Parenchymal Transit Research Articles

Usefulness of clearance parametric images in detection of regional renal parenchyma dysfunction.

The aim of the study was to examine whether parametric clearance images (PAR) enhance diagnostic potential of a dynamic renal scintigraphy with detection of local dysfunction of kidneys, on a model of kidneys after treatment with extracorporeal shock wave lithotripsy (ESWL), MATERIAL AND METHODS: Kidneys after ESWL were accepted as a proper model for the implementation of this objective because of the previously proven damaging effect of a shock wave on renal parenchyma and known region of ESWL application. Forty patients (23 males and 17 females) at the age of 37 to 70 years (mean value 54) with untreated earlier single, one-sided nephrolithiasis, currently treated with ESWL, underwent a study. A dynamic renal 99mTc-EC scintigraphy was performed three times: before ESWL, a week and a month after this therapeutic intervention. PAR images generated with use of an in-house developed software were compared with summation (SUM) of images obtained from radiopharmaceutical uptake phase and quantitative global function parameters (GFP) of each kidney, like split function, MTT - mean transit time and PTT - parenchymal transit time. PAR and SUM images of all 40 kidneys before ESWL were normal. PAR images revealed local or diffused defects a week and a month after therapeutic intervention in statistically significantly larger numbers of kidneys than SUM images (19 vs. 6, p = 0.002 and 16 vs. 5, p = 0.003, respectively). A week after ESWL, when defects in PAR images were observed in about a half of all renal segments (29/57 - 51%) all GFP values were significantly worse than in kidneys without defects. A month after ESWL defects in PAR images could be observed in ab. 1/3 (17/48 - 35%) of segments and were less extensive, whereas GFP values did not differ significantly from values in kidneys without clearance function impairment in the PAR images. PAR images enhance diagnostic potential of a dynamic renal scintigraphy with detection of local function defects. These images allow to detect more local renal function defects than SUM images.

533 Predictors of renal functional improvement after pyeloplasty in ureteropelvic junction obstruction: clinical value of visually assessed renal parenchymal tracer transit time in 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) renography?

533 Predictors of renal functional improvement after pyeloplasty in ureteropelvic junction obstruction: clinical value of visually assessed renal parenchymal tracer transit time in 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) renography?

Renal Transit Time Measurements in the Diagnosis of Ureteric Obstruction

Summary— Deconvolution analysis of the gamma camera renogram has been used in a prospective study of 60 cases presenting with radiologically demonstrated ureteric dilatation. The results show that ureteric dilatation due to obstruction can be differentiated from ureteric dilatation without obstruction on the basis of parenchymal tracer transit times.

Renal radiopharmaceuticals—An update

Noninvasive radionuclide procedures in the evaluation of renal disease have been accepted increasingly as effective and valuable alternatives to older clinical methods. The development of suitable radiopharmaceuticals labeled with high photon intensity radionuclides and with 99mTc in particular has stimulated this modality during the last few years. Currently several nearly ideal agents are available for anatomical and functional studies of kidney imparting very low absorbed radiation doses. These include 99mTc-GHA and 99mTc-DMSA for renal morphology and differential function evaluation, 99mTc-DTPA for GFR and 123I orthoiodohippurate for ERPF measurements. A suitable agent as a replacement for the latter labeled with 99mTc is actively being sought. Computer-assisted processing of dynamic renal function studies enables the observer to obtain a wealth of information related to the renal extraction, uptake, parenchymal transit and pelvic transit parameters of the agent administered into the bloodstream. Each of these parameters either globally or differentially contributes to a detailed evaluation of renal disease states. Several of these procedures have been validated against classical techniques clinically but more detailed information is being sought with the recently introduced radiopharmaceuticals. With the detailed validation and increasing recognition of the clinical utility of several of the radionuclidic procedures at many centers, it is hoped that radionuclide assessment of renal disorders ultimately will be made available routinely at all medical facilities.