A Deep Learning-based Model for Detecting Abnormalities on Brain MR Images for Triaging: Preliminary Results from a Multisite Experience.

PURPOSE: To develop a deep learning model for detecting brain abnormalities on MR images. MATERIALS AND METHODS: In this retrospective study, a deep learning approach using T2-weighted fluid-attenuated inversion recovery images was developed to classify brain MRI findings as "likely normal" or "likely abnormal." A convolutional neural network model was trained on a large, heterogeneous dataset collected from two different continents and covering a broad panel of pathologic conditions, including neoplasms, hemorrhages, infarcts, and others. Three datasets were used. Dataset A consisted of 2839 patients, dataset B consisted of 6442 patients, and dataset C consisted of 1489 patients and was only used for testing. Datasets A and B were split into training, validation, and test sets. A total of three models were trained: model A (using only dataset A), model B (using only dataset B), and model A + B (using training datasets from A and B). All three models were tested on subsets from dataset A, dataset B, and dataset C separately. The evaluation was performed by using annotations based on the images, as well as labels based on the radiology reports. RESULTS: Model A trained on dataset A from one institution and tested on dataset C from another institution reached an F1 score of 0.72 (95% CI: 0.70, 0.74) and an area under the receiver operating characteristic curve of 0.78 (95% CI: 0.75, 0.80) when compared with findings from the radiology reports. CONCLUSION: The model shows relatively good performance for differentiating between likely normal and likely abnormal brain examination findings by using data from different institutions.Keywords: MR-Imaging, Head/Neck, Computer Applications-General (Informatics), Convolutional Neural Network (CNN), Deep Learning Algorithms, Machine Learning Algorithms© RSNA, 2021Supplemental material is available for this article.

Relapsing polychondritis in childhood: three case reports, comparison with adulthood disease and literature review.

Relapsing polychondritis (RP) is a rare autoimmune systemic disease, especially in childhood. To report three new pediatric RP cases, to provide a literature review and to compare with adulthood disease, retrospective data collection from three childhood RP cases was observed in a Brazilian Pediatric Rheumatology Division. A literature review based on a MEDLINE database search was performed. Arthritis and auricular chondritis were present in our three patients. Two cases presented with early and severe laryngotracheal chondritis, besides initial and symptomatic costochondritis. The other case developed prominent epiphyseal plate involvement. Two patients were refractory to corticosteroids and immunosuppressants and required the use of TNF-alpha inhibitors to improve the symptoms, while corticosteroids plus methotrexate induced remission in the other patient. The literature review showed 44 cases of pediatric-onset disease in English language. Arthritis and ear chondritis are the most common initial and cumulative manifestations of RP in children and adults. Nasal and laryngotracheobronchial chondritis are also common manifestations observed during follow-up in childhood. There is also an early severity of respiratory chondritis in childhood, requiring aggressive treatment with corticosteroids, immunosuppressants and biologic agents. The data presented by those 3 children, considered in conjunction with the data from the 44 published cases, may reflect some distinguishing childhood RP features, such as more severe and frequent respiratory tract involvement, symptomatic costochondritis and the atypical pattern of persistent and destructive arthritis with epiphyseal plate involvement. Response to immunosuppressants and biologic agents is anecdotal, but steroids remain the main drug during the flares.

Magnetic resonance imaging of the lumbar spine with axial loading: a review of 120 cases.

PURPOSE: To evaluate the imaging findings of patients with clinical symptoms of lower back pain who underwent magnetic resonance imaging (MRI) of the lumbar spine with axial loading. MATERIALS AND METHODS: We examined 120 patients by MRI, before and after axial loading, using a compression device that applied 50% of their body weight for a load time of 5min. The dural sac cross area (DSCA) was examined by two experienced radiologists before and after axial load, and their findings were compared. Degenerative abnormalities within and adjacent to the spinal canal were also analyzed. RESULTS: A reduction in DSCA greater than 15mm(2) after axial load was defined as significant, and was found in 81 patients (67.5%) and 138 disc spaces (38.3%). Reduction was most frequent at L4-L5 (n=55). For other disorders, a 9% increase in cases of bulging disc was seen during axial loading, and seven disc spaces showed protrusion/extrusion only after load. Facet joint synovial cysts, foraminal stenosis, and hypertrophy of the flavum ligaments showed almost no differences, pre- and post-load. CONCLUSION: For adequate evaluation of lumbar symptoms, examination should be performed with axial loading, especially in cases of suspected spinal stenosis.

