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Power Doppler ultrasound (US) is a new technology that is superior to conventional color Doppler imaging in the detection of blood flow. Because of its greater sensitivity to flow and reduced angle dependence, power Doppler US demonstrates optimal color filling of renal pedicular vessels and allows improved evaluation of the renal parenchymal microvasculature. Power Doppler US was used as an adjunct to conventional color Doppler imaging in technically challenging cases and to improve evaluation of renal vascular disorders in a series of 916 patients. The primary clinical advantages of using power Doppler US compared with conventional color Doppler imaging include better morphologic appreciation of atherosclerotic changes in the renal artery wall, allowing improved diagnostic performance especially in hemodynamically nonsignificant plaques; ability to differentiate between subocclusive renal artery stenosis and occlusion; increased confidence in the diagnosis of renal vein thrombosis and in the assessment of caval tumor thrombus; and better appreciation of renal cortical perfusion defects. In addition, because of its greater sensitivity to perivascular artifact, power Doppler US has the potential to increase the detection rate for intrarenal arteriovenous fistulas.

Color Doppler sonography (CDS) of the male genital tract includes imaging of the prostate gland, of the cavernosal arteries and of the scrotum. It represents a unique means of significantly increasing the predictive positive value of hypoechoic nodules originating in the peripheral zone. In patients with a normal DRE and a PSA level between 4 and 10 ng/ml, it permits selection of patients with significant hypervascular cancers from those with hypovascular nodules or without TRUS/CDS abnormalities harbouring cancers of significantly lower Gleason score. CDS of the cavernosal arteries is the most accurate means of detecting impotence of vascular origin. Intermediate values of peak systolic velocities (25–35 cm/s) are not conclusive for arterial insufficiency and measurement of other Doppler parameters (systolic rise time and acceleration) are required to confirm arterial insufficiency. End diastolic velocity of below 5 cm/s is a reliable means of guaranteeing a normally functioning veno-occlusive system avoiding the need for cavernometry. Scrotal CDS is useful in evaluating acute scrotal disorders and permits the differentiation of acute torsions from epididymitis when the clinical examination is equivocal. Partial torsions are difficult to identify as they do not impair testicular arterial blood flow. Using spectral analysis may improve the sensitivity of color imaging in these cases. CDS of the spermatic veins is useful for quantifying the importance of non-palpable varicoceles by measuring the length and the pattern of the Doppler curve.

Unusual fat-containing renal tumors in a series of 27 cases comprised five categories: atypical and complicated angiomyolipomas (AMLs) (n = 15), including AMLs with extrarenal growth (n = 5), AMLs with undetectable fat (n = 4), and hemorrhagic AMLs (n = 6); fat-containing renal cell carcinomas (RCCs) (n = 9); lipoma (n = 1); liposarcoma (n = 1); and fat-containing renal oncocytoma (n = 1). Fat was present within RCCs by the following mechanisms; lipid-producing necrosis within a large RCC (n = 2), intratumoral bone metaplasia with fatty marrow elements and calcification within a small RCC (n = 2), and entrapment of perirenal (n = 4) or sinus (n = 1) fat by large irregular RCCs. Fat-containing RCC must be considered in cases of fat-containing renal tumors, even though the presence of intratumoral fat is characteristic of AML. A dedicated computed tomography scanning protocol and strict diagnostic criteria are mandatory for accurate diagnosis. Malignancy should be suspected on the basis of the following criteria: presence of intratumoral calcifications; large, irregular tumor invading the perirenal or sinus fat; large necrotic tumor with small foci of fat; and association with nonfatty lymph nodes or venous invasion.

Objective To evaluate the accuracy of endorectal magnetic resonance imaging (MRI) with fast spin-echo sequences in the local staging of clinically localized prostate cancer. Patients and methods Seventy-one patients with a clinical T1 (18 patients) or T2 tumour (53 patients) underwent endorectal MRI 2–12 weeks before radical prostatectomy. Extraprostatic tumour was diagnosed if MRI showed signs of capsular penetration and/or invasion of the seminal vesicle and/or distal urethra or bladder neck. If the pathological examination showed a single positive margin with no periprostatic tissue, the tumour was classified as indeterminate and not as a T3 tumour. Results Of the 25 cases of capsular penetration, MRI correctly identified 10 (sensitivity 42%, specificity 100%). Of the 14 cases with seminal vesicle invasion, MRI correctly identified six (sensitivity 43%, specificity 100%), but showed other signs of extraprostatic tumour spread in seven of the eight unidentified cases. Overall, MRI identified 16 of the 30 patients (53%) with occult extraprostatic spread of tumour; there was only one false-positive result. The sensitivity, specificity and accuracy of MRI were 53, 96 and 74%, respectively. Conclusion Endorectal MRI can reduce the rate of pre-operative understaging from 42% to 22% and it can be used for a given individual because it can detect extraprostatic invasion with 96% specificity, ensuring that very few, if any, patients will be deprived of curative surgery.

