RF coil that minimizes electronic components while enhancing performance for rodent MRI at 7 Tesla.

This study introduces a novel volume coil design that features two slotted end-plates connected by six rungs, resembling the traditional birdcage coil. The end rings are equipped with six evenly distributed circular slots, inspired by Mansfield's cavity resonator theory, which suggests that circular slots can generate a baseline resonant frequency. One notable advantage of this proposed coil design is its reduced reliance on electronic components compared to other volume coils, making it more efficient. Additionally, the dimensions of the coil can be theoretically computed in advance, enhancing its practicality. To evaluate the performance and safety of the coil, electromagnetic field and specific absorption rate simulations were simulated using a cylindrical saline phantom and the finite element method. Furthermore, a transceiver coil prototype optimized for 7 Tesla and driven in quadrature was constructed, enabling whole-body imaging of rats. The resonant frequency of the coil prototype obtained through experimental measurements closely matched the theoretical frequency derived from Mansfield's theory. To validate the coil design, phantom images were acquired to demonstrate its viability and assess its performance. These images also served to validate the magnetic field simulations. The experimental results aligned well with the simulation findings, confirming the reliability of the proposed coil design. Importantly, the prototype coil showcased significant improvements over a similarly-sized birdcage coil, indicating its potential for enhanced performance. The noise figure was lower in the prototype versus the birdcage coil (NFbirdcage-NFslotcage= 0.7). Phantom image data were also used to compute the image SNR, giving SNRslotcage/SNRbirdcage= 34.36/24.34. By proving the feasibility of the coil design through successful rat whole-body imaging, the study provides evidence supporting its potential as a viable option for high-field MRI applications on rodents.

Remote RF excitation for small-bore MR imager at 15.2 T.

We report a method for remote excitation of the RF signal for preclinical-equivalent ultra high field Magnetic Resonance Imaging (MRI). A parallel-plate waveguide together with a bio-inspired surface coil were used to perform remote excitation experiments to acquire images with a small-bore MR imager at 15.2 T. The imager bore size limits the RF coil transmitter dimensions, so the Gielis super-formula was used to design an RF coil with small dimensions. Electromagnetic simulations of the principal mode were run to study the waveguide filled with air and loaded with a saline solution-filled tube. Radiation patterns were also computed in a semi-anechoic chamber for the same scenarios as above. A saline solution-filled spherical phantom and a formaldehyde-fixed mouse phantom were used to acquire images. Radiation patterns showed an omnidirectional distribution with no side lobes, and a very smooth behaviour with almost no loss of information in the saline solution-filled tube and without. The theoretical wave impedance was calculated and compared with simulated results showing an excellent correspondence. Spherical phantom image data and simulation results of B1 were contrasted and showed an important correlation. Ex vivo mouse images were of high quality and exhibited clear delineation of anatomical structures. These imaging results are in very good agreement with the simulations. Numerical, theoretical and experimental results validate this approach, using a bio-inspired surface coil with a simple waveguide for preclinical small-bore MRI at ultra high field.

Polyorquidism: case report comparing ultrasonography and magnetic resonance imaging / Poliorquidismo: relato de caso comparando a ultrassonografia e a ressonância magnética

Abstract Introduction: polyorchidism is an unusual pathology, about 200 cases in the world literature. Case report: we reported a case of polyorchidism in a 16-year-old male patient diagnosed by ultrasound and confirmed by magnetic resonance imaging. Discussion: most of the cases presented, there is a supernumerary testis, but there are reports on more than three, up to five testicles with supranumerical gonads on both sides of the scrotum. The diagnosis is usually performed in late puberty, incidentally, with a painless scrotal mass or at the emergency room, presenting a testicular torsion of the whole hemiscrotum or supernumerary testisalone, and the differential diagnosis should be made with epididymal cyst and spermatocele, besides other extra-testicular masses (hydroceles, varicoceles, lipomas, tumors.) and para-testicular masses (hernias, scrotal calculi). After the initial clinical evaluation, ultrasound is the first line subsidiary exam. Magnetic Resonance Imaging is very helpful, just in case the ultrasound diagnosis is uncertain. The supernumerary testishave the same Magnetic Resonance Imaging characteristics as the normal testes (intermediate signal intensity on T1- weighted images and high signal intensity on T2-weighted images).

