Imaging Modalities for Renal Artery Stenosis in Suspected Renovascular Hypertension: Prospective Intraindividual Comparison of Color Doppler US, CT Angiography, GD-Enhanced MR Angiography, and Digital Substraction Angiography

Figures & data

Table 1 Distribution of findings among different methods

	TP	TN	FP	FN
US	15	87	10	5
CTA	17	98	7	1
MRA	18	97	6	2
DSA	20	112	—	—

Figure 1. MRA shows a left renal artery that has been interpreted as stenotic.

Figure 2. DSA of the same patient that demonstrates normal patency of the left renal artery.

Figure 3. Transverse color Doppler US image. The peak systolic velocity is below 100cm/sec, which is considered normal.

Figure 4. MRA demonstrates a severe stenosis, which was confirmed by DSA.

Table 2 Imaging findings of US, CTA, MRA, and DSA

Findings	US	CTA	MRA	DSA
Normal renal artery	90	92	90	98
Normal polar artery	2	7	9	13
Normal (distal) accessory artery	0	0	0	1
Atherosclerotic main renal artery stenosis	21	20	20	14
Atherosclerotic polar artery stenosis	0	0	0	2
Fibromuscular dysplasia	4	4	4	4
Invisible main renal artery	1	0	2	0
Invisible polar artery	14	9	7	0
Total number of examined arteries	117	123	123	132

Table 3 Distribution of true positive findings related to mild and severe stenosis among different methods

	Stenosis <50%	Stenosis 50–99%	FMD	Total
US	6	5	4	15
CTA	1	12	4	17
MRA	0	14	4	18
DSA	4	12	4	20

Table 4 Results of diagnostic efficacy of all three methodscompared with DSA

	Sensitivity	Specificity	Positive predictive accuracy	Negative predictive accuracy
US	75%	89.6%	60%	94.6%
CTA	94%	93%	71%	99%
MRA	90%	94.1%	75%	98%