Magnetic Resonance Imaging Interpretation Research Articles

Development of a Radiomic-Based Model Predicting Lymph Node Involvement in Prostate Cancer Patients.

Simple SummaryIn patients with prostate cancer, lymph node involvement is a risk factor of relapse. Current guidelines recommend extended lymph node dissection to better stage the disease. However, such a surgical procedure is associated with a higher morbidity than limited lymph node dissection. A better selection of patients is thus essential. Radiomics features are quantitative features automatically extracted from medical imaging. Combining clinical and radiomics features, a machine learning-based model seemed to provide added predictive performance compared to state of the art models regarding the risk prediction of lymph-node involvement in prostate cancer patients.Significant advances in lymph node involvement (LNI) risk modeling in prostate cancer (PCa) have been achieved with the addition of visual interpretation of magnetic resonance imaging (MRI) data, but it is likely that quantitative analysis could further improve prediction models. In this study, we aimed to develop and internally validate a novel LNI risk prediction model based on radiomic features extracted from preoperative multimodal MRI. All patients who underwent a preoperative MRI and radical prostatectomy with extensive lymph node dissection were retrospectively included in a single institution. Patients were randomly divided into the training (60%) and testing (40%) sets. Radiomic features were extracted from the index tumor volumes, delineated on the apparent diffusion coefficient corrected map and the T2 sequences. A ComBat harmonization method was applied to account for inter-site heterogeneity. A prediction model was trained using a neural network approach (Multilayer Perceptron Network, SPSS v24.0©) combining clinical, radiomic and all features. It was then evaluated on the testing set and compared to the current available models using the Receiver Operative Characteristics and the C-Index. Two hundred and eighty patients were included, with a median age of 65.2 y (45.3–79.6), a mean PSA level of 9.5 ng/mL (1.04–63.0) and 79.6% of ISUP ≥ 2 tumors. LNI occurred in 51 patients (18.2%), with a median number of extracted nodes of 15 (10–19). In the testing set, with their respective cutoffs applied, the Partin, Roach, Yale, MSKCC, Briganti 2012 and 2017 models resulted in a C-Index of 0.71, 0.66, 0.55, 0.67, 0.65 and 0.73, respectively, while our proposed combined model resulted in a C-Index of 0.89 in the testing set. Radiomic features extracted from the preoperative MRI scans and combined with clinical features through a neural network seem to provide added predictive performance compared to state of the art models regarding LNI risk prediction in PCa.

Development of an Online Curriculum for Surgeons on the Use of Pelvic Magnetic Resonance Imaging in Rectal Cancer and Results of a Pilot Study

High-resolution pelvic magnetic resonance imaging (MRI) is a critical tool in the management of patients with rectal cancer. An on-line curriculum was developed for surgical trainees on the interpretation of pelvic MRI in rectal cancer for clinical staging and surgical planning. The online curriculum was developed using the six-step approach to curriculum development for medical education. The curriculum incorporated case-based learning, annotated videos, and narrated presentations on key aspects of pelvic MRI in rectal cancer. A pilot study was conducted to assess curriculum effectiveness among Complex General Surgical Oncology (CGSO) fellows using pre- and post-intervention assessments. Of 15 eligible fellows, nine completed the pilot study (60%). The fellows' median confidence score after completing the online curriculum (40, IQR: 33-46) was significantly higher than their baseline median confidence score (23, IQR: 14-30), P=0.0039. The total practical assessment score significantly increased from a pre-median score of 9 (IQR: 8-11) to a post-median score of 14 (IQR: 13-14), P=0.0078. A subgroup analysis revealed a significant change in the knowledge assessment with a median score of 7 compared to a baseline median score of 4, Z=2.64, P=0.0078. However, the skills assessment showed no significant change. The case-based online curriculum had a positive impact on CGSO fellows' knowledge and confidence in the utilization of pelvic MRI for patients with rectal cancer. This unique on-line curriculum demonstrates a mechanism to enhance shared educational collaboration across CGSO fellowships and other surgical training programs.