Resumo Introdução: o poliorquidismo é uma patologia incomum, contando cerca de 200 casos na literatura mundial. Relato de caso: relatamos um caso de poliorquidismo em um paciente do sexo masculino de 16 anos, diagnosticado por ultrassom e confirmado por ressonância magnética. Discussão: na maioria dos casos apresentados, há um testículo supranumérico, mas há relatos de mais de três, até cinco testículos, com gônadas supranuméricas em ambos os lados do escroto. O diagnóstico geralmente é feito no final da puberdade, aliás, com massa escrotal indolor ou no pronto-socorro, apresentando torção de todo o hemiscroto ou somente do testículo supranumerário, e o diagnóstico diferencial deve ser feito com cisto epididimário e espermatocele, além de outros massas extratesticulares (hidroceles, varicoceles, lipomas, tumores) e massas paratesticulares (hérnias, cálculos escrotais). Após a avaliação clínica inicial, o ultrassom é a primeira linha do exame subsidiário. A ressonância magnética é muito útil se o diagnóstico por ultrassom não for certo. Os testículos supranumerários têm as mesmas características de ressonância magnética que os testículos normais (intensidade do sinal intermediário nas imagens ponderadas em T1 e alta intensidade do sinal nas imagens ponderadas em T2).

A fast field-cycling MRI relaxometer for physical contrasts design and pre-clinical studies in small animals.

We present a fast field-cycling NMR relaxometer with added magnetic resonance imaging capabilities. The instrument operates at a maximum proton Larmor frequency of 5 MHz for a sample volume of 35 mL. The magnetic field homogeneity across the sample is 1400 ppm. The main field is generated with a notch-coil electromagnet of own design, fed with a current whose stability is 220 ppm. We show that images of reasonable quality can still be produced under such conditions. The machine is being designed for concept testing of the involved instrumentation and specific contrast agents aimed for field-cycling magnetic resonance imaging applications. The general performance of the prototype was tested through localized relaxometry experiments, T1-dispersion weighted images, temperature maps and T1-weighted images at different magnetic field intensities. We introduce the concept of positive and negative contrast depending on the use of pre-polarized or non-polarized sequences. The system is being improved for pre-clinical studies in small animals.

Machine learning techniques for computer-aided classification of active inflammatory sacroiliitis in magnetic resonance imaging

Abstract Background: Currently, magnetic resonance imaging (MRI) is used to evaluate active inflammatory sacroiliitis related to axial spondyloarthritis (axSpA). The qualitative and semiquantitative diagnosis performed by expert radiologists and rheumatologists remains subject to significant intrapersonal and interpersonal variation. This encouraged us to use machine-learning methods for this task. Methods: In this retrospective study including 56 sacroiliac joint MRI exams, 24 patients had positive and 32 had negative findings for inflammatory sacroiliitis according to the ASAS group criteria. The dataset was randomly split with ∼ 80% (46 samples, 20 positive and 26 negative) as training and ∼ 20% as external test (10 samples, 4 positive and 6 negative). After manual segmentation of the images by a musculoskeletal radiologist, multiple features were extracted. The classifiers used were the Support Vector Machine, the Multilayer Perceptron (MLP), and the Instance-Based Algorithm, combined with the Relief and Wrapper methods for feature selection. Results: Based on 10-fold cross-validation using the training dataset, the MLP classifier obtained the best performance with sensitivity = 100%, specificity = 95.6% and accuracy = 84.7%, using 6 features selected by the Wrapper method. Using the test dataset (external validation) the same MLP classifier obtained sensitivity = 100%, specificity = 66.7% and accuracy = 80%. Conclusions: Our results show the potential of machine learning methods to identify SIJ subchondral bone marrow edema in axSpA patients and are promising to aid in the detection of active inflammatory sacroiliitis on MRI STIR sequences. Multilayer Perceptron (MLP) achieved the best results.(AU)

Elbow Injuries Detected on Magnetic Resonance Imaging in Athletes Participating in the Rio de Janeiro 2016 Summer Olympic Games.

