries (reperfusion) saves MI patients from immediate death, approximately 50% of these patients go on to develop chronic heart failure (CHF) and die within a 5-year period; however, why some patients accelerate towards CHF while others do not remains unclear. Here we show, using large animal models of reperfused MI, that intramyocardial hemorrhage - the most damaging form of reperfusion injury (evident in nearly 40% of reperfused ST-elevation MI patients) - drives delayed infarct healing and is centrally responsible for continuous fatty degeneration of the infarcted myocardium contributing to adverse remodeling of the heart. Specifically, we show that the fatty degeneration of the hemorrhagic MI zone stems from iron-induced macrophage activation, lipid peroxidation, foam cell formation, ceroid production, foam cell apoptosis and iron recycling. We also demonstrate that timely reduction of iron within the hemorrhagic MI zone reduces fatty infiltration and directs the heart towards favorable remodeling. Collectively, our findings elucidate why some, but not all, MIs are destined to CHF and help define a potential therapeutic strategy to mitigate post-MI CHF independent of MI size.


Subject(s)
Heart Failure , Myocardial Infarction , Animals , Myocardium , Myocardial Infarction/complications , Myocardial Infarction/therapy , Hemorrhage , Heart , Heart Failure/etiology , Iron , Ventricular Remodeling , Disease Models, Animal
9.
JACC Case Rep ; 4(5): 271-275, 2022 Mar 02.
Article in English | MEDLINE | ID: mdl-35257101

ABSTRACT

We present a case of pericardial amyloidosis with associated lymphoplasmacytic lymphoma in a patient with chronic worsening shortness of breath and cough. This case highlights the wide variation in the presentation of cardiac amyloidosis, and the rare occurrence of clinically significant light-chain and heavy-chain amyloidosis in the pericardium. (Level of Difficulty: Advanced.).

10.
Radiol Case Rep ; 15(9): 1562-1565, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32670460

ABSTRACT

Intracardiac metastasis of the testicular cancer is very rare phenomenon. A 30-year-old-man with a history of testicular rhabdomyosarcoma and lung metastases was found to have an intracardiac filling defect in a surveillance computed tomography scan 3 years after the initial diagnosis. A cardiac magnetic resonance imaging study was performed for further evaluation and demonstrated a lobulated, heterogeneously enhancing mobile mass within the right ventricle attaching to the anterior papillary muscle. Patient underwent an open surgical resection of the cardiac mass that was confirmed metastasis of testicular rhabdomyosarcoma into the right ventricular papillary muscle and tricuspid valve. To our knowledge, this is the first report in the literature that describes metastasis to a papillary muscle and tricuspid valve from a testicular neoplasm.

11.
Radiol Case Rep ; 15(6): 688-690, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32382363

ABSTRACT

Unilateral absence of pulmonary artery is a rare developmental anomaly. Infrahepatic inferior vena cava interruption is a well-recognized but uncommon developmental anomaly. Presence of both these anomalies in a single individual is extremely rare. A 58-year-old man with a history of recurrent lower extremity deep vein thrombosis and venous insufficiency presented to our emergency department with bilateral calf pain and swelling. Ultrasound demonstrated extensive deep vein thrombosis throughout bilateral lower extremities. Computed tomography angiography showed smooth tapering of the right pulmonary artery with absent distal most segment. To our knowledge, there is only 1 case report in the literature so far with both the abnormalities present in a single individual.