(99m)Tc-anti-TNF-α scintigraphy in RA: a comparison pilot study with MRI and clinical examination.

OBJECTIVE: To compare the use of radiolabelled human monoclonal anti-TNF-α scintigraphy with clinical examination and MRI of hands and wrists joints in patients with active RA. METHODS: Eight patients with active RA, 28-joint DAS (DAS-28) ≥ 3.2 and a healthy volunteer underwent whole body and hand/wrist scintigraphy after the administration of anti-human TNF-α labelled with technetium-99m ((99m)Tc). One hundred and ninety-eight joints were examined. Patients were also given clinical examinations in addition to MRI of the hands and wrists. RESULTS: Of the 198 joints examined, signs of inflammation were detected by MRI in 49 (24.7%) and by scintigraphy in 48 (24.2%) joints, with agreement between the two methods in 44 joints. In five joints, MRI was positive and scintigraphy negative. In another four joints, scintigraphy was positive and MRI negative for signs of inflammation. MRI and scintigraphy were in agreement for negative results for 145 joints. The sensitivity and specificity of scintigraphy was 89.8 and 97.3%, respectively. When clinical parameters (presence of swelling and tenderness of joints) were compared with the MRI findings, lower correlation coefficients were observed (sensitivity of 59.2% and 65.3%, respectively). CONCLUSIONS: Scintigraphy using (99m)Tc-anti-TNF-α showed high correlation with the presence of inflammatory signs detected by MRI in the hands and wrists of patients with active RA, and demonstrated a greater sensitivity than clinical examination. These results can assist in better understanding of anti-cytokine therapy and support the achievement of evidence-based biologic therapy.

Evaluation of hippocampal volume based on MR imaging in patients with bipolar affective disorder applying manual and automatic segmentation techniques.

PURPOSE: To compare the hippocampal volumes in patients with bipolar disorder (BD) and healthy controls, obtained by applying different segmentation methods (manual, Freesurfer [FS], and FSL). MATERIALS AND METHODS: The study included 27 patients with BD and 40 healthy controls. T1-weighted images in the sagittal plane were acquired on a 3 Tesla (T) MR scanner. Hippocampal volumetry was performed using one manual and two automated methods (FS and FSL). One-way repeated analysis of variance was applied to test the differences in hippocampal volumes using the three segmentation methods. To evaluate the agreement among the three tested volumetric segmentation methods the intraclass correlation coefficients (ICCs) were calculated. RESULTS: Hippocampal volumes obtained from all methods were significantly different (P < 0.05) in BD patients after intracranial volume correction, indicating a reduction in volume, unless from the manual method of the left hippocampal volume. The ICCs of the hippocampal volume between the manual method and FS were 0.846 (right) and 0.859 (left), and between the manual method and FSL were 0.746 (right) and 0.654 (left). CONCLUSION: Both manual and automatic segmentation methods detected reductions in the hippocampal volumes in BD patients. Automated segmentation methods are a robust and reproducible option for assessing hippocampal volume.

Diffusion MR imaging: an important tool in the assessment of brain tumors.

For over 20 years, conventional MR imaging has been used for assessing brain tumors. However, conventional MR imaging tends to underestimate the extent of the tumor, perhaps leading to suboptimal treatment. New MR imaging tools have been widely used to determine the grade, heterogeneity, and extent of brain tumors. Diffusion-weighted imaging has been studied extensively, helping in tumor grading, differential diagnosis, and postoperative evaluation. Diffusion tensor imaging can apparently delineate more accurately the tumor versus the infiltrating tumor between the peritumoral edema and the normal brain parenchyma. This article shows the main clinical applications of these sequences.

Diffusion imaging in brain infections.

