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
NON_RANDOMIZED
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
317
a single bolus injection of approx. 0.1mmol/kg
Unnamed facility
Tucson, Arizona, United States
Unnamed facility
Los Angeles, California, United States
Unnamed facility
Los Angeles, California, United States
Unnamed facility
Orange, California, United States
Unnamed facility
Jacksonville, Florida, 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 (reader 1, 2 and 3) and majority readers (the outcome determined by at least two of the blinded readers). The segments were predefined to standardize the blinded reader evaluations. A segment was assessable if it was visualized along its entire length and if any region of stenosis, was measured reliably. There were 6 segments assessed per participant (3 segments in the right renal artery and 3 segments in the left renal artery) and up to 9 segments in participants with renal transplant.
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 50 to 99 percent (%) stenosis of a segment, but not occluded as assessed by the SoR. For each segment, the most severe stenosis/narrowing was identified and considered for the evaluation of clinically significant disease.
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 (stenosis) was defined as 50 to 99 percent (%) stenosis of a segment, but not occluded as assessed by the SoR. For each segment, the most severe stenosis/narrowing was identified and considered for the evaluation of clinically significant disease. Specificity = percentage of participants for which the imaging modalities (unenhanced or gadobutrol-enhanced) in the detection and exclusion of clinically significant stenosis.
Time frame: Images were taken pre-injection and post-injection
Minimum Gadobutrol Performance for Sensitivity: Sensitivity More Than (>) 50%
Clinically significant disease was defined as \>50% stenosis of a segment, but not occluded as assessed by the SoR. 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 (stenosis) was defined as \>50% stenosis of a segment, but not occluded as assessed by the SoR. 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
Length of the Right and Left Renal Arteries Assessed by Gadobutrol-enhanced MRA and Unenhanced MRA - Blinded Reader
The length of the left and right renal arteries were measured from the origin at the aorta to the bifurcation into the upper and lower pole arteries or the most distal point of the renal artery which could be visualized. This distal margin was the point where the diameter was still assessable. If there were more than 2 distal branches then the first large branch that was the dominant supply to a renal pole was used as the distal point.
Time frame: Images were taken pre-injection and post-injection
Length of the Right and Left Renal Arteries Assessed by Computed Tomographic Angiography (CTA) - Blinded Reader
The length of the left and right renal arteries were measured from the origin at the aorta to the bifurcation into the upper and lower pole arteries or the most distal point of the renal artery which could be visualized. This distal margin was the point where the diameter was still assessable. If there were more than 2 distal branches then the first large branch that was the dominant supply to a renal pole was used as the distal point.
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 the ease of expression, the following abbreviations will be used: Diameter (DIA), Blinded Reader (BR).
Time frame: Images were taken pre-injection and post-injection
The Percentage of Location of Stenosis >= 50% (Within and Beyond 5 Millimeter From the Aorta) in the Proximal Segments Assessed by Gadobutrol-Enhanced MRA and Unenhanced MRA
Location within the right and left proximal segment was based on the point of greatest stenosis and was recorded for stenosis \>=50% as: - Within 5 mm of the aorta (or occlusion proximal to the origin of the segment); - Beyond 5 mm from the aorta.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Miami, Florida, United States
Unnamed facility
Savannah, Georgia, United States
Unnamed facility
Chicago, Illinois, United States
Unnamed facility
Baltimore, Maryland, United States
Unnamed facility
Durham, North Carolina, United States
...and 60 more locations
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 Assessed by Gadobutrol-enhanced MRA and Unenhanced MRA 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 Assessed by Gadobutrol-enhanced MRA and Unenhanced MRA 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 Assessed by Gadobutrol-enhanced MRA and Unenhanced MRA 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).
Time frame: Images were taken pre-injection and post-injection
The Percentage of Accessory (Non-dominant) Renal Artery Presence Assessed by Gadobutrol-Enhanced MRA and Unenhanced MRA
An accessory renal artery was defined as an additional, non-dominant, renal artery typically emanating from the aorta and anastomosing distal to the proximal third, segment of that renal artery. It was recorded only as present or absent on the right and left, regardless of how many accessory renal arteries were present.
Time frame: Images were taken pre-injection and post-injection
The Presence of Any Aneurysmal Dilatation in Each Segment (Proximal, Mid- and Distal) in the Right and the Left Renal Arteries Assessed by Gadobutrol-Enhanced MRA and Unenhanced MRA
Any focal dilatation (aneurysmal dilatation) of a segment was recorded. The diameter at the widest point was measured with the electronic calipers if a dilatation was present in any segment. The number of participants with an aneurysmal dilatation in each segment (proximal, mid- and distal) in the right and the left renal arteries assessed by gadobutrol-enhanced MRA and unenhanced MRA were reported.
Time frame: Images were taken pre-injection and post-injection
The Percentage of Participants With Diagnosis of Fibromuscular Dysplasia and Arteriosclerosis Assessed by Gadobutrol-Enhanced MRA and Unenhanced MRA
Any focal dilatation (aneurysmal dilatation) of a segment was recorded. The diameter at the widest point was measured with the electronic calipers if a dilatation was present in any segment. The number of participants with an aneurysmal dilatation in each segment (proximal, mid- and distal) in the right and the left renal arteries assessed by gadobutrol-enhanced MRA and unenhanced MRA were reported.
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; 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 Gadobutrol-Enhanced and Unenhanced 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 had recommended an additional imaging study for each participant, and the data were 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 Gadobutrol-Enhanced and Unenhanced 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 Gadobutrol-Enhanced and Unenhanced 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 Gadobutrol-Enhanced and Unenhanced 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