BACKGROUND: Athletes are prone to both acute and chronic overuse injuries of the elbow joint. The purpose of this study was to describe the frequency, anatomic distribution, and severity of magnetic resonance imaging (MRI)-detected elbow joint injuries among athletes who competed in the Rio de Janeiro 2016 Summer Olympics. METHODS: All sports injuries reported by the National Olympic Committee medical teams and the Organizing Committee medical staff during the 2016 Summer Olympics were analyzed. Magnetic resonance imaging was performed at the International Olympic Committee's polyclinic within the Olympic Village, using 3- and 1.5-T scanners. The MRIs were read centrally and retrospectively by musculoskeletal radiologists with expertise in sports injuries. The distribution of elbow joint injuries by anatomic location and sports discipline and the severity of injuries were recorded. RESULTS: A total of 1101 injuries were reported in the 11,274 athletes from 207 teams at the Games. Central review of MRI revealed elbow joint injuries in 15 athletes (60% male; median age, 22 years; range, 18-39 years). Ligamentous injuries were most common, with injuries of the ulnar collateral ligament being the most prevalent (n = 12; 80%), followed by the common flexor tendon (n = 8; 53%). Osseous injuries were far less common (n = 3; 20%), with no acute fractures seen. Weightlifting (n = 4; 27%) and judo (n = 4; 27%) athletes were most commonly affected. CONCLUSION: Magnetic resonance imaging-detected elbow injuries during the 2016 Summer Olympics affected mainly the ulnar collateral ligament and the common flexor tendon, with the highest occurrence in weight lifting and judo.

Resonancia magnética nuclear en cardiología infantil / Magnetic resonance imaging in pediatric cardiology

Los innegables progresos en la supervivencia de los pacientes con cardiopatía congénita en los últimos años fue acompañado de los avances en todas las áreas concurrentes a la cirugía cardiovascular, incluyendo la recuperación y los métodos diagnósticos que permiten una mejor comprensión de la patología cardíaca congénita o adquirida. La velocidad con que se desarrollan estas herramientas en el arsenal médico, exige una mejor comprensión a la hora de definir la estrategia diagnóstica para cada paciente en particular. Tradicionalmente, las imágenes diagnósticas de las cardiopatías congénitas eran dominio de la ecocardiografía y el cateterismo. En los últimos 10 años, la Resonancia y la Tomografía Computada fueron ganando terreno. La principal ventaja de la Resonancia es que no utiliza Rayos X para obtener las imágenes, diferencia de la angiografía por cateterismo y la tomografía axial computada. La resonancia magnética cardíaca se ha convertido en una herramienta importante para evaluar la enfermedad cardíaca congénita y también la adquirida en niños y adultos. La variedad y complejidad de la patología y sus posibilidades quirúrgicas hace indispensable la presencia del cardiólogo infantil durante la adquisición de las imágenes y su post procesamiento. En esta sección se presentarán algunas de las herramientas o secuencias que utiliza la Resonancia Magnética Cardíaca y su utilización práctica en el diagnóstico de las cardiopatías más frecuentes (AU)

The undeniable progress in survival of patients with congenital heart defects in recent years has been accompanied by advances in all areas related to cardiovascular surgery, including recovery and diagnostic methods that allow for a better understanding of congenital or acquired heart disease. The speed with which these tools are developed in the medical arsenal requires a better understanding when defining the diagnostic strategy for each individual patient. Traditionally, diagnostic images of choice for congenital heart disease were echocardiography and catheterization. Over the last 10 years, MRI. and CT scan have become more important. The main advantage of MRI is that it does not use X-rays to obtain the images, unlike catheterization and computed tomography angiogram. Cardiac MRI has become an important tool for assessing congenital and acquired heart disease in children and adults. The variety and complexity of the disease and its surgical possibilities warrant the presence of the child cardiologist during imaging acquisition and processing. This section will present some of the MRI tools and sequences and their practical use in the diagnosis of the most common heart diseases (AU)

7.0T ultrahigh-field MRI directly visualized the pedunculopontine nucleus in Parkinson's disease patients.

OBJECTIVES: The pedunculopontine nucleus (PPN) is considered a promising new target for neurostimulation in Parkinson's disease (PD) patients with postural instability and gait disturbance that is refractory to other treatment modalities. However, the PPN is typically difficult to visualize with magnetic resonance imaging (MRI) at clinical field strengths, which greatly limits the PPN as a viable surgical target for deep brain stimulation (DBS). Thus, the aim of this study is to directly visualize the PPN based on 7.0T ultrahigh-field MRI. METHODS: Five PD patients were enrolled and scanned using the MP2RAGE sequence on a 7.0T ultrahigh-field MRI scanner. Then, the MP2RAGE sequences were imported into a commercially available navigation system. The coordinates of the directly localized PPN poles were recorded in the navigation system relative to the anterior commissure-posterior commissure plane. RESULTS: Our results indicated that the PPN presented intermediate signal intensity in the 7.0T ultrahigh-field MR images in comparison with the surrounding structure, such as the hypo-intensity of the periaqueductal gray and the hyperintensity of the neighboring white matter tracts, in PD patients. The mean coordinates for the rostral and caudal poles of PPN were 6.50 mm and 7.20 mm lateral, 1.58 mm and 2.21 mm posterior, and 8.89 mm and 13.83 mm relative to the posterior commissure. CONCLUSION: Our findings provide, for the first time, direct visualization of the PPN using the MP2RAGE sequence on a 7.0T ultrahigh-field MRI, which may improve the accuracy of stereotactic targeting of the PPN and improve the outcomes in patients undergoing DBS.