Diffusion-weighted magnetic resonance imaging (DWI) provides image contrasts that are different from conventional magnetic resonance techniques. DWI is particularly sensitive for detecting acute ischemic stroke, but it also has many other clinical applications, including the evaluation of central nervous system (CNS) infections. This article addresses the role of DWI in the differential diagnosis of CNS infections, and discusses the most common DWI findings for each type of infection.

Diffusion imaging in traumatic brain injury.

Traumatic brain injury is a common cause of death worldwide, affecting mostly young people. The most feasible examination to be performed in the emergency room is computed tomography. Magnetic resonance (MR) imaging is becoming a significant tool in the evaluation of severe brain trauma. Diffusion-weighted imaging is an advanced MR imaging sequence that has been used to detect areas of ischemia and tumor malignancy. This article describes the recent advances in trauma based on diffusion-weighted MR imaging findings and in brain injury from head trauma based on diffusion-weighted MR imaging and diffusion tensor MR imaging findings. Current and potential clinical applications are discussed.

MR imaging in deep pelvic endometriosis: a pictorial essay.

Deep pelvic endometriosis is an important gynecologic disorder that is responsible for severe pelvic pain and is defined as subperitoneal invasion that exceeds 5 mm in depth. Deep pelvic endometriosis can affect the retrocervical region, uterosacral ligaments, rectum, rectovaginal septum, vagina, urinary tract, and other extraperitoneal pelvic sites. It is commonly associated with dysmenorrhea, dyspareunia, pelvic pain, urinary tract symptoms, and infertility. Because surgery remains the best therapeutic option for affected patients, the accurate preoperative assessment of the extension of endometriotic disease is extremely important. Pelvic magnetic resonance (MR) imaging is a noninvasive method with high spatial resolution that allows multiplanar evaluation of deep pelvic endometriosis and good tissue characterization, but without the use of ionizing radiation or iodinated contrast agents. MR imaging yields important findings that help grade the disease and identify subperitoneal lesion extension and other associated disease entities, thereby facilitating accurate diagnosis and adequate treatment. Radiologists should be familiar with the MR imaging findings of deep infiltrating endometriosis in various anatomic locations so that they can provide information that allows adequate presurgical counseling.

BMI and metabolic profile in patients with prolactinoma before and after treatment with dopamine agonists.

Hyperprolactinemia might be related to weight gain, metabolic syndrome (MS), and insulin resistance (IR). Treatment with dopamine agonist (DA) has been shown to reduce body weight and improve metabolic parameters. The objectives of this study were to determine the prevalence of obesity, overweight, MS, and IR in patients with prolactinoma before and after therapy with DA and to evaluate the relation between prolactin (PRL), body weight, fat distribution, leptin levels, IR, and lipid profile before treatment. In addition, we investigated the correlation of the reduction in PRL levels with weight loss and metabolic profile improvement. Twenty-two patients with prolactinoma completed 6 months of treatment with DA. These patients were submitted to clinical (BMI, waist circumference, blood pressure (BP)), laboratory evaluation (leptin, glucose, low-density lipoprotein (LDL)-cholesterol, and triglyceride (TG) levels) and abdominal computed tomography (CT) before and after treatment. The statistical analyses were done by nonparametric tests. At the beginning of the study, the prevalence of obesity, overweight, MS, and IR was 45, 27, 27, and 18%, respectively. After 6 months of treatment with DA, PRL levels normalized, but no significant difference in BMI was observed. However, there was a significant decrease on homeostasis model assessment of insulin resistance (HOMA(IR)) index, glucose, LDL-cholesterol, and TG levels. This study suggests a possible involvement of prolactinoma on the prevalence of obesity. We should consider that DA may be effective on improving metabolic parameters, and we speculate that a period longer than 6 months of treatment is necessary to conclude whether this drug can interfere in the body weight of patients with prolactinoma.

Diffusion tensor imaging of the cervical spinal cord of patients with relapsing-remising multiple sclerosis: a study of 41 cases.

