BackgroundProstatic diseases are common and mostly associated with enlargement of the accessory gland. Thus, determining the prostate size has become a main criterion for evaluating prostate health status. Computed tomography (CT) is recommended as a beneficial tool for evaluating prostate size, morphology and surrounding tissues. The purpose of this study was to establish an accurate procedure for volume estimation and afterwards evaluate the prostate volume in CT. Data of 95 dogs were analysed (58 male intact, 37 male neutered) using the slice addition technique with the Amira program. Accuracy of volumetric measurements by CT was validated by comparing them with those of phantoms of known volume. Patients were grouped according to age (< 4 yrs., 4–8 yrs., > 8 yrs) and prostate morphology in CT (H = homogeneous, I = inhomogeneous, C = cystic). The length of the sixth lumbar vertebra was measured to relate prostate volume to body size. This ratio was generated to compare prostate volume between the groups, irrespective of body size (ratio volume = Rv).ResultsA high correlation between the CT-derived and phantom volume was found. Overall, the mean prostate volume was 58.6 cm3. The mean ratio volume was 1.3 in intact male dogs, this being significantly higher than in neutered dogs (0.7). The lowest ratio volume values were found in group H for intact (Rv = 0.9) and neutered dogs (Rv = 0.6), followed by group I (intact: Rv = 1.1; neutered: Rv = 0.7) and C (intact: Rv = 1.4; neutered: Rv = 0.8). The length of the sixth lumbar vertebra was well correlated with the prostate volume (intact: r = 0.63, p < 0.001; neutered: r = 0.48, p = 0.003), while age exhibited a correlation only in intact dogs (r = 0.52, p < 0.001).ConclusionThe present study is pioneering in applying a slice addition technique to volumetric measurements of the prostate gland in CT, resulting in a highly precise method. Volumetric measurements of the canine prostate gland in CT images provide information about the prostate structure, castration status, age and body size of the patients. Therefore, prostate volume is a relevant parameter for evaluating prostate health status.Electronic supplementary materialThe online version of this article (10.1186/s12917-019-1778-z) contains supplementary material, which is available to authorized users.

BackgroundSince most prostatic diseases are associated with the organ’s enlargement, evaluation of prostatic size is a main criterion in the diagnosis of prostatic state of health. While enlargement is a non-uniform process, volumetric measurements are believed to be advantageous to any single dimensional parameter for the diagnosis of prostatomegaly. In a previous study, volume was analysed with a slice addition technique (SAT), which was validated as highly accurate. Irrespective of high accuracy, SAT represents a complex and time-consuming procedure, which limits its clinical use. Thus, demand exists for more practical volume assessment methods. In this study, the prostatic volume of 95 canine patients (58 intact males, 37 neutered males) were analysed retrospectively by using the ellipsoid formula (Formula) and an imaging “wrap” function tool (Wrap) to help assess accuracy and applicability. Accuracy was checked against phantom measurements and results were compared to SAT measurements of the same patient pool obtained from a previously published paper. Patients were grouped according to prostatic structure (H = homogeneous, I = inhomogeneous, C = cystic) and volume using the SAT (volume group = vg: 1, 2 and 3).ResultsHigh correlation between the Formula or Wrap volume and the phantom volume was found, the values being higher for the Formula. Mean Formula volumes (vg 1: 2.2 cm3, vg 2: 14.5 cm3, vg 3: 109.4 cm3, respectively) were significantly underestimated, while mean Wrap volumes (vg 1: 3.8 cm3, vg 2: 19.5 cm3, vg 3: 159.2 cm3) were statistically equivalent to SAT measurements (vg 1: 3.1 cm3, vg 2: 18.6 cm3, vg 3: 157.2 cm3, respectively). Differences between Formula and SAT volumes ranged from 22.4–31.1%, while differences between Wrap and SAT volumes were highest in small prostates (vg 1: 22.1%) and fell with increasing prostatic size (vg 3: 1.3%).ConclusionThe Wrap function is highly accurate, less time-consuming and complex compared to SAT and could serve as beneficial tool for measuring prostatic volume in clinical routine after further validation in future studies. The Formula method cannot be recommended as an alternative for volumetric measurements of the prostate gland due to its underestimation of volumes compared to SAT results.

No abstract

No abstract