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

Quantification of 3-Dimensional Confluence-Atrial Morphology in Supracardiac Total Anomalous Pulmonary Venous Connection

Background

Pulmonary vein stenosis (PVS) continues to be a major complication after surgical repair of total anomalous pulmonary venous connection (TAPVC). Recent studies suggest that the morphology of pulmonary venous confluence and the left atrium (LA) is associated with PVS. However, there are limited data on the prognostic value of integrating quantitative confluence-atrial morphology into risk stratification.

Objectives

This study sought to evaluate the prognostic impact of novel imaging metrics derived from 3-dimensional (3D) computed tomography angiography (CTA) modeling on postsurgical PVS (PPVS) in the supracardiac TAPVC (sTAPVC) setting.

Methods

Patients undergoing sTAPVC repair in 2017 to 2022 from 3 centers were retrospectively reviewed. Study investigators developed 3D CTA modeled geometric features to quantify confluence-atrial morphology that were analyzed with regard to PPVS.

Results

Of the 162 patients (median age 61 days; 55% having preoperative pulmonary venous obstruction [prePVO]) included, 47 (29%) with PPVS at a median of 1.5 months ([quartile 1-quartile 3: 1.5-3.0 months]). In the univariable analysis, the indexed total volume of the LA and confluence (iTVLC) and the ratio of the corresponding confluence length to the mean distance between the LA and confluence (CCL/mDBLC ratio) were significantly associated with PPVS. In a multivariable model adjusting for prePVO and age, the iTVLC and CCL/mDBLC ratio independently predicted PPVS (HR: 1.15; 95% CI: 1.06-1.25; and HR: 1.20; 95% CI: 1.08-1.35, respectively, all P < 0.01). Specifically, an iTVLC ≥20 cm3/m2 and a CCL/mDBLC ratio ≥7.7 were significantly associated with a reduced risk of PPVS.

Conclusions

Quantification of 3D confluence-atrial morphology appears to offer a deeper and better metric to predict PPVS in patients with sTAPVC.

Venous retrograde approach for endovascular angioplasty in chronic total pulmonary vein occlusion -a case report

INTRODUCTION

Fibrosing mediastinitis (FM) is a rare disease characterized by excessive proliferation of fibrous tissue in the mediastinum and can cause bronchial stenosis, superior vena cava obstruction, pulmonary artery and vein stenosis, etc. CASE PRESENTATION: An aging patient with intermittent chest tightness and shortness of breath was diagnosed with FM associated pulmonary hypertension (FM-PH) by echocardiography and enhanced CT of the chest, and CT pulmonary artery (PA)/ pulmonary vein (PV) imaging revealed PA and PV stenosis. Selective angiography revealed complete occlusion of the right upper PV, and we performed endovascular intervention of the total occluded PV. After failure of the antegrade approach, the angiogram revealed well-developed collaterals of the occluded RSPV-V2b, so we chose to proceed via the retrograde approach. We successfully opened the occluded right upper PV and implanted a stent.

CONCLUSIONS

This report may provide new management ideas for the interventional treatment of PV occlusion.

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.

Benefit of stereoscopic volume rendering for the identification of pediatric pulmonary vein stenosis from CT angiography

