Subjects referred for a routine CTA (computed tomography angiography) or MRA (magnetic resonance angiography) will be invited to participate in the study and subjects will be involved in the study for between 2 and 12 days. Two to three visits to the study doctor will be required. This study will compare the diagnostic results of Gadobutrol enhanced MRA images with MRA images taken without contrast agent using images from a CTA as the standard of reference, which may have been performed up to 60 days prior to enrolment. If a CTA has not been performed in this prior time period, a CTA is required for the study. MRA and CTA images will be collected for an independent review (blinded read).
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
479
A single bolus injection of approx. 0.1mmol/kg
Unnamed facility
Tucson, Arizona, United States
Unnamed facility
Jacksonville, Florida, United States
Unnamed facility
Savannah, Georgia, United States
Unnamed facility
Louisville, Kentucky, United States
Unnamed facility
Baltimore, Maryland, United States
Unnamed facility
Percentage of Assessable Vascular Segments Using Gadobutrol-Enhanced MRA and Unenhanced MRA
Each vascular segment was visualized using unenhanced MRA and gadobutrol-enhanced MRA, characterized by the on-site investigators, three independent blinded readers (BR) (BR 1, BR 2 and BR 3) and majority readers (the outcome determined by at least two of the blinded readers). A segment was assessable if it was visualized along its entire length and if any region of stenosis, was measured reliably. There were 21 segments of the supra-aortic arteries assessed per participant.
Time frame: Images were taken pre-injection and post-injection
Sensitivity for Detection of Clinically Significant Disease Using Gadobutrol-Enhanced MRA and Unenhanced MRA
Clinically significant disease was defined as 70 to 99% stenosis of a segment, but not occluded, as assessed by the standard of reference (SoR) (computed tomographic angiography \[CTA\]; blinded readers). This was determined using the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. For each segment, the most severe stenosis/narrowing was identified and considered for the evaluation of clinically significant disease. In case of multiple stenosis in any one segment, the most severe stenosis in the segment was recorded.
Time frame: Images were taken pre-injection and post-injection
Specificity for Exclusion of Clinically Significant Disease Using Gadobutrol-Enhanced MRA and Unenhanced MRA
Clinically significant disease was defined as 70 to 99% stenosis of a segment, but not occluded, as assessed by the SoR (CTA; blinded readers). This was determined using the NASCET criteria. For each segment, the most severe stenosis/narrowing was identified and considered for the evaluation of clinically significant disease. In case of multiple stenosis in any one segment, the most severe stenosis in the segment was recorded.
Time frame: Images were taken pre-injection and post-injection
Minimum Gadobutrol Performance for Sensitivity: Sensitivity > 50%
Clinically significant disease was defined as 70 to 99% stenosis of a segment, but not occluded as assessed by the SoR (CTA; blinded readers). For each segment, the most severe stenosis/narrowing was identified and considered for the evaluation of clinically significant disease. Gadobutrol minimum performance criteria was based on a stenosis of 50% calculated from the native vessel diameter.
Time frame: Images were taken pre-injection and post-injection
Minimum Gadobutrol Performance for Specificity: Specificity > 50%
Clinically significant disease was defined as 70 to 99% stenosis of a segment, but not occluded as assessed by the SoR (CTA; blinded readers). For each segment, the most severe stenosis/narrowing was identified and considered for the evaluation of clinically significant disease. Gadobutrol minimum performance criteria was based on a stenosis of 50% calculated from the native vessel diameter.
Time frame: Images were taken pre-injection and post-injection
Vessel Diameter (Millimeter [mm]) at the Normal Point and the Narrowest Point in Gadobutrol-Enhanced MRA, Unenhanced MRA and CTA Images
The segment reduction in diameter (DIA) of greater than 10% was considered abnormal and measured. The diameter of each of these abnormal segments was measured using electronic calipers (perpendicular to the long axis of the vessel) at the point of most severe stenosis within each segment. Mean of vessel diameters was calculated by segment separately for CTA and MRA readers. For ease of expression, the following abbreviations will be used: Diameter (DIA), Blinded Reader (BR), Clinical Investigator (CI).
Time frame: Images were taken pre-injection and post-injection
The Percentage of Segments With Artifacts Presence
Artifacts were collected for the MRA images on a segmental basis.
Time frame: Images were taken pre-injection and post-injection
Types of Artifacts on a Segment Basis by Blinded Reader 1
The following types of artifacts were considered: Motion artifact (including pulsatility, breathing, swallowing), venous opacification, saturation artifact (for example \[eg\], in-plane flow, turbulence, dephasing, saturation band), susceptibility artifacts (including devices, eg, stents), ringing artifact (eg, bands), bolus timing error, and other (artifact not specified above or no artifact).
Time frame: Images were taken pre-injection and post-injection
Types of Artifacts on a Segment Basis by Blinded Reader 2
The following types of artifacts were considered: Motion artifact (including pulsatility, breathing, swallowing), venous opacification, saturation artifact (for example \[eg\], in-plane flow, turbulence, dephasing, saturation band), susceptibility artifacts (including devices, eg, stents), ringing artifact (eg, bands), bolus timing error, and other (artifact not specified above or no artifact).
Time frame: Images were taken pre-injection and post-injection
Types of Artifacts on a Segment Basis by Blinded Reader 3
The following types of artifacts were considered: Motion artifact (including pulsatility, breathing, swallowing), venous opacification, saturation artifact (for example \[eg\], in-plane flow, turbulence, dephasing, saturation band), susceptibility artifacts (including devices, eg, stents), ringing artifact (eg, bands), bolus timing error, and other (artifact not specified above or no artifact).