12.
Br J Radiol ; 93(1109): 20190462, 2020 May 01.
Article in English | MEDLINE | ID: mdl-32045282

ABSTRACT

OBJECTIVES: To evaluate coronary artery calcification (CAC) on routine CT chest in hospitalised HIV patients and to assess individual risk factors. METHODS: Routine CT chests, May 2010-November 2015, of 143 hospitalised HIV-positive patients were reviewed for qualitative assessment of calcification in major coronary arteries by two radiologists. Presence, location and burden of calcification were evaluated on 3 mm axial images of CT chest. Cardiovascular risk factors and HIV lab parameters such as CD4 count, viral load and duration, and status of antiretroviral treatment were collected. Statistical analysis including multivariate logistic regression was performed. RESULTS: Forty-one patients (28.7%) showed CAC, left anterior descending (n = 38, 92.7%), circumflex (n = 18, 43.9%) and Right Coronary Artery (n = 13, 31.7%); mostly mild CAC burden and mostly proximal left coronary arteries with excellent interobserver and intraobserver agreements (K = 0.9, and 1). Age of CAC+ group (53.9 years) was significantly higher than CAC- group (43.4, p < 0.001, minimum age of CAC+, 27 years). No significant difference between two groups in sex, ethnicity and risk factors and HAART status. CAC+ group showed significantly longer HIV duration (12.3 years vs 8.6, p < 0.0344) and higher CD4 cell counts (mean = 355.9 vs 175.3, p = 0.0053) and significantly lower viral load (76 vs 414K, p = 0.02) than CAC- group. On multivariate logistic regression, age, HIV duration and CD4 were significantly associated with CAC+ (p-values < .05). CONCLUSIONS: One-third of hospitalised HIV patients showed subclinical CAC on CT chest. HIV duration and age of patients were independent risk factors for developing CAC. Higher CD4 cell count was strongly associated with CAC+. ADVANCES IN KNOWLEDGE: Routine CT chest with or without contrast performed for non-cardiac indications is helpful in identification of subclinical CAC in HIV patients and radiologists should be encouraged to report CAC.CAC is seen in younger age group in HIV, and awareness of this finding on routine CT chest would help guiding clinicians to assess risk stratification for primary prevention of ischemic heart disease in this population at an earlier stage when compared to normal population.Duration of HIV infection and age of patients were independent risk factors for developing CAC in our study and CD4 count was strongly associated with presence of CAC.


Subject(s)
Coronary Artery Disease/diagnostic imaging , HIV Infections/complications , Vascular Calcification/diagnostic imaging , Adult , Computed Tomography Angiography/methods , Coronary Angiography/methods , Coronary Artery Disease/complications , Coronary Vessels/diagnostic imaging , Early Diagnosis , Female , Hospitalization , Humans , Male , Middle Aged , Retrospective Studies , Tomography, X-Ray Computed , Vascular Calcification/complications
13.
Int J Cardiovasc Imaging ; 35(8): 1483-1497, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31030315

ABSTRACT

Magnetic resonance imaging (MRI) plays an increasingly important role in the non-invasive evaluation of the pulmonary vasculature. MR angiographic (MRA) techniques provide morphological information, while MR perfusion techniques provide functional information of the pulmonary vasculature. Contrast-enhanced MRA can be performed at high spatial resolution using 3D T1-weighted spoiled gradient echo sequence or at high temporal resolution using time-resolved techniques. Non-contrast MRA can be performed using 3D steady state free precession, double inversion fast spin echo, time of flight or phase contrast sequences. MR perfusion can be done using dynamic contrast-enhanced technique or using non-contrast techniques such as arterial spin labelling and time-resolved imaging of lungs during free breathing with Fourier decomposition analysis. MRI is used in the evaluation of acute and chronic pulmonary embolism, pulmonary hypertension and other vascular abnormalities, congenital anomalies and neoplasms. In this article, we review the different MR techniques used in the evaluation of pulmonary vasculature and its clinical applications.


Subject(s)
Hemodynamics , Lung Diseases/diagnostic imaging , Magnetic Resonance Angiography , Magnetic Resonance Imaging , Perfusion Imaging/methods , Pulmonary Artery/diagnostic imaging , Pulmonary Circulation , Humans , Image Interpretation, Computer-Assisted , Lung Diseases/physiopathology , Lung Diseases/therapy , Predictive Value of Tests , Prognosis , Pulmonary Artery/physiopathology
14.
Coron Artery Dis ; 30(4): 297-302, 2019 06.
Article in English | MEDLINE | ID: mdl-30888975

ABSTRACT

AIM: This study aimed to define the relationship between pulse pressure (PP) and coronary artery calcification (CAC), a proven surrogate marker for coronary heart disease. PATIENTS AND METHODS: A total of 170 participants 50-70 years of age from 11 villages of Yunnan Province of China were enrolled randomly into this study. They were examined routinely for diastolic and systolic blood pressure, PP, and CAC. RESULTS: The average PP in the CAC-positive group was significantly higher than that in the CAC-negative group. In the positive CAC group, there were significantly positive correlations between PP and CAC score, volume, mass, as well as density. The area under the receiver operating characteristic curve analysis showed that PP performed well in predicting CAC. CONCLUSION: In conclusion, among the rural people of southwest of China, PP correlates positively with the coronary calcium Agatston score, volume, mass, and density. PP predicted CAC as well as Framingham Risk Score. The measurement of PP widening may serve as an alternative and convenient method for assessing CAC risk in rural populations with poor accessibility and economic disadvantage over coronary computed tomography scanning.


