Imaging Appearance Research Articles

The effect of resizing on the natural appearance of scintigraphic images: an image similarity analysis

Background and objectiveThis study aimed to assess the impact of upsampling and downsampling techniques on the noise characteristics and similarity metrics of scintigraphic images in nuclear medical imaging.MethodsA physical phantom study using dynamic imaging was used to generate reproducible static images of varying count statistics. Naïve upsampling and downsampling with linear interpolation were compared against alternative methods based on the preservation of Poisson count statistics and principles of nuclear scintigraphic imaging; namely, linear interpolation with a Poisson resampling correction (upsampling) and a sliding window summation method (downsampling). For each resizing method, we computed the similarity of resized images to count-matched images acquired at the target grid size with the structural similarity index measure and the logarithm of the mean squared error. These image quality metrics were subsequently compared to those of two independent count-matched images at the target grid size (representing variance due to natural noise permutations) as a reference to establish an optimal resizing method.ResultsOnly upsampled images with the Poisson resampling correction after linear interpolation produced images that were similar to those acquired at the target grid size. For downsampling, both linear interpolation and sliding window summation yielded similar outcomes for a reduction factor of 2. However, for a reduction factor of 4, only sliding window summation resulted in image similarity metrics in agreement with those at the target grid size.ConclusionsThe study underlines the importance of applying appropriate resizing techniques in nuclear medical imaging to produce realistic images at the target grid size.

Clinical MR imaging of patients with spinal hardware at 0.55T: comparison of diagnostic assessment and metal artifact appearance with 1.5T.

The aim of this study is to assess inter-reader agreement of imaging findings and compare readers' assessment of image quality (IQ) and appearance of metal artifact (MA) in patients with spinal implants between 0.55T and 1.5T MRI. Patients imaged on Siemens Healthineers Magnetom Free.Max 0.55T (n = 42; avg. age 55 yrs.) with spinal hardware between 12/2021 and 3/2024 were included. Of these, 18 patients had a paired exam at 1.5T. All exams were reviewed independently by three neuroradiologists (R1-3). Readers selected imaging findings from a pick-list and rated sequences using a 4-point Likert scale for IQ and MA. At both 0.55T and 1.5T, raw agreement for the following findings ranged between 81 and 95%: cord signal abnormality, osteomyelitis/discitis, osseous metastatic disease, and compression fracture. Agreement on post-operative fluid collection and spinal canal stenosis was 64.3% and 66.7% at 0.55T, and 77.7% and 50.0% at 1.5T. Agreement on neural foraminal stenosis was low in both cohorts, 47.6% and 33.3% at 0.55T and 1.5T. No sequence at 0.55T was rated inferior to 1.5T in IQ or MA. Sequences rated higher at 0.55T compared to 1.5T were as follows for IQ: sagittal T1w TSE (R1) and as follows for MA: axial T1w TSE (R1, R2), sagittal T1w TSE (R1), axial T2w TSE (R1), sagittal T1w TSE Dixon post-contrast (R2), sagittal T2w STIR (R2: p = 0.01). Imaging patients with spinal hardware at 0.55T results in comparable inter-reader agreement for clinically-relevant imaging findings and equivalent or improved image quality compared to 1.5T.

The magnetic resonance imaging appearance of the normal anatomy and injury pattern of capsuloligamentous complex of the first metatarsophalangeal joint.

The capsuloligamentous complex injury of the first metatarsophalangeal joint (MTPJ) is a common cause of turf toe. To investigate whether high-resolution 3 T magnetic resonance imaging (MRI) could demonstrate all the normal anatomic structures and the MR features of the capsuloligamentous complex injury of the first MTPJ, and to evaluate the diagnostic performance of MRI in the diagnosis of the capsuloligamentous complex injuries of the first MTPJ. A total of 115 feet were included in this study, including 48 feet from 24 healthy volunteers and 67 feet from 67 patients with the capsuloligamentous complex of the first MTPJ injuries. All feet had MRI examination. The MRI features of the capsuloligamentous complex of the first MTPJ of the volunteers and patients were analyzed. Diagnostic sensitivity, specificity, and accuracy of MRI were calculated using the surgery as the standard of reference. The inter-observer agreement was assessed using kappa analysis. The central portion of the plantar plate and ligament injury manifested as discontinuity, with an indistinct appearance with hyperintense signal within the involved structures. The sensitivities, specificities, and diagnostic accuracy value of MRI for diagnosing most structures of the capsuloligamentous complex injuries of the first MTPJ were 67%-100%, 93%-100%, and 0.82-0.99, respectively, and overall good to perfect inter-observer agreements (kappa=0.63-0.95). High-resolution MRI allows adequate visualization of normal anatomic structures of the first MTPJ. The best visualized structure is sesamoid phalangeal ligament and the most frequent injury is complete tear of the medial sesamoid phalangeal ligament.