Magnetic Resonance Imaging (MRI): Basics for the Gynecologist

<h3>Study Objective</h3> The aim of our video is to provide fundamental knowledge regarding the use and interpretation of magnetic resonance imaging (MRI) in regard to gynecology. We will describe the mechanisms behind MRI and review clinical considerations such as indications for MRI, use of contrast, and contraindications. We will provide basic concepts in the interpretation of images and review common imaging findings the gynecologist may encounter. <h3>Design</h3> 6-minute educational video. <h3>Setting</h3> N/A. <h3>Patients or Participants</h3> Our video is targeted toward medical students, residents, fellows, and providers who practice gynecologic care. <h3>Interventions</h3> N/A. <h3>Measurements and Main Results</h3> N/A. <h3>Conclusion</h3> In addition to first-line diagnostic tools, MRI can serve as a helpful adjunct in the gynecologist's armamentarium. Through basic understanding of MRI and pattern recognition of common gynecologic pathologies, providers can better utilize MR images.

Musculoskeletal MRI Findings of Haematological Diseases

Abstract Background Hematologic diseases are a group of prevalent and clinically diverse diseases that can affect any organ system. Hematologic disorders frequently involve bone and associated tissues causing significant alterations in the bone marrow and may have relevant side effects on the skeleton. In order to evaluate findings in bone marrow on MR imaging, it is essential to understand the normal composition and distribution of bone marrow and the changes in marrow that occur with age, as well as the basis for the MR signals from marrow and the factors that affect those signals. Aim of the Work To describe the musculoskeletal MRI findings in patients with hematological diseases. Patients and Methods cross sectional study was conducted in Ain Shams University hospitals on patients confirmed with hematological disease undergoing musculoskeletal MRI. Conclusion Magnetic resonance imaging is very beneficial noninvasive modality to evaluate bone marrow and detecting marrow lesions due to its ability to provide information at the level of cellular and chemical composition. Knowing normal marrow components and composition and their variation, as well as of factors that affect MR signal intensity, is important for optimal interpretation of MR images. The signal intensity, morphology, and location of marrow findings on MRI can be used to provide accurate diagnoses and to guide treatment of the discussed hematological diseases.

Cytotoxic Edema Associated with Hemorrhage Predicts Poor Outcome after Traumatic Brain Injury.

Magnetic resonance imaging (MRI) is used rarely in the acute evaluation of traumatic brain injury (TBI) but may identify findings of clinical importance not detected by computed tomography (CT). We aimed to characterize the association of cytotoxic edema and hemorrhage, including traumatic microbleeds, on MRI obtained within hours of acute head trauma and investigated the relationship to clinical outcomes. Patients prospectively enrolled in the Traumatic Head Injury Neuroimaging Classification study (NCT01132937) with evidence of diffusion-related findings or hemorrhage on neuroimaging were included. Blinded interpretation of MRI for diffusion-weighted lesions and hemorrhage was conducted, with subsequent quantification of apparent diffusion coefficient (ADC) values. Of 161 who met criteria, 82 patients had conspicuous hyperintense lesions on diffusion-weighted imaging (DWI) with corresponding regions of hypointense ADC in proximity to hemorrhage. Median time from injury to MRI was 21 (10-30) h. Median ADC values per patient grouped by time from injury to MRI were lowest within 24 h after injury. The ADC values associated with hemorrhagic lesions are lowest early after injury, with an increase in diffusion during the subacute period, suggesting transformation from cytotoxic to vasogenic edema during the subacute post-injury period. Of 118 patients with outcome data, 60 had Glasgow Outcome Scale Extended scores ≤6 at 30/90 days post-injury. Cytotoxic edema on MRI (odds ratio [OR] 2.91 [1.32-6.37], p = 0.008) and TBI severity (OR 2.51 [1.32-4.74], p = 0.005) were independent predictors of outcome. These findings suggest that in patients with TBI who had findings of hemorrhage on CT, patients with DWI/ADC lesions on MRI are more likely to do worse.

Guidelines on postoperative magnetic resonance imaging in patients operated for cryptoglandular anal fistula: Experience from 2404 scans.