The use of three-dimensional (3D) technologies in medical practice is increasing; however, its use is largely untested. One 3D technology, stereoscopic volume-rendered 3D display, can improve depth perception. Pulmonary vein stenosis (PVS) is a rare cardiovascular pathology, often diagnosed by computed tomography (CT), where volume rendering may be useful. Depth cues may be lost when volume rendered CT is displayed on regular screens instead of 3D displays. The objective of this study was to determine whether the 3D stereoscopic display of volume-rendered CT improved perception compared to standard monoscopic display, as measured by PVS diagnosis. CT angiograms (CTAs) from 18 pediatric patients aged 3 weeks to 2 years were volume rendered and displayed with and without stereoscopic display. Patients had 0 to 4 pulmonary vein stenoses. Participants viewed the CTAs in 2 groups with half on monoscopic and half on stereoscopic display and the converse a minimum of 2 weeks later, and their diagnoses were recorded. A total of 24 study participants, comprised of experienced staff cardiologists, cardiovascular surgeons and radiologists, and their trainees viewed the CTAs and assessed the presence and location of PVS. Cases were classified as simple (2 or fewer lesions) or complex (3 or more lesions). Overall, there were fewer type 2 errors in diagnosis for stereoscopic display than standard display, an insignificant difference (p = 0.095). There was a significant decrease in type 2 errors for complex multiple lesion cases (≥3) vs simpler cases (p = 0.027) and improvement in localization of pulmonary veins (p = 0.011). Subjectively, 70% of participants stated that stereoscopy was helpful in the identification of PVS. The stereoscopic display did not result in significantly decreased errors in PVS diagnosis but was helpful for more complex cases.

Cardiac-type total anomalous pulmonary venous return is not benign

OBJECTIVE

The objective of this study was to investigate the association between morphological variation and postsurgical pulmonary vein (PV) stenosis (PPVS) in patients with cardiac total anomalous pulmonary venous connection (TAPVC).

METHODS

This single-center, retrospective study included 168 pediatric patients who underwent surgical repair of cardiac TAPVC from 2013 to 2019 (connection to the coronary sinus [CS], n = 136; connection directly to the right atrium [RA], n = 32). Three-dimensional computed tomography modeling and geometric analysis were performed to investigate the morphological features; their relevance to the PPVS was examined.

RESULTS

The connection type had no association with PPVS (CS type: 18% vs right atrial type: 19%; P = .89) but there was a higher incidence of PPVS in patients with a single PV orifice than > 1 orifice (P < .001). Confluence-to-total PV area ratio (hazard ratio, 4.78, 95% CI, 1.86-12.32; P = .001) and length of drainage route (hazard ratio, 1.22; 95% CI, 1.14-1.31; P < .001) had a 4- and 1-fold increase in the risk for PPVS in the CS type after adjustment for age and preoperative pulmonary venous obstruction. In the right atrial type, those with anomalous PV return to the RA roof were more likely to develop PPVS than to the posterior wall of the RA (P < .001).

CONCLUSIONS

The number of inter-junction PV orifice correlated with PPVS development in cardiac TAPVC. The confluence-to-total PV ratio, length of drainage route, and anomalous PV return to the RA roof are important predictors for PPVS. Morphological subcategorization in this clinical setting can potentially assist in surgical decision-making.

Lung and Pleural Findings of Children with Pulmonary Vein Stenosis with and without Aspiration: MDCT Evaluation

Purpose: To retrospectively compare the lung and pleural findings in children with pulmonary vein stenosis (PVS) with and without aspiration on multidetector computed tomography (MDCT). Materials and Methods: All consecutive children (≤18 years old) with PVS who underwent thoracic MDCT studies from August 2004 to December 2021 were categorized into two groups: children with PVS with aspiration (Group 1) and children with PVS without aspiration (Group 2). Two independent pediatric radiologists retrospectively evaluated thoracic MDCT studies for the presence of lung and pleural abnormalities as follows: (1) in the lung (ground-glass opacity (GGO), consolidation, nodule, mass, cyst(s), interlobular septal thickening, and fibrosis) and (2) in the pleura (thickening, effusion, and pneumothorax). Interobserver agreement between the two reviewers was evaluated by the proportion of agreement and the Kappa statistic. Results: The final study population consisted of 64 pediatric patients (36 males (56.3%) and 43 females (43.7%); mean age, 1.7 years; range, 1 day−17 years). Among these 64 patients, 19 patients (29.7%) comprised Group 1 and the remaining 45 patients (70.3%) comprised Group 2. In Group 1 (children with PVS with aspiration), the detected lung and pleural MDCT abnormalities were: GGO (17/19; 89.5%), pleural thickening (17/19; 89.5%), consolidation (16/19; 84.5%), and septal thickening (16/19; 84.5%). The lung and pleural MDCT abnormalities observed in Group 2 (children with PVS without aspiration) were: GGO (37/45; 82.2%), pleural thickening (37/45; 82.2%), septal thickening (36/45; 80%), consolidation (3/45; 6.7%), pleural effusion (1/45; 2.2%), pneumothorax (1/45; 2.2%), and cyst(s) (1/45; 2.2%). Consolidation was significantly more common in pediatric patients with both PVS and aspiration (Group 1) (p < 0.001). There was high interobserver agreement between the two independent reviewers for detecting lung and pleural abnormalities on thoracic MDCT studies (Kappa = 0.98; CI = 0.958, 0.992). Conclusion: Aspiration is common in pediatric patients with PVS who undergo MDCT and was present in nearly 30% of all children with PVS during our study period. Consolidation is not a typical radiologic finding of PVS in children without clinical evidence of aspiration. When consolidation is present on thoracic MDCT studies in pediatric patients with PVS, the additional diagnosis of concomitant aspiration should be considered.

