Total kidney volume in autosomal dominant polycystic kidney disease: intraobserver and interobserver agreement of two methods with MRI.

Background/aim: Total kidney volume (TKV) is a parameter used in both treatment decision and follow-up in autosomal dominant polycystic kidney disease (ADPKD) patients. The objective of this study was to evaluate intra- and interobserver agreement of the ellipsoid formula (EF) and manual boundary tracing method (MBTM) used in TKV measurement of ADPKD patients across different levels of experience radiologists. Additionally, the study aimed to evaluate the correlation between the EF and MBTM, which is considered the gold standard for TKV. Materials and methods: A retrospective evaluation was conducted on magnetic resonance imaging (MRI) data from 55 ADPKD patients who underwent abdominal MRI between January 2017 and November 2021 to evaluate TKV. TKV measurements were performed by three independent observers (observer 1, an abdominal imaging radiologist with 5 years of experience; observer 2, a fourth-year radiology resident; observer 3, a second-year radiology resident).To assess intraobserver variability, all observers repeated the measurements at two-week intervals. The ICC was used to assess both intraobserver and interobserver variability. A comparison of the two methods was performed by linear regression for all three observers. Results: The ICC (95% CI) indicated excellent agreement between the observers for both methods (among all observers, p < 0.001). Furthermore, excellent intraobserver agreement was found between all observer measurements either EF or MBTM based on ICC (95% CI) (p < 0.001). The results of the linear regression analysis demonstrated high correlations between the two methods in all three observers (r = 0.992, p < 0.001 for the first observer; r = 0.975, p < 0.001 for the second observer; r = 0.989, p < 0.001 for the third observer). Conclusion: Both the EF and MBTM methods used for the measurement of TKV provided excellent intra- and interobserver reproducibility. The EF is as accurate and precise as the MBTM. It may therefore be preferred in radiology departments with heavy workload, as it is a reliable method for rapid and easy assessment, independent of experience.

Pubertal testicular volume references for ruler, orchidometer, and ultrasonography measurements based on a longitudinal follow-up.

BACKGROUND: Testicular volume is a marker of male pubertal development. Various clinical conditions and their treatments may influence testicular growth. OBJECTIVES: To create ruler-based age-dependent pubertal testicular volume references that enable calculation of standard deviation (SD) scores. MATERIALS AND METHODS: Study cohort comprised 65 boys who attended clinical examination twice a year from the age of 8.5 years until the attainment of final testicular size. Forty-nine (75.4%) boys completed the follow-up and 16 (24.6%) boys dropped out before the attainment of final post-pubertal testicular size. At each follow-up visit testicular size was measured with a ruler, orchidometer, and ultrasonography. LMS or LMSP method served as the technique for creating reference growth curves for testicular volumes. Using the novel references for ruler measurements, development of SD scores was assessed in a cohort of boys with unilateral cryptorchidism. RESULTS: Reference growth curves were constructed separately for ruler, orchidometer, and ultrasonography measurements. Median orchidometer volume of 4 mL, marker of male pubertal onset, occurred at the age of 11.7 years, whereas +2SD curve surpassed 4 mL at 10.2 years and -2SD curve at 13.7 years. Modeled ages at the attainment of 4 mL testicular volume based on ruler measurements were 9.7 years for +2SD curve, 11.5 years for median curve, and 13.6 years for -2SD curve. Ultrasonography-based volume of 1.3 mL corresponded with the median modeled orchidometer-based volume of 4 mL. In boys with unilateral cryptorchidism, ruler-based SD scores decreased during puberty in undescended testes, but not in descended testes. DISCUSSION AND CONCLUSION: The present study provides reference values for pubertal testicular volume measured with a ruler enabling an age-dependent assessment of testicular size. Comparison with measurements by an orchidometer and ultrasonography is also presented.

Accuracy of formula-based volume and image segmentation-based volume in calculation of preoperative cystic jaw lesions' volume.

