MRI for detection, staging, and follow-up of prostate cancer: Synthesis of the PI-RADS v2.1, MET-RADS, PRECISE, and PI-RR guidelines.

Prostate cancer is very common among men. Radiology, mainly through MRI, plays a key role in the different stages of prostate cancer: diagnosis, staging and treatment assessment. The correct management of MRI requires knowledge and proper use of the different guidelines developed for the acquisition, interpretation and reporting of MRI in diagnosis (PI-RADS guide), whole body staging (MET-RADS guide), active surveillance (PRECISE guide) and local recurrence (PI-RR guide) in prostate cancer. The objective of this article is to show an update and synthesis of the most relevant aspects of these MRI guidelines for an optimal use and thus providing a more effective management of prostate cancer.

Review of imaging techniques for evaluating morphological and functional responses to the treatment of bone metastases in prostate and breast cancer.

Bone metastases are very common complications associated with certain types of cancers that frequently negatively impact the quality of life and functional status of patients; thus, early detection is necessary for the implementation of immediate therapeutic measures to reduce the risk of skeletal complications and improve survival and quality of life. There is no consensus or universal standard approach for the detection of bone metastases in cancer patients based on imaging. Endorsed by the Spanish Society of Medical Oncology (SEOM), the Spanish Society of Medical Radiology (SERAM), and the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM) a group of experts met to discuss and provide an up-to-date review of our current understanding of the biological mechanisms through which tumors spread to the bone and describe the imaging methods available to diagnose bone metastasis and monitor their response to oncological treatment, focusing on patients with breast and prostate cancer. According to current available data, the use of next-generation imaging techniques, including whole-body diffusion-weighted MRI, PET/CT, and PET/MRI with novel radiopharmaceuticals, is recommended instead of the classical combination of CT and bone scan in detection, staging and response assessment of bone metastases from prostate and breast cancer.Clinical trial registration: Not applicable.

Functional imaging in pancreatic disease. / Imagen funcional de la patología pancreática.

In addition to the classical morphological evaluation of pancreatic disease, the constant technological advances in imaging techniques based fundamentally on computed tomography and magnetic resonance imaging have enabled the quantitative functional and molecular evaluation of this organ. In many cases, this imaging-based information results in substantial changes to patient management and can be a fundamental tool for the development of biomarkers. The aim of this article is to review the role of emerging functional and molecular techniques based on computed tomography and magnetic resonance imaging in the evaluation of pancreatic disease.

Evaluation of MR imaging-targeted biopsies of the prostate in biopsy-naïve patients. A single centre study.

PURPOSE: To evaluate the differences in prostate cancer detection rate and biopsy effectiveness between magnetic resonance imaging (MRI) target biopsy (TB) and transperineal standard biopsy (SB) in biopsy-naïve patients. MATERIAL AND METHODS: Between October 2014 and April 2016, 60 men with a mean age of 64.1±6.7 (SD) years (range: 53-82 years) were prospectively enrolled. All patients underwent a prostate MRI study, evaluated by two radiologists, before undergoing the biopsy. A transperineal 12-core SB was carried out before TB, without the information from the MRI. The detection rate for all tumors and for clinically significant tumors (CS) was recorded. Sampling variables such as the proportion of cores positive for CS cancer (PCP-CS) and the maximum cancer core length (MCCL) were also calculated. The ability of MRI to predict the presence of a CS tumor at biopsy was studied using a sector analysis. Patients with negative biopsies were followed during a minimum of 12 months. RESULTS: The detection rate for SB and TB was 53.3% (32/60) and 46.7% (28/60) respectively for all tumors (P=0.289) and 45% (27/60) in both techniques for CS tumors. TB obtained a larger PCP-CS (P<0.001) and MCCL (P=0.018). The sensitivity, specificity, positive predictive value, negative predictive value and cancer prevalence was 83.3%, 92.9%, 83.3%, 92.9% and 30% for peripheral zone sectors and 43.8%, 97.1%, 70.0%, 91.8% and 13,3% for transitional zone sectors. The proportion of patients that showed an increase of PSA faster than 0.75ng/mL/year after a negative biopsy was 26.1%. CONCLUSION: Detection rate of prostate cancer did not show significant differences between a TB and a SB technique in biopsy-naïve patients. However, targeted prostate biopsies demonstrated a better sampling effectiveness thus reducing the cores needed to diagnose clinically significant tumors.