Subject(s)
Blood Pressure , Coronary Artery Disease/physiopathology , Rural Health , Vascular Calcification/physiopathology , Aged , China/epidemiology , Computed Tomography Angiography , Coronary Angiography , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/epidemiology , Female , Humans , Male , Middle Aged , Risk Assessment , Risk Factors , Vascular Calcification/diagnostic imaging , Vascular Calcification/epidemiology
15.
Future Cardiol ; 14(2): 125-130, 2018 03.
Article in English | MEDLINE | ID: mdl-29355029

ABSTRACT

AIM: Postmyocardial infarction ventricular septal defect (VSD) is a rare complication that can lead to rapid hemodynamic patient decompensation. The type of VSD repair relies on several factors including: size, location, timing and surgical expertise. CASE: A 63-year-old man with a ST-elevation myocardial infarction underwent percutaneous coronary intervention of the right coronary artery. A holosystolic murmur was notable postcatheterization, and transthoracic echocardiogram confirmed a VSD. To characterize the VSD, a cardiac MRI demonstrated a large, serpiginous VSD and longitudinal septal tear. Given the anatomic complexity and stable hemodynamics, a surgical trans-left ventricular patch repair was performed. CONCLUSION: We emphasize the importance of cardiac magnetic resonance as a decision-making tool, utilizing imaging to ascertain the anatomy combined with hemodynamics to determine optimal individualized therapy.


Subject(s)
Cardiac Catheterization/methods , Cardiac Surgical Procedures/methods , Heart Septal Defects, Ventricular/diagnosis , Heart Ventricles/diagnostic imaging , Magnetic Resonance Imaging, Cine/methods , ST Elevation Myocardial Infarction/complications , Septal Occluder Device , Echocardiography , Heart Septal Defects, Ventricular/etiology , Heart Septal Defects, Ventricular/surgery , Heart Ventricles/surgery , Humans , Male , Middle Aged , ST Elevation Myocardial Infarction/diagnosis
16.
Circulation ; 136(21): 1993-2005, 2017 Nov 21.
Article in English | MEDLINE | ID: mdl-28847895

ABSTRACT

BACKGROUND: Coronary artery calcium (CAC) is an established predictor of future major adverse atherosclerotic cardiovascular events in asymptomatic individuals. However, limited data exist as to how CAC compares with functional testing (FT) in estimating prognosis in symptomatic patients. METHODS: In the PROMISE trial (Prospective Multicenter Imaging Study for Evaluation of Chest Pain), patients with stable chest pain (or dyspnea) and intermediate pretest probability for obstructive coronary artery disease were randomized to FT (exercise electrocardiography, nuclear stress, or stress echocardiography) or anatomic testing. We evaluated those who underwent CAC testing as part of the anatomic evaluation (n=4209) and compared that with results of FT (n=4602). We stratified CAC and FT results as normal or mildly, moderately, or severely abnormal (for CAC: 0, 1-99 Agatston score [AS], 100-400 AS, and >400 AS, respectively; for FT: normal, mild=late positive treadmill, moderate=early positive treadmill or single-vessel ischemia, and severe=large ischemic region abnormality). The primary end point was all-cause death, myocardial infarction, or unstable angina hospitalization over a median follow-up of 26.1 months. Cox regression models were used to calculate hazard ratios (HRs) and C statistics to determine predictive and discriminatory values. RESULTS: Overall, the distribution of normal or mildly, moderately, or severely abnormal test results was significantly different between FT and CAC (FT: normal, n=3588 [78.0%]; mild, n=432 [9.4%]; moderate, n=217 [4.7%]; severe, n=365 [7.9%]; CAC: normal, n=1457 [34.6%]; mild, n=1340 [31.8%]; moderate, n=772 [18.3%]; severe, n=640 [15.2%]; P<0.0001). Moderate and severe abnormalities in both arms robustly predicted events (moderate: CAC: HR, 3.14; 95% confidence interval, 1.81-5.44; and FT: HR, 2.65; 95% confidence interval, 1.46-4.83; severe: CAC: HR, 3.56; 95% confidence interval, 1.99-6.36; and FT: HR, 3.88; 95% confidence interval, 2.58-5.85). In the CAC arm, the majority of events (n=112 of 133, 84%) occurred in patients with any positive CAC test (score >0), whereas fewer than half of events occurred in patients with mildly, moderately, or severely abnormal FT (n=57 of 132, 43%; P<0.001). In contrast, any abnormality on FT was significantly more specific for predicting events (78.6% for FT versus 35.2% for CAC; P<0.001). Overall discriminatory ability in predicting the primary end point of mortality, nonfatal myocardial infarction, and unstable angina hospitalization was similar and fair for both CAC and FT (C statistic, 0.67 versus 0.64). Coronary computed tomographic angiography provided significantly better prognostic information compared with FT and CAC testing (C index, 0.72). CONCLUSIONS: Among stable outpatients presenting with suspected coronary artery disease, most patients experiencing clinical events have measurable CAC at baseline, and fewer than half have any abnormalities on FT. However, an abnormal FT was more specific for cardiovascular events, leading to overall similarly modest discriminatory abilities of both tests. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01174550.


