Non-invasive assessment of congenital pulmonary vein stenosis in children using cardiac-non-gated CT with 64-slice technology

Multimodal Assessment and Intramodal Comparison of Imaging Techniques for Pediatric Pulmonary Vein Stenosis with Pulmonary Hypertension

Pulmonary vein stenosis (PVS) is a rare, serious, and progressive disease in the pediatric population. Evaluation is complex and involves multimodality imaging. Diagnosis is important as early treatment to prevent progressive pulmonary hypertension and right ventricular dysfunction is essential. Adult studies have shown good correlation between various imaging modalities; however, there are limited data in children. This is a single-center retrospective pilot study to determine the reliability of measurement of pulmonary vein stenosis and pulmonary hypertension across different imaging modalities-computed tomography angiography (CTA), echocardiography (echo), lung perfusion scan (LPS), and cardiac catheterization (cath). PVS was defined as > 2 mmHg by echo and cath and/or 50% reduction in diameter by CTA. Patients had to have an echo, CTA and cath performed within a 1-month timeframe of one another to be included in the study, with LPS data included if testing was completed at initial evaluation. Fifteen total patients were enrolled; 87% were categorized as primary PVS; a condition not directly related to direct injury or prior surgical intervention. Twenty-seven total stenotic pulmonary veins were identified (mean 1.8, range 1-4). CTA had a slightly better agreement with cath than echo in identifying PVS in different vein locations except in the LLPV. Additionally, echo and CTA had excellent sensitivity (91%) and specificity (100%) compared to cath for diagnosis of PH. We conclude that non-invasive imaging of echo and CTA has an acceptable correlation to cardiac catheterization for screening and initial evaluation of PVS and PH, as directly related to PVS, in pediatrics.

Evaluation of paediatric pulmonary vein stenosis by cardiac CT angiography: a comparative study with transthoracic echocardiography and catheter angiogram

AIM

To compare prospective electrocardiogram (ECG)-gated cardiac computed tomographic angiography (CCTA) with transthoracic echocardiography (TTE) and cardiac catheter angiography (CCA) for paediatric pulmonary vein (PV) stenosis.

MATERIALS AND METHODS

Retrospective chart review was undertaken of all patients who underwent CCTA for PV evaluation over a 4-year period. Patient demographics, findings of CCTA, TTE, and CCA, as well as interventions performed, were recorded for each PV.

RESULTS

Thirty-five patients were included (23 male patients). All patients had a prior TTE with time interval between TTE and CCTA ranging from 0 to 90 days. CCTA detected 92 abnormalities in 32 patients. TTE missed 16 PV abnormalities (16/92, 17%), detected 37 abnormalities with certainty (37/92, 40%), and was suggestive in 39 abnormalities (39/92, 42%). CCTA was negative for PV abnormalities when TTE was positive or suspicious in three patients. Nineteen patients underwent CCA (18 patients with 52 abnormalities and one patient with normal PV), confirming CCTA findings. Thirty-nine were treated with angioplasty/stenting (39/52,75%). Failed recanalisation occurred in three PVs (3/52, 6%) and no intervention was attempted for the rest as the gradient was not significant (10/52,19%). Nine patients underwent surgical repair (26/92, 28%). Five patients (14/92, 15%) were managed with no intervention based on CCTA findings and poor clinical prognosis.

CONCLUSIONS

CCTA plays an important role in detecting paediatric PV stenosis and identifies additional findings compared to TTE that have direct surgical/interventional implications. CCTA complements TTE in imaging these patients and helps guide management.

Computed tomography of pulmonary veins: review of congenital and acquired pathologies

Newer-generation CT scanners with ultrawide detectors or dual sources offer millisecond image acquisition times and significantly decreased radiation doses compared to historical cardiac CT and CT angiography. This technology is capable of nearly freezing cardiac and respiratory motion. As a result, CT is increasingly used for diagnosing and monitoring cardiac and vascular abnormalities in the pediatric population. CT is particularly useful in the setting of pulmonary vein evaluation because it offers evaluation of the entire pulmonary venous system and lung parenchyma. In this article we review a spectrum of congenital and acquired pulmonary venous abnormalities, including potential etiologies, CT imaging findings and important factors of preoperative planning. In addition, we discuss optimization of CT techniques for evaluating the pulmonary veins.