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Boston, Massachusetts, United States
Unnamed facility
Ann Arbor, Michigan, United States
Unnamed facility
Jackson, Mississippi, United States
Unnamed facility
Rochester, New York, United States
Unnamed facility
The Bronx, New York, United States
...and 46 more locations
Time frame: Images were taken pre-injection and post-injection
The Percentage of Location of Stenosis (>=70%) in the Proximal Segments Assessed by Gadobutrol-Enhanced MRA and Unenhanced MRA
Location within a segment was based on the point of greatest stenosis and was recorded for stenosis \>=70% (including occlusions) as: - At the bifurcation or proximal origin of a segment (occlusion proximal to the origin of the segment); - Within 5 mm of the bifurcation or proximal origin of a segment; - Beyond 5 mm from the bifurcation or proximal origin of a segment.
Time frame: Images were taken pre-injection and post-injection
Length of Stenosis (>=70%) in the Proximal Segments Assessed by Gadobutrol-Enhanced MRA and Unenhanced MRA
The length of stenosis was based on the most proximal (first point) in a segment where a stenosis exceeded 10% and the most distal point (last point) in the segment where a stenosis exceeded 10%. If a stenosis spanned more than one segment then the measurement was only included to the beginning or end (boundary) of the segment being evaluated. If there was no stenosis of \>=70% in a segment then the length was designated as 0.
Time frame: Images were taken pre-injection and post-injection
The Percentage of Presence of Secondary Radiologic Indicators for Diagnosis of Clinically Relevant Disease
Each segment was assessed for secondary signs of stenosis for diagnosis of clinically significant disease. The following indicators were considered for the MRA studies: - post-stenotic dilation or ulceration (segmental), - post-stenotic signal dropout, narrowing and intensity reduction, and - thrombus. Each of the three parameters were assessed as present or absent in the region distal to the stenosis. If they were found in any segment distal to the stenosis then they were assessed as present.
Time frame: Images were taken pre-injection and post-injection
Type of Secondary Radiologic Indicators for Diagnosis of Clinically Relevant Disease
Each segment was assessed for secondary signs of stenosis for diagnosis of clinically significant disease. The following indicators were considered for the MRA studies: - post-stenotic dilation or ulceration (segmental), - post-stenotic signal dropout, narrowing and intensity reduction, and - thrombus. Each of the three parameters were assessed as present or absent in the region distal to the stenosis. If they were found in any segment distal to the stenosis then they were assessed as present. If there were tandem (serial) stenosis in a vessel then the secondary signs were assigned to the stenosis of \>=70% that was proximal and closest in proximity to the secondary sign.
Time frame: Images were taken pre-injection and post-injection
Diagnostic Confidence by the Blinded Readers Using Gadobutrol-Enhanced MRA and Unenhanced MRA
Diagnostic confidence was evaluated to determine the level of certainty that the blinded readers assigned to a diagnosis for each segment. This was defined as the degree of confidence that the information on the MRA images represented the true and complete clinical picture of a particular segment. The degree of confidence was rated on a 4-point scale: 1 = Not confident, 2 = Somewhat confident, 3 = Confident, and 4 = Very confident.
Time frame: Images were taken pre-injection and post-injection
The Percentage of Participants With Additional Imaging Studies Recommended by the Blinded Readers and the Clinical Investigator After Evaluation of the Unenhanced and Gadobutrol-Enhanced MRA Images
A measure of diagnostic value was the reduction in the number of additional diagnostic imaging studies recommended/ordered. The clinical investigators and the blinded readers were asked if they would have recommended an additional imaging study for each participant and was recorded.
Time frame: Images were taken pre-injection and post-injection
Types of Additional Imaging Studies Recommended by the Blinded Readers After Evaluation of the Unenhanced and Gadobutrol-Enhanced MRA Images - Blinded Reader 1
An additional imaging study recommended was specified from the following list: Non-contrast MRA, Contrast-enhanced MRA, CTA, Ultrasound, Digital subtraction catheter angiogram (DSCA), and Nuclear medicine study.
Time frame: Images were taken pre-injection and post-injection
Types of Additional Imaging Studies Recommended by the Blinded Readers After Evaluation of the Unenhanced and Gadobutrol-Enhanced MRA Images - Blinded Reader 2
An additional imaging study recommended was specified from the following list: Non-contrast MRA, Contrast-enhanced MRA, CTA, Ultrasound, Digital subtraction catheter angiogram (DSCA), and Nuclear medicine study.
Time frame: Images were taken pre-injection and post-injection
Types of Additional Imaging Studies Recommended by the Blinded Readers After Evaluation of the Unenhanced and Gadobutrol-Enhanced MRA Images - Blinded Reader 3
An additional imaging study recommended was specified from the following list: Non-contrast MRA, Contrast-enhanced MRA, CTA, Ultrasound, Digital subtraction catheter angiogram (DSCA), and Nuclear medicine study.
Time frame: Images were taken pre-injection and post-injection
Types of Additional Imaging Studies Recommended by the Clinical Investigator After Evaluation of the Unenhanced and Gadobutrol-Enhanced MRA Images
An additional imaging study recommended was specified from the following list: Non-contrast MRA, Contrast-enhanced MRA, CTA, Ultrasound, Digital subtraction catheter angiogram (DSCA), and Nuclear medicine study.
Time frame: Images were taken pre-injection and post-injection