Multidetector computed tomography and 3-dimensional imaging: preoperative evaluation of thoracic vascular and tracheobronchial anomalies and abnormalities in pediatric patients

Persistence of aerodigestive symptoms after vascular ring repair

OBJECTIVE

Vascular rings are often associated with respiratory and swallowing difficulties due to tracheal or esophageal compression. While the results of a vascular ring repair are considered excellent, the long-term effect of tracheal and esophageal remodeling and the persistence of symptoms have scarcely been reported. Our study aims to evaluate the respiratory and swallowing outcomes of vascular ring repair.

STUDY DESIGN AND METHODS

A retrospective cohort study of children who underwent vascular ring repair between 2010 and 2022 in a tertiary-care children's hospital.

RESULTS

There were 108 patients enrolled: sixty-three patients (57.41 %) with a right aortic arch, 42 patients (38.89 %) with a double aortic arch, and 3 patients (2.78 %) with other vascular rings. Forty-three (39.81 %) patients were diagnosed prenatally. Of the 65 patients (60.19 %) diagnosed postnatally, 35/65 (53.85 %) had either respiratory or swallowing symptoms as the indication for diagnostic workup. Persistent respiratory and swallowing symptoms were noted in 34/108 (31.48 %) and 30/108 (27.78 %) patients, respectively, within a year of surgical repair. Fourteen patients underwent repeated laryngoscopy and bronchoscopy that demonstrated residual tracheomalacia; however, only 2/14 (1.9 %) patients required tracheostomy tube placement, and 6-out-of-7 patients were weaned off positive pressure airway support. Persistent respiratory symptoms were significantly more common in patients with a double aortic arch compared to a right aortic arch. No differences were noted in demographics, comorbidities, and preoperative aerodigestive symptoms between patients with residual symptoms and patients with no residual symptoms.

CONCLUSIONS

Persistent respiratory and swallowing symptoms after vascular ring repair are not uncommon. Postoperative evaluation should be pursued by a dedicated team, and treatment considered as appropriate.

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.

3D CT cinematic rendering of pediatric thoracic vascular anomalies

Thoracic vascular anomalies in the pediatric population are a heterogeneous group of diseases, with varied clinical presentations and imaging findings. High-resolution computed tomography is widely available and has become a standard part of the workup of these patients, often with three dimensional images. Cinematic rendering is a novel 3D visualization technique that utilizes a new, complex global lighting model to create photorealistic images with enhanced anatomic detail. The purpose of this pictorial review is to highlight the advantages of cinematic rendering compared to standard 2D computed tomography and traditional volume-rendered 3D images in the evaluation of thoracic vascular anomalies. Although cinematic rendering remains a new visualization technique under continued study, the improved anatomic detail and photorealistic quality of these images may be advantageous for surgical planning in cases of complex vascular abnormalities. Cinematic rendering may also help improve communication among clinicians, trainees, and patients and their families.

Long-term outcomes in children undergoing vascular ring division: a multi-institution experience

 

OBJECTIVES

Vascular rings are rare anomalies of congenital heart disease that cause respiratory and gastrointestinal symptoms. This study assessed the long-term outcomes of patients with vascular ring division.

METHODS

A multi-institution retrospective review of 371 patients with vascular rings undergoing surgical division at 3 paediatric cardiac institutions between November 2007 and October 2019 was performed.

RESULTS

The complete vascular rings consisted of a double aortic arch (24.5%), right aortic arch with left ligamentum arteriosum (36.7%) and left aortic arch, with right ligamentum arteriosum (0.5%). The incomplete vascular rings consisted of a pulmonary artery sling (22.9%), left aortic arch with aberrant right subclavian artery (15.1%) and innominate artery compression syndrome (0.3%). Respiratory symptoms included stridor (71.4%), wheezing (49.1%), coughing (31.5%), gastrointestinal symptoms included choking (12.4%), dysphagia (3.2%) and emesis (1.9%). Only one patient died after discharge, yielding a late mortality rate of 0.3% (1/360). The 10-year overall survival rate was 96.8%. Postoperative complications were reported in 51 patients, 15 of whom required reoperation. The 10-year freedom from reoperation rate was 95.9%. Follow-up was completed in 95.4% (354/371) of patients, with a mean follow-up time of 4.3 ± 2.9 years (range from 1 to 13 years). Twenty patients (5.6%) experienced residual symptoms during long-term follow-up.

