HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Claudon, M. Articles by Badawy, A.-B. Search for Related Content PubMed PubMed Citation Articles by Claudon, M. Articles by Badawy, A.-B.

Renal Blood Flow in Pigs: Changes Depicted with Contrast-enhanced Harmonic US Imaging during Acute Urinary Obstruction¹

¹ From the Departments of Radiology (M.C., C.E.B., G.A.T., P.S.D.) and Urology (R.G., A.B.B.), Children's Hospital and Harvard Medical School, 300 Longwood Ave, Boston, MA 02115. Received August 26, 1998; revision requested September 23; final revision received November 23; accepted March 29, 1999. G.A.T. supported in part by Alliance Pharmaceutical, San Diego, Calif, and Acuson, Mountain View, Calif. Address reprint requests to G.A.T. (e-mail: taylor_g@a1.tch.harvard.edu).

View larger version (153K): [in a new window]   Figure 1. Sagittal contrast-enhanced harmonic US image of the right kidney shows regions of interest used for upper-pole (C1), middle (C2), and lower-pole (C3) cortex and for medulla (M) to derive time-intensity curves for the kidney.

View larger version (9K): [in a new window]   Figure 2. Timeline shows sequence and duration of experimental protocols. In six animals (top bar), the ureter was obstructed for 90 minutes and released. In six additional animals (lower bar), the ureteral pressure was sequentially increased to mean arterial pressure. Upward arrows denote the timing of injections of microspheres and US contrast agent. Downward arrows denote the timing of furosemide injection.

View larger version (169K): [in a new window]   Figure 3a. Sagittal harmonic US images of the right kidney before ureteral obstruction, obtained (a) before the administration of contrast agent, (b) during peak cortical contrast enhancement, and (c) during peak medullary enhancement, show marked homogeneous cortical enhancement. Cortical mean pixel intensity increased from 85 intensity units before the administration of contrast agent to 162 intensity units at the peak effect of the contrast agent. Medullary enhancement is later and less intense than cortical enhancement. Mean medullary pixel intensity increased from 90 intensity units before the administration of contrast agent to 143 intensity units at the peak effect of the contrast agent.

View larger version (168K): [in a new window]   Figure 3b. Sagittal harmonic US images of the right kidney before ureteral obstruction, obtained (a) before the administration of contrast agent, (b) during peak cortical contrast enhancement, and (c) during peak medullary enhancement, show marked homogeneous cortical enhancement. Cortical mean pixel intensity increased from 85 intensity units before the administration of contrast agent to 162 intensity units at the peak effect of the contrast agent. Medullary enhancement is later and less intense than cortical enhancement. Mean medullary pixel intensity increased from 90 intensity units before the administration of contrast agent to 143 intensity units at the peak effect of the contrast agent.

View larger version (172K): [in a new window]   Figure 3c. Sagittal harmonic US images of the right kidney before ureteral obstruction, obtained (a) before the administration of contrast agent, (b) during peak cortical contrast enhancement, and (c) during peak medullary enhancement, show marked homogeneous cortical enhancement. Cortical mean pixel intensity increased from 85 intensity units before the administration of contrast agent to 162 intensity units at the peak effect of the contrast agent. Medullary enhancement is later and less intense than cortical enhancement. Mean medullary pixel intensity increased from 90 intensity units before the administration of contrast agent to 143 intensity units at the peak effect of the contrast agent.

View larger version (170K): [in a new window]   Figure 4a. Sagittal harmonic US images of the right kidney obtained (a) during peak cortical enhancement at baseline (190 intensity units), (b) during acute obstruction (168 intensity units), (c) 10 minutes after the intravenous injection of furosemide (163 intensity units), and (d) during peak ureteral pressure of 64 mm Hg (160 intensity units) show reduction in peak cortical enhancement during obstruction compared with baseline values. Note the small perinephric fluid collection (arrows) present at high ureteral pressure. (e) Graph of cortical time-intensity curves from the middle of the kidney shows changes in peak enhancement and the area under the curve. The mean pixel intensity refers to mean pixel intensity per number of pixels in the region of interest. B = baseline, F = furosemide, HP = high pressure, O = obstruction.