Deep unsupervised clustering for prostate auto-segmentation with and without hydrogel spacer

Abstract Introduction. Clinical datasets for training deep learning (DL) models often exhibit high levels of heterogeneity due to differences such as patient characteristics, new medical techniques, and physician preferences. In recent years, hydrogel spacers have been used in some prostate cancer patients receiving radiotherapy to separate the prostate and the rectum to better spare the rectum while achieving adequate dose coverage on the prostate. However, this substantially affects the computed tomography image appearance, which downstream reduced the contouring accuracy of auto-segmentation algorithms. This leads to highly heterogeneous dataset. Methods. To address this issue, we propose to identify underlying clusters within the dataset and use the cluster labels for segmentation. We collected a clinical dataset of 909 patients, including those with two types of hydrogel spacers and those without. First, we trained a DL model to locate the prostate and limit our field of view to the local area surrounding the prostate and rectum. We then used Uniform Manifold Approximation and Projection (UMAP) for dimensionality reduction and employed k-means clustering to assign each patient to a cluster. To leverage this clustered data, we propose a text-guided segmentation model, contrastive language and image pre-training (CLIP)-UNet, which encodes the cluster information using a text encoder and combines the encoded text information with image features for segmentation. Results. The UMAP results indicated up to three clusters within the dataset. CLIP-UNet with cluster information achieved a Dice score of 86.2% compared to 84.4% from the baseline UNet. Additionally, CLIP-UNet outperforms other state-of-the-art models with or without cluster information. Conclusion. Automatic clustering assisted by DL can reveal hidden data clusters in clinical datasets, and CLIP-UNet effectively utilizes clustered labels and achieves higher performance.

Imaging appearance of pre-osseous and osseous phase of fibrodysplasia ossificans progressiva: A rare entity

Imaging appearance of pre-osseous and osseous phase of fibrodysplasia ossificans progressiva: A rare entity

APLICAÇÃO DA PASTA CTZ NA TERAPIA PULPAR DE DENTES DECÍDUOS: UMA REVISÃO DE ESCOPO

ABSTRACT The aim of this study was to outline the current scientific basis for the use of CTZ paste in the treatment of irreversible pulp conditions through a scoping review. Bibliographic references were searched in the Scielo, BVS and MedLine/Pubmed databases, as well as the gray literature (Google Scholar). The scoping review was carried out in accordance with PRISMA-ScR standards and sought to answer the question: “What is the current scientific knowledge regarding the endodontic treatment of deciduous teeth using CTZ paste?”. The search period was June 1, 2021 to September 17, 2024. The main terms searched were: “CTZ paste”, “CTZ” and “deciduous teeth”, used alone or in combination with Boolean operators. The preliminary search resulted in 151 references (n=151). After removing duplicates, 112 studies had their titles analyzed and 52 were excluded by consensus because they were not related to the topic. The eligibility criteria were applied to the remaining 60 studies and 19 were selected for the review. CTZ antibiotic paste is an effective alternative for endodontic treatment of deciduous teeth. Clinical efficacy is assessed through the remission of signs and symptoms of infection as well as the maintenance of the deciduous element in the oral cavity until its physiological exfoliation. Radiographic efficacy is assessed mainly through the regression of the periapical lesion and the appearance of a radiolucent image in the furcation region, compatible with bone neoformation. The technique is simple, does not require root canal instrumentation and is inexpensive compared to other therapies. In the in vivo studies, which sought to evaluate the clinical and radiographic efficacy of the paste, it was considered satisfactory. The in vitro studies demonstrated the antimicrobial activity and biocompatibility of CTZ paste. The disadvantage addressed by the authors was tooth staining due to the antibiotic component tetracycline. The LSTR technique with CTZ paste appears to be an effective and promising therapy, its main advantages being the simplicity of the technique and its low cost. However, further longitudinal research is needed in order to provide a scientific basis for using the technique. Keywords: CTZ paste. CTZ. Deciduous teeth.