Multiparametric magnetic resonance imaging and prostate cancer: what's new? / Resonancia magnética multiparamétrica y cáncer de próstata: ¿qué hay de nuevo?

Prostatic multi-parametric magnetic resonance imaging (MP-MRI) has recently had a wide development becoming a key tool in the diagnostic and therapeutic decisions in prostate cancer (Pca). The fast development both in technology and in reading (PIRADS V2) requires a continuous updating of knowledge within this area. The aim of this article is to present an updated revision of technical aspects, reading patterns and prostatic MP-MRI in Pca, with a multidisciplinary approach. Currently guidelines establish the use of the MP-MRI when there is a high PSA and a negative prostatic biopsy; tumor staging; evaluation in candidates to active surveillance; focal treatments plans and tumoral recurrence evaluation. Although it is used in other indications in some centers, like its use in patients suspicious of Pca but with no previous biopsy, there is still the need of a cost/benefit assessment for its use to be wider.

Magnetic resonance imaging in the new paradigm for the diagnosis of prostate cancer. / La resonancia magnética en el nuevo paradigma del diagnóstico del cáncer de próstata.

For various reasons, prostate cancer is a major public health problem. It is a very common cancer, but has a very low mortality rate because it comprises two types of disease: one insignificant, indolent, and much more common, and the other aggressive, significant, and much less common. The routine diagnostic approach to prostate cancer has been systematic blind biopsies, which has low detection rates and might detect low risk, insignificant prostate cancer, leading to overdiagnosis and overtreatment of indolent cancers. The possibility of including multiparametric magnetic resonance imaging in the diagnostic management to improve the detection of aggressive cancer while reducing the overdiagnosis of indolent cancer represents a change in the diagnostic management. This article updates knowledge about the diagnostic management of prostate cancer including multiparametric magnetic resonance imaging.

Bone marrow invasion in multiple myeloma and metastatic disease. / Infiltración de la médula ósea, mieloma múltiple y enfermedad metastásica.

Magnetic resonance imaging (MRI) of the spine is the imaging study of choice for the management of bone marrow disease. MRI sequences enable us to integrate structural and functional information for detecting, staging, and monitoring the response the treatment of multiple myeloma and bone metastases in the spine. Whole-body MRI has been incorporated into different guidelines as the technique of choice for managing multiple myeloma and metastatic bone disease. Normal physiological changes in the yellow and red bone marrow represent a challenge in analyses to differentiate clinically significant findings from those that are not clinically significant. This article describes the findings for normal bone marrow, variants, and invasive processes in multiple myeloma and bone metastases.

Usefulness of 1H magnetic resonance spectroscopy in human testes: preliminary study.

AIM: To identify and quantify the metabolites detected on proton magnetic resonance spectroscopy ((1)H-MRS) in human testes. MATERIALS AND METHODS: The institutional review board approved the study, and all patients provided informed consent. A total of 27 patients consulting the Urology Department underwent single-voxel (1)H-MRS (4000 ms repetition time [RT], 31 ms echo time [TE], 128 averages for each TE) at 1.5 T. Spectroscopy was not evaluable in one patient, and four patients had only one testis; thus, 48 testes were studied. Choline-containing compounds (Cho) and methylene lipid (Lip) values were measured and the Cho/Lip ratio was calculated. Testes were classified as normal or abnormal based on conventional magnetic resonance imaging (MRI) findings. The Mann-Whitney U-test was used for correlated data and bootstrapping to compare mean Cho/Lip ratios between normal and abnormal testes, and the area under the receiver operating characteristic curve (AUC) was calculated. RESULTS: Thirty testes were classified as normal and 18 as abnormal. The mean Cho/Lip ratio was 1.02±0.46 in normal testes and 0.45±0.36 in abnormal testes (Mann-Whitney U, p=0.001; bootstrapping mean difference, 0.57; 95% confidence interval (CI) 0.32-0.82; AUC=0.833). CONCLUSION: (1)H-MRS could be useful in routine clinical practice to identify the major metabolites in the testes and help discriminate between normal and abnormal testes.

