Assessment of children with vascular ring

Effectiveness of low tube voltage scan in the exposure dose for lenses during paediatric thoracic CT examination: anthropomorphic phantoms study

To determine whether using lower-tube voltage reduces the scattered dose for the lens during paediatric thoracic computed tomography (CT). Two paediatric anthropomorphic phantoms (ATOM Phantom, CIRS, Norfolk, Virginia, USA) representing a newborn and 5-year-old were placed on the gantry of CT scanner, and optically stimulated luminescence dosemeters were placed on the left and right lenses, in front of the left and right thyroid glands, in front of the left and right mammary glands, and in front of and behind the mammary gland level and we measured scattered dose of the optically stimulated luminescence dosemeter was compared for each phantom between 80 and 120 kVp. Significant differences were observed in the scatter doses for the lens between 80 and 120 kVp (p < 0.01). Compared with the 120 kVp scan, the scatter doses for the lens were ~15-40% lower in newborn and 5-year-olds using the 80 kVp scan during paediatric CT.

Narrowing Down the Symptomatology of Isolated Vascular Rings in Children

Vascular rings may cause respiratory or gastrointestinal symptoms due to compression of the trachea and/or esophagus. Advances in imaging have enabled early detection in asymptomatic patients posing new management dilemmas. Surgery is expected to relieve symptoms, although this has not been well studied. We sought to evaluate the presence and pattern of symptoms associated with vascular rings before surgical intervention and to detail symptom resolution after surgery. A 10-year retrospective review of patients diagnosed with an isolated vascular ring was performed between January 2010 and December 2019. 100 patients were identified; 35 double aortic arch (DAA) and 65 right aortic arch and left ligamentum arteriosum (RALL). 73 patients were symptomatic on presentation; 47 had respiratory, 5 had gastrointestinal, and 21 had both types of symptoms. Surgical repair was performed in 75 patients; 74 were symptomatic. Respiratory symptoms were more likely in patients with preoperative tracheal narrowing (p < 0.001). Moderate-severe respiratory symptoms led to surgery in RALL patients (OR 10.6, p = 0.0001). DAA patients were more likely to undergo surgery (p < 0.001) irrespective of symptom severity. At a median post-surgical follow-up of 4 months, there was a significant reduction in symptom burden (p < 0.001), except for asthma symptoms (p = 0.131). Symptom resolution was not dependent on the vascular ring anatomy (p = 0.331) or the age at operation (p = 0.158). Vascular rings are typically accompanied by respiratory symptoms and less commonly GI symptoms, both of which resolve in most patients after surgery. Those who present predominantly with asthma-like symptoms may not achieve resolution after surgery.

Pediatric airway compression in aortic arch malformations: a multidisciplinary approach

Background

Aortic arch malformations (AAMs) should be suspected in the presence of persistent respiratory symptoms despite medical treatment or feeding problems at the pediatric age.

Aim

We report a descriptive cohort of patients with AAMs and the local management protocol applied.

Methods

A total of 59 patients with AAM were retrospectively reviewed. Three groups were identified: double aortic arch (DAA), group 1; complete vascular ring (non-DAA), group 2; and anomalous origin of the innominate artery (IA), group 3.

Results

Prenatal diagnosis was available for 62.7% of the patients. In all, 49.2% of children were symptomatic. There was a significantly different prevalence of respiratory symptoms within the three groups: 73.7% in group 1, 24.2% in group 2, and 100% in group 3 (p-value: <0.001). Surgery was considered in the presence of symptoms in patients with DAA and in those with reduction of the tracheal section area greater than 50%. A total of 52.5% of the patients underwent surgical repair (median age 6 months). The median follow-up interval was 21.9 months. Respiratory symptoms improved in most symptomatic patients.

Conclusions

No specific protocols are available for the management of patients with AAMs. Conservative treatment seems to be reasonable for asymptomatic patients or those with airway stenosis less than 50%. A close follow-up is necessary to identify early patients who become symptomatic.

