Coronary CT angiography

Question 1

role of CT coronary angiography

Answer 1

rule out significant CAD

Question 2

ACRIN-PA and ROMICAT II trials

Answer 2

2012 NEJM trials; early CCTA improves efficiency, clinical decision making, and shorter hospitalization

Question 3

how does EKG gating affect radiation dose

Answer 3

DLP x 0.017 to arrive at dose in millisieverts

Question 4

normal size of coronary arteries

Answer 4

3 mm

CT resolution able to grade >20% diameter stenosis; voxel resolution of 0.35-0.5 mm so 6-9 voxels

Question 5

CT stenosis grading

Answer 5

<20%, 20-50%, 50-70% and >70%

stenosis >50% considered potentially hemodynamically significant

Question 6

resolution of CT angiography for cardiac

Answer 6

0.16 mm, 18 pixels

Question 7

temporal resolution of cardiac CT

Answer 7

temporal resolution: 175 ms for rotation time of 330, single gantry rotation

temporal resolution: 75 ms, two xray sources

Question 8

desired HR for cardiac CT and patient prep/meds

Answer 8

below 60 bpm to maximize RR interval; given with beta blocker (metoprolol 5-25 mg)

sublingual nitroglycerin is also administered to dilate coronary arteries

Question 9

branches of RCA

Answer 9

RCA > SA nodal branch, Posterior descending artery, posteriolateral artery av nodal branch

> acute marginal

> conus branch

Question 10

Branches of LMCA

Answer 10

LMCA > circumflex > obtuse marginal

LMCA > ramus

LMCA > LAD and diagonal/septal branches

Question 11

coronary artery origin and most common origin anomaly

Answer 11

proximal aorta at sinuses of Valsalva
> 3 coronary artery sinuses (R, L, noncoronary)

most common anomaly is from sinotubular junction

Question 12

Course of LMCA

Answer 12

between pulmonary artery and left atrial appendange

bifurcates into LAD and LCx; ramus may also be present if trifurcation

Question 13

LAD course and branches

Answer 13

LAD courses in anterior interventricular groove

diagonal/septal branches; penetrate IV septum and anterior half of septum

Question 14

LCx artery course, branches

Answer 14

course: between left atrial appendage and left AV groove
branches: obtuse marginal (posterolateral wall of LV)

may also supply PDA (left dominant system)

Question 15

RCA course

Answer 15

right AV groove

branches: conal (RVOT), sinoatrial node branch, acute marginal, AV node branch, PDA&raquo_space; posterolateral artery (posterior LV)

Question 16

determination of cardiac dominance

Answer 16

side that supplies PDA, PLA, AV nodal branch; RCA commonly the dominant side

Question 17

malignant vs benign coronary artery anomaly

Answer 17

malignant anomaly carries risk of increased sudden death, usually with exercise

Question 18

coronary artery arising from pulmonary artery

Answer 18

malignant; either from R/L main coronary artery

• ALCAPA: anomalous left coronary artery from pulmonary artery
• ARCAPA: anomalous right coronary artery from pulmonary artery

Question 19

types of malignant coronary arteries

Answer 19

ALCAPA, ARCAPA (pulmonary artery); RCA from L coronary sinus, LMCA from R coronary sinus, LCx or LAD from R coronary sinus, artery from noncoronary sinus

Question 20

benign coronary artery courses

Answer 20

retroaortic, prepulmonic, septal coronary pulmonary artery

Question 21

malignant coronary artery course

Answer 21

interarterial course between aorta/pulmonary artery

Question 22

treatment for intramural coronary artery

Answer 22

bypass, reimplantation, unroofing procedure

Question 23

treatment for malignant interarterial course

Answer 23

surgical bypass grafting

Question 24

ALCAPA/Bland White Garland

Answer 24

anomalous left coronary artery (ALCAPA)

treat surgically with reimlantation or ligation + bypass grafting