L’hypofertilite d’origine excretoire represente de 10 a 15% des azoospermies ou des oligozoospermies severes (

We report two incide ntal observations of radiocontrast-induced sialadenitis which occurred in a patient with normal renal function and in another patient undergoing chronic haemodialysis. Our first observation consisted of parotid gland, enlargement noted 1 h after contrast injection and which presaged anaphy lactoid shock. In the second cast salivary gland enlargement developed 3 days after administration of iodinated agent. A review of the literature based on 27 published observations. In dicates that two different presentations of iodide-induced sialadenitis canbe recognisedaccording totheirpathogenesis. In patients with normally functioning kidneys, the occurrence of sialadenitis after a shortdelay(5 min to 24 h) evokes an anaphylactoidmechanism. Conversely, in patients with impaired renal function, the delayed onset (1–5 days) of this adverse reaction suggest a toxic effect.

A new technique for electroincision of a strictured ureterointestinal anastomosis is described that uses a sphincterotome and high frequency current. After placement of a percutaneous nephrostomy tube a 7F "wire guided" sphincterotome was placed into the stenosis. The cutting wire was then deflected while cutting current was applied intermittently. Injection of contrast medium through the papillotome probe assessed the depth of the incision. A 10 mm. angioplasty balloon was inflated at low pressure to verify that the anastomosis had been incised to a depth of 1 cm. The anastomosis was then stented for 8 weeks with an 18F stent. The operative time did not exceed 45 minutes. A total of 9 stenoses was treated in 7 patients: 4 were ileal conduit diversions and 5 were enterocystoplasties. No immediate complication was observed. In 1 case a small urinoma was surgically drained at removal of the stent. Six stenoses are patent with 2, 3, 4, 4, 10 and 13 months of followup after removal of the stent. One patient died of bladder tumor metastases during the stenting period and 1 with bilateral incision still has a stent. The technique can be performed without major complication (bleeding or digestive fistula). Long-term results remain to be assessed.

The results of 62 consecutive MR examinations were correlated with the subsequent clinical course and histologic results. Twenty-six cases of rejection showed a marked diminution of cortico-medullary differentiation (CMD). The renal parenchymal vascular pattern and visibility of renal sinus fat were not markedly altered in rejection and there was no difference between normal and rejected allograft shape. The ability of MR imaging to diagnose renal transplant rejection is only based on CMD, which, however, is non-specific. In 2 cases of severe acute rejection, T2 weighted images showed an abnormal signal intensity of the cortex due to renal infarction. Our preliminary results in 8 patients with Gd-DOTA injection showed 2 cases with necrosis seen as areas with absent contrast enhancement. This technique seems to be promising in the detection of perfusion defects.

We report a case of venous rupture complicating percutaneous transluminal angioplasty (PTA) applied on a failed dialysis vascular access (VA) in a patient on chronic steroid therapy. This complication resulted in a rapidly growing hematoma which was successfully controlled by a prolonged reinflation of the balloon catheter at the angioplasty site. The absence of oversizing of the balloon catheter and the low inflation pressure at which the perforation occurred suggest a vessel fragility which was probably induced by a long-standing steroid therapy. In dialysis patients in whom steroid therapy does not represent an infrequent therapeutic modality, this potential risk of vascular rupture should be carefully weighted while treating VA stenoses with the use of PTA.

Teleteaching aims to help universities and nonacademic institutions improve, update and upgrade their educational programs for a better control of health care cost-effectiveness in developed or developing countries. A multicontinental multilingual service therefore could be offered through multimedia information superhighways and telebroadcasting networks. Attractive programs can be made combining conventional lectures, workshops, talk-shows, reality-shows, teleconferencing and teleproctoring formulae similar to techniques used in ordinary show-business. When the problems of moral and financial sponsoring are solved, teleteaching will create a new job mixing medical and nonmedical specialists of telecommunications aiming to offer highly professional medical educational shows.