OBJECTIVE: To evaluate the fractional anisotropy (FA) values of the multiple sclerosis (MS) plaques and normal-appearing cervical spinal cord (NASC) by diffusion tensor MRI imaging (DTI). METHOD: Forty-one patients with relapsing-remising MS and 37 controls were evaluated. All MRI exams were performed using a conventional protocol, as well as diffusion tensor MR imaging. Regions of interest were placed within the spinal cord lesions and in the normal appearing spinal cord adjacent to the plaque. RESULTS: The FA values were statistically reduced in the plaques compared to the surrounding NASC and to equivalent location in controls. A reduction in FA values was also observed in the spinal cord of MS patients without visible lesions on T2WI. CONCLUSION: We observed reduced fractional anisotropy in the demyelinating plaques and in the NASC of MS patients, corroborating the hypothesis that the histological extension of the MS lesions is more severe than the abnormalities seen in the conventional MRI sequences.

Diffusion tensor imaging of the cervical spinal cord of patients with relapsing-remising multiple sclerosis: a study of 41 cases / Imagens por tensor de difusão da medula cervical de pacientes com esclerose múltipla remitente-recorrente: estudo de 41 casos

OBJECTIVE: To evaluate the fractional anisotropy (FA) values of the multiple sclerosis (MS) plaques and normal-appearing cervical spinal cord (NASC) by diffusion tensor MRI imaging (DTI). METHOD: Forty-one patients with relapsing-remising MS and 37 controls were evaluated. All MRI exams were performed using a conventional protocol, as well as diffusion tensor MR imaging. Regions of interest were placed within the spinal cord lesions and in the normal appearing spinal cord adjacent to the plaque. RESULTS: The FA values were statistically reduced in the plaques compared to the surrounding NASC and to equivalent location in controls. A reduction in FA values was also observed in the spinal cord of MS patients without visible lesions on T2WI. CONCLUSION: We observed reduced fractional anisotropy in the demyelinating plaques and in the NASC of MS patients, corroborating the hypothesis that the histological extension of the MS lesions is more severe than the abnormalities seen in the conventional MRI sequences.

OBJETIVO: Avaliar os valores da anisotropia fracionada (FA) em pacientes com esclerose múltipla (EM) nas placas e na medula espinhal aparentemente normal (MEAN). MÉTODO: Quarenta e um pacientes com EM remitente-recorrente e 37 controles foram examinados. Todos os exames foram realizados com protocolo convencional, assim como imagens por tensor de difusão. Regiões de interesse foram definidas nas placas da medula espinhal e na MEAN ao redor das placas. RESULTADOS: Os valores de FA estavam significativamente reduzidos nas placas, comparados à MEAN ao redor e às regiões equivalentes dos controles. Redução dos valores de FA também foi demonstrada na medula espinhal de pacientes com EM sem lesões visíveis nas imagens de RM pesadas em T2. CONCLUSÃO: Observamos redução dos valores de anisotropia fracionada nas placas de desmielinização e na MEAN, corroborando a hipótese de que a extensão histológica das lesões na EM é maior que as alterações de sinal vistas nas seqüências convencionais de ressonância magnética.

Whole-body MRI and FDG PET fused images for evaluation of patients with cancer.

OBJECTIVE: The purpose of this article is to illustrate the feasibility of fused whole-body MRI and PET for the evaluation of patients with cancer. CONCLUSION: MRI has proven to be superior to CT for studying several regions of the body, and PET FDG has become an established diagnostic tool in oncology. Because FDG accumulates avidly in tumor tissue, fusing FDG PET to whole-body MRI allows good anatomy-based evaluation of disease.

Diffusion-weighted MR images and pineoblastoma: diagnosis and follow-up.

Pineoblastomas are uncommon pineal tumors, which demonstrate rapid growing and poor prognosis. We report the case of a 43-year-old man with an enhancing pineal region mass, which showed restriction of the diffusion on diffusion-weighted (DW) MR images. The surgical biopsy defined the diagnosis of pineoblastoma and the therapy was initiated with radiation and chemotherapy. Three months later, the follow-up MR imaging showed areas suggestive of necrosis and the DW images demonstrate no significant areas of restricted diffusion. The differential diagnosis of pineal region masses that could show restriction of diffusion is discussed.