[Selection of candidates for prostate biopsy using multiparametric magnetic resonance imaging in patients with persistently raising PSA]. / Selección de pacientes candidatos a biopsia prostática mediante técnicas de resonancia magnética funcional en el seguimiento por elevación del PSA.

UNLABELLED: The current diagnosis of prostate cancer is based on randomized prostate biopsies to obtain histological material for study, without introducing any imaging technique in the diagnostic algorithm. OBJECTIVES: To conduct a literature review of the role of multiparametric MRI ( mMRI ) in the diagnosis of prostate cancer, and present preliminary data from our series of 233 patients undergoing mRMN and transrectal ultrasound (TRUS) prostate biopsy. MATERIAL AND METHODS: We performed a PubMed search for those articles that refer to the usefulness of mMRI in the follow-up and monitoring of patients with persistently elevated PSA without previous biopsies, and those with a previous negative biopsy, and assess the power of mRMN for detecting PCa in both the peripheral and the central gland. We present the preliminary results of our series, consisting of 233 patients selected between 2008 and 2011 undergoing mMRI and TRUS-guided prostatic biopsy because of elevated PSA levels or suspicious digital rectal examination. RESULTS: We discuss several articles published from 2003 to 2014. We compare our results with those from the literature. DISCUSSION: The diagnostic algorithm of prostate cancer to date does not include any imaging technique in the decision-making process. The mMRI is a functional imaging technique that provides increasing evidence in deciding which patients should be biopsied and which patients may avoid it despite persisting high levels of PSA. The advantage of this technique lies not only in its high detection rate in intermediate and high risk lesions, but also in its high specificity. It allows us to avoid diagnosing clinically insignificant tumors and thus, avoids overtreatment. CONCLUSION: The mRMN is a useful technique not yet incorporated in algorithms of prostate cancer diagnosis in urological societies. Its safety, effectiveness and efficiency are forcing to include its progressive use and with high probability will be soon incorporated into the decision-making charts.

Evaluating the effects of white matter multiple sclerosis lesions on the volume estimation of 6 brain tissue segmentation methods.

BACKGROUND AND PURPOSE: The accuracy of automatic tissue segmentation methods can be affected by the presence of hypointense white matter lesions during the tissue segmentation process. Our aim was to evaluate the impact of MS white matter lesions on the brain tissue measurements of 6 well-known segmentation techniques. These include straightforward techniques such as Artificial Neural Network and fuzzy C-means as well as more advanced techniques such as the Fuzzy And Noise Tolerant Adaptive Segmentation Method, fMRI of the Brain Automated Segmentation Tool, SPM5, and SPM8. MATERIALS AND METHODS: Thirty T1-weighted images from patients with MS from 3 different scanners were segmented twice, first including white matter lesions and then masking the lesions before segmentation and relabeling as WM afterward. The differences in total tissue volume and tissue volume outside the lesion regions were computed between the images by using the 2 methodologies. RESULTS: Total gray matter volume was overestimated by all methods when lesion volume increased. The tissue volume outside the lesion regions was also affected by white matter lesions with differences up to 20 cm(3) on images with a high lesion load (≈50 cm(3)). SPM8 and Fuzzy And Noise Tolerant Adaptive Segmentation Method were the methods less influenced by white matter lesions, whereas the effect of white matter lesions was more prominent on fuzzy C-means and the fMRI of the Brain Automated Segmentation Tool. CONCLUSIONS: Although lesions were removed after segmentation to avoid their impact on tissue segmentation, the methods still overestimated GM tissue in most cases. This finding is especially relevant because on images with high lesion load, this bias will most likely distort actual tissue atrophy measurements.

