# Textural Analysis Supports Prostate MR Diagnosis in PIRADS Protocol
###### Abstract
This approach uses a five-point assessment scale that indicates the probability that multi-parameter MRI (mp-MRI) findings correlate with the presence of clinically significant PCa in a particular anatomic location. The following assessment categories are defined:  
1. Very low (highly unlikely present clinically significant PCa);
2. Low (unlikely clinically significant PCa);
3. Intermediate (equivocal presence of PCa disease);
4. High (likely present clinically significant PCa);
5. Very high (highly likely present clinically significant PCa). All suspected intraprostatic lesions seen on mp-MRI should be assigned to their zonal location (e.g., peripheral zone, including the central zone, or transition zone) on the sector map and assigned a PIRADS general assessment category [22]. Next, selecting a parameter allows ordering of the images in the following analytic procedure. Although MR image analysis is performed most frequently using the PIRADS scale, there are some limitations to the effectiveness of this tool. Among other features, there is a significant difference in the subjective assessment of images by independent radiologists [23; 24]. Nevertheless, those discrepancies, a targeted biopsy following the PIRADS diagnosis procedure, showed prostate cancer foci diagnosed significantly more frequently. Especially for regions with tissue with increased aggressiveness measured on the scale of International Society of Urological Pathology (ISUP) [25]. This scale introduced the Gleeson grades that determine the aggressiveness of the cancer tissue. Originally, MRI scanning was used in the group of patients requiring a second biopsy. But it has also been shown to be effective in the group of patients who have undergone it for the first time, and MRI is now recommended as a necessary test before invasive diagnostics [26; 27; 28]. Adding MRI-targeted biopsy to systematic biopsy in biopsy-naive patients increases the number of PCa detected. The detection of tissue with Gleeson grade > 2 and grade > 3 increases approximately by 20% and 30%, respectively. In the repeated biopsy setting, the addition of MRI-targeted biopsy increases PCa detection by approximately 40% (Gleeson grade > 2) and 50% (grade > 3). Over the years, substantial scientific work has been performed to reduce interpretation bias. According to different studies, the overall performance of MRI PCa detection is high, with a sensitivity of 0.89 and a specificity of 0.73 [29]. The performance of PIRADS and lesion detection accuracy are negatively influenced by variations in the technical equipment used, differences in the patient population, or interpretational local habits [30]. Furthermore, the biological variations of the tumours make some prostate lesions undetectable and, therefore, missed during radiological evaluation [31; 32]. The subjectivity of interpretation, with the presence of local interpretational habits, limits the correct recognition of tissue types [33; 34]. It is a complex process, where any discrepancies between radiologist at the level of changed tissue signal, or then the determination of the changed region shape and border, influence the outcome. Therefore, in the PIRADS-based assessment, inter- and intra-reader variation is reported [35; 36]. Multireader efficacy presents moderate to good in the case of clinically insignificant PCa. Intra-reader reproducibility is not always achieved in the case of malignant prostate lesions in proven detections [37; 38; 39; 40]. Automated segmentation can significantly reduce interpretational differences, which is especially important in a group of less experienced imaging professionals or where lesions are less visible due to technical problems (e.g., reduced image quality). The use of automated systems shows an increase in the level of agreement between the readers [41]. This study aimed to find a relationship between the prostate gland assessment performed in the PIRADS protocol and the textural analysis of MRI scans.