7. 0T ultrahigh-field MRI directly visualized the pedunculopontine nucleus in Parkinson's disease patients

OBJECTIVES: The pedunculopontine nucleus (PPN) is considered a promising new target for neurostimulation in Parkinson's disease (PD) patients with postural instability and gait disturbance that is refractory to other treatment modalities. However, the PPN is typically difficult to visualize with magnetic resonance imaging (MRI) at clinical field strengths, which greatly limits the PPN as a viable surgical target for deep brain stimulation (DBS). Thus, the aim of this study is to directly visualize the PPN based on 7.0T ultrahigh-field MRI. METHODS: Five PD patients were enrolled and scanned using the MP2RAGE sequence on a 7.0T ultrahigh-field MRI scanner. Then, the MP2RAGE sequences were imported into a commercially available navigation system. The coordinates of the directly localized PPN poles were recorded in the navigation system relative to the anterior commissure-posterior commissure plane. RESULTS: Our results indicated that the PPN presented intermediate signal intensity in the 7.0T ultrahigh-field MR images in comparison with the surrounding structure, such as the hypo-intensity of the periaqueductal gray and the hyperintensity of the neighboring white matter tracts, in PD patients. The mean coordinates for the rostral and caudal poles of PPN were 6.50 mm and 7.20 mm lateral, 1.58 mm and 2.21 mm posterior, and 8.89 mm and 13.83 mm relative to the posterior commissure. CONCLUSION: Our findings provide, for the first time, direct visualization of the PPN using the MP2RAGE sequence on a 7.0T ultrahigh-field MRI, which may improve the accuracy of stereotactic targeting of the PPN and improve the outcomes in patients undergoing DBS.

Foot drop: an iatrogenic complication of spinal anesthesia / Pé caído: uma complicação iatrogênica da anestesia espinhal

Abstract Background and objectives Foot drop in postoperative period is very rare after spinal anesthesia. Early clinical assessment and diagnostic interventions is of prime importance to establish the etiology and to start appropriate management. Close follow-up is warranted in early postoperative period in cases when patient complain paresthesia or pain during needle insertion or drug injection. Case report A 22-year-old male was undergone lower limb orthopedic surgery in spinal anesthesia. During shifting from postoperative ward footdrop was suspected during routine assessment of regression of spinal level. Immediately the patient was referred to a neurologist and magnetic resonance imaging was done, which was inconclusive. Conservative management was started and nerve conduction study was done on the 4th postoperative day that confirmed pure motor neuropathy of right peroneal nerve. Patient was discharged with ankle splint and physiotherapy after slight improvement in motor power (2/5). Conclusions Foot drop is very rare after spinal anesthesia. Any suspected patient must undergo emergent neurological consultation and magnetic resonance imaging to exclude major finding and need for early surgical intervention.

Resumo Justificativa e objetivos Pé caído no período pós-operatório é muito raro após a anestesia espinhal. Avaliação clínica e intervenções diagnósticas precoces são de primordial importância para estabelecer a etiologia e iniciar o tratamento adequado. Um acompanhamento atento é justificado no pós-operatório imediato nos casos em que o paciente se queixa de parestesia ou dor durante a inserção da agulha ou da injeção de fármacos. Relato de caso Paciente do sexo masculino, 22 anos, submetido a cirurgia ortopédica de membros inferiores sob anestesia espinhal. Durante a transferência para a sala de recuperação pós-operatória, houve suspeita de pé caído durante a avaliação rotineira da regressão do nível espinhal. O paciente foi imediatamente enviado ao neurologista e uma ressonância magnética foi feita, mas não foi conclusiva. O manejo conservador foi iniciado e o estudo de condução nervosa foi feito no 4° dia de pós-operatório, o que confirmou a neuropatia motora pura do nervo fibular direito. O paciente foi dispensado com imobilizador de tornozelo e fisioterapia após ligeira melhoria da força motora (2/5). Conclusões Pé caído é muito raro após a anestesia espinhal. Qualquer paciente suspeito deve ser submetido à consulta neurológica de emergência e ressonância magnética para excluir o principal achado e a necessidade de intervenção cirúrgica precoce.

