Role of gated cardiac computed tomographic angiography in the evaluation of postsurgical complications after stage I Norwood procedure and its implications on management: a comparative study with two-dimensional echocardiography.

BACKGROUND: The Norwood procedure is the first part of a three-stage surgical palliation for patients with functionally single ventricle anatomy. Complications after the stage I operation are not uncommon. Transthoracic echocardiography (TTE) is traditionally the mainstay for evaluation. OBJECTIVE: The purpose of our study is to compare gated cardiac computed tomographic angiography (CCTA) with TTE when evaluating for postoperative complications after stage I Norwood procedure and to describe management implications. MATERIALS AND METHODS: A retrospective chart review of all patients over a 4-year period who underwent nonelective urgent CCTA for suspected complications related to stage I Norwood procedure was performed. Elective CCTA studies before stage II palliation were excluded. Patient demographics, CCTA and TTE findings, as well as interventions performed, were recorded. RESULTS: Thirty-four patients were included. The mean age at CCTA was 63 days (range: 4-210 days). All patients had a recent TTE with a mean time interval between TTE and CCTA of 2 days. CCTA detected 56 abnormalities in 30 patients, with 23 directly related to postsurgical complications, including shunt-related complications (10/23, 43%), Damus-Kaye-Stansel anastomotic narrowing (2/23, 9%) and neo-aortic arch/branch vessel abnormalities (11/23, 48%). These complications were managed as follows: surgery (9, 39%), catheter-based intervention (7, 30%), medical (4, 17%) and no change in management (3, 13%). TTE did not detect 8/23 (35%) findings found on CCTA, of which 75% were either managed with surgery (4/8, 50%) or catheter-based intervention (2/8, 25%). CONCLUSION: CCTA plays an important role in detecting surgical complications after stage I Norwood procedure and demonstrates additional findings that have direct management implications.

MR imaging of iliofemoral peripheral vascular calcifications using proton density-weighted, in-phase three-dimensional stack-of-stars gradient echo.

PURPOSE: The presence of vascular calcifications helps to determine percutaneous access for interventional vascular procedures and has prognostic value for future cardiovascular events. Unlike CT, standard MRI techniques are insensitive to vascular calcifications. In this prospective study, we tested a proton density-weighted, in-phase (PDIP) three-dimensional (3D) stack-of-stars gradient-echo pulse sequence with approximately 1 mm3 isotropic spatial resolution at 1.5 Tesla (T) and 3T to detect iliofemoral peripheral vascular calcifications and correlated MR-determined lesion volumes with CT angiography (CTA). METHODS: The study was approved by the Institutional Review Board. The prototype PDIP stack-of-stars pulse sequence was applied in 12 patients with iliofemoral peripheral vascular calcifications who had undergone CTA. RESULTS: Vascular calcifications were well visualized in all subjects, excluding segments near prostheses or stents. The location, size, and shape of the calcifications were similar to CTA. Quantitative analysis showed excellent correlation (r2 = 0.84; P < 0.0001) between MR- and CT-based measures of calcification volume. In one subject in whom three pulse sequences were compared, PDIP stack-of-stars outperformed cartesian 3D gradient-echo and point-wise encoding time reduction with radial acquisition (PETRA). CONCLUSION: In this pilot study, a PDIP 3D stack-of-stars gradient-echo pulse sequence with high spatial resolution provided excellent image quality and accurately depicted the location and volume of iliofemoral vascular calcifications. Magn Reson Med 77:2146-2152, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

The combined effect of multidetector-row computed tomographic tube voltage, tube current, and image reconstruction algorithm on the detection of pneumothorax after intervention.

OBJECTIVES: The objective of the study was to determine the lowest multidetector-row computed tomographic radiation dose parameters for the detection of pneumothorax after thoracic intervention. MATERIALS AND METHODS: An anthropomorphic chest phantom containing pneumothoraces was imaged with different tube voltages (80, 100, and 120 kV[p]) and tube currents (10, 20, 40, 75, and 110 mAs). The images were reconstructed with both filtered back projection (FBP) and iterative reconstruction (IR) algorithms. Two blinded radiologists scored images independently for the presence or absence of pneumothorax. Effective dose, image noise, contrast-to-noise ratio, and signal-to-noise ratio were recorded. RESULTS: At radiation dose below 0.48 mSv, sensitivity for the detection of pneumothorax decreased in both reconstruction algorithms (80% for FBP vs 83% for IR; P > 0.05). Interobserver agreement was good (k = 0.78). The IR data sets showed lower image noise as well as higher signal-to-noise ratio and contrast-to-noise ratio when compared with FBP on all acquisition parameters (P < 0.0001). CONCLUSIONS: Very low computed tomographic dose parameters may be suitable for confident detection of small pneumothoraces after intervention.

