Coronary CT angiography Flashcards
role of CT coronary angiography
rule out significant CAD
ACRIN-PA and ROMICAT II trials
2012 NEJM trials; early CCTA improves efficiency, clinical decision making, and shorter hospitalization
how does EKG gating affect radiation dose
DLP x 0.017 to arrive at dose in millisieverts
normal size of coronary arteries
3 mm
CT resolution able to grade >20% diameter stenosis; voxel resolution of 0.35-0.5 mm so 6-9 voxels
CT stenosis grading
<20%, 20-50%, 50-70% and >70%
stenosis >50% considered potentially hemodynamically significant
resolution of CT angiography for cardiac
0.16 mm, 18 pixels
temporal resolution of cardiac CT
temporal resolution: 175 ms for rotation time of 330, single gantry rotation
temporal resolution: 75 ms, two xray sources
desired HR for cardiac CT and patient prep/meds
below 60 bpm to maximize RR interval; given with beta blocker (metoprolol 5-25 mg)
sublingual nitroglycerin is also administered to dilate coronary arteries
branches of RCA
RCA > SA nodal branch, Posterior descending artery, posteriolateral artery av nodal branch
> acute marginal
> conus branch
Branches of LMCA
LMCA > circumflex > obtuse marginal
LMCA > ramus
LMCA > LAD and diagonal/septal branches
coronary artery origin and most common origin anomaly
proximal aorta at sinuses of Valsalva
> 3 coronary artery sinuses (R, L, noncoronary)
most common anomaly is from sinotubular junction
Course of LMCA
between pulmonary artery and left atrial appendange
bifurcates into LAD and LCx; ramus may also be present if trifurcation
LAD course and branches
LAD courses in anterior interventricular groove
diagonal/septal branches; penetrate IV septum and anterior half of septum
LCx artery course, branches
course: between left atrial appendage and left AV groove
branches: obtuse marginal (posterolateral wall of LV)
may also supply PDA (left dominant system)
RCA course
right AV groove
branches: conal (RVOT), sinoatrial node branch, acute marginal, AV node branch, PDA»_space; posterolateral artery (posterior LV)
determination of cardiac dominance
side that supplies PDA, PLA, AV nodal branch; RCA commonly the dominant side
malignant vs benign coronary artery anomaly
malignant anomaly carries risk of increased sudden death, usually with exercise
coronary artery arising from pulmonary artery
malignant; either from R/L main coronary artery
- ALCAPA: anomalous left coronary artery from pulmonary artery
- ARCAPA: anomalous right coronary artery from pulmonary artery
types of malignant coronary arteries
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
benign coronary artery courses
retroaortic, prepulmonic, septal coronary pulmonary artery
malignant coronary artery course
interarterial course between aorta/pulmonary artery
treatment for intramural coronary artery
bypass, reimplantation, unroofing procedure
treatment for malignant interarterial course
surgical bypass grafting
ALCAPA/Bland White Garland
anomalous left coronary artery (ALCAPA)
treat surgically with reimlantation or ligation + bypass grafting