Contemporary Outcomes in Fetuses Diagnosed with Vascular Rings

Vascular rings are increasingly identified on fetal echocardiography. The purpose of this study is to analyze clinical outcomes and patterns of diagnostic testing in fetuses with vascular rings diagnosed by echocardiography. A retrospective cohort study was performed of fetuses with postnatally confirmed vascular rings from 2017 to 2022. Clinical outcomes included type and timing of symptoms, and timing of surgical intervention. Freedom from symptoms and/or surgery was assessed by Kaplan-Meier analysis. Frequency of genetic and diagnostic testing (barium esophagogram, CT/MRI angiogram, and bronchoscopy) was also assessed. Overall, 46 patients were evaluated (91% with a right aortic arch/left ductus and 4% with a double aortic arch). A vascular ring was isolated in 59%, associated with structural heart lesions in 33%, and associated with noncardiac anomalies in 8%. Prenatal diagnoses increased over time. Symptoms developed in 24% (11/46); 82% (9/11) had respiratory and 45% (5/11) had gastroesophageal complaints. Surgery was performed in 17% (11/46). Symptoms presented bimodally, prior to 100 or after 400 days of life. There was no difference in the type of symptoms for early (< 100 days) or late (> 400 days) presenters. Symptomatic patients received more diagnostic testing. Genetic testing was obtained in 46% and positive in 33%, with 22q11 deletion and Trisomy 21 being identified. Prenatal diagnoses of vascular rings increased over time, with subjects developing symptoms bimodally in early or late infancy. The frequency of genetic testing was suboptimal given the prevalence of genetic abnormalities seen in this population.

Vascular ring: prenatal diagnosis and prognostic management based on sequential cross-sectional scanning by ultrasound

BACKGROUND

In terms of embryonic origin, vascular ring is a congenital anomaly in which the aortic arch and its branches completely or incompletely encircle and compress the trachea or esophagus. Early and accurate diagnosis of a vascular ring is the key to treatment. Prenatal diagnosis mainly relies on fetal echocardiography, but the rate of missed diagnosis and misdiagnosis is still very high, and the prognosis has not been evaluated. The aim of this study was to investigate the accuracy of prenatal diagnosis and to evaluate the prognosis semi-quantitatively according to the shape of the ring and the distance between the vessel and the trachea.

METHODS

From 2019 to 2021, 37,875 fetuses underwent prenatal ultrasound examination in our center. All fetal cardiac examinations were performed using the fetal echocardiography method proposed by the American Institute of Ultrasound in Medicine (AIUM) combined with dynamic sequential cross-sectional observation (SCS). For SCS, the standard abdominal section was taken as the initial section, and the probe was moved cephalically along the long axis of the body until the superior mediastinum had disappeared. If a vascular ring was found, the shape of the ring and the distance of the branch to the airway were observed. The distance relationship with the airway was divided into three grades: I-III; the closer the distance, the lower the grade. The vascular rings were monitored every 4 weeks before birth. All were monitored before surgery or 1 year after birth.

RESULTS

A total of 418 cases of vascular rings were detected. There was no missed diagnoses or misdiagnoses by SCS. The vessels formed different shaped rings according to their origin and route. Grade I, "" and "O" rings have a poor prognosis and are associated with the highest risk of respiratory symptoms.

CONCLUSIONS

SCS can accurately diagnose vascular rings before delivery, evaluate the shape and size of the rings to conduct prenatal monitoring of children until birth, which plays a guiding role in airway compression after birth.

Application of deep learning image reconstruction algorithm to improve image quality in CT angiography of children with Takayasu arteritis

BACKGROUND

The inflammatory indexes of children with Takayasu arteritis (TAK) usually tend to be normal immediately after treatment, therefore, CT angiography (CTA) has become an important method to evaluate the status of TAK and sometime is even more sensitive than laboratory test results.

OBJECTIVE

To evaluate image quality improvement in CTA of children diagnosed with TAK using a deep learning image reconstruction (DLIR) in comparison to other image reconstruction algorithms.