Pleuropulmonary MDCT Findings: Comparison between Children with Pulmonary Vein Stenosis and Prematurity-Related Lung Disease

Purpose: To retrospectively compare the pleuropulmonary MDCT findings in children with pulmonary vein stenosis (PVS) and prematurity-related lung disease (PLD). Materials and Methods: All consecutive infants and young children (≤18 years old) who underwent thoracic MDCT studies from July 2004 to November 2021 were categorized into two groups—children with PVS (Group 1) and children with PLD without PVS (Group 2). Two pediatric radiologists independently evaluated thoracic MDCT studies for the presence of pleuropulmonary abnormalities as follows—(1) in the lung (ground-glass opacity (GGO), triangular/linear plaque-like opacity (TLO), consolidation, nodule, mass, cyst(s), interlobular septal thickening, and fibrosis); (2) in the airway (bronchial wall thickening and bronchiectasis); and (3) in the pleura (thickening, effusion, and pneumothorax). Interobserver agreement between the two reviewers was evaluated with the Kappa statistic. Results: There were a total of 103 pediatric patients (60 males (58.3%) and 43 females (41.7%); mean age, 1.7 years; range, 2 days−7 years). Among these 103 patients, 49 patients (47.6%) comprised Group 1 and the remaining 54 patients (52.4%) comprised Group 2. In Group 1, the observed pleuropulmonary MDCT abnormalities were—pleural thickening (44/49; 90%), GGO (39/49; 80%), septal thickening (39/49; 80%), consolidation (4/49; 8%), and pleural effusion (1/49; 2%). The pleuropulmonary MDCT abnormalities seen in Group 2 were—GGO (45/54; 83%), TLO (43/54; 80%), bronchial wall thickening (33/54; 61%), bronchiectasis (30/54; 56%), cyst(s) (5/54; 9%), pleural thickening (2/54; 4%), and pleural effusion (2/54; 4%). Septal thickening and pleural thickening were significantly more common in pediatric patients with PVS (Group 1) (p < 0.001). TLO, bronchial wall thickening, and bronchiectasis were significantly more frequent in pediatric patients with PLD without PVS (Group 2) (p < 0.001). There was high interobserver kappa agreement between the two independent reviewers for detecting pleuropulmonary abnormalities on thoracic MDCT angiography studies (k = 0.99). Conclusion: Pleuropulmonary abnormalities seen on thoracic MDCT can be helpful for distinguishing PVS from PLD in children. Specifically, the presence of septal thickening and pleural thickening raises the possibility of PVS, whereas the presence of TLO, bronchial wall thickening and bronchiectasis suggests PLD in the pediatric population.

Pulmonary vein stenosis: Anatomic considerations, surgical management, and outcomes

OBJECTIVE

The study objective was to evaluate outcomes of pulmonary vein stenosis repair in a large single-center cohort.