[Applications of diffusion techniques in magnetic resonance imaging of musculoskeletal tumors]. / Aplicaciones de la técnica de difusión por resonancia magnética en el manejo de la patología tumoral osteomuscular.

Magnetic resonance imaging (MRI) is the technique of choice in the diagnosis, staging, and follow-up of musculoskeletal tumors. Diffusion imaging is a new functional MRI technique that provides information that is complementary to that obtained in conventional MRI sequences. Diffusion imaging has proven useful in different clinical situations like the characterization of disease involving the bone marrow (bone metastases, benign fractures, or hematological disease), the evaluation of tumors of the bones and soft tissues, and the monitoring of the response to treatment in patients with tumors. The aim of this article is to review the diffusion technique in MRI and its current clinical applications in the management of musculoskeletal tumors.

[Literature review of the subject of a research project]. / Revisión bibliográfica del tema de estudio de un proyecto de investigación.

It can be very complicated to obtain relevant information through searching the medical literature if you do not know how it is organized and indexed or if you do not know how to use the specialized databases. For a successful review of the literature, you need to know what you are looking for and the key words for an effective search of the specialized databases and libraries and especially of the internet. It is essential to critically evaluate the information selected. Finally, using a reference manager can facilitate the gathering, organization, systematization, and integration of the bibliographic references in the documents generated in the study. This article aims to provide guidelines for efficient searching for information and for accurate, critical use of the literature. It makes recommendations about strategies for managing references to help to ensure the success of a research project.

Spectral clustering of shape and probability prior models for automatic prostate segmentation.

Imaging artifacts in Transrectal Ultrasound (TRUS) images and inter-patient variations in prostate shape and size challenge computer-aided automatic or semi-automatic segmentation of the prostate. In this paper, we propose to use multiple mean parametric models derived from principal component analysis (PCA) of shape and posterior probability information to segment the prostate. In contrast to traditional statistical models of shape and intensity priors, we use posterior probability of the prostate region determined from random forest classification to build, initialize and propagate our model. Multiple mean models derived from spectral clustering of combined shape and appearance parameters ensure improvement in segmentation accuracies. The proposed method achieves mean Dice similarity coefficient (DSC) value of 0.96±0.01, with a mean segmentation time of 0.67±0.02 seconds when validated with 46 images from 23 datasets in a leave-one-patient-out validation framework.

Joint probability of shape and image similarities to retrieve 2D TRUS-MR slice correspondence for prostate biopsy.

This paper presents a novel method to identify the 2D axial Magnetic Resonance (MR) slice from a pre-acquired MR prostate volume that closely corresponds to the 2D axial Transrectal Ultrasound (TRUS) slice obtained during prostate biopsy. The method combines both shape and image intensity information. The segmented prostate contours in both the imaging modalities are described by shape-context representations and matched using the Chi-square distance. Normalized mutual information and correlation coefficient between the TRUS and MR slices are computed to find image similarities. Finally, the joint probability values comprising shape and image similarities are used in a rule-based framework to provide the MR slice that closely resembles the TRUS slice acquired during the biopsy procedure. The method is evaluated for 20 patient datasets, of which 18 results match at least one of the two clinical expert choices.

Comparative study of whole-body MRI and bone scintigraphy for the detection of bone metastases.