The purpose of this study was to describe endorectal sonography and color Doppler sonography features of nonpalpable prostate cancer and to assess the value of endorectal MR imaging for the preoperative local staging of these tumors.Ninety-four patients with nonsuspicious findings on digital rectal examination and a mean prostate-specific antigen level of 16.3 +/-10 ng/mL (median, 13 ng/mL) underwent endorectal sonography, color Doppler sonography, sextant endorectal sonographically guided biopsy, and endorectal MR imaging before radical prostatectomy.Tumors were visible in 48 cases and not visible in 46. The mean Gleason biopsy score, the frequency of tumors involving three sextants or more of the prostate gland at biopsies, and the frequency of stage pT3 tumors were significantly higher in patients with visible tumors (5.9+/-0.9, 42%, and 37.5%) than in those with invisible tumors (5.4+/-1.1, 17%, and 17%). The 42 hypervascular tumors were hypoechoic in every case and had a higher rate of Gleason tumor grades 4 and 5 at biopsy than did the 52 hypovascular tumors (33% versus 11.5%). Six hypovascular tumors (6/52, 11.5%, two visible) had an insignificant tumor volume. Established extraprostatic tumor spread was detected on MR imaging in six of 18 cases (sensitivity, 33%; specificity, 100%0, all of which had the following four features: hypervascularity, prostate-specific antigen level greater than 20 ng/mL, three or more sextants of the gland having positive findings at biopsy, and seminal vesicle invasion.Endorectal sonography and color Doppler sonography are useful to differentiate low-risk invisible and hypovascular tumors from high-risk visible and hypervascular tumors. However, MR imaging has a poor sensitivity for the detection of extraprostatic spread and is accurate only in a minority of highly selected high-risk hypervascular tumors.

Noninvasive diagnosis of peripheral vascular disease started with the introduction of Doppler technology. The development of high frequency ultrasound and color Doppler imaging allows continuous assessment of vascular disorders along the arterial tree. However. the technique remains operator dependent. It also suffers from anatomic limitations, such as bowel gas and ultrasound attenuation due to depth or wall calcification. Ultrasound contrast agents increase the Doppler signal intensity and should therefore reduce the rate of technical failures. They are useful for detecting the flux in cases of attenuated ultrasound beam and reduced blood flow. Their administration using continuous infusion protocols increases the duration of the effect. New imaging modalities such as harmonic imaging and pulse inversion imaging reduce Doppler artifacts and allow real time detection of the microbubbles flowing in the blood stream. Future directions include ultrasound-guided therapy of occlusion using encapsulated drugs targeted to the thrombus.

Varicocele can be very easily diagnosed by physical examination and subsequently treated when it is painful or associated with testicular hypotrophy. However, palpability of the spermatic vein and reflux in low grade or even questionable varicoceles can be difficult to assess without imaging modalities. This can be a common problem for all physicians treating hypofertile men to decide whether the varicele needs to be treated or not. However, a gold standard that defines the presence of a subclinical varicocele has not yet been established. The different diagnostic tools based on ultrasonography investigated these past years to define a flow reversal in incontinent spermatic veins are presented in the first part of this review, with emphasis on subclinical varicocele. In the second part, we present our experience, together with a review of the literature concerning embolization of the spermatic veins as an alternative to surgery to treat varicoceles.

To compare results of color Doppler-guided ultrasonography (CDUS) versus those of systematic biopsies in 591 patients with an elevated serum PSA level and to correlate them with digital rectal examination (DRE) findings.Biopsies were directed into hypervascularized (CDUS+) or hypovascularized (CDUS-) hypoechoic peripheral zone nodules (443 cases). When transrectal ultrasound (TRUS) was normal (148 cases), biopsies were directed into hypervascular area. Six additional posterior biopsies were also performed in every patient, together with four anterior biopsies in 117 patients with normal DRE and prostate weight above 40 g.Biopsies were positive in 339 patients (57%). Positive biopsy rate (PBR) of directed biopsies was 84% in hypervascular abnormalities (264 of 316) and 17% in hypovascular nodules (23 of 134) (P0.001). PBR of combined biopsies was 84% in CDUS+ patients (266 of 316) and 26% in CDUS- patients (73 of 275) (P0.001). Comparison of TRUS and CDUS showed a sensitivity of 0.9 and 0.78, respectively, and a specificity of 0.46 and 0.8, respectively. Of the 131 patients with a PSA level between 4 and 10 ng/mL and a normal DRE, PBR was 59% (22 of 37) when CDUS was positive and 11% (10 of 94) when it was negative, regardless of TRUS abnormalities (P0.001). Nonpalpable cancers with a negative CDUS showed a significantly (P0.001) lower Gleason score (5.5 +/- 0.9) than that of CDUS+ cancer (6.5 +/- 1.1). Eleven cancers were diagnosed by only anterior positive biopsies. All of them had a negative CDUS and a PSA level above 10 ng/mL.CDUS does not modify prostate biopsy policy except in patients with negative CDUS, normal DRE, and PSA level between 4 and 10 ng/mL, where deferment of biopsy can be advocated. Anterior biopsies are only useful in patients with a PSA level above 10 ng/mL and a negative CDUS.

