It heavily depends on the body part and the indication. For lower extremities and sometimes neck, it's most often looking for areas of stenosis, the degree of stenosis, or vascular occlusion. For head and neck CT angiogram in the acute setting with suspected stroke, it's looking for vascular occlusion of large vessels. For CT angiograms for a head bleed, it's looking for aneurysms or sources of potential bleeding. Patients with a syndromic condition may be looking for aneurysms.

A broad summary would be abnormalities of arteries such as stenosis due to atherosclerotic disease, occlusion due to an embolic or thrombotic source, or aneurysmal dilation. It heavily depends on the body part and indication.

First I like to describe the anatomy.

Then,

For any arterial stenosis: Ostial caliber at the origin, Prestenotic caliber, degree of stenosis , length of stenosed segment, post stenotic caliber, degree of positive remodelling by a plaque, ulcerations/ fissured plaque, collateral channels.

Other findings : Aneurysm , AV malformation, feeders, draining veins etc.

David H Ballard Thank you for your response. I am interested in finding the parameters for CT Angiogram done for the heart to diagnose blockage

CT Coronary Calcium Scoring:   • LMA = (), LAD = (), LCX = (), RCA = (), PDA = ()   

• Total calcium score = () using the AJ-130 method and () volume score   • () percentile rank for age and gender, meaning that ()% of patients of the same age and gender will have a higher score

Coronary CT Angiography:  

 • Coronary arterial dominance (right, left, codominant)  

 • Left main, LAD and diagonals, LCX and obtuse marginal, RCA and posterior descending, ramus intermedius, and any anatomic variants  

 • Quantification of stenoses (mild < 50%/mod 50–70%/severe > 70%)

Cardiac Structure, Morphology, and Function:   

• Evaluation of short- and long-axis LV cines demonstrates (normal regional left ventricular wall motion) or (hypokinesis, akinesis, or dyskinesis; specify wall or if global)   

• LV functional parameters: end-diastolic volume, end-systolic volume, stroke volume, cardiac output, ejection fraction, LV mass

Coronary Arteries:  

 • Calcium score with age/sex percentile rank   • Coronary artery origin, course, and dominance   • Atherosclerosis (plaque composition, luminal narrowing)

Noncoronary Cardiovascular Structures:   

• Quantitative evaluation of left ventricle (LV)     

 – Stroke volume (SV),

ejection fraction (EF),

cardiac output (CO),

end-diastolic and end-systolic volumes (EDV and ESV)   

• Qualitative evaluation of LV wall motion   

• Cardiac chamber size and morphology (LV mass)   

• Cardiac valve morphology  

 • Pericardium  

 • Other cardiovascular structures      – Aorta, pulmonary artery tree, and pulmonary veins      – Superior and inferior venae cavae      – Coronary veins

Noncardiovascular Structures:   • Lungs, pleura, airways   • Esophagus, mediastinal and hilar lymph nodes   • Diaphragm, body wall including osseous structures   • Upper abdominal contents (organs, bowel loops, mesentery)

Summary:   1. Total coronary calcium score = ().   2. (Normal coronary arteries or specify abnormality).   3. (Normal or abnormal) left ventricular wall motion. LV ejection fraction = ().   4. (Normal or abnormal) cardiac chamber size

Ishan Kumar Thank you so much for the insight. Would appreciate if you could answer these questions too:

1. How to calculate percentile rank of age and gender?

2. In point 2 of summary, what contributes to a patient developing an abnormal artery?

3. Could you give us an idea of the range in which all these values usually fall under?

The percentile can be calculated on the MESA website

(http://www.mesa-nhlbi.org/Calcium/input.aspx)

abnormality in coronary includes - anatomical abnormality (origin or course),   • Atherosclerosis (plaque composition, luminal narrowing), calcium score .

Ishan Kumar

1. Is there a particular formula to calculate the calcium score?

2. Does cardiac chamber size and family history of coronary disease affect the angioplasty procedure in any way?

Thank you in advance.

The calculation is based on the weighted density score given to the highest attenuation value (HU) multiplied by the area of the calcification speck.

Density factor

• 130-199 HU: 1
• 200-299 HU: 2
• 300-399 HU: 3
• 400+ HU: 4

if a calcified speck has a maximum attenuation value of 300 HU and occupies 5 sq mm area, then its calcium score will be 15.

The score of every calcified speck is summed up to give the total calcium score.

Ishan Kumar Thank you. Also

1. What is the size range between which most heart blocks fall?

2. What's the average size?

• A score of 401 -999 is associated with relative risk of 7.2 for any major cardiovascular event.
• 100-400-relative risk of 4.3
• 401-999-relative risk of 7.2
• 1000-relative risk of 10.8