Multidetector computed tomography of congenital aortic abnormalities

Multi-detector computed tomography (MDCT) as a diagnostic tool in assessment of thoracic aortic anomalies in pediatric patients

Background

A wide variety of congenital thoracic aortic variants and pathological anomalies could be assessed recently in diagnostic and interventional radiology. Multi-detector computed tomography (MDCT) is one of the most important non-invasive diagnostic tools for their detection. The aim of the study was to evaluate role of MDCT scanning for diagnosis of thoracic aortic anatomic variants and diseases in pediatric patients.

Results

Thirty patients (15 male and 15 female), mean age (8.49 ± 20.29 months) were diagnosed with different thoracic aortic anomalies by MDCT then confirmed by surgical results. MDCT was more sensitive than echocardiography in detection of hypo plastic arch, vascular rings, interrupted aortic arch anomalies, and aortic coarctation. Both MDCT and echocardiography showed 100% sensitivity in their detection of TGA, TOF, and PDA. MDCT detected 6 cases of right-sided aortic arch while echo missed 2 cases. Different aortic arch branching patterns and coronary origin were better demonstrated by MDCT.

Conclusion

320-Multi-detector computed tomography is a reliable tool for optimal detection of thoracic aortic anomalies and preoperative planning.

Syndromes with aortic involvement: pictorial review

A variety of syndromes are associated with thoracoabdominal aortic pathologies. While these diseases are collectively rare, the presence of advanced or unusual aortic disease at a young age should raise suspicion of an underlying syndrome. Similarly, patients with a known syndrome require close monitoring in anticipation of future aortic disease. In this article, the syndromes most commonly encountered in clinical practice are reviewed, including Marfan syndrome (MFS) and other connective tissue disorders, Turner syndrome (TS), autosomal dominant polycystic kidney disease (ADPKD), neurofibromatosis (NF), Williams syndrome (WS), Alagille syndrome (AGS), and DiGeorge syndrome (DGS). The distinct clinical, imaging, and management features of each disorder are discussed. Attention is focused on the unique patterns of aortic disease in each syndrome, emphasizing the role of recent imaging modalities and treatment strategies. Ancillary and distinguishing aspects of the syndromes that aid in diagnosis are also highlighted.

A prospective national survey of coronary CT angiography radiation doses in the United Kingdom

BACKGROUND

Little real-world radiation dose data exist for the majority of cardiovascular CT. Some data have been published for coronary CT angiography (coronary CTA) specifically, but they invariably arise from high-volume centres with access to the most recent technology.

OBJECTIVE

The aim of this study was to document real-world radiation doses for coronary CTA in the United Kingdom, and to establish their relationship to clinical protocol selection, acquisition heart rate, and scanner technology.

METHODS

A dose survey questionnaire was distributed to members of the British Society of Cardiovascular Imaging and other UK cardiac CT units. All participating centres collected data for consecutive coronary CTA cases over one month. The survey captured information about the exam conducted, patient demographics, pre-scan details such as beta-blocker administration, acquisition heart rate and scan technique, and post-scan dose indicators - series volumetric CT dose index (CTDI_vol), series dose-length product (DLP), and exam DLP.

RESULTS

Fifty centres provided data on a total of 1341 coronary CTA exams. Twenty-nine centres (58%) performed at least 20 coronary CTA scans in the collection period. The median BMI, acquisition heart rate and exam DLP were 28 kg/m², 60 bpm and 209 mGycm respectively. The corresponding effective dose was estimated as 5.9 mSv using a conversion factor of 0.028 mSv/mGycm. There was no statistically significant difference in radiation dose between low and high-volume centres. Median exam DLP increased with the acquisition heart rate due to the selection of wider temporal windows. The highest exam DLPs were obtained on the older scanner technology.

CONCLUSION

This study provides baseline data for benchmarking practice, optimizing radiation dose and improving service quality locally.

Congenital arch vessel anomalies in CHARGE syndrome: A frequent feature with risk for co-morbidity

Background

CHARGE syndrome is a complex multiple congenital malformation disorder with variable expression that is caused by mutations in the CHD7 gene. Variable heart defects occur in 74% of patients with a CHD7 mutation, with an overrepresentation of atrioventricular septal defects and conotruncal defects — including arch vessel anomalies.

Methods and results

We report an index patient with an arch vessel anomaly underlying serious feeding problems that resolved after arch vessel surgery. This led us to examine the incidence of arch vessel anomalies in our previously studied cohort of 299 patients with a CHD7 mutation. Forty-two patients (14%) had an aortic arch anomaly, mostly aberrant subclavian artery or right aortic arch, which usually occurred in combination with other congenital heart defects (81%). The majority of these patients also had feeding problems that may be linked to their arch anomaly, but insufficient information was available to exclude other causes.

Conclusions

Arch vessel anomalies occur in a significant proportion of patients with a CHD7 mutation, and these anomalies may cause morbidity due to compression of the esophagus or trachea. Since symptoms of vascular compression can mimic those caused by other abnormalities in CHARGE syndrome, it is important to be aware of arch vessel anomalies in this complex patient category. Whether a solitary arch vessel anomaly is an indicator for CHARGE syndrome still needs to be studied, but doctors should look out for other CHARGE syndrome features in patients with arch vessel anomalies.

The Thebesian valve height/coronary sinus ostium diameter ratio (H/D-Ratio) as a new indicator for specifying the morphological shape of the valve itself in multisliced computed tomography

BACKGROUND

The coronary sinus ostium (CSO) is covered by the Thebesian valve (ThebV), which has a variable shape when assessed subjectively. The ThebV is an anatomical barrier during CS cannulation, which may be complicated due to the valves' size. The types of valves are: cord, remnant, semilunar, fold, and mesh/fenestrated. The ThebV can be visible using multisliced computed tomography (MSCT), however, this method cannot show the ThebV's morphological shape, only its size.

METHODS

301 randomly selected autopsied human hearts were examined. The shape of the valve was subjectively assessed, whereas the ThebV height (H) and the CSO diameter (D) were measured. The H/D-Ratio was computed as the ThebV height divided by the CSO diameter, afterwards k-means cluster analysis was performed to estimate H/D-Ratio's range of values between valves. MSCT scans from 114 patients that underwent CSO cannulation were objectively evaluated based on similar measured parameters in accordance with received H/D-Ratio values.

RESULTS

Boundaries of ratio evaluations between remnant and semilunar, and semilunar and fold types were 0.35 and 0.65 respectively. In MSCT scans, the ThebV was recorded in 61 cases (remnant=5.3%, semilunar=24.6%, fold=16.7%, cord=0.0%, mesh/fenestrated=7.9%). Except for the remnant and cord types, the other types appear similarly as in the cadaveric and MSCT studies. There were no differences between ThebV height and the CSO diameter in cadavers and MSCT studies.

CONCLUSION

The H/D-Ratio can be useful in assessing ThebV shape as visualized in MSCT. We give threshold values for the H/D-Ratio which easily allow the ThebV shape to be determined.