Thoracic Aortic Aneurysm
Conditions
Keywords
Suspected or confirmed, TAA, Computed tomography angiography, CTA, Contrast agent, Radiation dose, Thoracoabdominal aortic aneurysm
Brief summary
The purpose of this study is to compare the contrast agents and imaging techniques used for thoracoabdominal aortic imaging in CT. Imaging parameters and contrast volume are changed and adjusted based on the contrast agent, since contrast agents have varying iodine concentrations. If the contrast iodine concentration is higher, it may be possible to adjust the imaging parameters and lower the overall radiation dose to the patient.
Interventions
DRUGIsovue
iodine contrast
Sponsors
Duke University
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Patients undergoing thoracoabdominal aortic (TAA) CTA * Able to provide informed consent * Body Mass Index (BMI) equal to or less than 30
Exclusion criteria
* Creatinine greater than 2.0 * Allergy to contrast media * Pregnant women
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Radiation Dose | 30 minutes |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Signal to Noise Ratio | 30 minutes | Calculated as the ratio of mean attenuation values divided by the standard deviation of attenuation values gathered using a circular region of interest in the thoracic aorta. |
| Hounsfield Unit Attenuation Values | 30 minutes | Grayscale values on CT scans are given as Hounsfield units. These Hounsfield units reflect the attenuation of x-ray beams traversing the aortic lumen. We will use Hounsfield units to assess whether the tool contrast agents achieve similar attenuation characteristics essential for diagnosing aortic abnormalities. We will use circular regions of interest in the thoracic aorta to extract the Hounsfield unit measurements. |
| Variation in Contrast for the Entire Vascular System (coV) | 30 minutes | The change in contrast was measured at the proximal segment of the aorta and at the Iliac arteries for each subject. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Isovue 300 (75mL) 75mL Isovue 300 injected 120kvp, 250mAs used to obtain CT scan | 50 |
| Isovue 370 (75mL) 75mL Isovue 370 injected 100 kVp, 250 mAs used for obtaining CT | 50 |
| Isovue 370 (60mL) 60mL Isovue 370 injected 100 kVp, 240 mAs used to obtain CT | 50 |
| Total | 150 |
Baseline characteristics
| Characteristic | Isovue 300 (75mL) | Isovue 370 (75mL) | Total | Isovue 370 (60mL) |
|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 29 Participants | 35 Participants | 100 Participants | 36 Participants |
| Age, Categorical Between 18 and 65 years | 21 Participants | 15 Participants | 50 Participants | 14 Participants |
| Sex: Female, Male Female | 19 Participants | 19 Participants | 65 Participants | 27 Participants |
| Sex: Female, Male Male | 31 Participants | 31 Participants | 85 Participants | 23 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 50 | 0 / 50 | 0 / 50 |
| serious Total, serious adverse events | 0 / 50 | 0 / 50 | 0 / 50 |
Outcome results
Primary
Radiation Dose
Time frame: 30 minutes
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Isovue 300 75mL | Radiation Dose | 35.1 mSv | Standard Deviation 6.2 |
| Isovue 370 75mL | Radiation Dose | 25.4 mSv | Standard Deviation 5.3 |
| Isovue 370 60mL | Radiation Dose | 25.5 mSv | Standard Deviation 7 |
Secondary
Hounsfield Unit Attenuation Values
Grayscale values on CT scans are given as Hounsfield units. These Hounsfield units reflect the attenuation of x-ray beams traversing the aortic lumen. We will use Hounsfield units to assess whether the tool contrast agents achieve similar attenuation characteristics essential for diagnosing aortic abnormalities. We will use circular regions of interest in the thoracic aorta to extract the Hounsfield unit measurements.
Time frame: 30 minutes
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Isovue 300 75mL | Hounsfield Unit Attenuation Values | 289.7 Hounsfield units | Standard Deviation 23.8 |
| Isovue 370 75mL | Hounsfield Unit Attenuation Values | 400.9 Hounsfield units | Standard Deviation 31.1 |
| Isovue 370 60mL | Hounsfield Unit Attenuation Values | 393.9 Hounsfield units | Standard Deviation 28.1 |
Secondary
Signal to Noise Ratio
Calculated as the ratio of mean attenuation values divided by the standard deviation of attenuation values gathered using a circular region of interest in the thoracic aorta.
Time frame: 30 minutes
Population: Hiatus region of each subject group
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Isovue 300 75mL | Signal to Noise Ratio | 12.0 Signal-to-Noise Ratio | Standard Deviation 4.8 |
| Isovue 370 75mL | Signal to Noise Ratio | 11.8 Signal-to-Noise Ratio | Standard Deviation 3.5 |
| Isovue 370 60mL | Signal to Noise Ratio | 13.8 Signal-to-Noise Ratio | Standard Deviation 6.3 |
Secondary
Variation in Contrast for the Entire Vascular System (coV)
The change in contrast was measured at the proximal segment of the aorta and at the Iliac arteries for each subject.
Time frame: 30 minutes
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Isovue 300 75mL | Variation in Contrast for the Entire Vascular System (coV) | 0.113 unitless | Standard Deviation 0.073 |
| Isovue 370 75mL | Variation in Contrast for the Entire Vascular System (coV) | 0.124 unitless | Standard Deviation 0.063 |
| Isovue 370 60mL | Variation in Contrast for the Entire Vascular System (coV) | 0.107 unitless | Standard Deviation 0.059 |