Magnetic resonance imaging (MRI) is considered the gold standard for the evaluation of anal fistulas. There is sufficient literature available outlining the interpretation of fistula MRI before performing surgery. However, the interpretation of MRI becomes quite challenging in the postoperative period after the surgery of fistula has been undertaken. Incidentally, there are scarce data and no set guidelines regarding analysis of fistula MRI in the postoperative period. In this article, we discuss the challenges faced while interpreting the postoperative MRI, the timing of the postoperative MRI, the utility of MRI in the postoperative period for the management of anal fistulas, the importance of the active involvement and experience of the treating clinician in interpreting MRI scans, and the latest advancements in the field.

Standardized Classification of Lumbar Spine Degeneration on Magnetic Resonance Imaging Reduces Intra- and Inter-subspecialty Variability

Background and PurposeTo determine the efficacy of standardized definitions of degenerative change in reducing variability in interpretation of lumbar spine magnetic resonance imaging within and between groups of subspecialty-trained neuroradiologists (NR) and musculoskeletal radiologists (MSK). Materials and MethodsSix radiologists, three from both NR and MSK groups were trained on a standardized classification system of degenerative change. After an 11-month washout period, they independently re-interpreted fifty exams at the L4-L5 and L5-S1 levels. Responses were converted to a six-point ordinal scale for the assessment of neural foraminal stenosis and spinal canal stenosis (SCS), three-point scale for lateral recess stenosis, and four-point scale for facet osteoarthritis (FO). Intra-subspecialty and inter-subspecialty analysis was performed using the weighted Cohen's kappa with a binary matrix of all reader pairs. ResultsInter-subspecialty agreement improved from k=0.527 (moderate) to k=0.602 (substantial) for neural foraminal stenosis, from k=0.540 (moderate) to k=0.652 (substantial) for SCS, from k=0.0818 (slight) to k=0.337 (fair) for lateral recess stenosis, and from k=0.176 (slight) to k=0.495 (moderate) for FO. The NR group demonstrated improved intra-subspecialty agreement for the assessment of SCS, from k=0.368 (fair) to k=0.638 (substantial). The MSK group demonstrated improved intra-subspecialty agreement for the assessment of FO, from k=0.134 (slight) to k=0.413 (moderate). Intra-subspecialty agreement was similar for other parameters before and after training. ConclusionsAs result of the standardized definitions training, the NR and MSK groups each improved in one of the four parameters, while inter-subspecialty variability improved in all four parameters. These definitions may be useful in clinical practice across radiology subspecialties.

Abdominal fellowship-trained versus generalist radiologist accuracy when interpreting MR and CT for the diagnosis of appendicitis.

To compare the diagnostic accuracy of generalist radiologists working in a community setting against abdominal radiologists working in an academic setting for the interpretation of MR when diagnosing acute appendicitis among emergency department patients. This observational study examined MR image interpretation (non-contrast MR with diffusion-weighted imaging and intravenous contrast-enhanced MR) from a prospectively enrolled cohort at an academic hospital over 18 months. Eligible patients had an abdominopelvic CT ordered to evaluate for appendicitis and were > 11 years old. The reference standard was a combination of surgery and pathology results, phone follow-up, and chart review. Six radiologists blinded to clinical information, three each from community and academic practices, independently interpreted MR and CT images in random order. We calculated test characteristics for both individual and group (consensus) diagnostic accuracy then performed Chi-square tests to identify any differences between the subgroups. Analysis included 198 patients (114 women) with a mean age of 31.6 years and an appendicitis prevalence of 32.3%. For generalist radiologists, the sensitivity and specificity (95% confidence interval) were 93.8% (84.6-98.0%) and 88.8% (82.2-93.2%) for MR and 96.9% (88.7-99.8%) and 91.8% (85.8-95.5%) for CT. For fellowship-trained radiologists, the sensitivity and specificity were 96.9% (88.2-99.5%) and 89.6% (82.8-94%) for MR and 98.4% (90.5-99.9%) and 93.3% (87.3-96.7%) for CT. No statistically significant differences were detected between radiologist groups (p = 1.0, p = 0.53, respectively) or when comparing MR to CT (p = 0.21, p = 0.17, respectively). MR is a reliable, radiation-free imaging alternative to CT for the evaluation of appendicitis in community-based generalist radiology practices. • There was no significant difference in MR image interpretation accuracy between generalist and abdominal fellowship-trained radiologists when evaluating sensitivity (p = 1.0) and specificity (p = 0.53). • There was no significant difference in accuracy comparing MR to CT imaging for diagnosing appendicitis for either sensitivity (p = 0.21) or specificity (p = 0.17). • With experience, generalist radiologists enhanced their MR interpretation accuracy as demonstrated by improved interpretation sensitivity (OR 2.89 CI 1.44-5.77, p = 0.003) and decreased mean interpretation time (5 to 3.89 min).