METHODS

hirty-two TAK patients (9.14±4.51 years old) underwent neck, chest and abdominal CTA using 100 kVp were enrolled. Images were reconstructed at 0.625 mm slice thickness using Filtered Back-Projection (FBP), 50%adaptive statistical iterative reconstruction-V (ASIR-V), 100%ASIR-V and DLIR with high setting (DLIR-H). CT number and standard deviation (SD) of the descending aorta and back muscle were measured and contrast-to-noise ratio (CNR) for aorta was calculated. The vessel visualization, overall image noise and diagnostic confidence were evaluated using a 5-point scale (5, excellent; 3, acceptable) by 2 observers.

RESULTS

There was no significant difference in CT number across images reconstructed using different algorithms. Image noise values (in HU) were 31.36±6.01, 24.96±4.69, 18.46±3.91 and 15.58±3.65, and CNR values for aorta were 11.93±2.12, 15.66±2.37, 22.54±3.34 and 24.02±4.55 using FBP, 50%ASIR-V, 100%ASIR-V and DLIR-H, respectively. The 100%ASIR-V and DLIR-H images had similar noise and CNR (all P > 0.05), and both had lower noise and higher CNR than FBP and 50%ASIR-V images (all P < 0.05). The subjective evaluation suggested that all images were diagnostic for large arteries, however, only 50%ASIR-V and DLIR-H met the diagnostic requirement for small arteries (3.03±0.18 and 3.53±0.51).

CONCLUSION

DLIR-H improves CTA image quality and diagnostic confidence for TAK patients compared with 50%ASIR-V, and best balances image noise and spatial resolution compared with 100%ASIR-V.

Performance evaluation of a deep learning image reconstruction (DLIR) algorithm in "double low" chest CTA in children: a feasibility study

BACKGROUND

Chest CT angiography (CTA) is a convenient clinical examination for children with an increasing need to reduce both radiation and contrast medium doses. Iterative Reconstruction algorithms are often used to reduce image noise but encounter limitations under low radiation dose and conventional 100 kVp tube voltage may not provide adequate enhancement under low contrast dose.

PURPOSE

To evaluate the performance of a deep learning image reconstruction (DLIR) algorithm in conjunction with lower tube voltage in chest CTA in children under reduced radiation and contrast medium (CM) dose.

MATERIALS AND METHODS

46 Children (age 5.9 ± 4.2 years) in the study group underwent chest CTA with 70 kVp and CM dose of 0.8-1.2 ml/kg. Images were reconstructed at 0.625 mm using a high setting DLIR (DLIR-H). The control group consisted of 46 age-matching children scanned with 100 kVp, CM dose of 1.3-1.8 ml/kg and images reconstructed with 50% and 100% adaptive statistical iterative reconstruction-V. Two radiologists evaluated images subjectively for overall image noise, vessel contrast and vessel margin clarity separately on a 5-point scale (5, excellent and 1, not acceptable). CT value and image noise of aorta and erector spinae muscle were measured.

RESULTS

Compared to the control group, the study group reduced the dose-length-product by 11.2% (p = 0.01) and CM dose by 24% (p < 0.001), improved the enhancement in aorta (416.5 ± 113.1HU vs. 342.0 ± 57.6HU, p < 0.001) and reduced noise (15.1 ± 3.5HU vs. 18.6 ± 4.4HU, p < 0.001). The DLIR-H images provided acceptable scores on all 3 aspects of the qualitative evaluation.

CONCLUSION

"Double low" chest CTA in children using 70 kVp and DLIR provides high image quality with reduced noise and improved vessel enhancement for diagnosis while further reduces radiation and CM dose.

Right aortic arch forming a true vascular ring: a clinical review

OBJECTIVES

This review aims at presenting and summarizing the current state of literature on the presentation and surgical management of a right-sided aortic arch with a left-sided ligamentum forming a complete vascular ring around the oesophagus and trachea.

METHODS

A systematic database search for appropriate literature was conducted on PubMed/MEDLINE. Articles were considered relevant when providing details on the presentation, diagnosis and surgical treatment of this specific congenital arch anomaly in human beings.