CONCLUSIONS

The outcomes of vascular ring division are excellent. A Kommerell diverticulum >1.5 times the aberrant left subclavian artery origin is an operative indication for primary resection. Tracheomalacia is a risk factor for reoperation and residual symptoms, and preoperative fibrobronchoscopy is important for evaluation.

Diagnostic Accuracy of Three-dimensional Turbo Field Echo Magnetic Resonance Imaging Sequence in Pediatric Tracheobronchial Anomalies with Congenital Heart Disease

Tracheobronchial anomalies are common in congenital heart disease (CHD), including tracheobronchial stenosis, tracheal bronchus, cardiac bronchus, and bronchial isomerism, which can cause varying degrees of respiratory illness. It is necessary to assess tracheobronchial anomalies and make a preoperative airway evaluation. Multi-slice computed tomography (MSCT) and cardiac magnetic resonance imaging (MRI) are the most effective noninvasive modalities for the diagnosis of CHD and the associated tracheobronchial anomalies. However, MSCT remains an ionizing procedure despite using low dose protocols. The aim of this study was to evaluate diagnostic accuracy of tracheobronchial anomalies in patients with CHD using three-dimensional turbo field echo(3D-TFE) magnetic resonance imaging sequence for preoperative airway evaluation. The results indicated that 3D-TFE provided better image quality as compared to that of 3D-balanced turbo field echo (3D-bTFE), and it can clearly demonstrated the tracheobronchial tree and tracheobronchial anomalies in CHD. This study confirms the clinical value of 3D-TFE in diagnosing tracheobronchial anomalies and supply helpful tracheobronchial information for preoperative strategies and postoperative follow-up.

Evaluation of pulmonary sequestration with multidetector computed tomography angiography in a select cohort of patients: A retrospective study

OBJECTIVES

This study aimed to evaluate the role of multidetector computed tomography angiography in diagnosing patients with pulmonary sequestration.

METHODS

We retrospectively analyzed the computed tomography studies and clinical materials of 43 patients who had undergone preoperative multidetector computed tomography angiography in our hospital and had pathologically proven pulmonary sequestration. Each examination of pulmonary sequestration was reviewed for type, location, parenchymal changes, arterial supply and venous drainage on two-dimensional and three-dimensional computed tomography images.

RESULTS

Multidetector computed tomography successfully detected all pulmonary sequestrations in the 43 patients (100%). This included 40 patients (93.0%) with intralobar sequestration and 3 patients (7.0%) with extralobar sequestration. The locations of pulmonary sequestration were left lower lobe (28 cases, 70% of intralobar sequestrations), right lower lobe (12 cases, 30% of intralobar sequestrations) and costodiaphragmatic sulcus (3 cases). Cases of sequestered lung presented as mass lesions (37.2%), cystic lesions (32.6%), pneumonic lesions (16.3%), cavitary lesions (9.3%) and bronchiectasis (4.6%). The angioarchitecture of pulmonary sequestration, including feeding arteries from the thoracic aorta (86.1%), celiac truck (9.3%), abdominal aorta (2.3%) and left gastric artery (2.3%) and venous drainage into inferior pulmonary veins (86.0%) and the azygos vein system (14.0%), was visualized on multidetector computed tomography. Finally, the multidetector computed tomography angiography results of the sequestered lungs and angioarchitectures were surgically confirmed in all the patients.

CONCLUSIONS

As a noninvasive modality, multidetector computed tomography angiography is helpful for making diagnostic decisions regarding pulmonary sequestration with high confidence and for visualizing the related parenchymal characteristics, arterial supply, and venous drainage features to help plan surgical strategies.

Role of Computed Tomography in Pediatric Chest Conditions

CT is the preferred cross-sectional imaging modality for detailed evaluation of anatomy and pathology of the lung and tracheobronchial tree, and plays a complimentary role in the evaluation of certain chest wall, mediastinal, and cardiac abnormalities. The article provides an overview of indications and different types of CT chest, findings in common clinical conditions, and briefly touches upon the role of each team member in optimizing and thus reducing radiation dose.