METHODS

Clinical data from a pulmonary vein stenosis registry were retrospectively reviewed identifying patients who underwent pulmonary vein stenosis repair. The primary/index operation was defined as the patient's first pulmonary vein stenosis operation during the study period.

RESULTS

Between January 2007 and August 2019, 174 patients underwent pulmonary vein stenosis repair. Bilateral pulmonary vein stenosis occurred in 111 patients (64%); 71 patients (41%) had 4-vessel disease. Fifty-nine patients (34%) had primary pulmonary vein stenosis. Median age was 9 months (interquartile range, 5-27) and weight was 6.5 kg (4.7-10.2). Surgical techniques evolved and included ostial resection, unroofing, reimplantation, sutureless, modified sutureless, and a newer anatomically focused approach of pulmonary vein stenosis resection with lateralization or patch enlargement of the pulmonary vein-left atrium connection. Twenty-three patients (13%) required reoperation. Cumulative 2-year incidence of postoperative transcatheter intervention (balloon dilation ± stenting) was 64%. One-, 2-, and 5-year survivals were 71.2%, 66.8%, and 60.6%, respectively. There was no association between surgery type and reoperation rate (hazard ratio, 2.38, P = .25) or transcatheter intervention (hazard ratio, 0.97, P = .95). The anatomically focused repair was associated with decreased mortality on univariate (hazard ratio, 0.38, P = .042) and multivariable analyses (hazard ratio, 0.19, P = .014). Antiproliferative chemotherapy was also associated with decreased mortality (hazard ratio, 0.47, P = .026).

CONCLUSIONS

This large single-center surgical pulmonary vein stenosis experience demonstrates encouraging midterm results. A new anatomically focused repair strategy aims to alleviate pulmonary vein angulation to minimize turbulence and shows promising early outcomes. Continued follow-up is required to understand longer-term outcomes for this surgical approach.

Thoracic Multidetector Computed Tomography Angiography of Primary Pulmonary Vein Stenosis in Children: Evaluation of Characteristic Extravascular Findings

PURPOSE

The purpose of this study was to investigate the extravascular thoracic multidetector computed tomography (MDCT) angiography findings of pediatric primary pulmonary vein stenosis (PVS) by comparing extravascular thoracic MDCT angiography findings in children with and without PVS.

MATERIALS AND METHODS

All pediatric patients (age 18 y and below) with a known diagnosis of primary PVS, confirmed by echocardiogram and/or conventional angiography, who underwent thoracic MDCT angiography studies from July 2006 to December 2020 were included. A comparison group, comprised of age-matched and sex-matched pediatric patients without PVS who underwent thoracic MDCT angiography studies during the same study period, was also generated. Two pediatric radiologists independently evaluated thoracic MDCT angiography studies for the presence of extravascular thoracic abnormalities in the lung (ground-glass opacity [GGO], consolidation, pulmonary nodule, mass, cyst, septal thickening, fibrosis, and bronchiectasis), pleura (pleural thickening, pleural effusion and pneumothorax), and mediastinum (lymphadenopathy and mass). When a thoracic abnormality was identified, the location and distribution of the abnormality (in relation to the location of PVS) were also evaluated. Extravascular thoracic MDCT angiography findings of pediatric patients with and without primary PVS were compared. Interobserver agreement between the 2 independent reviewers was evaluated with κ statistics.

RESULTS

The study group consisted of 15 thoracic MDCT angiography studies from 15 individual pediatric patients with primary PVS (8 males [53%] and 7 females [47%]; mean age: 10.9 mo; SD: 11.7 mo; range: 1 to 48 mo). The comparison group consisted of 15 thoracic MDCT angiography studies from 15 individual pediatric patients without PVS (8 males [53%] and 7 females [47%]; mean age: 10.2 mo; SD: 11.5 mo; range: 1 to 48 mo). In children with primary PVS, the characteristic extravascular thoracic MDCT angiography findings were GGO (14/15; 93%), septal thickening (5/15; 33%), pleural thickening (14/15; 93%), and ill-defined, mildly heterogeneously enhancing, noncalcified soft tissue mass (14/15; 93%) following the contours of PVS in the mediastinum. There was excellent interobserver κ agreement between 2 independent reviewers for detecting extravascular abnormalities on thoracic MDCT angiography studies (κ=0.99 for the study group and κ=0.98 for the comparison group).