Rare case of bilateral primary breast angiosarcoma and review of literature

Primary angiosarcoma of the breast is very rare, accounting for 0.05% of all malignant breast tumors, and it usually occurs in younger individuals. To the best of our knowledge, bilateral primary angiosarcoma is extremely rare, with only 16 cases reported in the published literature. The imaging features might give a false impression of a benign lesion, delaying diagnosis. We report a case of a 34-year-old woman with a left breast lump. Her initial core needle biopsy was negative, and she was briefly lost to follow-up. However, when she returned with worsening symptoms, a vacuum-assisted biopsy revealed angiosarcoma. After undergoing surgery, she received radiation therapy but subsequently developed angiosarcoma in the contralateral breast. Our case is unique because we present the variable imaging appearances of angiosarcoma using imaging modalities such as mammography, ultrasound, MRI, and PET-CT, at the time of initial presentation, final diagnosis, and recurrence. We also report the successful use of a vacuum-assisted breast biopsy following a non-diagnostic core needle biopsy without experiencing overt bleeding during the procedure in a case of angiosarcoma. There have been very few reported cases in which vacuum-assisted biopsy has been performed in cases of angiosarcoma, indicating that it can be used in hypervascular masses without the risk of excessive bleeding, especially when an initial core biopsy is discordant.

Neoplastic premalignant pancreatobiliary lesions: current update on the spectrum of lesions and their imaging appearances.

Common pancreatobiliary epithelial malignancies such as pancreatic ductal adenocarcinoma, cholangiocarcinoma and gallbladder carcinoma have poor prognosis. A small but significant portion of these malignancies arise from mass-forming grossly and radiologically visible premalignant epithelial neoplasms in the pancreatobiliary tree. Several lesions, including a few recently described entities, fall under this category and predominantly include papillary epithelial lesions with or without mucin production. These include common lesions such as intraductal papillary mucinous lesions (IPMN) in pancreas and less common to rare lesions such intraductal papillary neoplasms of the bile ducts (IPNB), pancreatic and biliary intraductal oncocytic papillary neoplasms (IOPN) and intraductal tubulopapillary neoplasms (ITPN), intracholecystic neoplasms (ICN) in the gallbladder, intra-ampullary papillary-tubular neoplasms (IAPN) in the ampulla and mucinous cystic neoplasms in the pancreas, biliary tree and gallbladder. These lesions have an excellent prognosis before malignant transformation and even with malignant transformation, often fare better than the conventional malignant counterparts. These lesions have characteristic histologic, radiologic, and molecular characteristic features. Several of these neoplastic lesions are associated with field-effect phenomenon which means that in presence of even one of these lesions, the entire background ductal epithelium is at risk of developing synchronous or metachronous malignancies. Awareness of these lesions and their imaging appearances as well as utilization of relevant molecular diagnostics can help practicing radiologists and clinicians improve patient outcomes by detecting early and treating or surveilling such lesions before malignant transformation or before metastatic dissemination.

Leptomeningeal Dissemination in Choroid Plexus Tumors: Magnetic Resonance Imaging Appearance and Risk Factors.

Intracranial choroid plexus tumors (CPT) are rare and primarily affect young children. Leptomeningeal dissemination (LMD) has been reported not only in high-grade choroid plexus carcinoma (CPC) but also in lower histological grades; however, a systematic evaluation of CPT-specific imaging characteristics remains lacking. We analyzed the imaging characteristics of LMD in a single-center pediatric cohort of 22 CPT patients (thirteen choroid plexus papilloma (CPP), six atypical choroid plexus papilloma (aCPP), three CPC), comparing LMD features with those of the primary tumor. Additionally, we examined the correlation between resection status and LMD development during follow-up. At diagnosis, we observed true LMD in three (two CPCs, one CPP) and pseudo-LMD in one case (CPP). During follow-up, two CPP patients developed cystic LMD, and one aCPP patient developed a solid metastasis. LMD had characteristics of the primary tumor in 3/4 cases. Incomplete resection was associated with a higher risk of LMD (p = 0.025). LMD can occur in both high- and lower-grade CPT, presenting at diagnosis as well as in relapsed lower-grade cases. Notable MR-imaging features include pseudo-LMD at diagnosis and cystic LMD in relapsed CPP cases. Incomplete tumor resection may increase the risk of LMD, although further validation is needed.

Body image research among sexual minority men in the Mekong region: A scoping review.