Reoperation after vascular ring repair

The majority of patients having surgical intervention for a vascular ring have resolution of their symptoms. However, 5% to 10% of these patients develop recurrent symptoms related either to airway or esophageal compression and may require reoperation. In our series of 300 patients with vascular rings, we performed a reoperation on 26 patients, not all of whom were originally operated on at our institution. The four primary indications for reoperation were Kommerell diverticulum (n = 18), circumflex aorta (n = 2), residual scarring (n = 2), and tracheobronchomalacia requiring aortopexy (n = 4). All patients undergoing reoperation have had preoperative evaluation with bronchoscopy and computed tomographic scanning (CT) with 3-dimensional reconstruction. Patients with dysphagia have had a barium esophagram and esophagoscopy. Patients with a Kommerell diverticulum have undergone resection of the diverticulum and transfer of the left subclavian artery to the left carotid artery. The aortic uncrossing procedure has been used in patients with a circumflex aorta. Aortopexy has been used to treat anterior compression of the trachea by the aorta. Results of these reinterventions have been successful in nearly all cases. Lessons learned from these reoperations can be applied to prevent the need for reoperation by properly selecting the correct initial operation. A dedicated team caring for these children consisting of medical imaging, otolaryngology, cardiovascular-thoracic surgery, and critical care is imperative.

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.

Evaluation of pediatric thoracic disorders: comparison of unenhanced fast-imaging-sequence 1.5-T MRI and contrast-enhanced MDCT

OBJECTIVE

The purpose of this study was to investigate the efficacy of thoracic MRI with fast imaging sequences without contrast administration at 1.5 T for evaluating thoracic abnormalities by comparing MRI findings with contrast-enhanced MDCT findings.

SUBJECTS AND METHODS

A prospective study included consecutively registered pediatric patients who from December 2009 to January 2012 underwent thoracic MDCT followed within 2 days by MRI for evaluation of thoracic abnormalities. The final study sample consisted of 71 children (36 boys, 35 girls; mean age, 8.6 ± 4.5 years; range, 2 months-16 years) and 71 paired thoracic MRI and MDCT studies. Thoracic MRI was performed in the axial and coronal planes with the following fast imaging sequences: T1-weighted fast-field echo inversion prepulse, T2-weighted balanced fast-field echo multiple 2D, T1- and T2-weighted turbo spin-echo cardiac-triggering parallel imaging technique without cardiac monitoring, and STIR. Thoracic MDCT was performed with i.v. contrast administration. Two pediatric radiologists independently reviewed each MRI and MDCT study for abnormalities in the lung, large airways, and mediastinal, pleural, and musculoskeletal structures. The sensitivity, specificity, and overall accuracy of MRI were calculated. Interobserver agreement was measured with the kappa coefficient.

RESULTS

With MDCT as the reference standard, 51 of 71 (72%) patients had abnormal findings on MDCT studies, including infections in 21 (42%) cases, neoplasms in 19 (37%) cases, interstitial lung disease in seven (14%) cases, pleural effusion in three (6%) cases, and congenital bronchogenic cyst in one (2%) case. The overall diagnostic accuracy, sensitivity, and specificity of MRI for detecting thoracic abnormalities were 69 of 71 (97%), 49 of 51 (96%), and 20 of 20 (100%). Two undiagnosed findings with MRI that were detected with MDCT were mild bronchiectasis and small pulmonary nodule (3 mm). Almost perfect interobserver agreement was found between two reviewers with 70 of 71 agreements (κ = 0.97; 95% CI, 0.92-1.00; p < 0.001). CONCLUSION; MRI with fast imaging sequences without contrast administration is comparable to contrast-enhanced MDCT for detecting thoracic abnormalities in pediatric patients. Use of MRI with fast imaging sequences without contrast administration as a first-line cross-sectional imaging study in lieu of contrast-enhanced MDCT has the potential to benefit this patient population owing to reduced radiation exposure and i.v. contrast administration.

Advanced large airway CT imaging in children: evolution from axial to 4-D assessment

Continuing advances in multidetector computed tomography (MDCT) technology are revolutionizing the non-invasive evaluation of congenital and acquired large airway disorders in children. For example, the faster scanning time and increased anatomical coverage that are afforded by MDCT are especially beneficial to children. MDCT also provides high-quality multiplanar 2-dimensional (2-D), internal and external volume-rendering 3-dimensional (3-D), and dynamic 4-dimensional (4-D) imaging. These advances have enabled CT to become the primary non-invasive imaging modality of choice for the diagnosis, treatment planning, and follow-up evaluation of various large airway disorders in infants and children. It is thus essential for radiologists to be familiar with safe and effective techniques for performing MDCT and to be able to recognize the characteristic imaging appearances of large airway disorders affecting children.

Computed tomography guided thoracoscopic segmentectomy for lung cancer with variant bronchus

Lung segmentectomy with bronchial variation has rarely been reported. We report the case of a lung cancer patient with variant anatomy of the right upper lobe bronchus.Thoracoscopic posterior segmentectomy of the right upper lobe was performed. Variant bronchus and related blood vessels were confirmed preoperatively by three-dimensional multidetector computed tomography (3D-MDCT), which facilitated visualization of the patient's anatomy during surgery.

