First name
Ammie
Middle name
M
Last name
White

Title

Determination of Contrast Timing by Time-Resolved Magnetic Resonance Angiography in Patients With Bidirectional Glenn and Hemi-Fontan Anastomoses.

Year of Publication

2022

Number of Pages

742-746

Date Published

05/2022

ISSN Number

1532-3145

Abstract

PURPOSE: Children with single-ventricle congenital heart disease undergo a series of operations to maintain their pulmonary circulation including bidirectional Glenn (BDG) or hemi-Fontan in the second stage to create a superior cavopulmonary anastomosis. We aimed to optimize cardiovascular angiography protocols by determining optimal contrast timing of pulmonary and systemic circulation on magnetic resonance angiography (MRA) performed with the technique of time-resolved imaging with interleaved stochastic trajectories (TWIST).

METHODS AND MATERIALS: Cardiac TWIST MRA with lower extremity (LE) contrast injection was analyzed in 92 consecutive patients with a BDG or hemi-Fontan anastomosis. Contrast arrival time to inferior vena cava was set to zero to determine the relative time-to-peak (TTP) of the target vessels. Time-to-peak of each vessel was compared by age (<2 or ≥2 y), ejection fraction (<54% or ≥54%), the median values of heart rate (<111 or ≥111 beats per minute), body surface area (BSA, <0.59 or ≥0.59), cardiac index (<6.04 or ≥6.04), and indexed ascending aorta flow (AscAo_i, <5.3 or ≥5.3). The TTP of the vessels was also correlated with the volumetric parameters.

RESULTS: The mean age of 92 patients (32 female, 60 male) was 3.1 years (0.7-5.6 years). With LE injection, the first peak was depicted in AscAo. Time-to-peak of the pulmonary arteries was approximately 9 seconds later than AscAo. The TTP difference between pulmonary arteries and AscAo was shorter in high heart rate group (8.3 vs 10 seconds, P < 0.001). The TTP difference between AscAo and the mean of pulmonary arteries was significantly shorter in high cardiac index group (8.4 vs 9.9 seconds, P < 0.01) and high AscAo_i group (8.7 vs 9.7 seconds, P = 0.03). The TTP differences were not significant by age, ejection fraction, and BSA. Cardiac index and AscAo_i were negatively correlated with all TTPs except AscAo. The ejection fraction, stroke volume, and atrioventricular regurgitation fraction did not correlate with the TTP.

CONCLUSIONS: In patients with BDG or hemi-Fontan anastomosis, TTP of the pulmonary arteries on TWIST MRA via LE intravenous injection is approximately 9 seconds later than AscAo, approximately 8 and 10 seconds later in high and low heart rate groups, respectively. Cardiac index and AscAo_i have less effect on the TTP than the heart rate. There was no TTP difference of the pulmonary arteries by age, BSA, and ejection fraction and no correlation with ejection fraction, stroke volume, and atrioventricular regurgitation fraction. These data can be used to guide timing of pulmonary arterial enhancement of single-ventricle patients after BDG or hemi-Fontan anastomosis.

DOI

10.1097/RCT.0000000000001332

Alternate Title

J Comput Assist Tomogr

PMID

35617648

Title

Spectral imaging in the pediatric chest: past, present and future.

Year of Publication

2022

Number of Pages

1910-1920

Date Published

06/2022

ISSN Number

1432-1998

Abstract

Computed tomography technology continues to undergo evolution and improvement with each passing decade. From its inception in 1971, to the advent of commercially available dual-energy CT just over a decade ago, and now to the latest innovation, photon-counting detector CT, CT's utility for resolving and discriminating tissue types improves. In this review we discuss the impact of spectral imaging, including dual-energy CT and the recently available photon-counting detector CT, on the imaging of the pediatric chest. We describe the current capabilities and future directions of CT imaging, encompassing both the lungs and the surrounding tissues.

DOI

10.1007/s00247-022-05404-9

Alternate Title

Pediatr Radiol

PMID

35726069

Title

Dual-source computed tomography protocols for the pediatric chest - scan optimization techniques.