View larger version (170K): [in a new window]   Figure 4b. Sagittal harmonic US images of the right kidney obtained (a) during peak cortical enhancement at baseline (190 intensity units), (b) during acute obstruction (168 intensity units), (c) 10 minutes after the intravenous injection of furosemide (163 intensity units), and (d) during peak ureteral pressure of 64 mm Hg (160 intensity units) show reduction in peak cortical enhancement during obstruction compared with baseline values. Note the small perinephric fluid collection (arrows) present at high ureteral pressure. (e) Graph of cortical time-intensity curves from the middle of the kidney shows changes in peak enhancement and the area under the curve. The mean pixel intensity refers to mean pixel intensity per number of pixels in the region of interest. B = baseline, F = furosemide, HP = high pressure, O = obstruction.

View larger version (174K): [in a new window]   Figure 4c. Sagittal harmonic US images of the right kidney obtained (a) during peak cortical enhancement at baseline (190 intensity units), (b) during acute obstruction (168 intensity units), (c) 10 minutes after the intravenous injection of furosemide (163 intensity units), and (d) during peak ureteral pressure of 64 mm Hg (160 intensity units) show reduction in peak cortical enhancement during obstruction compared with baseline values. Note the small perinephric fluid collection (arrows) present at high ureteral pressure. (e) Graph of cortical time-intensity curves from the middle of the kidney shows changes in peak enhancement and the area under the curve. The mean pixel intensity refers to mean pixel intensity per number of pixels in the region of interest. B = baseline, F = furosemide, HP = high pressure, O = obstruction.

View larger version (175K): [in a new window]   Figure 4d. Sagittal harmonic US images of the right kidney obtained (a) during peak cortical enhancement at baseline (190 intensity units), (b) during acute obstruction (168 intensity units), (c) 10 minutes after the intravenous injection of furosemide (163 intensity units), and (d) during peak ureteral pressure of 64 mm Hg (160 intensity units) show reduction in peak cortical enhancement during obstruction compared with baseline values. Note the small perinephric fluid collection (arrows) present at high ureteral pressure. (e) Graph of cortical time-intensity curves from the middle of the kidney shows changes in peak enhancement and the area under the curve. The mean pixel intensity refers to mean pixel intensity per number of pixels in the region of interest. B = baseline, F = furosemide, HP = high pressure, O = obstruction.

View larger version (21K): [in a new window]   Figure 4e. Sagittal harmonic US images of the right kidney obtained (a) during peak cortical enhancement at baseline (190 intensity units), (b) during acute obstruction (168 intensity units), (c) 10 minutes after the intravenous injection of furosemide (163 intensity units), and (d) during peak ureteral pressure of 64 mm Hg (160 intensity units) show reduction in peak cortical enhancement during obstruction compared with baseline values. Note the small perinephric fluid collection (arrows) present at high ureteral pressure. (e) Graph of cortical time-intensity curves from the middle of the kidney shows changes in peak enhancement and the area under the curve. The mean pixel intensity refers to mean pixel intensity per number of pixels in the region of interest. B = baseline, F = furosemide, HP = high pressure, O = obstruction.

View larger version (18K): [in a new window]   Figure 5. Graph shows weak but significant correlation between the area under the curve and cortical blood flow (r = 0.43, P < .001; linear regression).

View larger version (17K): [in a new window]   Figure 6a. Graphs show the correlation between interlobar RI and renal hemodynamics. (a) There is a strong correlation between RI and renal perfusion pressure (r = 0.721, P < .001; linear regression). RI is (b) a poor predictor of cortical blood flow (r = 0.13, P = .15) and (c) only a weak predictor of renovascular resistance (r = 0.38, P < .001).

View larger version (20K): [in a new window]   Figure 6b. Graphs show the correlation between interlobar RI and renal hemodynamics. (a) There is a strong correlation between RI and renal perfusion pressure (r = 0.721, P < .001; linear regression). RI is (b) a poor predictor of cortical blood flow (r = 0.13, P = .15) and (c) only a weak predictor of renovascular resistance (r = 0.38, P < .001).

View larger version (18K): [in a new window]   Figure 6c. Graphs show the correlation between interlobar RI and renal hemodynamics. (a) There is a strong correlation between RI and renal perfusion pressure (r = 0.721, P < .001; linear regression). RI is (b) a poor predictor of cortical blood flow (r = 0.13, P = .15) and (c) only a weak predictor of renovascular resistance (r = 0.38, P < .001).