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

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.

Technical Feasibility on the Use of Optical Coherence Tomography in the Evaluation of Pediatric Pulmonary Venous Stenosis

Pulmonary vein stenosis (PVS) in children is a morbid disease and limited progress has been made in improving outcomes for this heterogenous group of patients. Evaluation is currently limited to imaging techniques that fail to provide an adequate overview of the intraluminal and luminal pathology perpetuating our limited understanding of this condition. Optical coherence tomography (OCT) is an imaging modality which provides intraluminal profiling with microstructural detail through optical reflective technology. We sought to evaluate whether its use was technically feasible in pediatric PVS and whether the imaging data provided potentially useful outputs for clinical utility. Eleven patients were prospectively selected from our cardiac catheterization for OCT evaluation of their pulmonary veins (PV) during elective catheterization for PVS. Measurements were taken both pre and post intervention using both manual and automated tools. Stent morphology was characterized. Eleven patients had evaluation of 34 pulmonary veins, with 7 patients having more than one assessment, for a total of 25 overall catheterizations. Most patients were female (75%). Median age at cardiac catheterization was 35 months (range 5-45 months). Median weight of subjects was 10.6 kg (3.7-14.2) with a median BSA documented at 0.505 m² (0.21-0.57). Median number of pulmonary veins involved was 3, (range 1-5 veins) and median contrast volume of 2.9 mL/kg (0.7-3.7) given. Median radiation dose (DAP) was 6095 µGy·cm² (1670-12,400). Median number of previous cardiac catheterizations was 7 (range 1-11). All of the vessels with a diameter < 5 mm were adequately visualized. Of all the OCT images acquired, in 15 vessels (44%) contrast was used to clear the vessels from blood as an angiogram was required at the time, in the other 19 vessels (56%), saline was used with adequate imaging. There were no complications related to OCT. OCT is technically feasible to use in pediatric patients without any directly related complications. It provides intraluminal anatomy in children with both native and treated pulmonary venous stenosis when vessel size is less than 5 mm.

Essential role of cardiac computed tomography for surgical decision making in children with total anomalous pulmonary venous connection and single ventricle

BACKGROUND

Total anomalous pulmonary venous connection (TAPVC) is a major risk factor in infants with single ventricle (SV). Exact definition of TAPVC anatomy is crucial for surgical planning.

AIM

To evaluate the role of cardiac computed tomography (CT) in this setting.

METHODS

Retrospective review of 13 infants who underwent TAPVC repair associated with SV from May 2016 to October 2021. Anatomy, incidence, and mechanisms of pulmonary venous obstruction (PVO) were described. Cardiac CT diagnostic yield was compared to echocardiography (echo).

RESULTS

Of 13 infants, median age and weight were 24 days (range 2-303 days) and 3.2 (range 2.6-9.1) kg, 8 (62%) were male, 4 (31%) premature, and 11 (85%) had heterotaxy syndrome. All infants had pre- and postoperative echo; 13 had preoperative and 8 (62%) had postoperative cardiac CT. Type of TAPVC: six (46%) supracardiac, two (15%) intracardiac, one (8%) infracardiac, and four (31%) mixed, with pulmonary veins draining in >1 confluence in nine (69%). PVO was present in 6/13 (46%) preoperatively and 5/13 (31%) postoperatively. Mechanisms of PVO: 9/11 (82%) stenosis, 1/9 (9%) membrane formation, and 1/9 (9%) external compression. The sensitivity to diagnose PVO was 45.5% for echo and 100% for cardiac CT, the specificity was 100% for both. No discrepancy was found between cardiac CT and intraoperative findings, but echo had a complete preoperative diagnosis in 1/13 (8%) (p < .00001, Fisher exact test).