Detection of anomalous aortic origin of a coronary artery (AAOCA) by echocardiogram: When does computed tomographic angiography add value?

BACKGROUND AND OBJECTIVE: There is limited literature comparing TTE and CCTA in children with suspected AAOCA. To determine the distribution of various coronary anomalies comparing TTE and CCTA data, and define the added value advanced imaging brings in clinical decision-making. MATERIALS AND METHODS: Retrospective review of data was obtained in patients aged 0-18 years who underwent TTE and CCTA for suspected AAOCA. Patient demographics, CCTA and TTE findings, and interventions performed were recorded. RESULTS: 100 consecutive patients were included (60% male), mean age 11 years (7 days-18 years old). In 93 patients, CCTA detected 94 anomalous coronaries. Definitive coronary abnormality was reported on TTE in 77 patients; 76 of which were confirmed by CCTA, 1 patient was found to have a normal variant. Suspected anomalous origin was reported in 16 patients on TTE, 13 of which were abnormal on CCTA. The coronary origin was not seen on TTE in 6 patients; of these, 3 had AAOCA on CCTA and 3 had hypoplastic RCA with left dominant system. Only 1 patient who had a normal TTE was found to have AAOCA on CCTA. CCTA was better than TTE in defining ostial characteristics and the course of the anomalous coronary artery, and detecting myocardial bridge. CONCLUSIONS: CCTA adds value in diagnosing AAOCA when the coronary origins are not well assessed or suspected anomalous origin is suggested on TTE. In addition, when a confident definitive diagnosis of AAOCA is reported on TTE, CCTA demonstrates better performance in determining additional features of AAOCA.

Aortic Volumetry at Contrast-Enhanced Magnetic Resonance Angiography: Feasibility as a Sensitive Method for Monitoring Bicuspid Aortic Valve Aortopathy.

OBJECTIVES: Bicuspid aortic valve patients can develop thoracic aortic aneurysms and therefore require serial imaging to monitor aortic growth. This study investigates the reliability of contrast-enhanced magnetic resonance angiography (CEMRA) volumetry compared with 2-dimensional diameter measurements to identify thoracic aortic aneurysm growth. MATERIALS AND METHODS: A retrospective, institutional review board-approved, and Health Insurance Portability and Accountability Act-compliant study was conducted on 20 bicuspid aortic valve patients (45 ± 8.9 years, 20% women) who underwent serial CEMRA with a minimum imaging follow-up of 11 months. Magnetic resonance imaging was performed at 1.5 T with electrocardiogram-gated, time-resolved CEMRA. Independent observers measured the diameter at the sinuses of Valsalva (SOVs) and mid ascending aorta (MAA) as well as ascending aorta volume between the aortic valve annulus and innominate branch. Intraobserver/interobserver coefficient of variation (COV) and intraclass correlation coefficient (ICC) were computed to assess reliability. Growth rates were calculated and assessed by Student t test (P < 0.05, significant). The diameter of maximal growth (DMG), defined as the diameter at SOV or MAA with the faster growth rate, was recorded. RESULTS: The mean time of follow-up was 2.6 ± 0.82 years. The intraobserver COV was 0.01 for SOV, 0.02 for MAA, and 0.02 for volume (interobserver COV: 0.02, 0.03, 0.04, respectively). The ICC was 0.83 for SOV, 0.86 for MAA, 0.90 for DMG, and 0.95 for volume. Average aortic measurements at baseline and (follow-up) were 42 ± 3 mm (42 ± 3 mm, P = 0.11) at SOV, 46 ± 4 mm (47 ± 4 mm, P < 0.05) at MAA, and 130 ± 23 mL (144 ± 24 mL, P < 0.05). Average size changes were 0.2 ± 0.6 mm/y (1% ± 2%) at SOV, 0.5 ± 0.8 mm/y (1% ± 2%) at MAA, 0.7 ± 0.7 mm/y (2% ± 2%) at DMG, and 6 ± 3 mL/y (4% ± 3%) with volumetry. CONCLUSIONS: Three-dimensional CEMRA volumetry exhibited a larger effect when examining percentage growth, a better ICC, and a marginally lower COV. Volumetry may be more sensitive to growth and possibly less affected by error than diameter measurements.

A Papillary Fibroelastoma Involving Aortic and Pulmonary Valves: Findings on Multimodality Imaging.

Cardiac papillary fibroelastoma, a rare entity, is the second most common benign primary cardiac tumor. Commonly involving the cardiac valves, this entity is increasingly diagnosed using different imaging modalities. We present a rare case of simultaneous involvement of both the aortic and pulmonary valves in an asymptomatic patient who underwent different imaging modalities, including transthoracic and transesophageal echocardiography, nongated and gated computed tomography, and magnetic resonance imaging. We will discuss the imaging findings and differential diagnosis.