Digital Subtraction Angiography
Digital Subtraction Angiography - Related Videos
01:22
Detection of Internal Carotid Artery Narrowing Using Digital Subtraction Angiography
0 Views •
2025
Position a human patient with internal carotid stenosis, a condition characterized by narrowing of the internal carotid artery, on the imaging table for digital subtraction angiography (DSA). Insert an angiocatheter into the common carotid artery at the fourth cervical vertebra level. Capture a pre-contrast X-ray image to record background structures like bones and soft tissues using X-ray irradiation. Administer an iodine-based contrast medium into the carotid artery. The contrast medium...
04:31
Assessing Vessel Perfusion via Angiography: A Technique to Introduce Contrast Agent in Descending Aorta to Visualize Blood Vessel Perfusion in Rabbit Model
0 Views •
2025
This video describes the technique for performing angiography by injecting a contrast agent into the descending aorta to visualize blood vessel perfusion in a rabbit model. This technique helps to understand the perfusion in blood vessels with blockages and after treatment during recovery.
09:43
Measuring Reaction Time and Donders' Method of Subtraction
0 Views •
2023
Source: Laboratory of Jonathan Flombaum—Johns Hopkins University The ambition of experimental psychology is to characterize the mental events that support the human ability to solve problems, perceive the world, and turn thoughts into words and sentences. But people cannot see or feel those mental events; they cannot be weighed, combined in test tubes, or grown in a dish. Wanting to study mental life, nonetheless, Franciscus Donders, a Dutch ophthalmologist in the early 1800s, came up with a...
01:17
Time-of-Flight Magnetic Resonance Angiography to Visualize Blood Vasculature
0 Views •
2025
Position the patient's head inside the radiofrequency, or RF, coil of a magnetic resonance imaging, or MRI, machine.Initiate the time-of-flight magnetic resonance angiography or TOF MRA, a non-invasive technique for visualizing blood vessels.Select a tissue slice for imaging to visualize arteries and veins.Apply an RF pulse to excite the protons within the selected imaging slice. These protons release energy, which is detected as an MR signal.Repeated application of RF pulses saturates the MR...
10:24
Detecting Abnormalities in Choroidal Vasculature in a Mouse Model of Age-related Macular Degeneration by Time-course Indocyanine Green Angiography
0 Views •
Cited by 13 •
2014
Indocyanine Green Angiography (or ICGA) performed by tail vein injection provides high quality ICGA time course images to characterize abnormalities in mouse choroid.
FAQs
DSA uses a pre-contrast image as a reference, or mask, for subsequent images acquired after iodinated contrast reaches the circulation. Software aligns the image sequence and subtracts corresponding background information. Structures that remain strongly visible are contrast-filled vessels, improving vessel-to-background contrast for examining vascular anatomy.
Alignment ensures that anatomical structures occupy matching positions in the mask and later images. When registration is accurate, stationary background features can be removed more effectively, leaving the vascular signal. Poor alignment reduces subtraction quality and may obscure or distort vessel findings, so image matching directly influences the usefulness of the final angiographic view.
Motion can cause subtraction artifacts because the baseline mask and later contrast images no longer correspond precisely. Residual background structures may appear where anatomy has shifted, making vessels harder to interpret. Minimizing motion is therefore important when evaluating vascular anatomy, blood flow, stenosis, aneurysms, or other abnormalities.
The procedure begins with acquisition of a baseline mask image before contrast enters the circulation. Iodinated contrast is then introduced, and sequential X-ray images are captured as it passes through the vessels. The images are aligned and digitally subtracted from the mask, producing views that emphasize contrast-filled vascular structures.
The resulting images can characterize vascular anatomy and show the passage of contrast through blood vessels. This supports assessment of blood flow, stenosis, aneurysms, and other vascular abnormalities. Because background structures are reduced, the technique can reveal vessel-related findings with high vessel-to-background contrast for diagnostic evaluation and treatment planning.
In biology and clinical research, DSA provides detailed observations of vascular structure and flow while supporting image-guided endovascular procedures. Researchers and clinicians can use these views to investigate abnormal vessels, describe vascular anatomy, and plan interventions. Interpretation should also account for motion artifacts and the need to consider contrast exposure appropriately.