CONCLUSIONS

Cardiac CT is essential to evaluate pre- and postoperative TAPVC in SV for surgical decision making and long term follow up.

Prognostic Significance of Computed Tomography Findings in Pulmonary Vein Stenosis

(1) Pulmonary vein stenosis (PVS) can be a severe, progressive disease with lung involvement. We aimed to characterize findings by computed tomography (CT) and identify factors associated with death; (2) Veins and lung segments were classified into five locations: right upper, middle, and lower; and left upper and lower. Severity of vein stenosis (0–4 = no disease–atresia) and lung segments (0–3 = unaffected–severe) were scored. A PVS severity score (sum of all veins + 2 if bilateral disease; maximum = 22) and a total lung severity score (sum of all lung segments; maximum = 15) were reported; (3) Of 43 CT examinations (median age 21 months), 63% had bilateral disease. There was 30% mortality by 4 years after CT. Individual-vein PVS severity was associated with its corresponding lung segment severity (p < 0.001). By univariate analysis, PVS severity score >11, lung cysts, and total lung severity score >6 had higher hazard of death; and perihilar induration had lower hazard of death; (4) Multiple CT-derived variables of PVS severity and lung disease have prognostic significance. PVS severity correlates with lung disease severity.

Pediatric Cardiothoracic CT Guideline Provided by the Asian Society of Cardiovascular Imaging Congenital Heart Disease Study Group: Part 2. Contemporary Clinical Applications

The use of pediatric cardiothoracic CT for congenital heart disease (CHD) was traditionally limited to the morphologic evaluation of the extracardiac thoracic vessels, lungs, and airways. Currently, the applications of CT have increased, owing to technological advancements in hardware and software as well as several dose-reduction measures. In the previously published part 1 of the guideline by the Asian Society of Cardiovascular Imaging Congenital Heart Disease Study Group, we reviewed the prerequisite technical knowledge for clinical applications in a user-friendly and vendor-specific manner. Herein, we present the second part of our guideline on contemporary clinical applications of pediatric cardiothoracic CT for CHD based on the consensus of experts from the Asian Society of Cardiovascular Imaging CHD Study Group. This guideline describes up-to-date clinical applications effectively in a systematic fashion.

The many faces and outcomes of pulmonary vein stenosis in early childhood

Pulmonary vein stenosis is a rare and poorly understood condition causing obstruction of the large pulmonary veins and of blood flow from the lungs to the left atrium. This results in elevated pulmonary venous pressure and pulmonary edema, pulmonary hypertension, potentially cardiac failure, and death. Clinical signs of the disease include failure to thrive, increasingly severe dyspnea, hemoptysis, respiratory difficulty, recurrent respiratory tract infections/pneumonia, cyanosis, and subcostal retractions. On chest radiograph, the most frequent finding is increased interstitial, ground-glass and/or reticular opacity. Transthoracic echocardiography with pulsed Doppler delineates the stenosis, magnetic resonance imaging and multislice computerized tomography are used for further evaluation. Interventional cardiac catherization, surgical techniques, and medical therapies have been used with varying success as treatment options.

Proximal pulmonary vein stenosis detection in pediatric patients: value of multiplanar and 3-D VR imaging evaluation

BACKGROUND

One of the important benefits of using multidetector computed tomography (MDCT) is its capability to generate high-quality two-dimensional (2-D) multiplanar (MPR) and three-dimensional (3-D) images from volumetric and isotropic axial CT data. However, to the best of our knowledge, no results have been published on the potential diagnostic role of multiplanar and 3-D volume-rendered (VR) images in detecting pulmonary vein stenosis, a condition in which MDCT has recently assumed a role as the initial noninvasive imaging modality of choice.

OBJECTIVE

The purpose of this study was to compare diagnostic accuracy and interpretation time of axial, multiplanar and 3-D VR images for detection of proximal pulmonary vein stenosis in children, and to assess the potential added diagnostic value of multiplanar and 3-D VR images.