OBJECTIVE: The aim of this study was to assess the accuracy of formula-based volume measurements and the 3D volume analysis with different software packages in the calculation of preoperative cystic jaw lesions' volume. The secondary aim was to assess the reliability and the accuracy of 3 imaging software programs for measuring the cystic jaw lesions' volume in CBCT images. MATERIALS AND METHODS: This study consisted of two parts: an in vitro part using 2 dry human mandibles that were used to create simulated osteolytic lesions to assess the accuracy of the volumetric analysis and formula-based volume. As a gold standard, the volume of each bone defect was determined by taking an impression using rapid soft silicone (Vinylight) and then quantifying the volume of the replica. Afterward, each tooth socket was scanned using a high-resolution CBCT. A retrospective part using archived CBCT radiographs that were taken from the database of the outpatient clinic of the oral and maxillofacial radiology department, Faculty of Dentistry, Minia University to assess the reliability of the 3 software packages. The volumetric data set was exported for volume quantification using the 3 software packages (MIMICS-OnDemand and InVesalius software). Also, the three greatest orthogonal diameters of the lesions were calculated, and the volume was assessed using the ellipsoid formula. Dunn's test was used for pair-wise comparisons when Friedman's test was significant. The inter-examiner agreement was assessed using Cronbach's alpha reliability coefficient and intra-class correlation coefficient. RESULTS: Regarding the results of the retrospective part, there was a statistically significant difference between volumetric measurements by equation and different software (P value < 0.001, Effect size = 0.513). The inter-observer reliability of the measurements of the cystic lesions using the different software packages was very good. The highest inter-examiner agreement for volume measurement was found with InVesalius (Cronbach's alpha = 0.992). On the other hand, there was a statistically significant difference between dry mandible volumetric measurements and Gold Standard. All software showed statistically significantly lower dry mandible volumetric measurements than the gold standard. CONCLUSION: Computer-aided assessment of cystic lesion volume using InVesalius, OnDemand, and MIMICS is a readily available, easy to use, non-invasive option. It confers an advantage over formula-based volume as it gives the exact morphology of the lesion so that potential problems can be detected before surgery. Volume analysis with InVesalius software was accurate in determining the volume of simulated periapical defects in a human cadaver mandible as compared to true volume. InVesalius software proved that open-source software can be robust yet user-friendly with the advantage of minimal cost to use.

Unveiling the Accuracy of Ultrasonographic Assessment of Thyroid Volume: A Comparative Analysis of Ultrasonographic Measurements and Specimen Volumes.

In endocrine surgery, a precise ultrasonographic measurement of thyroid volume is crucial. However, there is limited comparative research between ultrasonographic and specimen volumes, which has left this issue open to debate. This study aims to assess the accuracy of recommended formulas for ultrasonographic thyroid volume measurement by comparing them to specimen volumes and analyzing the influencing variables. From the data of 120 eligible patients, different formulas, including ultrasonographic thyroid volume (US-TV) based on the ellipsoid formula, lower correction factor thyroid volume (LCF-TV), and calculated ultrasonographic (derived formula) thyroid volume (CU-TV), were used to estimate the thyroid volume based on measurements taken prior to surgery. These measurements were compared with the intraoperative specimen volume (IO-TV) derived using Archimedes' principle. According to our findings, the mean values for US-TV and LCF-TV were significantly lower, whereas CU-TV was higher than IO-TV. Deviations were more significant in patients who had surgery for benign indications or compressive symptoms and in those with suppressed thyroid-stimulating hormone levels. Although the ellipsoid formula tends to underestimate the actual thyroid volume, it remains the most accurate method for measuring ultrasonographic thyroid volume. The deviation is greater for larger volumes.

Is the Ellipsoid Formula Reliable in Prostate MRI?

Our study seeks to study the accuracy of the ellipsoidal formula in prostate MRI of different sizes and to establish the limits of its use. The study included 31 patients with a well-visualized, intact prostatic capsule, excluding malignantly transformed prostates, as well as treated prostates, in which the contrast between the prostatic capsule and parenchyma is reduced. Each patient's prostatic volume was recalculated according to the ellipsoidal formula, and then it was compared with the prostatic volume calculated by the segmentation method. The two calculated volumes were similar, in some cases almost identical, with a slight tendency to underestimate prostate volume below 100cm3, in total in 18 cases, on average by 7.6% (+/-6%), overestimation of those with a volume over 100cm3, a total of 13 cases, on average by 3.2% (+/-2.5%), and of all, in 4 cases the difference between the two formulas was below 1%. There was no statistical difference between the two variables, Student's t-test p-value=0.039. With a precision of 92% (+/-6%), the ellipsoidal formula can be considered accurate when it is correctly performed, but if we take into account the importance that PSA density is starting to have in diagnosis, treatment and follow-up, the calculation of a secondary value through the segmentation method or high-precision software can be motivated when the ellipsoidal formula returns a value close to a threshold.

