Ladder-Like Low Iodine Delivery Rate Injection Protocols Based on BMI at 70 KV by Automated Tube Voltage Selection in Coronary CTA

Table 5

Comparison with the unit of BMI subgroups.

Vessel segment	Group	≤20	20–21	21–22	22–23	23–24	24–25	25–26
Aortic root	Experimental group	537 ± 102	533 ± 89	494 ± 77	525 ± 65	530 ± 81	540 ± 68	504 ± 90
	Control group	690 ± 84	618 ± 104	624 ± 89	636 ± 55	624 ± 65	650 ± 89	598 ± 98
	t	−5.65	−3.25	−4.45	−6.48	−4.47	−3.88	−3.65
	P	0.001	0.004	0.001	0.001	0.001	0.001	0.002
Proximal RCA	Experimental group	485 ± 101	490 ± 84	444 ± 85	471 ± 78	480 ± 90	496 ± 87	448 ± 99
	Control group	705 ± 115	628 ± 123	630 ± 82	632 ± 62	651 ± 77	647 ± 84	599 ± 127
	t	−6.95	−5.03	−6.59	−8.04	−6.89	−5.09	−6.05
	P	0.001	0.001	0.001	0.001	0.001	0.001	0.001
Mid-RCA	Experimental group	444 ± 114	438 ± 83	433 ± 94	441 ± 82	441 ± 93	475 ± 107	410 ± 113
	Control group	681 ± 107	603 ± 136	582 ± 106	614 ± 80	629 ± 59	615 ± 83	564 ± 106
	t/Z	−6.60	−5.45	−4.80	−6.75	−9.33	−3.80	−3.77^a
	P	0.001	0.001	0.001	0.001	0.001	0.001	0.001
Distal RCA	Experimental group	395 ± 74	357 ± 75	392 ± 109	398 ± 86	389 ± 80	423 ± 126	380 ± 100
	Control group	619 ± 124	565 ± 147	553 ± 130	596 ± 93	575 ± 92	619 ± 94	545 ± 123
	t	−7.21	−8.09	−3.80	−6.76	−6.92	−4.61	−5.27
	P	0.001	0.001	0.001	0.001	0.001	0.001	0.001
Proximal LAD	Experimental group	506 ± 90	480 ± 90	471 ± 90	491 ± 71	515 ± 84	518 ± 62	458 ± 87
	Control group	638 ± 104	585 ± 109	603 ± 86	590 ± 69	593 ± 69	647 ± 95	558 ± 104
	t	−4.46	−3.12	−4.10	−5.20	−3.42	−3.48	−3.88
	P	0.001	0.006	0.001	0.001	0.003	0.002	0.001
Mid-LAD	Experimental group	444 ± 114	438 ± 83	433 ± 94	441 ± 82	441 ± 93	475 ± 107	410 ± 113
	Control group	610 ± 97	552 ± 96	559 ± 77	546 ± 76	557 ± 89	560 ± 102	507 ± 97
	t	−5.04	−4.66	−4.76	−4.45	−4.31	−2.32	−3.75
	P	0.001	0.001	0.001	0.001	0.001	0.032	0.001
Distal LAD	Experimental group	359 ± 80	345 ± 63	342 ± 91	366 ± 77	362 ± 64	392 ± 73	377 ± 75
	Control group	529 ± 97	471 ± 104	455 ± 92	494 ± 63	475 ± 84	484 ± 126	467 ± 74
	t/Z	−5.60	−4.75	−3.30^a	−5.41	−4.71	−2.68	−4.21
	P	0.001	0.001	0.001	0.001	0.001	0.015	0.001
Proximal LCX	Experimental group	483 ± 84	472 ± 76	446 ± 90	482 ± 70	498 ± 91	506 ± 72	464 ± 94
	Control group	633 ± 135	565 ± 95	567 ± 88	588 ± 69	582 ± 72	592 ± 95	565 ± 95
	t/Z	−4.20	−4.04	−3.89	−5.38	−2.65^a	−2.82	−4.00
	P	0.001	0.001	0.001	0.001	0.008	0.011	0.001
Distal LCX	Experimental group	393 ± 94	354 ± 64	334 ± 97	382 ± 76	373 ± 64	393 ± 71	374 ± 78
	Control group	497 ± 127	477 ± 103	487 ± 90	479 ± 96	493 ± 78	486 ± 76	472 ± 91
	t	−2.90	−5.11	−5.14	−3.61	−5.21	−3.39	−4.97
	P	0.009	0.001	0.001	0.002	0.001	0.003	0.001

a: using the Wilcoxon rank-sum test. A difference exists in mid-RCA and mid-LAD of the control group. Mid-RCA Dunnett’s T3 test shows that BMI ≤ 20 subgroup differs from the 25 to 26 subgroup ( = 0.026 ＜ 0.05). LSD method shows BMI ≤ 20 subgroup differs from 20 to 21, 22–23, and 25–26 subgroups of mid-LAD ( = 0.045, 0.026, 0.001).