Development and validation of a predictive model for determining clinically significant prostate cancer in men with negative magnetic resonance imaging after transrectal ultrasound-guided prostate biopsy.

The interpretation of negative magnetic resonance imaging (MRI) screening results for clinically significant prostate cancer (csPCa) (International Society of Urological Pathology grade ≥group 2) is debatable and poses a clinical dilemma for urologists. No nomograms have been developed to predict csPCa in such populations. In this study, we aimed to develop and validate a model for predicting the probability of csPCa in men with negative MRI (PI-RADS score 1-2) results after transrectal ultrasound-guided systematic prostate biopsy. The development cohort consisted of 728 patients with negative MRI results who underwent subsequent prostate biopsy at our center between January 1, 2014 and December 31, 2017. The patients' clinicopathologic data were recorded. The Lasso regression was used for data dimension reduction and feature selection, then multivariable binary logistic regression was used to build a predictive model with regression coefficients. The model was validated in an independent cohort of 334 consecutive patients from January 1, 2018 and June 30, 2020. The performance of the predictive model was assessed with respect to discrimination, calibration, and decision curve analysis. The predictors incorporated in this model included age, history of previous negative prostate biopsy, prostate specific antigen density (PSAD), and lower urinary tract symptoms, with PSAD being the strongest predictor. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.875 (95% confidence interval, 0.816-0.933) and good calibration (unreliability test, p = .540). Decision curve analysis demonstrated that the model was clinically useful. This study presents a good nomogram that can aid pre-biopsy risk stratification for the detection of csPCa, and that may help inform biopsy decisions in patients with negative MRI results.

Accuracy of Brain MRI Interpretation of Emergency Medicine Specialists Versus Radiologist and Neurologist in Suspected Acute Ischemic Stroke Patients; a Diagnostic Accuracy Study

Background: Despite numerous brain magnetic resonance imaging (MRI) utilization in the emergency department (ED), certainly, imaging alone is not enough, and it is necessary to have a correct interpretation by a physician who has sufficient skills in this regard. Objectives: Here, we decided to investigate the accuracy of interpreting brain MRI of suspected acute ischemic stroke (AIS) patients conducted by emergency medicine physicians (EMPs) in comparison with a radiologist and a neurologist. Methods: This diagnostic accuracy study was conducted from April to November 2019 in Tehran, Iran. All attending EMPs of one major educational, medical center, a radiologist, and a neurologist also participated. A set of brain MRI stereotypes related to patients suspected of having a AIS was randomly selected. By reviewing the brain MRI interpretation of EMPs, once in comparison with the radiologist and once in comparison with the neurologist, misinterpretations (presence or absence of findings compatible with the diagnosis of AIS) were extracted. Results: Brain MRI stereotypes of 287 suspected AIS patients were interpreted of these patients, 160 cases (55.7%) were male. The mean age of the study patients was 65.0 ± 14.1 (range of 18 to 98) years. The value of the agreement for diagnosis between EMPs and neurologists was 0.684 (95% CI: 0.580 to 0.787). Considering the neurologist as the gold standard, the accuracy of AIS diagnosis by the EMPs was 0.85% (95% CI: 79.3 to 89.6). The agreement value for diagnosis between EMPs and radiologist was 0.673 (95% CI: 0.553 to 0.794). Considering the radiologist as the gold standard, the accuracy of AIS diagnosis by the EMPs was 86.3% (95% CI: 79.8 to 91.3). The agreement value for diagnosis in these two groups was 0.752 (95% CI: 0.627 to 0.877). Conclusions: The findings of the current study revealed that the accuracy of brain MRI interpretation performed by the EMPs, compared with both neurologist and radiologist was proper.