Three-Dimensional Convolutional Neural Network for Prostate MRI Segmentation and Comparison of Prostate Volume Measurements by Use of Artificial Neural Network and Ellipsoid Formula.

OBJECTIVE. The purposes of this study were to assess the performance of a 3D convolutional neural network (CNN) for automatic segmentation of prostates on MR images and to compare the volume estimates from the 3D CNN with those of the ellipsoid formula. MATERIALS AND METHODS. The study included 330 MR image sets that were divided into 260 training sets and 70 test sets for automated segmentation of the entire prostate. Among these, 162 training sets and 50 test sets were used for transition zone segmentation. Assisted by manual segmentation by two radiologists, the following values were obtained: estimates of ground-truth volume (VGT), software-derived volume (VSW), mean of VGT and VSW (VAV), and automatically generated volume from the 3D CNN (VNET). These values were compared with the volume calculated with the ellipsoid formula (VEL). RESULTS. The Dice similarity coefficient for the entire prostate was 87.12% and for the transition zone was 76.48%. There was no significant difference between VNET and VAV (p = 0.689) in the test sets of the entire prostate, whereas a significant difference was found between VEL and VAV (p < 0.001). No significant difference was found among the volume estimates in the test sets of the transition zone. Overall intraclass correlation coefficients between the volume estimates were excellent (0.887-0.995). In the test sets of entire prostate, the mean error between VGT and VNET (2.5) was smaller than that between VGT and VEL (3.3). CONCLUSION. The fully automated network studied provides reliable volume estimates of the entire prostate compared with those obtained with the ellipsoid formula. Fast and accurate volume measurement by use of the 3D CNN may help clinicians evaluate prostate disease.

Stone volume measuring methods: Should the CT based three-dimensional-reconstructed algorithm be proposed as the gold standard? What did the three-dimensional printed models show us? / Métodos de medida del volumen del cálculo: ¿Debería proponerse el algoritmo de reconstrucción 3D basado en TAC como el patrón de referencia? ¿Qué nos han enseñado los modelos de impresión 3D?

OBJECTIVES: We researched to detect the optimal method for evaluating stone volume, by comparing the ellipsoid formula and 3D reconstructed volume to gold standard of water displacement volume using 3D printed models. METHODS: We retrospectively analyzed out patient database and evaluated 27 patients who had percutaneous nephrolithotripsy. From the DICOM data of patient's preoperative CT images, stone structures were obtained using an image identification system. All DICOM files were saved in the stereolithography file format and a 3D printed model was created. True stone volume was found by water displacement method using this model and this volume compared with ellipsoid formula and 3D-reconstructed volume. RESULTS: Stone volume on water displacement ranged from 0.38-29.8cm3 with a median of 17.5cm3, stone volume on ellipsoid formula ranged from 0.46-34.7cm3 with a median of 19.6cm3 and stone volume on CT based 3D-reconstructed ranged from 0.48-31.8cm3 with a median of 18.9cm3. There was a significant difference between ellipsoid formula and water displacement ( p <   0.0001 ); however, there was no difference between 3D-reconstructed volume and water displacement ( p = 0.051 ). CONCLUSION: Stone volume calculation using CT based 3D-reconstructed algorithm improves the accuracy of stone volume estimation and this measurement is superior to ellipsoid formula.

OBJETIVOS: Realizamos una investigación para detectar el método óptimo de evaluación del volumen del cálculo comparando la fórmula del elipsoide y la reconstrucción 3D del volumen con el patrón de referencia, el volumen de agua desplazado utilizando modelos de impresión 3D. MÉTODOS: Analizamos retrospectivamente la base de datos de pacientes y evaluamos 27 que fueron sometidos a nefrolitotricia percutánea. Desde los datos del DICOM de las imágenes del TAC preoperatorio se obtuvieron las estructuras de los cálculos utilizando un sistema de identificación de imagen. Todos los archivos DICOM fueron guardados en un formato estereolitográfico y se creó un modelo 3D impreso. El volumen verdadero de la litiasis fue hallado mediante el método del desplazamiento de agua utilizando este modelo y se comparó con la fórmula del elipsoide y el volumen de reconstrucción 3D. RESULTADOS: El volumen del cálculo con el desplazamiento de agua osciló entre 0,38-29,8 cm3 con una mediana de 17,5 cm3. Con la fórmula del elipsoide, el volumen tenía un rango entre 0,46-34,7 cm3 con una mediana de 19,6 cm3 y con la reconstrucción 3D basada en TAC el rango fue de 0,48-31,8 cm3 con una mediana de 19,6 cm3. Había una diferencia significativa entre la fórmula del elipsoide y el desplazamiento de agua ( p < 0,0001 ); sin embargo, no había diferencias entre el volumen por reconstrucción 3D y el desplazamiento de agua ( p = 0,051 ). CONCLUSION: El cálculo del volumen de la litiasis utilizando algoritmos de reconstrucción 3D basada en TAC mejora la precisión de la estimación del volumen de la litiasis y esta medida es superior a la fórmula del elipsoide.