Color Doppler ultrasound (CDUS) seems to be an effective imaging technique for the diagnosis of renal vascular diseases. It is already the modality of choice for the detection of acute renal vein thrombosis and nonocclusive intrarenal vascular disorders including iatrogenic arteriovenous fistula and false aneurysm, particularly in patients with impaired renal function that precludes the use of iodinated contrast agents. Although proximal Doppler interrogation remains an important step in diagnosing renal artery (RA) stenosis, useful hemodynamic information can be obtained from the distal arterial bed. When CDUS fails in identifying proximal RAs, normal waveform velocity and morphology obtained from intrarenal arteries enable one to rule out RA occlusion and most of the severe stenoses (> or = 80%). Such information, which is not subject to a significant risk of technical failure, seems to be particularly useful in studying patients with acute renal failure of suspected vascular origin. Despite the extreme variability in reported performance between studies, CDUS has seemed to be a valuable tool compared with other noninvasive modalities in the diagnosis of RA stenosis. Whereas a CDUS-based strategy is already accepted in numerous specialized centers, a thorough evaluation of diagnostic criteria and extensive training of operators will allow CDUS to be widely accepted for the screening of patients at high risk for renovascular hypertension.

We determined the long-term outcome of a new technique for incising ureterointestinal anastomotic strictures using a transrenal percutaneously inserted papillotome. Procedures using fluoroscopic and endoscopic guidance were compared.Of 33 stenoses incised in 30 patients 15 were in ileal conduit diversions and 15 were in enterocystoplasties. The papillotome was inserted percutaneously over a guide wire into the stenosis, and then deflected and gently withdrawn under fluoroscopic (11 cases) or endoscopic (22) guidance using a flexible pediatric gastroscope or a lateral duodenoscope inserted retrograde into the ileal loop or neobladder. Air filling provided an excellent view of the stenotic area. Operative time did not exceed 45 minutes. The only major complication was damage to a right internal iliac artery.Followup data were available for 31 stenoses, with 27 followed for longer than 12 months after stent removal. Of the stenoses 22 are completely patent (actuarial long-term patency rate 71%), 3 showed partial improvement and 6 recurred requiring further treatment.Combined endoscopic and fluoroscopic guidance is preferable to fluoroscopy alone. The technique is simple if the endoscope is inserted retrograde. Long-term results are satisfactory and we believe that incision should be the initial approach to strictures of uro-digestive anastomoses.

One hundred eighty-seven native kidneys in 96 patients were examined with color Doppler ultrasound (US) to (a) determine the color Doppler US characteristics of renovascular disorders and (b) assess the value of color Doppler US in detection of such disorders. Correlative angiography or computed tomography was performed in 94 patients. The following renovascular disorders were found: renal artery (RA) stenosis (40 cases), RA thrombosis (13 cases), RA aneurysm (four cases), renal vein thrombosis (three cases), arteriovenous fistula (three cases), peripheral infarction (one case of bilateral infarcts), and distal occlusive disease (three cases). One case of aortal coarctation was also found. Color Doppler US failed to demonstrate the proximal main RA in 25% of cases (among 193 RAs total including supernumerary RAs). The sensitivity and specificity of color Doppler US for the detection of RA stenosis or thrombosis were 89% and 99%, respectively. Color Doppler US thus appears to be effective in the diagnosis of renovascular disease in native kidneys.