MAGNETIC RESONANCE IMAGING OF LATERAL MENISCAL POSTERIOR ROOT TEARS IN THE ADOLESCENT KNEE: IS THE DIAGNOSIS MISSED, MENTIONED, OR MADE?

Background:The meniscal roots play a vital role in maintaining proper knee kinematics. Neglected meniscal root tears place excess stress on the articular cartilage and increase the risk of premature osteoarthritis. As opposed to medial meniscal root tears, lateral meniscal posterior root tears (LMPRTs) are more likely to be associated with anterior cruciate ligament (ACL) pathology. Failure to identify and address meniscal root tears may place undue loads on ACL grafts and lead to inferior post-surgical outcomes.Purpose:To examine preoperative knee magnetic resonance imaging (MRI) radiologist interpretations for the identification of lateral meniscal root pathology in children and adolescents.Methods:We performed a retrospective review of children and adolescents that underwnent knee arthroscopy between 3/1/2010 and 4/1/2020 and had an arthroscopically confirmed LMPRT. Arthroscopic findings were compared to the reading radiologist’s preoperative MRI interpretations. LMPRTs were graded using the LaPrade classification. ANOVA was performed to assess if body mass index (BMI), open physes, time from injury to MRI, time from MRI to surgery, MRI magnet field strength, musculoskeletal radiologist designation, insurance type and tear grade were associated with the preoperative MRI identification of a LMPRT.Results:During the study period, 1285 knee arthroscopies were performed. 607 of which were ACL reconstructions. 54 children were found to have a LMPRT arthroscopically and all were associated with an ACL tear 54/607 (9%). One patient had 2 preoperative MRIs for a total of 55 MRIs in 54 pateints. Average age was 16 years (range 14-21). Preoperative MRI diagnosis of a LMPRT was made in only 14/55 (25%) and missed in 22/55 (40%). In 19/55 (35%), pathology of the lateral meniscus nonspecific to the root was mentioned. Lateral joint line tenderness was present in 23/54 (46%). There was no statistical significance found in regards to patient BMI, skeletal maturity, time from injury to MRI, time from MRI to surgery, MRI magnet strength, if the radiologist was musculoskeletal fellowship-trained, or insurance type, with a reliable diagnosis. (Table)Conclusion:The final interpretation of preoperative MRIs did not provide a clear definitive diagnosis of a LMPRT in 75 % in patients. As the intraoperative management of LMPRTs can be involved and diverge from standard meniscal work, preoperative diagnosis would be advantageous. All LMPRTs in this study were associated with a concomitant ACL tear. Surgeons caring for ACL tears in children and adolescents should be prepared to treat a LMPRT regardless of a inconclusive MRI interpretation for meniscal root pathology.

The Value of Combination of Dynamic Contrast-Enhanced Magnetic Resonance Imaging and Diffusion-Weighted Imaging in the Evaluation of Breast Masses

Aim of the study: The aim was to characterize benign and malignant breast lesions on the basis of their magnetic resonance imaging (MRI) morphology and dynamic contrast enhancement in combination with the diffusion-weighted imaging (DWI) and their apparent diffusion coefficient (ADC) values at 1.5 T MRI, along with histopathological correlation. Patients and Methods: In this prospective study, 56 patients with suspicious breast mass who underwent 1.5 T MRI and proved by histopathology were included. Morphology was studied depending on the MRI signal intensity and dynamic contrast-enhanced imaging plus kinetic curve of enhancement of breast lesions. DWI and ADC values were calculated at b values of 0, 600, and 850 s/mm. The ADC value and histopathology correlation were analyzed. Results: Out of the 56 lesions, 27 lesions were histologically malignant (48.2%) and 29 were histologically benign (51.8%), with age range between 25 and 75 years, with a mean of 54.1 years, and with a standard deviation of ±12.69 years. The MRI results found a sensitivity (SN) of 85.2%, a specificity (SP) of 72.4%, a positive predictive value (PPV) of 74.2%, a negative predictive value (NPV) of 84%, and an accuracy of 78.6%. The DWI findings were as follows: 100% SN, 82.8% SP, 84.4% PPV, 100% NPV, and 85.3% accuracy. The combined MRI interpretation and DWI and ADC findings were as follows: 100% SN, 92.1% SP, 71.1% PPV, 100% NPV, and 86.4% accuracy. All malignant lesions showed restriction at DWI, while only 17.2% of the benign lesions are restricted at DWI. The mean of ADC value was higher in benign cases as compared to the malignant lesions (0.815 vs. 1.287 × 10−3) with statistically significant difference (P = 0.001). Conclusions: The combination of contrast-enhanced breast MRI with DWI and ADC value increases the diagnostic accuracy and SP in the characterization of benign and malignant breast lesions.