Polymer gel dosimetry by nuclear Overhauser enhancement (NOE) magnetic resonance imaging.

The response to radiation of polymer gel dosimeters has previously been measured by magnetic resonance imaging (MRI) in terms of changes in the water transverse relaxation rate (R 2w) or magnetization transfer (MT) parameters. Here we report a new MRI approach, based on detecting nuclear Overhauser enhancement (NOE) mediated saturation transfer effects, which can also be used to detect radiation and measure dose distributions in MAGIC-f (Methacrylic and Ascorbic Acid and Gelatin Initiated by Copper Solution with formaldehyde) polymer gels. Results show that the NOE effects produced by low powered radiofrequency (RF) irradiation at specific frequencies offset from water may be quantified by appropriate measurements and over a useful range depend linearly on the radiation dose. The NOE effect likely arises from the polymerization of methacrylic acid monomers which become less mobile, facilitating dipolar through-space cross-relaxation and/or relayed magnetization exchange between polymer and water protons. Our study suggests a potential new MRI method for polymer gel dosimetry.

Atrial myxoma in a patient with patent foramen ovale: evaluation with multimodal imaging. Case report / Mixoma auricular en un paciente con foramen oval permeable: evaluación con imágenes multimodales. Reporte de un caso

Abstract: Primary cardiac tumors in adults are rare and mostly benign, approximately 75%, being the myxoma the most frequent in half of that percentage. One-fourth of the primary cardiac tumors are malignant and 95% of the cases are sarcomas. Metastases are more frequent than primary tumors. Cardiac surgery is indicated specially in benign masses and therapies such as chemotherapy and/or radiotherapy should be reserved for unresectable or metastatic malignancies. Hence the importance of a diagnostic approach, which leads to the best therapeutic conduct and in many cases, a multimodal image approach is necessary, as it is exposed in our case.(AU)

Resumen: Los tumores cardiacos primarios en adultos son raros y en su mayoría benignos, aproximadamente el 75%, siendo el mixoma el más frecuente en la mitad de ese porcentaje. Un cuarto de los tumores cardiacos primarios son malignos y el 95% de los casos son sarcomas. Las metástasis son más frecuentes que los tumores primarios. La cirugía cardiaca está indicada especialmente en masas benignas y las terapias como la quimioterapia y/o la radioterapia deben reservarse para tumores malignos o metástasis irresecables. De ahí la importancia de un enfoque de diagnóstico, que conduzca a la mejor conducta terapéutica y, en muchos casos, es necesario un enfoque de imagen multimodal, como está expuesto en nuestro caso.(AU)

Fast nonlinear susceptibility inversion with variational regularization.

PURPOSE: Quantitative susceptibility mapping can be performed through the minimization of a function consisting of data fidelity and regularization terms. For data consistency, a Gaussian-phase noise distribution is often assumed, which breaks down when the signal-to-noise ratio is low. A previously proposed alternative is to use a nonlinear data fidelity term, which reduces streaking artifacts, mitigates noise amplification, and results in more accurate susceptibility estimates. We hereby present a novel algorithm that solves the nonlinear functional while achieving computation speeds comparable to those for a linear formulation. METHODS: We developed a nonlinear quantitative susceptibility mapping algorithm (fast nonlinear susceptibility inversion) based on the variable splitting and alternating direction method of multipliers, in which the problem is split into simpler subproblems with closed-form solutions and a decoupled nonlinear inversion hereby solved with a Newton-Raphson iterative procedure. Fast nonlinear susceptibility inversion performance was assessed using numerical phantom and in vivo experiments, and was compared against the nonlinear morphology-enabled dipole inversion method. RESULTS: Fast nonlinear susceptibility inversion achieves similar accuracy to nonlinear morphology-enabled dipole inversion but with significantly improved computational efficiency. CONCLUSION: The proposed method enables accurate reconstructions in a fraction of the time required by state-of-the-art quantitative susceptibility mapping methods. Magn Reson Med 80:814-821, 2018. © 2018 International Society for Magnetic Resonance in Medicine.

Tackling variability: A multicenter study to provide a gold-standard network approach for frontotemporal dementia.