Year of Publication

2022

Date Published

08/2022

ISSN Number

1432-1998

Abstract

The gold standard for pediatric chest imaging remains the CT scan. An ideal pediatric chest CT has the lowest radiation dose with the least motion degradation possible in a diagnostic scan. Because of the known inherent risks and costs of anesthesia, non-sedate options are preferred. Dual-source CTs are currently the fastest, lowest-dose CT scanners available, utilizing an ultra-high-pitch mode resulting in sub-second CTs. The dual-energy technique, available on dual-source CT scanners, gathers additional information such as pulmonary blood volume and includes relative contrast enhancement and metallic artifact reduction, features that are not available in high-pitch flash mode. In this article we discuss the benefits and tradeoffs of dual-source CT scan modes and tips on image optimization.

DOI

10.1007/s00247-022-05468-7

Alternate Title

Pediatr Radiol

PMID

35948645

Title

Magnetic resonance lymphangiography in post-Fontan palliation patients with MR non-conditional cardiac electronic devices: An institutional experience.

Year of Publication

2022

Number of Pages

43-52

Date Published

2022 Feb 23

ISSN Number

1873-4499

Abstract

<p>Magnetic resonance imaging (MRI) is a routinely used imaging modality for the diagnosis and treatment planning of many health conditions in children and adults. Yet, its use has been limited in many institutions for patients with cardiac implantable electronic devices (CIEDs) due to safety concerns. Current evidence relates primarily to devices with transvenous leads. However, patients with complex cardiac anatomy and palliative surgery procedures often require epicardial pacemakers. To date, very few studies have addressed MRI safety considerations with non-conditional CIEDs or abandoned epicardial leads in infants, and to our knowledge, this is the first report that shows Fontan palliation patients who underwent Dynamic Contrast enhanced MR Lymphangiography (DCMRL) with these types of devices. We present our institutional experience with five cases where a DCMRL was safely performed in three children and two adults with Fontan palliation to evaluate their lymphatic anatomy and guide interventional procedures. Regarding our brief experience, we concluded that DCMRL may be considered in post-Fontan patients with non-conditional CIEDs, including epicardial leads, seeking the best diagnostic and treatment options available. Institutional protocols must be revised in advance to perform this technique in a controlled setting.</p>

DOI

10.1016/j.clinimag.2022.02.016

Alternate Title

Clin Imaging

PMID

35334301

Title

Dynamic contrast-enhanced MR lymphangiography: feasibility of using ferumoxytol in patients with chronic kidney disease.

Year of Publication

2022

Date Published

2022 Jan 10

ISSN Number

1432-1084

Abstract

<p><strong>PURPOSE: </strong>To assess the feasibility of direct intra-lymphatic administration of diluted ferumoxytol as a T1-positive contrast agent for dynamic contrast-enhanced MR lymphangiography (DCMRL) imaging of the central lymphatics in children with renal disease.</p>

<p><strong>METHODS: </strong>In vitro scan of dilute ferumoxytol was initially performed using time-resolved and high-resolution 3D gradient echo (GRE) sequences with short TE values (1 to 1.5&nbsp;ms). A ferumoxytol concentration of 0.25 to 0.40&nbsp;mg/mL was found to retain high signal in the T1-weighted sequences. DCMRL was then performed in 4 children with renal disease with the same 3D GRE sequences administrating diluted ferumoxytol via intra-mesenteric (IM), intra-hepatic (IH), and intra-nodal (IN) routes (6 to 9&nbsp;mL to each site; average total dose of 0.75&nbsp;mg/kg) by slow hand injection (0.5 to 1.0&nbsp;mL/min). The signal-to-noise ratio (SNR) of the lymphatics was measured for quantitative evaluation.</p>

<p><strong>RESULTS: </strong>Ferumoxytol-enhanced DCMRL was technically successful in all patients. Contrast conspicuity within the lymphatics was sufficient without subtraction. The mean SNR was significantly higher than the muscle (50.1 ± 12.2 vs 13.2 ± 2.8; t = 15.9; p &lt; .001). There were no short-term complications attributed to the administration of ferumoxytol in any of the four patients.</p>

