Circulatory and Vascular Imaging: Key Concepts and Techniques

What two systems make up the circulatory system?

Blood-vascular system and lymphatic system.

Which vessels carry blood away from the heart, and which carry blood toward it?

Arteries carry blood away; veins carry blood toward the heart.

What do capillaries connect, and what is their main exchange function?

They connect arterioles and venules, supplying oxygen and removing wastes.

What are the heart's two circulation circuits?

Systemic circulation and pulmonary circulation.

Which two main trunk vessels arise from the heart?

Aorta begins systemic circulation; pulmonary trunk begins pulmonary circulation.

What is the portal system?

Venous drainage from abdominal organs passes through the liver before returning to the inferior vena cava.

What type of blood does each side of the heart handle?

Right side: venous/deoxygenated blood. Left side: arterial/oxygenated blood.

What do the coronary arteries supply?

The myocardium of the heart.

How does lymph move without a pump, and what prevents backflow?

Extrinsic pressure from surrounding organs and muscles moves it; valves prevent backflow.

Trace the thoracic duct.

It extends from about L2 to the base of the neck and empties where the left subclavian and internal jugular veins join.

Angiography

Radiologic examination of vascular structures after contrast introduction.

Arteriography

Radiologic examination of arteries after radiopaque contrast injection.

Venography

Radiologic examination of veins after radiopaque contrast injection.

Claudication

Leg pain and cramping associated with vascular disease.

Stenosis

Narrowing or constriction of a vessel, most often from atherosclerosis.

Occlusion

Obstruction or closure of a vessel from causes such as atherosclerosis, thrombus, foreign material, or spasm.

Aneurysm

A weakened arterial area that balloons outward.

Why is nonionic contrast generally preferred to ionic contrast?

It causes fewer cardiovascular effects, less intense sensations, fewer allergic reactions, and is less nephrotoxic.

What findings characterize a moderate iodinated-contrast reaction in this chapter?

Hives, slight shortness of breath, and congestion.

What findings characterize a severe iodinated-contrast reaction in this chapter?

Anaphylactic shock, shallow breathing, elevated pulse, loss of consciousness, and angioedema.

What can an automatic injector control?

Injection rate, total volume, maximum pressure, and timing.

Why does an automatic injector have a time-delay setting?

To reduce the chance of catheter whiplash.

What must occur before angiography, and what medication category is excepted from the usual routine?

Explain the procedure/risks/benefits/alternatives and obtain written consent; anticoagulant therapy is not continued as a routine medication.

What are major angiographic complications listed in the deck?

Vasovagal reaction, stroke, myocardial infarction, death, puncture-site bleeding, tissue/nerve/vessel damage, and contrast reaction.

What advantages does a catheter provide during angiography?

Less extravasation risk, selective vessel injection, flexible positioning, and safe retention while images are acquired.

What is the preferred/popular access artery now, and which was historically most common?

Radial artery now; common femoral artery historically.

How does the modified Seldinger puncture differ from the classic technique shown?

Modified Seldinger punctures only the anterior arterial wall; the classic method passes through the artery and withdraws the needle until blood flow returns.

What is the basic catheter-placement sequence?

Puncture vessel → confirm blood return → insert guidewire → remove needle while controlling the wire → pass catheter over wire → remove guidewire.

Why is an introducer sheath used?

It maintains controlled vascular access for repeated catheter exchanges, limits vessel-wall trauma, and can assist vascular closure.

What do the back-bleed valve and sidearm port do?

The valve limits blood loss; the sidearm can infuse medications, monitor pressure, or inject contrast.

How is French size assigned to a sheath?

It is named for the catheter size it accepts; its outer diameter is 1.5-2 Fr larger, so a 5-Fr sheath accepts a 5-Fr catheter but measures nearly 7 Fr externally.

What length range is listed for introducer sheaths?

About 10-90 cm (4-35 inches).

Which should enter the vasculature first: guidewire or catheter?

Guidewire first; the catheter is advanced over it to reduce complications.

How do Teflon-coated and hydrophilic guidewires help?

Teflon reduces friction; hydrophilic polymer provides a smooth, pliable, highly maneuverable wire.

What is a vascular stent and how is it deployed?

A flexible metal-mesh tube mounted collapsed on a balloon; balloon inflation expands it to hold the vessel open and press plaque against the wall.

Bare-metal stent versus drug-eluting stent

A drug-eluting stent releases medication to limit tissue regrowth; a bare-metal stent has no drug coating.

With the image receptor above the table and x-ray tube below a supine patient, what projection results?

The beam enters posteriorly and exits anteriorly, producing a PA projection; AP is also commonly used.

What are the main purposes of thoracic aortography?

Evaluate congenital pathology, measure/assess aortic anatomy, and assess postinterventional or postsurgical conditions.

Which body positions are emphasized for thoracic aortography?

45° RPO or 45° LAO.

For lateral thoracic aortography, how are the arms positioned, and why is SID increased?

Move arms superiorly; increase lateral SID to reduce magnification.

Where is the CR centered for thoracic aortography?

Perpendicular to T7.

What is the injection rate for thoracic aortography?

15-25 mL/s.

What is the total contrast volume for thoracic aortography?

30-50 mL.

What are the breathing instructions for thoracic aortography?

Suspend respiration—stop breathing without taking a deep breath first.

What vessels should thoracic aortography demonstrate?

Thoracic aorta and proximal brachiocephalic, carotid, and subclavian vessels.

What must be recognized at the aortic arch on a subtracted image?

The origins of the great vessels; focal narrowing is a key sign of stenosis.

What is the main purpose of abdominal aortography?

Assess aortic anatomy/pathology before intervention or after surgery.

What are the patient setup and CR level for abdominal aortography?