CONCLUSIONS

Children with primary PVS have characteristic extravascular thoracic MDCT angiography findings. In the lungs and pleura, GGO, septal thickening, and pleural thickening are common findings. Importantly, in the mediastinum, the presence of a mildly heterogeneously enhancing, noncalcified soft tissue mass in the distribution of PVS is a novel characteristic thoracic MDCT angiography finding unique to pediatric primary PVS. When this constellation of extravascular thoracic MDCT angiography findings is detected, although rare, primary PVS should be considered as a possible underlying diagnosis, especially in symptomatic children.

Secondary Pulmonary Vein Stenosis Due to Total Anomalous Pulmonary Venous Connection Repair in Children: Extravascular MDCT Findings

Purpose: To evaluate extravascular findings on thoracic MDCT angiography in secondary pulmonary vein stenosis (PVS) due to total anomalous pulmonary venous connection (TAPVC) repair in children. Materials and Methods: All patients aged ≤18 years with a known diagnosis of secondary PVS after TAPVC repair, confirmed by echocardiography, conventional angiography, and/or surgery, who underwent thoracic MDCT angiography studies between July 2008 and April 2021 were included. Two pediatric radiologists independently examined MDCT angiography studies for the presence of extravascular thoracic abnormalities in the lung, pleura, and mediastinum. The location and distribution of each abnormality (in relation to the location of PVS) were also evaluated. Interobserver agreement between the two independent pediatric radiology reviewers was studied using kappa statistics. Results: The study group consisted of 20 consecutive pediatric patients (17 males, 3 females) with secondary PVS due to TAPVC repair. Age ranged from 2 months to 8 years (mean, 16.1 months). In children with secondary PVS due to TAPVC repair, the characteristic extravascular thoracic MDCT angiography findings were ground-glass opacity (19/20; 95%), septal thickening (7/20; 35%), pleural thickening (17/20; 85%), and a poorly defined, mildly heterogeneously enhancing, non-calcified soft tissue mass (17/20; 85%) which followed the contours of affected pulmonary veins outside the lung. There was excellent interobserver kappa agreement between two independent reviewers for detecting extravascular abnormalities on thoracic MDCT angiography studies (k = 0.99). Conclusion: Our study characterizes the extravascular thoracic MDCT angiography findings in secondary pediatric PVS due to TAPVC repair. In the lungs and pleura, ground-glass opacity, interlobular septal thickening, and pleural thickening are common findings. Importantly, the presence of a mildly heterogeneously enhancing, non-calcified mediastinal soft tissue mass in the distribution of the PVS is a novel characteristic thoracic MDCT angiography finding seen in pediatric secondary PVS due to TAPVC repair.

Extravascular MDCT Findings of Pulmonary Vein Stenosis in Children with Cardiac Septal Defect

