Step-and-Shoot: a new low radiation coronary computed tomography angiography technology: our initial experience with 125 consecutive asymptomatic patients.
BACKGROUND
Coronary CTangiography is an accurate imaging modality; however, its main drawback is the radiation dose. A new technology, the "step and shoot," which reduces the radiation up to one-eighth, is now available.


OBJECTIVE
To assess our initial experience using the "step-and-shoot" technology for various vascular pathologies.


METHODS
During a 10 month period 125 consecutive asymptomatic patients (111 men and 14 women aged 25-82, average age 54.9 years) with various clinical indications that were appropriate for step-and-shoot CCTA (regular heart rate < 65 beats/minute and body weight < 115 kg) were scanned with a 64-slice multidetector computed tomography Brilliance scanner (Philips, USA). The preparation protocol for the scan was the same as for regular coronary CTA. All examinations were interpreted by at least one experienced radiologist and one experienced interventional cardiologist. The quality of the examinations was graded from 1 (excellent imaging quality of all coronary segments) to 4 (poor quality, not diagnostic). There were 99 patients without a history of coronary intervention, 13 after coronary stent deployment (19 stents) and 3 after coronary artery bypass graft.


RESULTS
Coronary interpretation was obtained in 122 examinations (97.6%). The imaging quality obtained was as follows: 103 patients scored 1 (82.4%), 15 scored 2 (12%), 4 scored 3 (3.2%) and 3 scored 4 (2.4%). The grades were unrelated to cardiac history or type of previous examinations. Poor image quality occurred because of sudden heart rate acceleration during the scan (one patient), movement and respiration (one patient), and arrhythmia and poor scan timing (in one). Two patients were referred to percutaneous coronary intervention based on the CCTA findings, which correlated perfectly.


CONCLUSIONS
Step-and-shoot CCTA is a reliable technique and CCTA algorithm comparable to regular CCTA. This technique requires the lowest radiation dose, as compared to other coronary imaging modalities, that can be used for all CCTA indications based on the inclusion criteria of low (> 65 bpm) and stable heart rate.
Department of Diagnostic Radiology, Hasharon Hospital, Rabin Medical Center, Petah Tikva, Israel. Atareli@hotmail.com
Eli
E
Atar
Ran
R
Kornowski
Gil N
GN
Bachar
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D007472:Iohexol; C038192:iopromide