Biomarkers represent a critical research area in neurodegeneration disease as they can contribute to studying potential disease-modifying agents, fostering timely therapeutic interventions, and alleviating associated financial costs. Functional connectivity (FC) analysis represents a promising approach to identify early biomarkers in specific diseases. Yet, virtually no study has tested whether potential FC biomarkers prove to be reliable and reproducible across different centers. As such, their implementation remains uncertain due to multiple sources of variability across studies: the numerous international centers capable conducting FC research vary in their scanning equipment and their samples' socio-cultural background, and, more troublingly still, no gold-standard method exists to analyze FC. In this unprecedented study, we aim to address both issues by performing the first multicenter FC research in the behavioral-variant frontotemporal dementia (bvFTD), and by assessing multiple FC approaches to propose a gold-standard method for analysis. We enrolled 52 bvFTD patients and 60 controls from three international clinics (with different fMRI recording parameters), and three additional neurological patient groups. To evaluate FC, we focused on seed analysis, inter-regional connectivity, and several graph-theory approaches. Only graph-theory analysis, based on weighted-matrices, yielded consistent differences between bvFTD and controls across centers. Also, graph metrics robustly discriminated bvFTD from the other neurological conditions. The consistency of our findings across heterogeneous contexts highlights graph-theory as a potential gold-standard approach for brain network analysis in bvFTD. Hum Brain Mapp 38:3804-3822, 2017. © 2017 Wiley Periodicals, Inc.

Prostate cancer detection using multiparametric 3 – tesla MRI and fusion biopsy: preliminary results

ABSTRACT Objective: To evaluate the diagnostic efficacy of transrectal ultrasonography (US) biopsy with imaging fusion using multiparametric (mp) magnetic resonance imaging (MRI) in patients with suspicion of prostate cancer (PCa), with an emphasis on clinically significant tumors according to histological criteria. Materials and Methods: A total of 189 consecutive US/MRI fusion biopsies were performed obtaining systematic and guided samples of suspicious areas on mpMRI using a 3 Tesla magnet without endorectal coil. Clinical significance for prostate cancer was established based on Epstein criteria. Results: In our casuistic, the average Gleason score was 7 and the average PSA was 5.0ng/mL. Of the 189 patients that received US/MRI biopsies, 110 (58.2%) were positive for PCa. Of those cases, 88 (80%) were clinically significant, accounting for 46.6% of all patients. We divided the MRI findings into 5 Likert scales of probability of having clinically significant PCa. The positivity of US/MRI biopsy for clinically significant PCa was 0%, 17.6% 23.5%, 53.4% and 84.4% for Likert scores 1, 2, 3, 4 and 5, respectively. There was a statistically significant difference in terms of biopsy results between different levels of suspicion on mpMRI and also when biopsy results were divided into groups of clinically non-significant versus clinically significant between different levels of suspicion on mpMRI (p-value <0.05 in both analyzes). Conclusion: We found that there is a significant difference in cancer detection using US/MRI fusion biopsy between low-probability and intermediate/high probability Likert scores using mpMRI.

Prostate cancer detection using multiparametric 3 - tesla MRI and fusion biopsy: preliminary results.

OBJECTIVE: To evaluate the diagnostic efficacy of transrectal ultrasonography (US) bi¬opsy with imaging fusion using multiparametric (mp) magnetic resonance imaging (MRI) in patients with suspicion of prostate cancer (PCa), with an emphasis on clini¬cally significant tumors according to histological criteria. MATERIALS AND METHODS: A total of 189 consecutive US/MRI fusion biopsies were per¬formed obtaining systematic and guided samples of suspicious areas on mpMRI using a 3 Tesla magnet without endorectal coil. Clinical significance for prostate cancer was established based on Epstein criteria. RESULTS: In our casuistic, the average Gleason score was 7 and the average PSA was 5.0ng/mL. Of the 189 patients that received US/MRI biopsies, 110 (58.2%) were positive for PCa. Of those cases, 88 (80%) were clinically significant, accounting for 46.6% of all patients. We divided the MRI findings into 5 Likert scales of probability of having clinically significant PCa. The positivity of US/MRI biopsy for clinically significant PCa was 0%, 17.6% 23.5%, 53.4% and 84.4% for Likert scores 1, 2, 3, 4 and 5, respectively. There was a statistically significant difference in terms of biopsy results between dif¬ferent levels of suspicion on mpMRI and also when biopsy results were divided into groups of clinically non-significant versus clinically significant between different lev¬els of suspicion on mpMRI (p-value < 0.05 in both analyzes). CONCLUSION: We found that there is a significant difference in cancer detection using US/MRI fusion biopsy between low-probability and intermediate/high probability Likert scores using mpMRI.