AIM: To assess and compare the diagnostic accuracy of whole-body magnetic resonance imaging (MRI) and bone scintigraphy in the detection of metastases to bone. MATERIAL AND METHODS: Forty randomly selected patients with known malignant tumours were prospectively studied using bone scintigraphy and whole-body MRI. Two patients were excluded. Symptoms of bone metastasis were present in 29 (76%) patients and absent in nine (24%). Findings were classified into four categories according to the probability of bone metastasis: (1) negative, (2) probably negative, (3) probably positive, and (4) positive. Diagnostic accuracy was determined according to the area under the receiver operating characteristic (ROC) curve. The definitive diagnosis was reached using other imaging techniques, biopsy, or 12 months clinical follow-up. RESULTS: Metastases were present in 18 patients. The sensitivity, specificity, and diagnostic accuracy were 94, 90, and 92%, respectively, for whole-body MRI and 72, 75, and 74%, respectively, for bone scintigraphy. Diagnostic accuracy measured by the area under the ROC curve was significantly higher for whole-body MRI (96%) than for bone scintigraphy (77%; p<0.05). Interobserver agreement measured by the kappa index was significantly higher for whole-body MRI (0.895) than for bone scintigraphy (0.524; p<0.05). Whole-body MRI detected lesions in tissues other than bone in 17 (45%) patients. CONCLUSIONS: Whole-body MRI is more accurate and more objective than bone scintigraphy for the detection of bone metastases. Whole-body MRI can also detect lesions in tissues other than bone.

[Usefulness of magnetic resonance imaging in prostate cancer]. / Utilidad de la resonancia magnética en el cáncer de próstata.

In the last decade, technical advances in magnetic resonance imaging (MRI) have made it the technique of choice in the overall management of patients with suspected or confirmed prostate cancer. MR makes it possible to acquire information about morphology and function in the same examination by using techniques like spectroscopy, diffusion, and dynamic sequences with intravenous contrast material administration. Moreover, MRI enables both focused study of the prostate gland and of regional and/or whole-body involvement, depending on the clinical indications, in less than an hour. The main clinical indications for MRI of the prostate are a) staging local, regional, and/or remote disease; b) detecting prostate cancer or guiding prostate biopsy in cases of clinical suspicion or negative findings in previous biopsy specimens; and c) monitoring the response to treatment. It is important to know the different protocols with specific MRI sequences for the prostate, depending on the different clinical indications, to ensure that they are performed and interpreted correctly. This article provides up-to-date information about the use of MRI for the study of the prostate to show how the morphological and functional information can be used in clinical practice.

[Functional imaging of tumors. Part 2]. / Imagen funcional tumoral. Parte 2.

Most advances in conventional diagnostic imaging techniques have focused on improving the spatial resolution and speed of acquisition of images or on new contrast agents. However, tumors are extremely complex biological models with a series of characteristics like hypoxia, metabolism, cellularity, angiogenesis, and functionality of the lymph nodes that are very important in oncology but cannot be adequately studied with these diagnostic imaging methods. In this article, we discuss the possible contributions of different functional imaging techniques based on computed tomography, magnetic resonance imaging, or positron emission tomography to obtain information about different biological processes and characteristics that are very important for diagnosing, staging, planning treatment, evaluating the response to treatment, and monitoring the evolution of cancer patients, as well as for the development of new drugs.

[Diagnostic imaging of liposclerosing myxofibrous tumor of bone]. / Diagnóstico por imagen del fibromixoma lipoesclerosante óseo.

Liposclerosing myxofibrous tumor of bone is a benign lesion with a complex histologic structure. Its origin is uncertain, although it seems to be related to intraosseous lipomas and fibrous dysplasia, and it is sometimes impossible to distinguish from these two entities. It is usually located in the intertrochanteric region of the femur. Radiologically, it is a well-defined lytic lesion with sclerotic margins and high signal intensity in T2- weighted MR images. We present two cases with radiologic characteristics and location compatible with liposclerosing myxofibrous tumor of bone. In one case, PET studies suggested a malignant lesion. The diagnosis can be established on the basis of the radiological characteristics and location of the lesion: PET and histologic examination can sometimes lead to the wrong diagnosis.