Doctors take pictures of blood clots in arm veins using ultrasounds and venographies, and in arteries of the arm using arteriographies, according to MedicineNet. Ultrasounds produce pictures of blood clots through the mapping of sound waves, while venographies and arteriographies rely on the use of injected dyes.
During ultrasound procedures, doctors or technicians place gel on patients' arms, then wave over the arms with probes emitting sound waves through the skin, according to MedicineNet. In some cases, they may need to press the probe into the skin in order to get clear pictures of blood clots. Doctors and technicians use venographies to take pictures of blood clots in arms by injecting a contrast dye into veins in the hand, then mapping the dye as it travels through the arm to the heart. Medical professionals can take a picture of a blood clot in the arm after the dye fills the clot and it becomes visible.
To take pictures of blood clots in arm arteries, doctors use arteriographies, also known as extremity angiographies, in which they first inject an anesthetic into patients' arms, then place needles into the arteries, states MedlinePlus. Doctors then insert catheters through which a dye is injected, and pictures of blood clots are taken via X-rays. Doctors may opt to provide treatment immediately during arteriographies by dissolving blood clots in the arm or opening arteries with balloons or stents.