Subject(s)
Angina Pectoris/etiology , Computed Tomography Angiography , Coronary Angiography/methods , Coronary Artery Disease/diagnosis , Dyspnea/etiology , Echocardiography, Stress/methods , Electrocardiography/methods , Exercise Test , Multidetector Computed Tomography , Vascular Calcification/diagnosis , Aged , Angina, Unstable/etiology , Comparative Effectiveness Research , Coronary Artery Disease/complications , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/mortality , Diagnosis, Differential , Disease Progression , Female , Hospitalization , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Myocardial Infarction/etiology , North America , Predictive Value of Tests , Prognosis , Proportional Hazards Models , Prospective Studies , Risk Factors , Time Factors , Vascular Calcification/complications , Vascular Calcification/diagnostic imaging , Vascular Calcification/mortality
17.
JAMA Intern Med ; 177(6): 810-817, 2017 06 01.
Article in English | MEDLINE | ID: mdl-28395000

ABSTRACT

Importance: Radiation doses for computed tomography (CT) vary substantially across institutions. Objective: To assess the impact of institutional-level audit and collaborative efforts to share best practices on CT radiation doses across 5 University of California (UC) medical centers. Design, Setting, and Participants: In this before/after interventional study, we prospectively collected radiation dose metrics on all diagnostic CT examinations performed between October 1, 2013, and December 31, 2014, at 5 medical centers. Using data from January to March (baseline), we created audit reports detailing the distribution of radiation dose metrics for chest, abdomen, and head CT scans. In April, we shared reports with the medical centers and invited radiology professionals from the centers to a 1.5-day in-person meeting to review reports and share best practices. Main Outcomes and Measures: We calculated changes in mean effective dose 12 weeks before and after the audits and meeting, excluding a 12-week implementation period when medical centers could make changes. We compared proportions of examinations exceeding previously published benchmarks at baseline and following the audit and meeting, and calculated changes in proportion of examinations exceeding benchmarks. Results: Of 158 274 diagnostic CT scans performed in the study period, 29 594 CT scans were performed in the 3 months before and 32 839 CT scans were performed 12 to 24 weeks after the audit and meeting. Reductions in mean effective dose were considerable for chest and abdomen. Mean effective dose for chest CT decreased from 13.2 to 10.7 mSv (18.9% reduction; 95% CI, 18.0%-19.8%). Reductions at individual medical centers ranged from 3.8% to 23.5%. The mean effective dose for abdominal CT decreased from 20.0 to 15.0 mSv (25.0% reduction; 95% CI, 24.3%-25.8%). Reductions at individual medical centers ranged from 10.8% to 34.7%. The number of CT scans that had an effective dose measurement that exceeded benchmarks was reduced considerably by 48% and 54% for chest and abdomen, respectively. After the audit and meeting, head CT doses varied less, although some institutions increased and some decreased mean head CT doses and the proportion above benchmarks. Conclusions and Relevance: Reviewing institutional doses and sharing dose-optimization best practices resulted in lower radiation doses for chest and abdominal CT and more consistent doses for head CT.