In 21 recipients of renal transplants suspected of allograft necrosis, the authors correlated the results of imaging to pathologic and histologic data in order to describe the magnetic resonance (MR) imaging and color Doppler ultrasonographic (US) characteristics of infarction. All patients underwent MR imaging performed with and without gadolinium tetraazacyclododecanetetraacetic acid (DOTA) and color Doppler US. Nonenhanced T1-weighted images showed no obvious changes, whereas nonenhanced T2-weighted images demonstrated a slight increase in signal intensity in areas of ischemic necrosis and low or heterogeneous signal intensity in areas of hemorrhagic necrosis. Gd-DOTA-enhanced MR images showed no contrast material uptake in infarcted areas. Color Doppler US characteristics of infarction included absence of Doppler signal and alteration of the cortical echogenic structure, particularly in cases of ischemic necrosis. Color Doppler US allows measurement of vascular resistance and assessment of intrarenal vasculature and the renal pedicle. Gd-DOTA-enhanced MR imaging is useful in confirming the diagnosis of infarction and provides an accurate evaluation of the extent of the infarct.

Sixteen of 227 patients referred for percutaneous placement of a ureteral stent had impassable stenoses. Stenoses were benign (n = 8) or attributed to malignant retroperitoneal neoplasm (n = 8). Electrocautery was used to create a neotract between the stenosed ureter and the bladder or ileal loop. A double-J stent was placed after dilation of the tract by use of angioplasty. Neotracts were established and stents were placed in all patients. Complications (digestive tract fistulas) developed in two patients. This technique is safe if the electrode is placed close to the bladder or ileal loop. The procedure can be used as an alternative to surgery or permanent nephrostomy or in initial treatment of benign anastomotic stenosis.

OBJECTIVE: We report three cases of a rare form of cavernoma developed within the wall of the common bile duct. CONCLUSION: To our knowledge, this kind of portal cavernoma has not been described in the literature. Because the cavernoma may be easily confused with other causes of bile duct wall thickening, color Doppler sonography is mandatory for a correct diagnosis.

Sonographic examinations of 17 patients revealed 21 kidneys with anechoic sonolucent areas within the renal sinus. Computerized tomography was obtained in 3 patients and the mass effects were proven to be multilocular parapelvic cysts. These parapelvic cysts simulated renal sinus lipomatosis.

In 10 years the authors have observed 16 cases of upper urinary tract tumors, appearing from 2 to 16 years after the initial diagnosis of bladder carcinoma. Such lesions are more frequent than has been suggested in the literature and represent 25% of all tumors of the renal pelvis and ureter seen in our service during this period. We have shown vesicoureteral reflux directly in 6 cases, indirectly in a further 6 with suggestive signs in 3 more. We believe that reflux causing the implantation of desquamated tumor cells from the bladder tumor is the most important pathogenetic mechanism for upper urinary tract "recurrences." The interval between the initial diagnosis of bladder tumor and the appearance of secondary foci may be longer than 20 years. Prolonged surveillance is therefore necessary, particularly if vesicoureteral reflux has been shown.

Renal biopsies were performed in 211 patients within 10 days of excretory urography or renal arteriography in which diatrizoate, iothalamate or ioxithalamate had been used. In 47 renal specimens, osmotic nephrosis of the proximal tubular cells was found. Previous renal function had been normal in 10 patients, moderately impaired in 19, and severely impaired in 18. Tubular atrophy and/or necrosis was associated with histological features in 29 of 47 patients. Diffuse osmotic nephrosis was more often found in patients biopsied soon after roentgenography and also with severe renal insufficiency, but was not necessarily associated with declining renal function. The mechanism(s) by which contrast media may induce osmotic nephrosis remains unclear.

