Usefulness of Renal Volume Measurements Obtained by a 3-Dimensional Sonographic Transducer With Matrix Electronic Arrays

Abstract

Objective. The purpose of this study was to examine the feasibility of 3-dimensional (3D) sonography using a matrix array transducer to measure renal volume. Methods. One hundred consecutive patients with a normal serum creatinine level and kidney appearance on computed tomography (CT) performed within 2 months before sonography were enrolled in this study. Two hundred individual renal volumes were blindly obtained by the ellipsoid formula, the stacked ellipse method, the voxel count method using routine 2-dimensional (2D) sonographic data, 3D sonographic data using a matrix array transducer, and CT data, respectively. The voxel count method was validated as the reference standard by the water displacement method in 10 cadaveric pig kidneys (r = 0.99; P < .001). Renal volumes determined by 2D and 3D sonography were compared with volumes determined by CT. Results. Volumes determined by 2D sonography were significantly lower than those determined by CT (P < .001) but similar to those determined by 3D sonography (P = .78). The percent volume error of 3D sonography (mean ± SD, -2.2% ± 3.7%) was significantly lower than that of 2D sonography (-15.7% ± 11.8%) with CT as the standard (P < .001). The correlation coefficient between 3D sonography and CT (r = 0.98; P < .0001) was better than that between 2D sonography and CT (r = 0.83; P < .0001). In addition, Bland-Altman analysis revealed that the limits of agreement between 3D sonography and CT (-9.7% to 5.1%) were narrower than those between 2D sonography and CT (-45.6% to 9.8%). Conclusions. Three-dimensional sonography with a matrix array transducer can significantly reduce renal volume measurement errors and offers a reliable means of determining renal volumes.

The Kidney from Prenatal to Adult Life: Perinatal Programming and Reduction of Number of Nephrons during Development

“…Since serum Cys-C levels are frequently superior to serum creatinine levels as an index of renal function [95] with some limitations, it might be introduced as a marker of renal function and follow-up in these patients. Moreover, low renal volume detected by ultrasound measurement of renal length [96, 97] and 3-dimensional ultrasound volume [98, 99] might represent suitable parameters of reduced renal reserve in newborns and children. Scintigraphic measurement may provide a comparison of the renal reserve between kidneys and their relative variation by age in congenital unilateral reduced renal reserve [63].…”

Renal volume assessment with 3D ultrasound

“…According to the literature, the 3D technique appears to produce an underestimation of renal volume [19], even though this underestimation is lower than that of the ellipsoid formula [19]. In our study conducted on 49 patients and a total of 98 kidneys, 3D-US revealed higher values compared with MSCT in 11 cases only (11%), with a mean difference of 17 ml; in the remaining 87 cases (89%), MSCT yielded higher values (mean difference 24 ml).…”

“…Tuttavia, nonostante il riconoscimento di questa sottostima, la metodica ecografi ca è stata considerata comunque adeguata alle necessità cliniche in quanto non risulta fondamentale il valore assoluto del volume renale ma la sua variazione nel tempo. Da quanto noto in letteratura, anche la tecnica 3D appare caratterizzata da una sottostima del valore del volume renale [19], ma tale sottostima risulta inferiore a quella che si verifi ca con la tecnica dell'ellisoide [19]. Dal nostro studio su 49 pazienti per un totale di 98 reni, l'ecotomografi a 3D ha fornito un valore superiore a quello della TCMS in soli 11 (11%) casi con differenza media pari a 17 ml); nei restanti 87 (89%) casi, la TCMS ha fornito un valore superiore (differenza media pari a 24 ml).…”

“…The introduction of 3D-US imaging with dedicated probes allowing direct and automatic breath-hold acquisition of kidney sections reconstructed in the axial, sagittal and coronal planes [8, [13][14][15][16][17][18][19][20] has opened up new possibilities, in part thanks to limited costs, noninvasiveness, absence of ionising radiation and consequently contraindications.…”

“…La comparsa nella pratica clinica della ecotomografi a tridimensionale (ECO 3D) con sonda dedicata che permette, durante una singola apnea, l'acquisizione diretta ed automatica di sezioni del rene ricostruite nei piani assiali, sagittali e coronali [8,[13][14][15][16][17][18][19][20] ha aperto una nuova possibilità anche in ragione dei costi contenuti, della non invasività, dell'assenza di radiazioni ionizzanti e, quindi, della mancanza sostanziale di controindicazioni.…”