Fully Automatic Deep Learning in Bi-institutional Prostate Magnetic Resonance Imaging: Effects of Cohort Size and Heterogeneity.

The potential of deep learning to support radiologist prostate magnetic resonance imaging (MRI) interpretation has been demonstrated. The aim of this study was to evaluate the effects of increased and diversified training data (TD) on deep learning performance for detection and segmentation of clinically significant prostate cancer-suspicious lesions. In this retrospective study, biparametric (T2-weighted and diffusion-weighted) prostate MRI acquired with multiple 1.5-T and 3.0-T MRI scanners in consecutive men was used for training and testing of prostate segmentation and lesion detection networks. Ground truth was the combination of targeted and extended systematic MRI-transrectal ultrasound fusion biopsies, with significant prostate cancer defined as International Society of Urological Pathology grade group greater than or equal to 2. U-Nets were internally validated on full, reduced, and PROSTATEx-enhanced training sets and subsequently externally validated on the institutional test set and the PROSTATEx test set. U-Net segmentation was calibrated to clinically desired levels in cross-validation, and test performance was subsequently compared using sensitivities, specificities, predictive values, and Dice coefficient. One thousand four hundred eighty-eight institutional examinations (median age, 64 years; interquartile range, 58-70 years) were temporally split into training (2014-2017, 806 examinations, supplemented by 204 PROSTATEx examinations) and test (2018-2020, 682 examinations) sets. In the test set, Prostate Imaging-Reporting and Data System (PI-RADS) cutoffs greater than or equal to 3 and greater than or equal to 4 on a per-patient basis had sensitivity of 97% (241/249) and 90% (223/249) at specificity of 19% (82/433) and 56% (242/433), respectively. The full U-Net had corresponding sensitivity of 97% (241/249) and 88% (219/249) with specificity of 20% (86/433) and 59% (254/433), not statistically different from PI-RADS (P > 0.3 for all comparisons). U-Net trained using a reduced set of 171 consecutive examinations achieved inferior performance (P < 0.001). PROSTATEx training enhancement did not improve performance. Dice coefficients were 0.90 for prostate and 0.42/0.53 for MRI lesion segmentation at PI-RADS category 3/4 equivalents. In a large institutional test set, U-Net confirms similar performance to clinical PI-RADS assessment and benefits from more TD, with neither institutional nor PROSTATEx performance improved by adding multiscanner or bi-institutional TD.

Barium Defecating Proctography and Dynamic Magnetic Resonance Proctography: Their Role and Patient's Perception.