Subject(s)
Radiography, Abdominal/standards , Radiography, Thoracic/standards , Tomography, X-Ray Computed/standards , California , Dose-Response Relationship, Radiation , Female , Head/diagnostic imaging , Humans , Male , Neoplasms, Radiation-Induced/prevention & control , Pelvis/diagnostic imaging , Radiation Dosage , Risk Assessment , Tomography, X-Ray Computed/adverse effects
18.
Radiology ; 282(1): 182-193, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27438166

ABSTRACT

Purpose To determine patient, vendor, and institutional factors that influence computed tomography (CT) radiation dose. Materials and Methods The relevant institutional review boards approved this HIPAA-compliant study, with waiver of informed consent. Volume CT dose index (CTDIvol) and effective dose in 274 124 head, chest, and abdominal CT examinations performed in adult patients at 12 facilities in 2013 were collected prospectively. Patient, vendor, and institutional characteristics that could be used to predict (a) median dose by using linear regression after log transformation of doses and (b) high-dose examinations (top 25% of dose within anatomic strata) by using modified Poisson regression were assessed. Results There was wide variation in dose within and across medical centers. For chest CTDIvol, overall median dose across all institutions was 11 mGy, and institutional median dose was 7-16 mGy. Models including patient, vendor, and institutional factors were good for prediction of median doses (R2 = 0.31-0.61). The specific institution where the examination was performed (reflecting the specific protocols used) accounted for a moderate to large proportion of dose variation. For chest CTDIvol, unadjusted median CTDIvol was 16.5 mGy at one institution and 6.7 mGy at another (adjusted relative median dose, 2.6 mGy [95% confidence interval: 2.5, 2.7]). Several variables were important predictors that a patient would undergo high-dose CT. These included patient size, the specific institution where CT was performed, and the use of multiphase scanning. For example, while 49% of patients (21 411 of 43 696) who underwent multiphase abdominal CT had a high-dose examination, 8% of patients (4977 of 62 212) who underwent single-phase CT had a high-dose examination (adjusted relative risk, 6.20 [95% CI: 6.17, 6.23]). If all patients had been examined with single-phase CT, 69% (18 208 of 26 388) of high-dose examinations would have been eliminated. Patient size, institutional-specific protocols, and multiphase scanning were the most important predictors of dose (change in R2 = 8%-32%), followed by manufacturer and iterative reconstruction (change in R2, 0.2%-15.0%). Conclusion CT doses vary considerably within and across facilities. The primary factors that influenced dose variation were multiphase scanning and institutional protocol choices. It is unknown if the variation in these factors influenced diagnostic accuracy. © RSNA, 2016.


Subject(s)
Radiation Dosage , Tomography, X-Ray Computed/methods , Abdomen/radiation effects , Adolescent , Adult , Aged , Female , Head/radiation effects , Humans , Male , Middle Aged , Prospective Studies , Thorax/radiation effects
20.
Eur J Radiol ; 84(7): 1249-58, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25956492

ABSTRACT

OBJECTIVES: Quantitative assessment of left ventricular (LV) functional parameters in cardiac MR requires time-consuming contour tracing across multiple short axis images. This study assesses global LV functional parameters using 3-slice segmentation on steady state free precision (SSFP) cine short axis images and compares the results with conventional multi-slice segmentation of LV. METHODS: Data were collected from 61 patients who underwent cardiac MRI for various clinical indications. Semi-automated cardiac MR software was used to trace LV contours both at multiple slices from base to apex as well as just 3 slices (base, mid, and apical) by two readers. Left ventricular ejection fraction (LVEF), LV volumes, and LV mass were calculated using both methods. RESULTS: Bland-Altman plot revealed narrow limits of agreement (-4.4% to 5.1%) between LVEF obtained by the two methods. Bland-Altman analysis showed slightly wider limits of agreement between end-diastolic volumes (-5.0 to 12.0%; -3.9 to 8.5 ml/m(2)), end-systolic volumes (-10.9 to 14.7%; -4.1 to 6.5 ml/m(2)), and LV mass (-5.2 to 12.7%; -4.8 to 10.2g/m(2)) obtained by the two methods. There was a small mean difference between LV volumes and LV mass obtained using multi-slice and 3-slice segmentation. No statistically significant difference existed between the LV parameters obtained by the two readers using 3-slice segmentation (p>0.05). Multi-slice assessment required approximately 15 min per study while 3-slice assessment required less than 5 min. CONCLUSIONS: 3-slice segmentation of the left ventricle at basal, mid, and apical levels on cine SSFP short axis images can provide rapid and reliable assessment of LVEF with good reproducibility. The 3-slice method also provides a reasonable estimate of the LV volumes and LV mass.


Subject(s)
Magnetic Resonance Imaging, Cine , Ventricular Dysfunction, Left/diagnosis , Adult , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging, Cine/methods , Male , Middle Aged , Reproducibility of Results , Retrospective Studies , Ventricular Dysfunction, Left/pathology , Ventricular Function, Left
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