Purpose: To retrospectively investigate the extravascular thoracic MDCT angiography findings of pulmonary vein stenosis (PVS) in children with a cardiac septal defect. Materials and Methods: Pediatric patients (age ≤ 18 years) with cardiac septal defect and PVS, confirmed by echocardiogram and/or conventional angiography, who underwent thoracic MDCT angiography studies from April 2009 to April 2021 were included. Two pediatric radiologists independently evaluated thoracic MDCT angiography studies for the presence of extravascular thoracic abnormalities in: (1) lung and airway (ground-glass opacity (GGO), consolidation, pulmonary nodule, mass, cyst, septal thickening, fibrosis, and bronchiectasis); (2) pleura (pleural thickening, pleural effusion, and pneumothorax); and (3) mediastinum (mass and lymphadenopathy). Interobserver agreement between the two independent pediatric radiology reviewers was evaluated with kappa statistics. Results: The final study group consisted of 20 thoracic MDCT angiography studies from 20 consecutive individual pediatric patients (13 males (65%) and 7 females (35%); mean age: 7.5 months; SD: 12.7; range: 2 days to 7 months) with cardiac septal defect and PVS. The characteristic extravascular thoracic MDCT angiography findings were GGO (18/20; 90%), septal thickening (9/20; 45%), pleural thickening (16/20; 80%), and ill-defined, mildly heterogeneously enhancing, non-calcified soft tissue mass (9/20; 45%) following the contours of PVS in the mediastinum. There was a high interobserver kappa agreement between two independent reviewers for detecting extravascular abnormalities on thoracic MDCT angiography studies (k = 0.99). Conclusion: PVS in children with a cardiac septal defect has a characteristic extravascular thoracic MDCT angiography finding. In the lungs and pleura, GGO, septal thickening, and pleural thickening are frequently seen in children with cardiac septal defect and PVS. In the mediastinum, a mildly heterogeneously enhancing, non-calcified soft tissue mass in the distribution of PVS in the mediastinum is seen in close to half of the pediatric patients with cardiac septal defect and PVS.

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.

Outcomes in Establishing Individual Vessel Patency for Pediatric Pulmonary Vein Stenosis

The purpose of this study was to determine what patient and pulmonary vein characteristics at the diagnosis of intraluminal pulmonary vein stenosis (PVS) are predictive of individual vein outcomes. A retrospective, single-center, cohort sub-analysis of individual pulmonary veins of patients enrolled in the clinical trial NCT00891527 using imatinib mesylate +/− bevacizumab as adjunct therapy for the treatment of multi-vessel pediatric PVS between March 2009 and December 2014 was performed. The 72-week outcomes of the individual veins are reported. Among the 48 enrolled patients, 46 patients and 182 pulmonary veins were included in the study. Multivariable analysis demonstrated that patients with veins without distal disease at baseline (odds ratio, OR 3.69, 95% confidence interval, CI [1.52, 8.94], p = 0.004), location other than left upper vein (OR 2.58, 95% CI [1.07, 6.19], p = 0.034), or veins in patients ≥ 1 y/o (OR 5.59, 95% CI [1.81, 17.3], p = 0.003) were at higher odds of having minimal disease at the end of the study. Veins in patients who received a higher percentage of eligible drug doses required fewer reinterventions (IRR 0.76, 95% CI [0.68, 0.85], p < 0.001). The success of a multi-modal treatment approach to aggressive PVS depends on the vein location, disease severity, and drug dose intensity.

Treatment of Congenital and Acquired Pulmonary Vein Stenosis

PURPOSE OF REVIEW

Pulmonary vein stenosis (PVS) is a rare entity that until the last 2 decades was seen primarily in infants and children. Percutaneous and surgical interventions have limited success due to relentless restenosis, and mortality remains high. In adults, acquired PVS following ablation for atrial fibrillation has emerged as a new syndrome. This work will review these two entities with emphasis on current treatment.

RECENT FINDINGS

Greater emphasis on understanding and addressing the mechanism of restenosis for congenital PVS has led to the use of drug-eluting stents (DES) and systemic drug therapy to target neo-intimal growth. Frequent reinterventions are positively affecting outcomes. Longer-term outcomes of percutaneous treatment for acquired PVS are emerging. Treatment of congenital PVS continues to be plagued by restenosis. DES show promise, but frequent reinterventions are required. Larger upstream vein diameter predicts success for congenital and acquired PVS interventions. Efforts to induce/maintain vessel growth are important for future treatment strategies.