Diagnostic procedures and long-term prognosis in bilateral renal cortical necrosis. Thirty-eight patients with bilateral renal cortical necrosis (BRCN) were studied with special reference to etiology, diagnostic procedures and ultimate prognosis. BRCN was of obstetrical origin in 26 patients and more frequent during the third trimester of pregnancy (21%) than earlier (1.5%). Renal biopsy, renal arteriography and hemodynamic data were useful procedures in the early differentiation of total from patchy BRCN. In patients with patchy BRCN, the percentage of destroyed glomeruli on the kidney biopsy specimen was lower than in those with total BRCN, renal arteriography showed that the cortical nephrogram was present but non-homogeneous and mean renal blood flow (MRBF) (85Kr method) fell within the range observed in patients with acute tubular nephropathy undergoing full recovery. In patients with total BRCN, cortical tissue was uniformly necrotic, the cortical nephrogram was completely absent, MRBF was always below 50 ml/100 g·min and a first component was never recognizable. Biological evidence of intravascular coagulation was inconstant. Intrarenal vascular thrombi were only found in the renal biopsy specimens of those patients with short survival. Partial recovery occurred in 16 patients and GFR increased over a one year period. Subsequent deterioration of renal function occurred in nine patients requiring chronic hemodialysis and/or renal transplantation. Diagnostic et pronostic lointain des necroses corticales bilaterales des reins. Trente-huit malades atteints de necrose corticale bilaterale des reins (NCR) ont ete specialement etudies du point de vue de l'etiologie, des methodes de diagnostic et du pronostic lointain. La NCR a ete d'origine obstetricale chez 26 malades et a ete plus souvent observee pendant le troisieme trimestre de la grossesse (21%) que plus precocement (1, 5%). La biopsie renale, l'arteriographie renale et les donnees hemodynamiques ont ete utiles pour distinguer les NCR totales et partielles. Chez les malades atteints de NCR partielle, la biopsie renale a montre que le pourcentage de glomerules detruits etait plus bas que dans les NCR totales, l'arteriographie renale a montre que la nephrographie corticale etait presente mais non-homogene et le flux sanguin renal moyen (FSRM) (methode au 85Kr) restait compris dans les limites observees chez les malades atteints de nephropathie tubulaire aigue avec guerison complete. Chez les malades atteints de NCR totale, le tissu renal cortical etait uniformement necrotique, la nephrographie corticale totalement absente, le FSRM etait toujours inferieur a 50 ml/100 g·mn et aucun premier composant n'etait individualisable. Les preuves biologiques d'une coagulation intravasculaire ont ete inconstantes. Des thrombi vasculaires intrarenaux n'ont ete rencontres en biopsie que chez les malades ayant une courte survie. Une recuperation partielle a ete observee chez 16 malades et la FG a continue a s'elever au-dela de la premiere annee. Une aggravation secondaire de la fonction renale est survenue chez neuf malades, necessit ant des hemodialyses periodiques et/ou une transplantation renale.

A false arterial aneurysm of a transplanted kidney was discovered by ultrasonography a few weeks after an open renal biopsy. The rapid increase in volume led to treatment of the lesion by bucrylate transcatheter embolization. The lesion disappeared without complications or sequelae. The renal transplant was functioning normally 30 months later.

French physicians must obtain their patient's consent before carrying out an action that interferes with the patient's corporal integrity. The doctor must use simple, approximate, intelligent, and honest words that help the patient to reach the indispensable decision. Proof of lack of consent lies with the patient. Three lawsuits dealing with contrast media use illustrate the application of the French general principles of medical responsibility and compliance with present standards of information for the patient.

A urographic pattern of renal clubbing and scarring was found in 182 scarred kidneys of 110 adult patients. Homolateral vesicoureteric reflux was demonstrated by reliable techniques in 90/135 scarred kidneys. Urinary tract infections occurred in 75 patients. Hypertension developed in 20 patients with normal renal function and was not related to the extent of scarring. Chronic renal failure occurred in 30 patients with diffuse bilateral scarring. Four patients showed histologic changes of chronic pyelonephritis. Two hypertensive patients had a typical histologic pattern of Ask-Upmark kidney (segmental hypoplasia). Development of renal scars in adulthood was demonstrated in 2 cases.

1. In forty-one patients who underwent renal homotransplantation the following measurements were made: (a) blood flow and its distribution in the transplanted kidney as measured by the 85Kr washout method; (b) renin release in the renal vein of the transplant; (c) arteriovenous difference in plasma renin activity (PRA) of the recipient's remaining left kidney. 2. Eleven transplanted patients were normotensive. Renal haemodynamic data were comparable with those obtained in potential kidney donors. 3. Three hypertensive patients had chronic rejection. The mean renal blood flow and the percentage of flow in the first component of the washout curve were reduced. Renin release from the transplant, however, was normal. 4. Ten hypertensive patients had transplant artery stenosis. In eight of them renin release from the graft as well as peripheral PRA were within normal range. This result is similar to experimental data obtained in Goldblatt renovascular hypertension. The two patients with the tightest artery stenosis had an elevated renin release from the transplant. 5. Thirteen hypertensive patients had elevated arteriovenous difference in PRA of the recipient's own left kidney. Peripheral PRA was significantly higher than in normotensive patients. Left nephrectomy relieved hypertension in ten of them; three have not so far undergone nephrectomy. 6. In four other cases hypertension was also relieved by removal of the patient's own kidney; however, the arteriovenous difference in PRA of that kidney fell within normal range.