Variations in renal morphometry: A hospital-based Indian study.

INTRODUCTION: The currently available standard renal nomograms for comparison of renal dimensions in India are based on the measurements made in the Western population. The objectives of our study were to identify variations in renal morphometric parameters in subjects with no known renal disease in a hospital-based Indian population and to find out any correlation between renal volumes with split renal functions and body mass index (BMI). MATERIALS AND METHODS: One hundred and fifty-one subjects undergoing contrast-enhanced computerized tomography (CT) scan for various purposes, including donor nephrectomy, from June 2012 to August 2014 were included in the study. The renal and ureteral dimensions were assessed from the contrast-enhanced CT scan images of these patients. RESULTS: The mean length, width, thickness and volume of the left kidney were 11.02 ± 1.13 cm, 5.21 ± 0.75 cm, 4.65 ± 0.84 cm and 138.22 ± 29.81 mL, respectively, and those for the right kidney were 10.86 ± 1.12 cm, 5.13 ± 0.77 cm, 4.73 ± 0.95 cm and 137.54 ± 34.48 mL, respectively. The mean length of the left ureter was 23.51 ± 1.48 cm and that of the right ureter was 23.24 ± 1.93 cm. The mean volume of the kidneys in males and females was also different. The volume of the kidney did not statically correlate with the split glomerular filtration rate ((P = 0.12) and BMI (P = 0.52)). CONCLUSIONS: Our study revealed that there exist differences in various morphometric parameters of the kidney and ureter in different subsets of the Indian population attending our hospital as compared with the standard values quoted in the world literature.

Increasing volume of non-neoplastic parenchyma in partial nephrectomy specimens is associated with chronic kidney disease upstaging.

INTRODUCTION: We examined the effect of non-neoplastic parenchymal volumes (NNPVs) in partial nephrectomy (PN) surgical specimens on long-term postoperative renal function. PN for renal cortical neoplasms has demonstrated superior long-term renal function outcomes compared with radical nephrectomy. Minimizing the distance between the surgical margin and tumor will reduce the NNPV removed. The role of NNPV on postoperative outcomes has been preliminarily investigated, with varying results. Thus, we sought to determine the association between the NNPV removed and postoperative chronic kidney disease (CKD) staging. MATERIALS AND METHODS: Our institutional database was queried for patients who had undergone PN from 1990 to 2012. The demographic and pathologic data were collected. The ellipsoid formula was used to calculate the surgical specimen and tumor volumes, which were then subtracted from each other to determine the NNPV. The estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease formula. Binary logistic regression analysis was used to determine the predictors of postoperative CKD upstaging according to the eGFR. RESULTS: A total of 584 patients meeting the inclusion criteria had undergone PN. On binary logistic regression analysis, controlling for age, tumor volume, surgical modality, and preoperative CKD stage, an increasing NNPV in the surgical specimen was independently associated with postoperative CKD upstaging (odds ratio, 1.004; P = .007). CONCLUSION: An increasing NNPV removed during PN correlated with CKD upstaging using the eGFR; therefore, additional emphasis should be placed on healthy parenchymal preservation, with long-term follow-up to ensure adequate oncologic outcomes.

Measurement of renal dimensions in vivo: A critical appraisal.

Kidney volume is regarded as the most precise indicator of kidney size. However, volume assessment is not widely used clinically because its measurement is difficult due to the complex kidney shape. Apart from the conventional methods of measurement of renal dimensions from X-rays, ultrasound scan, computed tomography scan and magnetic resonance imaging have evolved as the three best modalities for this purpose currently. Assessment of kidney size should also be made individually since many factors like body mass index, height, gender, age, position of kidneys, sex, stenoses and number of renal arteries influence the measurements. In this paper, we have critically analysed the advantages and disadvantages of the various methods of renal morphometry, by reviewing the literature spanning over the period of 1976 - 2009.