Optimization of Pediatric Body CT Angiography: What Radiologists Need to Know

OBJECTIVE. Pediatric CT angiography (CTA) presents unique challenges compared with adult CTA. Because of the ionizing radiation exposure, CTA should be used judiciously in children. The pearls offered here are observations gleaned from the authors' experience in the use of pediatric CTA. We also present some potential follies to be avoided. CONCLUSION. Understanding the underlying principles and paying meticulous attention to detail can substantially optimize dose and improve the diagnostic quality of pediatric CTA.

Characterisation of computed tomography angiography findings in paediatric patients with heterotaxy

BACKGROUND

Heterotaxy refers to the abnormal arrangement of organs across the left-right axis and is typically associated with complex cardiovascular malformations.

OBJECTIVE

To characterise the range of cardiac and extracardiac CT angiography findings in children with heterotaxy using the latest nomenclature consensus and to compare the different types of isomerism.

MATERIALS AND METHODS

We retrospectively analysed the data of 64 consecutive paediatric patients referred to our tertiary paediatric cardiovascular centre who underwent CT angiography for the evaluation of known or suspected heterotaxy within a 52-month period.

RESULTS

Right atrial isomerism was identified in 44 (69%) children, while left atrial isomerism was identified in 18 (28%) children. Atrial appendage anatomy and situs could not be determined in 2 children (3%). Associated heart defects included complete atrioventricular canal (CAVC) in 51 (80%) children, total anomalous pulmonary venous return in 43 (67%) and pulmonary atresia in 23 (36%). The bronchial branching pattern corresponded to atrial appendage morphology in all children except in the two in whom atrial appendage morphology could not be defined. In children with right atrial isomerism, the most common associated abnormalities were CAVC (n=41, 93%) and asplenia (n=34, 77%), while in those with left atrial isomerism, the most common associated abnormalities were polysplenia (n=17, 94%) and an interrupted inferior vena cava with azygos continuation (n=15, 83%).

CONCLUSION

CT angiography provides useful cardiovascular and extracardiac data on heterotaxy, which frequently involves a pattern of side-related findings but has great anatomical variability.

Radiation dose management for pediatric cardiac computed tomography: a report from the Image Gently 'Have-A-Heart' campaign

Children with congenital or acquired heart disease can be exposed to relatively high lifetime cumulative doses of ionizing radiation from necessary medical imaging procedures including radiography, fluoroscopic procedures including diagnostic and interventional cardiac catheterizations, electrophysiology examinations, cardiac computed tomography (CT) studies, and nuclear cardiology examinations. Despite the clinical necessity of these imaging studies, the related ionizing radiation exposure could pose an increased lifetime attributable cancer risk. The Image Gently "Have-A-Heart" campaign is promoting the appropriate use of medical imaging studies in children with congenital or acquired heart disease while minimizing radiation exposure. The focus of this manuscript is to provide a comprehensive review of radiation dose management and CT performance in children with congenital or acquired heart disease.

CT-defined phenotype of pulmonary artery stenoses in Alagille syndrome

BACKGROUND

Alagille syndrome is a rare disorder commonly associated with pulmonary artery stenosis. Studies exist discussing the cardiovascular sequela but no consistent phenotype, or pattern of pulmonary artery stenosis, has been described.

OBJECTIVE

The objective of this study was to characterize the distribution and severity of pulmonary artery stenosis in patients with Alagille syndrome based on computed tomography angiography.

MATERIALS AND METHODS

A retrospective chart review identified patients with Alagille syndrome who had undergone CT angiography. Pulmonary trunk (MPA), left main pulmonary artery (LPA) and right main pulmonary artery (RPA) diameters in Alagille patients were compared with those from matched control subjects. Stenoses at lobar and segmental pulmonary arteries were categorized as: Grade 1 (<33% stenosis), Grade 2 (33-66% stenosis) or Grade 3 (>66% stenosis). Involvement among the different lung regions was then compared.