RESULTS

Affected patients present with respiratory and/or oesophageal difficulties due to tracheoesophageal compression. Conservative treatment might be reasonable in asymptomatic or mildly symptomatic cases; however, once moderate-to-severe symptoms develop, surgical intervention is definitely indicated. Surgery is commonly performed through a left thoracotomy or median sternotomy and includes the division of the left ductal ligamentum; if a Kommerell's diverticulum is present that is >1.5 times the diameter of the subclavian artery, then concomitant resection of the large diverticulum and translocation of the aberrant left subclavian artery is also conducted. Postoperative morbidity and mortality are low and are rather related to concomitant intracardiac and extracardiac anomalies than to the procedure itself. In a majority of patients, full resolution of symptoms is seen within months to years from the surgery. Nevertheless, there is also a subset of patients who remain with some tracheobronchial narrowing, sometimes even requiring reintervention during follow-up due to persisting or recurring symptoms.

CONCLUSIONS

Overall, the surgical management of a right aortic arch forming a true vascular ring in infancy, childhood and adulthood seems relatively safe and effective in providing symptomatic relief despite some persistent tracheobronchial and/or oesophageal narrowing in some cases.

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 long-term outcome of an isolated vascular ring - A single-center experience

BACKGROUND AND OBJECTIVES

The aim of this study is to document the long-term outcome of patients with a vascular ring.

METHODS

A single-center retrospective review of clinical symptoms was conducted in all patients born between 1980 and 2013, diagnosed with a complete vascular ring and at least 2 years of follow-up. Data were extracted from patient files and clinical symptoms were assessed by questionnaires sent to the parents. Age and diagnostic tools, type of surgery, postoperative complications, and the prevalence of clinical symptoms (stridor at rest, stridor with exercise, cough, exercise intolerance, dysphagia, and frequent respiratory infections) were reviewed.

RESULTS

Fifty-one patients were included. The diagnosis was made before the age of 2 in 35/51. Surgery was performed in 41/51 patients with a limited number of reversible complications. The median follow-up was 8 (IQR 5-12) years. After 2 years, 21/51 patients were asymptomatic: 2/7 asymptomatic patients at diagnosis became symptomatic and symptoms resolved in 16/44 initially symptomatic patients. Consequently, 30/51 patients still had symptoms after 2 years. Of these, 16 had partial improvement, 5 stable symptoms, and 9 aggravation of symptoms. After 10 years, 26/36 patients were free of complaints. The most frequent long-term symptom was stridor.

CONCLUSION

Surgical treatment of a congenital vascular ring is safe and mostly performed in patients with a double aortic arch. Conservative treatment for patients with little symptoms seems to be justifiable. A considerable number of patients have residual long-term symptoms after surgical relief of the vascular ring.

Congenital vascular ring

A vascular ring is a rare congenital cardiovascular anomaly, which encircles and compresses the trachea or esophagus, or both. In this review we discuss the pathophysiology, theoretical embryopathogenesis, diagnostic modalities, and surgical treatment of the different types of vascular ring. Knowledge of the normal embryonic development of the aortic arch and related structures is important for understanding and classifying the various forms of vascular ring. The development of a vascular ring begins with the embryonic aortic arch system. The persistence, involution, or regression of the arches determines the multiple variations of vascular ring. With the development of new technologies, multi-detector computed tomography (MDCT) has become a good diagnostic modality for pre- and postoperative evaluation. MDCT provides an excellent image of aortic arch abnormalities and the related anatomy, as well as the tracheal pathology. For patients with symptoms, surgical division of the vascular ring usually achieves excellent outcomes with marked resolution of symptoms and a low risk of morbidity and mortality. Symptomatic vascular rings require early surgical intervention to prevent prolonged vascular compression of the airway and serious complications.

Atretic anomalous left subclavian artery as part of an unusual vascular ring

In this report, a unique case of a symptomatic vascular ring formed by right aortic arch, aberrant left subclavian artery, and left ligamentum arteriosus in which there is atresia of the proximal left subclavian artery is described. Imaging modalities were non-diagnostic and the patient was sent to surgery based on strong clinical suspicion. Her anatomy was delineated in the operating room and the ring was successfully repaired.