Paediatric multi-detector row chest CT: what you really need to know

Background

The emergence of multi-detector row CT (MDCT) has established and extended the role of CT especially in paediatric chest imaging. This has altered the way in which data is acquired and is perceived as the 'gold standard' in the detection of certain chest pathologies. The range of available post-processing tools provide alternative ways in which CT images can be manipulated for review and interpretation in order to enhance diagnostic accuracy.

Methodology

Paediatric imaging technique/protocol together with radiation dose reduction is discussed in detail. The use of different post-processing tools to best demonstrate the wide range of important congenital anomalies and thoracic pathologies is outlined and presented pictorially.

Conclusion

MDCT with its isotropic resolution and fast imaging acquisition times reduces the need for invasive diagnostic investigations. However, users must be vigilant in their imaging techniques to minimise radiation burden, whilst maintaining good image quality.

Main Messages

• CT examinations should be clinically justified by the referring clinician and radiologist.

• MDCT is invaluable for evaluating the central airway, mediastinal structures and lung parenchyma.

• MDCT is more sensitive than plain radiographs in detection of structural changes within the lungs.

Radiation, thoracic imaging, and children: radiation safety

The chest is the most frequently evaluated region of the body in children. The majority of thoracic diagnostic imaging, namely "conventional" radiography (film screen, computed radiography and direct/digital radiography), fluoroscopy and angiography, and computed tomography, depends on ionizing radiation. Since errors, oversights, and inattention to radiation exposure continue to be extremely visible issue for radiology in the public eye it is incumbent on the imaging community to maximize the yield and minimize both the real and potential radiation risks with diagnostic imaging. Technical (e.g. equipment and technique) strategies can reduce exposure risk and improve study quality, but these must be matched with efforts to optimize appropriate utilization for safe and effective healthcare in thoracic imaging in children. To these ends, material in this chapter will review practice patterns, dose measures and modality doses, radiation biology and risks, and radiation risk reduction strategies for thoracic imaging in children.

Multidetector computed tomography of pediatric large airway diseases: state-of-the-art

Advances in multidetector computed tomography (MDCT) technology have given rise to improvements in the noninvasive and comprehensive assessment of the large airways in pediatric patients. Superb two-dimensional and three-dimensional reconstruction MDCT images have revolutionized the display of large airways and enhanced the ability to diagnose large airway diseases in children. The 320-MDCT scanner, which provides combined detailed anatomic and dynamic functional information assessment of the large airways, is promising for the assessment of dynamic large airway disease such as tracheobronchomalacia. This article discusses imaging techniques and clinical applications of MDCT for assessing large airway diseases in pediatric patients.

Central airway stabilization for tracheobronchomalacia improves quality of life in patients with COPD

BACKGROUND

Tracheobronchomalacia (TBM) is characterized by excessive collapsibility of the central airways, typically during expiration. TBM may be present in as many as 50% of patients evaluated for COPD. The impact of central airway stabilization on symptom pattern and quality of life is poorly understood in this patient population.

METHODS

Patients with documented COPD were identified from a cohort of 238 patients assessed for TBM at our complex airway referral center. Pulmonary function testing, exercise tolerance, and health-related quality-of-life (HRQOL) measures were assessed at baseline and 2 to 4 weeks following tracheal stent placement/operative tracheobronchoplasty (TBP). Severity of COPD was classified according to the GOLD (Global Initiative for Chronic Obstructive Lung Disease) staging system.

RESULTS

One hundred three patients (48 women) with COPD and moderately severe to severe TBM were identified. Statistically and clinically significant improvements were seen in HRQOL measures, including the transitional dyspnea index (stent, P = .001; TBP, P = .008), the St. George Respiratory Questionnaire (stent, P = .002; TBP, P < .0001), and the Karnofsky performance score (stent, P = .163; TBP, P < .0001). The improvement appeared greatest following TBP and was seen in all GOLD stages. Clinical improvement was also seen in measured FEV(1) and exercise capacity as assessed by 6-min walk test.

CONCLUSIONS

Central airway stabilization may provide symptomatic benefit for patients with severe COPD and concomitant severe airway malacia. Operative airway stabilization appears to impart the greatest advantage. Long-term follow-up study is needed to fully ascertain the ultimate efficacy of both stenting and surgical airway stabilization in this patient group.