Objectives:The objectives of the study were to compare the imaging findings and patient’s perception of barium defecating proctography and dynamic magnetic resonance (MR) proctography in patients with pelvic floor disorders.Material and Methods:This is a prospective study conducted on patients with pelvic floor disorders who consented to undergo both barium proctography and dynamic MR proctography. Imaging findings of both the procedures were compared. Inter-observer agreement (IOA) for key imaging features was assessed. Patient’s perception of these procedures was assessed using a short questionnaire and a visual analog scale.Results:Forty patients (M: F =19:21) with a mean age of 43.65 years and range of 21–75 years were included for final analysis. Mean patient experience score was significantly better for MR imaging (MRI) (p < 0.001). However, patients perceived significantly higher difficulty in rectal evacuation during MRI studies (p = 0.003). While significantly higher number of rectoceles (p = 0.014) were diagnosed on MRI, a greater number of pelvic floor descent (p = 0.02) and intra-rectal intussusception (p = 0.011) were diagnosed on barium proctography. The IOA for barium proctography was substantial for identifying rectoceles, rectal prolapse and for determining M line, p < 0.001. There was excellent IOA for MRI interpretation of cystoceles, peritoneoceles, and uterine prolapse and substantial to excellent IOA for determining anal canal length and anorectal angle, p < 0.001. The mean study time for the barium and MRI study was 12 minutes and 15 minutes, respectively.Conclusion:Barium proctography was more sensitive than MRI for detecting pelvic floor descent and intrarectal intussusception. Although patients perceived better rectal emptying with barium proctography, the overall patient experience was better for dynamic MRI proctography.

Variability in Interpretation of Magnetic Resonance Imaging of the Pediatric Sacroiliac Joint.

Magnetic resonance imaging (MRI) is pivotal in the assessment of early sacroiliitis in children. We aimed to evaluate the agreement between local radiology reports and central imaging reviewers for active inflammation and structural damage at the sacroiliac (SI) joints. Eight hospitals each contributed up to 20 cases of consecutively imaged children and adolescents with juvenile idiopathic arthritis and suspected sacroiliitis. Studies were independently reviewed by 3 experienced musculoskeletal pediatric radiologists. Local assessments of global impression and lesions were coded from the local radiology reports by 2 study team members. Test properties of local reports were calculated using the central imaging team's majority as the reference standard. For 120 evaluable subjects, the median age was 14 years, half of the cases were male, and median disease duration at the time of imaging was 0.8 years (interquartile range 0-2). Sensitivity of local reports for inflammation was high, 93.5% (95% confidence interval [95% CI] 78.6-99.2), and specificity was moderate, 69.7% (95% CI 59.0-79.0), but positive predictive value (PPV) was low, 51.8% (95% CI 38.0-65.3). Twenty-seven cases (23%) had active inflammation reported locally but rated normal at the central reading, 19 (70%) with subsequent medication changes. The sensitivity of local reports detecting structural damage was low, 45.7% (95% CI 28.8-63.4), and specificity was high, 88.2% (95% CI 79.4-94.2); PPV was low, 61.5% (95% CI 40.6-79.8). Substantial variation exists in the interpretation of inflammatory and structural lesions at the SI joints in children. To reliably identify pathology, additional training in the MRI appearance of the maturing SI joint is greatly needed.

3D MRI of the Hand and Wrist: Technical Considerations and Clinical Applications.

In the last few years, major developments have been observed in the field of magnetic resonance imaging (MRI). Advances in both scanner hardware and software technologies have witnessed great leaps, enhancing the diagnostic quality and, therefore, the value of MRI. In musculoskeletal radiology, three-dimensional (3D) MRI has become an integral component of the diagnostic pathway at our institutions. This technique is particularly relevant in patients with hand and wrist symptoms, due to the intricate nature of the anatomical structures and the wide range of differential diagnoses for most presentations. We review the benefits of 3D MRI of the hand and wrist, commonly used pulse sequences, clinical applications, limitations, and future directions. We offer guidance for enhancing the image quality and tips for image interpretation of 3D MRI of the hand and wrist.

A Multicenter Diagnostic Accuracy Study on Prehospital Stroke Screening Scales.