MATERIALS AND METHODS

We used our hospital information system to identify all consecutive children (< 18 years of age) with proximal pulmonary vein stenosis who had both a thoracic MDCT angiography study and a catheter-based conventional angiography within 2 months from June 2005 to February 2012. Two experienced pediatric radiologists independently reviewed each MDCT study for the presence of proximal pulmonary vein stenosis defined as ≥ 50% of luminal narrowing on axial, multiplanar and 3-D VR images. Final diagnosis was confirmed by angiographic findings. Diagnostic accuracy was compared using the z-test. Confidence level of diagnosis (scale 1-5, 5 = highest), perceived added diagnostic value (scale 1-5, 5 = highest), and interpretation time of multiplanar or 3-D VR images were compared using paired t-tests. Interobserver agreement was measured using the chance-corrected kappa coefficient.

RESULTS

The final study population consisted of 28 children (15 boys and 13 girls; mean age: 5.2 months). Diagnostic accuracy based on 116 individual pulmonary veins for detection of proximal pulmonary vein stenosis was 72.4% (84 of 116) for axial MDCT images, 77.5% (90 of 116 cases) for multiplanar MDCT images, and 93% (108 of 116 cases) for 3-D VR images with significantly higher accuracy with 3-D VR compared to axial (z = 4.17, P < 0.001) and multiplanar (z = 3.34, P < 0.001) images. Confidence levels for detection of proximal pulmonary vein stenosis were significantly higher with 3-D VR images (mean level: 4.6) compared to axial MDCT images (mean level: 1.7) and multiplanar MDCT images (mean level: 2.0) (paired t-tests, P < 0.001). Thus, 3-D VR images (mean added diagnostic value: 4.7) were found to provide added diagnostic value for detecting proximal pulmonary vein stenosis (paired t-test, P < 0.001); however, multiplanar MDCT images did not provide added value (paired t-test, P = 0.89). Interpretation time was significantly longer and interobserver agreement was higher when using 3-D VR images than using axial MDCT images or MPR MDCT images for diagnosing proximal pulmonary vein stenosis (paired t-tests, P < 0.001).

CONCLUSIONS

Use of 3-D VR images in the diagnosis of proximal pulmonary vein stenosis in children significantly increases accuracy, confidence level, added diagnostic value and interobserver agreement. Thus, the routine use of this technique should be encouraged despite its increased interpretation time.

Pertinent reportable incidental cardiac findings on chest CT without electrocardiography gating: review of 268 consecutive cases

BACKGROUND

Pertinent reportable cardiac findings on non-electrocardiography (ECG)-gated chest CT examinations have become easier to detect given recent advancements in multidetector CT technology. However, those findings are easily overlooked on routine chest CT without ECG gating given residual inherent cardiac motion artifact and non-cardiac indications.

PURPOSE

To describe and quantify the types of pertinent reportable cardiac findings that can be detected on chest CT examinations without ECG gating and evaluate how often they were reported.

MATERIAL AND METHODS

Two radiologists retrospectively reviewed (blinded to the original interpretation) 268 consecutive routine adult chest CT examinations without ECG gating for the presence of pertinent reportable cardiac findings. Retrospective interpretations were then compared with the original radiological reports.

RESULTS

One hundred and sixty-three patients (61%) had pertinent reportable cardiac findings. The findings encountered included: coronary artery disease (n = 131; 80.0%), coronary artery bypass grafts (n = 10; 6.1%), left ventricular aneurysm (n = 1; 0.6%), valve calcification (n = 131; 80.0%), valve repair/replacement (n = 5; 3.1%), pericardial effusion (n = 33; 20.2%), left atrial appendage thrombus (n = 1; 0.6%), cardiac mass (n = 1; 0.6%), and cardiac chamber enlargement (n = 29; 17.8%). On the original radiological reports 22.3% of the pertinent reportable cardiac findings, detected by the two radiologists retrospectively, were not reported.

CONCLUSION

Detection of pertinent reportable cardiac findings on routine chest CT examinations without ECG gating is possible. The high volume of chest CT examinations without ECG gating represents an opportunity for radiologists to comment on the presence or absence of cardiac disease which may influence future clinical decisions.