<p><strong>CONCLUSION: </strong>Magnetic resonance lymphangiography using ferumoxytol via IN, IH, and IM access is a new method to directly visualize the central lymphatic system and can be applied safely in patients with renal failure based on our preliminary report of four cases. Ferumoxytol-enhanced DCMRL shows diagnostic image quality by using 3D GRE sequences with short TE values and appropriate dilution of ferumoxytol.</p>

<p><strong>KEY POINTS: </strong>• MR lymphangiography using ferumoxytol via intra-nodal, intra-hepatic, and intra-mesenteric access is a new method to directly visualize the central lymphatic system from the groin to the venous angle. • FDCMRL can be applied safely in patients with renal failure based on our preliminary report of four cases. • FDCMRL shows diagnostic image quality by using 3D GRE sequences with short TE values and appropriate dilution of the ferumoxytol.</p>

DOI

10.1007/s00330-021-08448-x

Alternate Title

Eur Radiol

PMID

35001156

Title

Optimizing neonatal cardiac imaging (magnetic resonance/computed tomography).

Year of Publication

2021

Date Published

2021 Oct 17

ISSN Number

1432-1998

Abstract

<p>Magnetic resonance imaging (MRI) and CT perform an important role in the evaluation of neonates with congenital heart disease (CHD) when echocardiography is not sufficient for surgical planning or postoperative follow-up. Cardiac MRI and cardiac CT have complementary applications in the evaluation of cardiovascular disease in neonates. This review focuses on the indications and technical aspects of these modalities and special considerations for imaging neonates with CHD.</p>

DOI

10.1007/s00247-021-05201-w

Alternate Title

Pediatr Radiol

PMID

34657169

Title

Computed tomography of the airways and lungs in congenital heart disease.

Year of Publication

2021

Date Published

2021 Sep 25

ISSN Number

1432-1998

Abstract

<p>The presence of airway and lung disease in children with congenital heart disease is commonly observed with both cardiac CT angiography and routine chest CT. In this review we discuss abnormalities encountered on CT imaging of the chest beyond the heart and central vasculature, focusing on the airways, lung parenchyma and peripheral vasculature. Preoperative and postoperative findings are reviewed as well.</p>

DOI

10.1007/s00247-021-05186-6

Alternate Title

Pediatr Radiol

PMID

34562108

Title

Normal age-related quantitative CT values in the pediatric lung: from the first breath to adulthood.

Year of Publication

2021

Number of Pages

111-118

Date Published

2021 Jan 04

ISSN Number

1873-4499

Abstract

<p><strong>OBJECTIVE: </strong>To characterize the normal progression of quantitative CT parameters in normal children from birth to adulthood.</p>

<p><strong>MATERIALS AND METHODS: </strong>Patients aged 0-18&nbsp;years with non-contrast-enhanced chest CT and evidence of normal lung parenchyma were included. Patients with respiratory symptoms, incomplete anthropometric measurements, or sub-optimal imaging technique were excluded. Segmentation was performed using an open-source software with an automated threshold segmentation. The following parameters were obtained: mean lung density, kurtosis, skewness, lung volume, and mass. Linear and exponential regression models were calculated with age and height as independent variables. A p-value of &lt;0.05 was considered significant.</p>

<p><strong>RESULTS: </strong>220 patients (111 females, 109 males) were included. Mean age was 9.6&nbsp;±&nbsp;5.9&nbsp;years and mean height was 133.9&nbsp;±&nbsp;35.1&nbsp;cm. Simple linear regression showed a significant relationship between mean lung density with age (R 2&nbsp;=&nbsp;0.70) and height (R 2&nbsp;=&nbsp;0.73). Kurtosis displayed a significant exponential correlation with age (R 2&nbsp;=&nbsp;0.70) and height (R 2&nbsp;=&nbsp;0.71). Skewness showed a significant exponential correlation with age (R 2&nbsp;=&nbsp;0.71) and height (R 2&nbsp;=&nbsp;0.73). Lung mass showed a correlation with age (R 2&nbsp;=&nbsp;0.93) and height (R 2&nbsp;=&nbsp;0.92). Exponential regression showed a significant relationship between lung volume with age (R 2&nbsp;=&nbsp;0.88) and height (R 2&nbsp;=&nbsp;0.93).</p>

<p><strong>CONCLUSION: </strong>Quantitative CT parameters of the lung parenchyma demonstrate changes from birth to adulthood. As children grow, the mean lung density decreases, and the lung parenchyma becomes more homogenous.</p>

DOI

10.1016/j.clinimag.2020.12.021

Alternate Title

Clin Imaging

PMID

33524938

Title

Diagnostic performance of CT angiography to detect pulmonary vein stenosis in children.

