An observational study in Descending Aortic Aneurysm, Ultrasound and Accuracy, sponsored by Imperial College London. Not yet recruiting at 1 site in United Kingdom. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-07.
Sponsored by Imperial College London · Observational
The goal of this observational study is to assess the applicability of non-invasive ultrasound in aneurysms of the descending thoracic aorta.
The main question it aims to answer is:
What is the feasibility of Ultrasound to visualise the Descending Thoracic Aorta, and can this imaging modality accurately measure the maximum size of aneurysms and residual sacs with acceptable reproducibility?
Participants are having their diagnosis confirmed or excluded by conventional imaging techniques (CT scans). Participants receive exactly the same standard of care regardless of their participation. The study offers an additional ultrasound scan, and the results will be compared with previous imaging.
Aneurysms of the aortic artery are a significant public health issue. The number of newly diagnosed aneurysms of the thoracic aorta is on the rise, and aneurysm rupture is a catastrophic event associated with high mortality rates. The most proximal sections of the aorta (ascending and the aortic arch) are routinely scanned by echocardiography practitioners. The abdominal aorta is also easily visualised on transabdominal ultrasound, and there is a screening programme in the UK that is highly cost-effective and reduced the aneurysm-related number of deaths. However, the portion of the aorta in the chest (descending thoracic aorta) is not routinely assessed by ultrasound practitioners.
The diagnosis of descending thoracic aneurysms relies mostly on imaging techniques that use ionising radiation. In addition, these techniques are expensive and may not be widely available in some regions. In contrast, ultrasound is a non-invasive technique that allows visualisation of most parts of the body. Ultrasound machine suppliers have invested in better systems and transducers over the years and visualisation of the descending thoracic aorta may now be possible.
The main aims of this study are to assess the feasibility (Part 1), accuracy (Part 2) and reproducibility (Part 3) ultrasound in the diagnosis and monitoring of descending thoracic aortic aneurysms. Participants will be recruited from the vascular lab and outpatient clinics, and diameters of the descending thoracic aorta will be measured with non-invasive ultrasound. Data obtained from study measurements will be compared with computed tomography scans that patients had as part of their standard of care.
If the feasibility, accuracy and reproducibility of Ultrasound are clearly demonstrated, routine ultrasound scans of the descending thoracic aorta may be suggested.
222 studies on the registry are indexed under Aortic Aneurysm; 63 are open to participants now.
This study's planned enrollment of 60 is below the median of 150 across 117 observational studies indexed under Aortic Aneurysm.
Browse Aortic Aneurysm studies →Imperial College London is the lead sponsor of 843 studies on the registry; 180 are open to participants now.
Of its 9 completed or terminated interventional studies of FDA-regulated products, 6 (67%) have results posted.
Counted across the registry records on this site, refreshed daily.
All Participants will receive a single Ultrasound scan as part of this study. All Patients had at least one CT scan of the thoracic aorta prior to the study as part of their standard of care. No additional radiation or invasive imaging techniques will be used in the Thorus study. The data obtained from the CT will be analysed by an independent reviewer and compared with Ultrasound measurements. Participants will be recruited prospectively from a single NHS Trust in London - Imperial College Healthcare NHS Trust.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients with healthy DTA (30 patients)
Patients with DTAA or TEVAR (30 patients)
Part 1 - Feasibility - Proportion of participants with successful ultrasound measurement of the diameter of the descending thoracic aorta
Number and percentage of participants in whom the descending thoracic aortic diameter can be obtained by transthoracic ultrasound. The units of Measure are total number and percentages.
Time frame: Day 1 - At the single ultrasound study visit.
Part 1 - Feasibility - Length of the descending thoracic aorta by Ultrasound
Total length of the descending thoracic aorta from the aortic isthmus to the coeliac axis. The unit of Measure is Centimetres (cms).
Time frame: Day 1 - At the single ultrasound study visit.
Part 1 - Feasibility - Ultrasound Quality Score
Number of ultrasound windows that allow visualisation of the descending thoracic aorta (0 to 3 windows) and allocation of a quality score. The Unit of Measure is a score created for this study (0-Windows: No views; 1 window: Poor; 2 windows: Moderate; 3 windows: Good). Higher scores mean better image quality.
Time frame: Day 1 - At the single ultrasound study visit.
Part 2 - Accuracy - Comparision between Transthoracic Ultrasound and CT
Calculate mean differences and limits of agreement between TUS and CT. Achieve high sensitivity and specificity.
Time frame: Day 1 - At the single ultrasound study visit.
Part 3 - Reproducibility - Intraclass correlation coefficient
Calculate inter- and intra-operator variability by intraclass correlation coefficient (ICC). The study aims to achieve good or excellent reliability.
Time frame: Day 1 - At the single ultrasound study visit.
Part 1 - Feasibility - Factors limiting visualisation of the Descending Thoracic Aorta
Number and percentages of participants in whom limiting factors such as body habitus or rib shadowing are reported after the ultrasound test. The units of measure are the number of participants with raised BMI (kg/m\^2) and acoustic shadowing due to bone density.
Time frame: Day 1 - At the single ultrasound study visit.
Part 1 - Feasibility - Duration of Ultrasound Examination
Total time needed to complete the ultrasound scan of the descending thoracic aorta. The unit of measure is minutes.
Time frame: Day 1 - At the single ultrasound study visit.
Part 1 - Feasibility - Patient Feedback Questionnaire
Scores are obtained from the patient feedback questionnaire that was created specifically for this study and consists of 5 questions relating to comfort, tolerability and overall experience of the ultrasound scan. The unit of measure is a score ranging from 1-Strongly Disagree to 5-Strongly Agree. Higher scores mean better patient satisfaction.
Time frame: Day 1 - At the single ultrasound study visit.
Plan to share: No — Sharing IPD is not required to answer the research question.
No publications or documents are linked to this record.
Start is estimated for Sep 2026; primary completion for Apr 2027, 6 months later.
Of 44 observational studies under Aortic Aneurysm, half reached primary completion within 67 months of starting (the median), counting those still running; a quarter within 23 and three quarters within 107. This study's planned 6 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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