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Cine-computed tomographic assessment of regional renal blood flow
W Jaschke1, R S Sievers, M J Lipton
1Institut für Klinische Radiologie, Universität Heidelberg, West Germany.
Insights
Cine-computed tomography (CT) effectively assessed renal blood flow changes during hemorrhage and atrial natriuretic factor (ANF) administration. This technique shows promise for measuring regional renal blood flow distribution.
Area of Science:
- Nephrology
- Medical Imaging
- Physiology
Background:
- Hemorrhagic hypotension significantly impacts renal blood flow distribution.
- Atrial natriuretic factor (ANF) influences renal hemodynamics, but its precise effects on regional flow require further elucidation.
- Assessing regional renal blood flow is crucial for understanding kidney function and disease.
Purpose of the Study:
- To evaluate the utility of cine-computed tomography (CT) in assessing regional renal blood flow.
- To investigate the effects of hemorrhagic hypotension on cortical and inner medullary blood flow.
- To examine the impact of atrial natriuretic factor (ANF) on renal blood flow distribution.
Main Methods:
- Utilized cine-computed tomography (CT) to measure regional renal blood flow in a study setting.
- Induced hemorrhagic hypotension in subjects to observe its effects on renal perfusion.
- Administered atrial natriuretic factor (ANF) to assess its influence on renal blood flow dynamics.
Main Results:
- Hemorrhagic hypotension disproportionately reduced cortical blood flow compared to inner medullary flow, altering their ratio.
- Administration of ANF did not significantly change cortical blood flow but decreased inner medullary flow, increasing the cortical to inner medullary ratio.
- Cine-CT demonstrated clear changes in the distribution of intrarenal blood flow under different physiological conditions.
Conclusions:
- Cine-computed tomography (CT) is a suitable imaging modality for assessing regional renal blood flow.
- The study provides insights into the differential effects of hemorrhage and ANF on renal perfusion.
- Cine-CT offers a potential alternative for measuring regional renal blood flow distribution.
Abstract:
The new modality of cine-computed tomography was used to assess regional renal blood flow following hemorrhagic hypotension and administration of atrial natriuretic factor (ANF). As has also been established with other techniques, hypotension induced by hemorrhage caused cortical blood flow to fall from 5.3 (SD 0.8) to 2.1 (SD 1.1) ml.min-1g-1 (p less than 0.005; n = 7) proportionally more than inner medullary blood flow which fell from 0.45 (SD 0.24), to 0.26 (SD 0.08) ml.min-1g-1 (p less than 0.05) so that the ratio of the cortical to inner medullary blood flow decreased from 11.8 (SD 4.8) to 8.2 (SD 5.1) (p less than 0.01). In contrast, during natriuresis induced by ANF, cortical blood flow was unaltered (5.8, SD 1.1, vs 5.4, SD 0.9 ml.min-1g-1; NS; n = 5) while inner medullary blood flow declined from 0.66 (SD 0.13) to 0.51 (SD 0.11) (p less than 0.005) so the ratio of cortical to inner medullary blood flow increased from 8.8 (SD 1.3) to 10.9 (SD 1.7) (p less than 0.005). These results indicate that cine-CT appears to be an appropriate technique for demonstrating changes in distribution of intrarenal blood flow. Cine-CT may, therefore, be an attractive alternative for measuring regional renal blood flow.