Diffusion-weighted MR images and pineoblastoma: diagnosis and follow-up

Pineoblastomas are uncommon pineal tumors, which demonstrate rapid growing and poor prognosis. We report the case of a 43-year-old man with an enhancing pineal region mass, which showed restriction of the diffusion on diffusion-weighted (DW) MR images. The surgical biopsy defined the diagnosis of pineoblastoma and the therapy was initiated with radiation and chemotherapy. Three months later, the follow-up MR imaging showed areas suggestive of necrosis and the DW images demonstrate no significant areas of restricted diffusion. The differential diagnosis of pineal region masses that could show restriction of diffusion is discussed.

Pineoblastomas são tumores incomuns da glândula pineal, os quais têm crescimento rápido e prognóstico reservado. Os autores objetivam relatar o caso de um homem de 43 anos de idade com uma massa na região pineal com realce pelo contraste, a qual demonstrou restrição da difusão nas imagens de ressonância magnética (RM) pesadas em difusão. A biópsia cirúrgica definiu o diagnóstico de pineoblastoma e o tratamento foi iniciado com radio e quimioterapia. Três meses mais tarde, a RM de controle demonstrou áreas sugestivas de necrose e não mais eram observadas áreas de restrição da difusão da água. O diagnóstico diferencial das massas na região pineal que podem apresentar restrição da difusão é discutido.

Quantitative analysis of somatostatin receptor subtypes (1-5) gene expression levels in somatotropinomas and correlation to in vivo hormonal and tumor volume responses to treatment with octreotide LAR.

OBJECTIVE: To determine whether the somatostatin receptor subtype (SSTR) expression profile correlates with hormonal and tumor volume responses to postsurgical octreotide long acting repeatable (OCT LAR) treatment. DESIGN AND METHODS: Quantitative real-time RT-PCR was used to evaluate the absolute mRNA copy numbers for all five SSTR subtypes in 22 somatotropinomas. Response to OCT LAR was studied by hormone levels (GH and IGF-I) and tumor volume (sella turcica magnetic resonance imaging). RESULTS: SSTR5 was present at the highest level followed by SSTR2, SSTR3, SSTR1, and SSTR4 (2327 (1046-5555), 2098 (194-23 954), 97 (0-460), 14 (0-29 480), and 0 (0-652) copies respectively). Positive correlations were found between SSTR2 levels and the percentage decrease of GH and IGF-I after 3 (r=0.49, P<0.027 and r=0.49, P<0.029 respectively) and 6 (r=0.59, P<0.006 and r=0.58, P<0.008 respectively) months of OCT LAR. A negative correlation was found between SSTR5 mRNA levels and the percentage decrease of GH after 3 months of OCT LAR (r=-0.52, P=0.016, n=21). A higher SSTR2/SSTR5 ratio was observed among patients who obtained hormonal control with OCT LAR, when compared with those uncontrolled (2.4 (0.7-10) vs 0.3 (0.1-7.7), P=0.001). A ROC curve analysis showed a SSTR2/SSTR5 ratio of 1.3 as the best predictor of disease control, with a sensitivity of 88% and a specificity of 92% - area under curve, 0.9. A positive correlation was also found between SSTR2 mRNA levels and the percentage decrease in tumor volume after 6 months of OCT LAR (r=0.79, P=0.002, n=12). CONCLUSIONS: Somatostatin receptor subtype 2 mRNA expression levels in somatotropinomas correlate positively with in vivo hormonal and tumor volume responses to OCT LAR.

Walker-warburg syndrome: reports of two cases

The purpose of this study is to describe two infants that were diagnosed with Walker-Warburg syndrome (WWS), a rare form of congenital muscular dystrophy (CMD). They were studied in their clinical, laboratory, and neuroradiologic features. The index case had a brain magnetic resonance imaging (MRI) and the second patient had a head computerized tomography (CT). In addition, a literature review was performed to describe the main forms of CMD. The index case fulfilled all criteria for WWS. A brain MRI performed at age 4 months served to corroborate the clinical diagnosis, showing severe hydrocephalus, type II lissencephaly, cerebellar vermian aplasia, and a hypoplastic brain stem. The authors were able to establish a retrospective diagnosis of WWS in the index cases's older sister, based upon her clinical picture and head CT report.