RESULTS

Fifteen patients ages 6 months to 17 years were identified; one had surgical augmentation of the central pulmonary arteries and was excluded from the central (main, right and left) pulmonary artery analysis. The proximal LPA and RPA, but not the MPA, were significantly smaller than those of the control subjects (P<0.01). The proximal LPA was significantly smaller than the proximal RPA (P<0.01) in the Alagille group (0.55 LPA:RPA ratio). Within the Alagille group, 75% of the lobar and segmental branches showed mild or no stenoses (Grade 1), 17% showed moderate stenosis (Grade 2) and 8% showed severe stenosis (Grade 3). While not statistically significant, the right lung demonstrated a greater percentage of Grades 2 and 3 stenoses (28%, right vs. 20% left, P=0.1). The right middle and lingula lobes of both lungs showed more Grade 2 and 3 stenoses (33% upper/middle vs. 18% lower, P<0.01).

CONCLUSION

We describe a common pattern pulmonary artery stenosis in Alagille patients consisting of severe proximal LPA stenosis, heavy involvement of the lobar and segmental branches (more often right than left), and a greater involvement of the upper lobes. Knowledge of this phenotypic pattern can help in the diagnosis of Alagille syndrome in patients presenting with pulmonary artery stenosis.

Analysis of Image Gently Abdominal CT Protocol With the Use of Body Phantom Adapted to the Japanese Size

OBJECTIVE

The purpose of this study was to analyze in detail the quality of abdominal CT images obtained using three protocols reported by Image Gently in 2014 (hereafter referred to as Image Gently 2014), with the use of a handmade body phantom adapted to typical body sizes of the Japanese population. Moreover, we converted the findings of Image Gently 2014 to match Japanese body sizes and referred to our converted findings as Image Gently Japan.

MATERIALS AND METHODS

We scanned each phantom in a mechanical isocenter in accordance with the Image Gently 2014 abdominal imaging protocol. We changed the tube current-exposure time product per rotation from 25 to 250 mAs. The bowtie filter was set with a minimum FOV for the phantom size. We then analyzed the volume CT dose index (CTDIvol)-measured CT number curve. We then used this CT number curve to calculate the CT number recommended by Image Gently Japan for each of the designated patient ages.

RESULTS

The CTDIvol-measured CT number curve showed that, as the CTDIvol increased with each age, image noise decreased. When we assumed that the CTDIvol value for adults was 20 mGy, the measured CT number was 12.5 HU. We then multiplied each reduction coefficient by age (neonate and 1, 5, 10, and 15 years). The measured CT numbers for Image Gently Japan performed to attain limited dose reduction were 3.0, 3.9, 4.9, 6.0, and 9.0 HU, respectively, whereas those for Image Gently Japan performed to achieve moderate dose reduction were 3.3, 4.3, 5.3, 6.3, and 9.3 HU, respectively, and those for Image Gently Japan performed to attain aggressive dose reduction were 4.1, 5.1, 5.8, 6.8, and 9.5 HU, respectively.

CONCLUSION

We analyzed the abdominal image quality demanded by Image Gently 2014, and we were able to adapt the results to the Japanese population and present them as our own Image Gently Japan recommendations. If the results of the present study become a foundation for scanning parameters for Japanese patients, we believe that they will eventually lead to a reduction in medical radiation exposure for this patient population.

Developmental lung malformations in children: recent advances in imaging techniques, classification system, and imaging findings

Congenital lung anomalies represent a diverse group of developmental malformations of the lung parenchyma, arterial supply, and venous drainage, which may present anywhere from the prenatal period through adulthood. It is imperative for radiologists to be aware of imaging techniques and imaging appearance of these anomalies across the pediatric age range. This review presents the spectrum of these lesions that are often encountered in daily clinical practice. Each anomaly is discussed in terms of underlying etiology, clinical presentation, and imaging characterization with emphasis on the most up-to-date research and treatment. Knowledge of these areas is essential for accurate, timely diagnosis, which aids in optimizing patient outcomes.