Year of Publication

2019

Date Published

2019 Sep 09

ISSN Number

1875-8312

Abstract

<p>To assess the diagnostic efficiency of CT angiography (CTA) to detect pulmonary vein stenosis in children. We retrospectively identify patients between 0 and 3&nbsp;years old with confirmed pulmonary vein stenosis with conventional angiography or surgery and available CTA. Patients without confirmed stenosis of the pulmonary veins were included as controls. We excluded patients with previous surgery involving the pulmonary veins, exclusively right-heart conventional angiography or insufficient data in the operation note to confirm the status of the pulmonary veins. Two pediatric radiologists evaluated and determine the presence of stenosis and the pulmonary veins affected. Disagreement between the readers were solved by consensus with a third reader. A pediatric cardiologist reviewed the available angiographic images to determine the presence of stenosis. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. Kappa statistics was performed. 26 patients (15 boys, 11 Girls) were included. Conventional angiography (n = 20) and cardiothoracic surgery (n = 6) confirmed the diagnosis of pulmonary vein stenosis in 13 children. The diagnostic performance at patient level showed the sensitivity, specificity, PPV, and NPV were 84.6%, 92.3%, 91.6%, 87.5%, and 88.4%, respectively. The interobserver was k = 0.76. The performance at pulmonary vein level showed the sensitivity, specificity, PPV, and NPV were 63.3%, 97.4%, 90.4%,85.7% and 87.9%, respectively. The interobserver agreement was k = 0.62. Computed Tomography Angiography is an excellent and reliable image technique for ruling in pulmonary vein stenosis in young children.</p>

DOI

10.1007/s10554-019-01693-8

Alternate Title

Int J Cardiovasc Imaging

PMID

31502067

Title

Gender Differences Among Academic Pediatric Radiology Faculty in the United States and Canada.

Year of Publication

2019

Date Published

2019 Jul 29

ISSN Number

1878-4046

Abstract

<p><strong>OBJECTIVE: </strong>It is currently unknown whether efforts in recent years to create equal opportunities for female faculty in academic medicine have succeeded. We looked at faculty members in academic pediatric radiology departments across the United States and Canada to assess for evidence of gender disparities and differences in academic performance between males and females.</p>

<p><strong>METHODS: </strong>The analysis included diagnostic radiology programs across the United States and Canada, as specified by the American Medical Association's Fellowship and Residency Electronic Interactive Database (FREIDA Online) and the Canadian Resident Matching Service website. The Scopus database was used to retrieve the H-index, number of publications, and number of citations for each faculty member. We examined the distribution of male and female faculty members across geographical regions, academic ranks, and leadership roles. Academic performance was also compared.</p>

<p><strong>RESULTS: </strong>Across all regions and academic ranks, disparities exist between the number of male and female faculty members. The greatest disparity was found amongst the professor rank, where more than 70% of positions were occupied by males. Female professors were found to demonstrate similar levels of academic performance compared to their male counterparts, although this parity was not observed amongst assistant and associate professors.</p>

<p><strong>CONCLUSION: </strong>Women occupied almost half (46.6%) of the total academic pediatric radiology workforce, despite having been previously shown to make up only 21% of radiologists. However, gender disparities currently exist among academic pediatric radiology faculty, with a significantly higher percentage of men in pediatric radiology faculty positions. Women, however, currently occupy a greater percentage of leadership positions compared to men, even though the majority of senior academic ranks are held by men.</p>

DOI

10.1016/j.acra.2019.06.011

Alternate Title

Acad Radiol

PMID

31371209

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