Stroke is one of the most common debilitating diseases. Although effective treatment is available, a golden time has been defined in this regard. Therefore, prompt action is needed to identify patients with stroke as soon as possible, even in the pre-hospital stage. In recent years, several clinical scales have been introduced for this purpose. We performed the present study to examine the accuracy of eight clinical scales in terms of stroke diagnosis. This multicenter diagnostic accuracy study was conducted in 2019. All patients older than 18 years who were admitted to the emergency department (ED) and underwent brain magnetic resonance imaging (MRI) for a suspected stroke were eligible. All data were gathered through a pre-prepared checklist consisting of three sections, using the clinical records of the patients. The first section of the checklist included basic characteristics and demographic data. The second part included physical examination findings of 19 items related to the 8 scales. The third part was dedicated to the final diagnosis based on the interpretation of brain MRI, which was considered the gold standard for the diagnosis of acute ischemic stroke (AIS) in the current study. The data from 805 patients suspected of stroke were analyzed. In all, 463 patients (57.5%) were male. The participants' age was 6-95 years with a mean age of 66.9 years (SD = 13.9). Of all the registered patients, 562 (69.8%) had an AIS. The accuracy of screening tests was 63.0% to 84.4%. The sensitivity and specificity were 71.9% to 95.7% and 46.5% to 82.8%, respectively. Among all the screening tests, Los Angeles Pre-Hospital Stroke Screening (LAPSS) had the lowest sensitivity, and Medic Prehospital Assessment for Code Stroke (Med PACS) had the highest sensitivity. In addition, Pre-Hospital Ambulance Stroke Test (PreHAST) had the lowest specificity and LAPSS had the highest specificity. Based on the findings of the present study, highly sensitive tests that can be used in this regard are Cincinnati Prehospital Stroke Scale (CPSS), Face-Arm-Speech-Time (FAST), and Med PACS, all of which have about 95% sensitivity. On the other hand, none of the studied tools were desirable (specificity above 95%) in any of the examined cut-offs.

Posterior shoulder labrocapsular structures in all aspects; 3D volumetric MR arthrography study.

Pathologies of the posterior labrocapsular structures of the shoulder joint are far less common than anterior labrocapsuloligamentous lesions. Most of these pathologies have been associated with traumatic posterior dislocation. A smaller portion of the lesions include posterior extension of superior labral anteroposterior lesions, posterior superior internal impingement, and damage to the posterior band of the inferior glenohumeral ligament. Labrocapsular anatomic variations of the posterior shoulder joint can mimic labral pathology on conventional MR and occasionally on MR arthrographic images. Knowledge of this variant anatomy is key to interpreting MR images and studying MR arthrography of the posterior labrocapsular structure to avoid misdiagnosis and unnecessary surgical procedures. In this article, we review normal and variant anatomy of the posterior labrocapsular structure of the shoulder joint based on MR arthrography and discuss how to discriminate normal anatomic variants from labrocapsular damage.

Applications of artificial intelligence in prostate cancer imaging.

The purpose of this review was to identify the most recent lines of research focusing on the application of artificial intelligence (AI) in the diagnosis and staging of prostate cancer (PCa) with imaging. The majority of studies focused on the improvement in the interpretation of bi-parametric and multiparametric magnetic resonance imaging, and in the planning of image guided biopsy. These initial studies showed that AI methods based on convolutional neural networks could achieve a diagnostic performance close to that of radiologists. In addition, these methods could improve segmentation and reduce inter-reader variability. Methods based on both clinical and imaging findings could help in the identification of high-grade PCa and more aggressive disease, thus guiding treatment decisions. Though these initial results are promising, only few studies addressed the repeatability and reproducibility of the investigated AI tools. Further, large-scale validation studies are missing and no diagnostic phase III or higher studies proving improved outcomes regarding clinical decision making have been conducted. AI techniques have the potential to significantly improve and simplify diagnosis, risk stratification and staging of PCa. Larger studies with a focus on quality standards are needed to allow a widespread introduction of AI in clinical practice.

Whole-body MRI: a practical guide for imaging patients with malignant bone disease

Whole-body magnetic resonance imaging (MRI) is now a crucial tool for the assessment of the extent of systemic malignant bone disease and response to treatment, and forms part of national and international recommendations for imaging patients with myeloma or metastatic prostate cancer. Recent developments in scanners have enabled acquisition of good-quality whole-body MRI data within 45 minutes on modern MRI systems from all main manufacturers. This provides complimentary morphological and functional whole-body imaging; however, lack of prior experience and acquisition times required can act as a barrier to adoption in busy radiology departments. This article aims to tackle the former by reviewing the indications and providing guidance for technical delivery and clinical interpretation of whole-body MRI for patients with malignant bone disease.