Usually supine; arms superior for a lateral; CR perpendicular to L2.

What is the injection rate for abdominal aortography?

15-20 mL/s.

What is the total contrast volume for abdominal aortography?

25-40 mL.

What are the breathing instructions for abdominal aortography?

Suspend respiration.

For lateral abdominal aortography, what must be included and why may compensation filters be needed?

Include the entire abdomen anterior-to-posterior; filters compensate for superficial anterior bowel gas and the dense posterior lumbar spine.

What anatomy is demonstrated on AP abdominal aortography?

Renal artery origins, aortic bifurcation, and the course/general condition of visceral branches.

What anatomy is emphasized on lateral abdominal aortography?

Origins of the celiac artery and superior mesenteric artery.

At what vertebral level does the celiac artery arise, and what organs does it supply according to the deck?

T12; stomach, proximal duodenum, liver, spleen, and pancreas.

What bowel region is specifically listed as receiving blood from the superior mesenteric artery?

Ascending colon.

What does abdominal visceral arteriography evaluate?

Tumor vascularity and suspected atherosclerosis, thrombosis, occlusion, or bleeding.

What are the general patient position and CR rule for abdominal visceral arteriography?

Supine, with an oblique if needed; CR is perpendicular and its entrance point depends on the selected artery.

Where is the CR centered for selective celiac arteriography?

L1.

Where is the CR centered for selective hepatic arteriography?

Center of the right upper quadrant.

Where is the CR centered for selective splenic arteriography?

Center of the left upper quadrant.

Where is the CR centered for selective superior mesenteric arteriography?

L3.

Where is the CR centered for selective inferior mesenteric arteriography?

Between the descending colon and rectum.

Where is the CR centered for selective renal arteriography?

L1-L2.

Where does the CR enter for a selective left renal arteriogram?

At L1, midway between the patient's left side and the center of the spine.

What does celiac arteriography demonstrate?

The three celiac branches supplying the stomach, liver, spleen, and pancreas.

What anatomy does a renal flush aortogram demonstrate?

Right and left renal arteries, distal aorta, and aortic bifurcation.

What total contrast volume is typical for a renal flush aortogram?

20-40 mL.

What does the inferior mesenteric artery supply, and where does it arise?

Splenic flexure, descending colon, and rectosigmoid; it arises from the left side of the aorta near L3.

Which projection best displays the IMA during selective injection?

15° RAO or 15° LPO.

What are the typical patient position and projection set for pulmonary arteriography?

Supine, using AP and oblique projections; it is commonly performed before an intervention.

What is the injection rate for pulmonary arteriography?

10-20 mL/s.

What is the total contrast volume for pulmonary arteriography?

20-40 mL.

What are the breathing instructions for pulmonary arteriography?

Suspend respiration.

What anatomy does pulmonary arteriography demonstrate?

Pulmonary arteries, left atrium, left ventricle, and thoracic aorta.

Why is an aortofemoral study performed?

To assess lower-limb vascular pathology accurately.

How is the patient positioned for bilateral lower-limb arteriography?

Supine with the midsagittal plane centered.

How are the legs positioned for lower-limb arteriography?

Internally rotated 30°.

Which projections may be used for the popliteal fossa or foot during lower-limb arteriography?

AP, lateral, or both.

What are the breathing instructions for lower-limb arteriography?

Suspend respiration.

What injection rate and total contrast volume are used for lower-limb bolus arteriography?

5-10 mL/s for 40-60 mL total.

What injection rate and total contrast volume are used for stationary lower-limb DSA?

5-10 mL/s for 10-30 mL total.

Why is less contrast used for stationary DSA than for a bolus runoff?

The system remains at one station instead of chasing the bolus down the limb.

What are the main indications for upper-limb arteriography?

Traumatic injury, atherosclerotic disease, and other vascular lesions.

How is the patient positioned for upper-limb arteriography?

Supine with the arm extended and hand either supinated or pronated.

What injection rate is used for upper-limb arteriography with a distally positioned catheter?

3-4 mL/s.

What injection rate may be used for upper-limb arteriography with a proximally positioned catheter?

Up to 10 mL/s.

What is upper-limb venography commonly used to evaluate, and where is contrast injected?

Thrombosis or occlusion; inject through a superficial vein at the elbow or wrist.

What is lower-limb venography commonly used to evaluate, and where is contrast injected?

Deep-vein thrombosis before intervention; injection commonly enters the popliteal vein.

What four trunk vessels supply the brain?

Right and left common carotids plus right and left vertebral arteries.

Which vessels form anterior versus posterior circulation?

Common carotids form anterior circulation; vertebral arteries form posterior circulation.

Where do the common carotids divide, and into what vessels?

At C4 into internal and external carotid arteries.

How do the internal carotids enter the skull?

Through the carotid foramina/canals of the temporal bones.

Into which major arteries do the internal carotids bifurcate?

Anterior cerebral and middle cerebral arteries.

Trace the vertebral arteries into the basilar artery.

They ascend through cervical transverse foramina, enter through the foramen magnum, and unite to form the basilar artery.

Into what vessels does the basilar artery bifurcate?

Right and left posterior cerebral arteries.

What forms the circle of Willis?

Anterior and posterior cerebral circulations joined by communicating arteries at the midbrain level.

Which major vessels did the lecture specifically emphasize recognizing?

Anterior cerebral arteries, internal carotids, posterior cerebral arteries, basilar artery, and vertebral arteries.

What lesions is cerebral angiography used to investigate?

Aneurysms, arteriovenous malformations, tumors, atherosclerosis, and stenosis.

What projection series is listed for cerebral angiography of the aortic arch?

Simultaneous biplane oblique projections with AP and lateral imaging.