Normal renal artery spectral Doppler waveform: a closer look.
OBJECTIVE
To characterize the spectral Doppler tracing of the normal renal artery.


METHODS
Doppler tracings were obtained from a phantom of a vessel with variable compliance and from the kidneys of 15 healthy volunteers.


RESULTS
In the phantom, vascular compliance had the following effects on systolic flow velocity patterns: low compliance, little change in the sharp appearance of the systolic component of the transmitted pulse; mildly increased compliance, down-stream dampening of early systolic acceleration (ESA) with the appearance of a sharp early systolic transmitted peak and of a more rounded late systolic compliance peak; high compliance, delayed and diminished transmitted peak that eventually disappeared within the enlarging down-stream compliance peak. Healthy subjects with compliant vessels had greater ESA and more frequently visualized early systolic peaks in the renal hilum than in the renal sinus.


CONCLUSIONS
Absence of a discrete early systolic peak is a normal finding in young patients, especially in the more distal interlobar arteries. Loss of the early systolic peak may be explained on the basis of vascular compliance.
Halpern
E J
EJ
Department of Radiology, Jefferson Medical College of Thomas Jefferson University Hospital, Philadelphia, PA 19107-5244, USA.
Deane
C R
CR
Needleman
L
L
Merton
D A
DA
East
S A
SA
D000054:Acceleration; D000328:Adult; D001783:Blood Flow Velocity; D006801:Humans; D008961:Models, Structural; D015588:Observer Variation; D011673:Pulsatile Flow; D011674:Pulse; D012039:Regional Blood Flow; D012077:Renal Artery / Q000000981:diagnostic imaging*; D016037:Single-Blind Method; D013599:Systole; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance