PI-RADS is an acronym for Prostate Imaging Reporting and Data System, defining standards of high-quality clinical service for multi-parametric magnetic resonance imaging (mpMRI), including image creation and reporting.
In 2007, the AdMeTech Foundation's International Prostate MRI Working Group [1] convened the key global experts, including members of the European Society of Urogenital Radiology (ESUR) and the American College of Radiology (ACR). In March 2009 in Vienna an ESUR Prostate MRI Committee was formed, with the aim to produce minimal and maximal standards for acquisition and reporting of prostate MRI. This standardization was endorsed by the results of a consensus meeting in London in December 2009 [2]
Dr. Jelle Barentsz published with the ESUR Prostate MRI Committee the first PI-RADS (v.1) version in December 2011. [3] Following this initiative the ACR, ESUR, and the AdMeTech Foundation formed a Joint Steering Committee, and by 2016 published a second version of PI-RADS (v.2) in European Urology. [4] This paper enabled acceptance of the urologists of prostate MRI and was awarded “Best clinical scientific paper of 2016 in European Urology”. In 2019 the PI-RADS Steering Committee published an updated version: PI-RADS v2.1. [5]
The aim of prostate MRI using PI-RADS is to assess the risk of clinically significant prostate cancer being present. Furthermore, the PI-RADS v2 system is designed to standardize prostate MRI.
Various studies have compared the predictive performance of PI-RADS v1 for detecting significant prostate cancer against either image-guided biopsy results (definitive pathology) and/or prostatectomy specimens (histopathology). In a 2015 articles in the Journal of Urology, Thompson reported multi-parametric MRI detection of significant prostate cancer had sensitivity of 96%, specificity of 36%, negative predictive value and positive predictive values of 92% and 52%; when PI-RADS was incorporated into a multivariate analysis (PSA, digital rectal exam, prostate volume, patient age) the area under the curve (AUC) improved from 0.776 to 0.879, p<0.001. [6] A similar paper in European Radiology found that when correlated with histopathology, PI-RADS v2 correctly identified 94-95% of prostate cancer foci ≥0.5 mL, but was limited for the assessment of GS ≥4+3 (significant) tumors ≤0.5 mL; in their series, DCE-MRI offered limited added value to T2WI+DW-MRI. [7] Other applications for which PI-RADS may be useful include prediction of termination of Active Surveillance due to tumor progression/aggressiveness, [8] detection of extraprostatic extension of prostate cancer, [9] and supplemental information when considering whether to re-biopsy patients with a history of previous negative biopsy. [10]
PI-RADS v2 is designed to improve detection, characterization and risk stratification in patients suspected of prostate cancer with a goal of better treatment decisions, improved outcomes and simplified reporting. However, multi-center validation trials are needed and expected to lead to modifications in the scoring system. [11]
Calculators designed to assist with PI-RADS criteria application have been developed to streamline the evaluation of prostate MRI. These tools, while not officially endorsed by the ACR, are becoming more popular among radiologists for their ability to reduce variability and improve diagnostic efficiency. Examples include PI-RADS v. 2.1 calculators available on independent online platforms, [12] which helps in systematically applying the PI-RADS scoring system. These tools are increasingly recognized for their potential to enhance clinical workflow and reporting accuracy.
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body. MRI does not involve X-rays or the use of ionizing radiation, which distinguishes it from computed tomography (CT) and positron emission tomography (PET) scans. MRI is a medical application of nuclear magnetic resonance (NMR) which can also be used for imaging in other NMR applications, such as NMR spectroscopy.
Bladder cancer is any of several types of cancer arising from the tissues of the urinary bladder. Symptoms include blood in the urine, pain with urination, and low back pain. It is caused when epithelial cells that line the bladder become malignant.
Mammography is the process of using low-energy X-rays to examine the human breast for diagnosis and screening. The goal of mammography is the early detection of breast cancer, typically through detection of characteristic masses or microcalcifications.
Prostate-specific antigen (PSA), also known as gamma-seminoprotein or kallikrein-3 (KLK3), P-30 antigen, is a glycoprotein enzyme encoded in humans by the KLK3 gene. PSA is a member of the kallikrein-related peptidase family and is secreted by the epithelial cells of the prostate gland in men and the paraurethral glands in women.
Prostate biopsy is a procedure in which small hollow needle-core samples are removed from a man's prostate gland to be examined for the presence of prostate cancer. It is typically performed when the result from a PSA blood test is high. It may also be considered advisable after a digital rectal exam (DRE) finds possible abnormality. PSA screening is controversial as PSA may become elevated due to non-cancerous conditions such as benign prostatic hyperplasia (BPH), by infection, or by manipulation of the prostate during surgery or catheterization. Additionally many prostate cancers detected by screening develop so slowly that they would not cause problems during a man's lifetime, making the complications due to treatment unnecessary.
The sentinel lymph node is the hypothetical first lymph node or group of nodes draining a cancer. In case of established cancerous dissemination it is postulated that the sentinel lymph nodes are the target organs primarily reached by metastasizing cancer cells from the tumor.
Prostate cancer screening is the screening process used to detect undiagnosed prostate cancer in men without signs or symptoms. When abnormal prostate tissue or cancer is found early, it may be easier to treat and cure, but it is unclear if early detection reduces mortality rates.
Magnetic resonance elastography (MRE) is a form of elastography that specifically leverages MRI to quantify and subsequently map the mechanical properties of soft tissue. First developed and described at Mayo Clinic by Muthupillai et al. in 1995, MRE has emerged as a powerful, non-invasive diagnostic tool, namely as an alternative to biopsy and serum tests for staging liver fibrosis.
The Breast Imaging-Reporting and Data System (BI-RADS) is a quality assurance tool originally designed for use with mammography. The system is a collaborative effort of many health groups but is published and trademarked by the American College of Radiology (ACR).
KH domain-containing, RNA-binding, signal transduction-associated protein 3 is a protein that in humans is encoded by the KHDRBS3 gene.
Molecular breast imaging (MBI), also known as scintimammography, is a type of breast imaging test that is used to detect cancer cells in breast tissue of individuals who have had abnormal mammograms, especially for those who have dense breast tissue, post-operative scar tissue or breast implants.
Prostate cancer antigen 3 is a gene that expresses a non-coding RNA. PCA3 is only expressed in human prostate tissue, and the gene is highly overexpressed in prostate cancer. Because of its restricted expression profile, the PCA3 RNA is useful as a tumor marker.
The objective of cancer screening is to detect cancer before symptoms appear, involving various methods such as blood tests, urine tests, DNA tests, and medical imaging. The purpose of screening is early cancer detection, to make the cancer easier to treat and extending life expectancy. In 2019, cancer was the second leading cause of death globally; more recent data is pending due to the COVID-19 pandemic.
The triple test score is a diagnostic tool for examining potentially cancerous breasts. Diagnostic accuracy of the triple test score is nearly 100%. Scoring includes using the procedures of physical examination, mammography and needle biopsy. If the results of a triple test score are greater than five, an excisional biopsy is indicated.
In medicine, breast imaging is a sub-speciality of diagnostic radiology that involves imaging of the breasts for screening or diagnostic purposes. There are various methods of breast imaging using a variety of technologies as described in detail below. Traditional screening and diagnostic mammography uses x-ray technology and has been the mainstay of breast imaging for many decades. Breast tomosynthesis is a relatively new digital x-ray mammography technique that produces multiple image slices of the breast similar to, but distinct from, computed tomography (CT). Xeromammography and galactography are somewhat outdated technologies that also use x-ray technology and are now used infrequently in the detection of breast cancer. Breast ultrasound is another technology employed in diagnosis and screening that can help differentiate between fluid filled and solid lesions, an important factor to determine if a lesion may be cancerous. Breast MRI is a technology typically reserved for high-risk patients and patients recently diagnosed with breast cancer. Lastly, scintimammography is used in a subgroup of patients who have abnormal mammograms or whose screening is not reliable on the basis of using traditional mammography or ultrasound.
In the field of medicine, radiomics is a method that extracts a large number of features from medical images using data-characterisation algorithms. These features, termed radiomic features, have the potential to uncover tumoral patterns and characteristics that fail to be appreciated by the naked eye. The hypothesis of radiomics is that the distinctive imaging features between disease forms may be useful for predicting prognosis and therapeutic response for various cancer types, thus providing valuable information for personalized therapy. Radiomics emerged from the medical fields of radiology and oncology and is the most advanced in applications within these fields. However, the technique can be applied to any medical study where a pathological process can be imaged.
Fluciclovine (18F), also known as anti-1-amino-3-18F-fluorocyclobutane-1-carboxylic acid, and sold under the brand name Axumin, is a diagnostic agent used for positron emission tomography (PET) imaging in men with suspected prostate cancer recurrence based on elevated prostate specific antigen (PSA) levels.
An MRI pulse sequence in magnetic resonance imaging (MRI) is a particular setting of pulse sequences and pulsed field gradients, resulting in a particular image appearance.
Caroline M. Moore is the first woman to be made a professor of urology in the United Kingdom. She works in the diagnosis and treatment of prostate cancer at University College London.
Hashim U. Ahmed is a British surgeon, medical researcher and author of publications in the field of prostate cancer diagnostics and treatment; his research has contributed to changes in the way men with suspected prostate cancer and men with prostate enlargement are diagnosed and treated. He is Professor and Chair of Urology at Imperial College Healthcare NHS Trust and Consultant Urological Surgeon at both Charing Cross Hospital and BUPA Cromwell Hospital.