Body image among sexual minority men (SMM) has received increasing attention. However, the current literature has primarily focused on white SMM and body image and physical appearance concerns among SMM. In response to a call for more nuance in understanding how SMM perceive and make sense of their body image in a broader sociocultural context, we conducted a scoping review to examine the extent and nature of body image research among SMM in the Mekong region. We searched CINAHL, MEDLINE, Scopus, PsycInfo-1806 (Ovid), ProQuest Central, Social Science Premium Collection, and Web of Science and identified 25 studies that met the inclusion criteria. Overall, the findings suggest that body image research in the Mekong region is limited in the range of topics, study populations, and methods, with quantitative studies on preferences for masculine physical traits among young and well-educated Chinese SMM dominating. Furthermore, the current literature is primarily influenced by Western scholarship, which predominantly uses Western measurement and theories. We encourage scholars from other countries in the region, including Vietnam, Laos, Cambodia, Myanmar, and Thailand, to engage sociocultural approaches in research on the body image of SMM.

Clinical and Imaging Features of Head and Neck Metastasis of High-Grade Glioma: A Single-Center Case Series.

High-grade gliomas are the most frequent primary brain tumors, yet extraneural metastasis is exceedingly rare. This is in part secondary to the relatively poor survival of these patients and likely the shielding effect of the blood-brain barrier. Given the rarity of extraneural metastasis, the pathophysiology and imaging appearance of extraneural metastasis is under-reported and poorly understood. In this case series we present 6 patients with pathology-confirmed high-grade glioma and extraneural head and neck metastasis. We highlight imaging features of metastasis on CT, MRI, and PET/CT. We also explore potential correlations and pathophysiology of high-grade glioma metastasis to the head and neck region.

Chronic Lymphocytic Inflammation With Pontine Perivascular Enhancement Responsive to Steroids Presenting With Predominantly Neuro-Ophthalmic Features.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare and poorly understood inflammatory disorder of the central nervous system centered on the pons. It has a characteristic imaging appearance with enhancing and T2-hyperintense punctate and curvilinear lesions in the pons. The lesions lack restricted diffusion and have relatively little perilesional edema. Although patients typically present with gait ataxia and other sequelae of brainstem inflammation including diplopia, there is scant literature focusing on patients who present with primarily neuro-ophthalmic manifestations. Case series of 3 patients presenting with diplopia who had a final diagnosis of CLIPPERS. Case descriptions of a 71-year-old man, 61-year-old woman, and 38-year-old man are reported. Diplopia was the chief presenting complaint, owing to internuclear ophthalmoplegia, sixth nerve palsy, or skew deviation. All patients had nystagmus and gait ataxia. Brain MRI displayed punctate or curvilinear enhancement of pontine/middle cerebellar peduncle lesions without restricted diffusion. All patients achieved rapid improvement after corticosteroid treatment. In 3 patients with CLIPPERS, the main presenting complaint was diplopia. The distinctive imaging signs led to a strong presumption of CLIPPERS, permitting a truncated evaluation and early corticosteroid treatment, which provided rapid reversal of clinical and imaging manifestations.

Imaging Findings and Management Strategies for Liver Masses in Children with Predisposition Disorders: A Review by the Pediatric LI-RADS Group.

Liver masses in children with underlying systemic disease or a predisposing syndrome can be benign or malignant, ranging from focal fat to hepatocellular carcinoma (HCC). Knowledge of the underlying condition, the pathophysiologic effect on the liver, and the development of liver disease and specific liver lesions allows radiologists to guide imaging with regard to modality and frequency and give recommendations for biopsy when appropriate. In some predisposition disorders, such as Beckwith Wiedemann spectrum, familial adenomatous polyposis syndrome, and tuberous sclerosis complex, established guidelines for imaging screening exist. In many of the syndromes discussed, masses may occur outside of the liver and the liver may not be the primary focus of screening. For other entities, no consensus recommendations exist. Screening recommendations may be based on the risk of development of chronic liver disease. Once cirrhosis occurs, the risk of developing HCC is elevated. The authors summarize the spectrum of liver lesions that may be encountered in children with predisposing syndromes and systemic diseases, the imaging appearance of the lesions with various modalities, and screening guidelines where published. ©RSNA, 2024 See the invited commentary by Rutten and Chavan in this issue.

Imaging in Hydatid Disease: Pictorial Review

AbstractHydatid disease (HD) can affect any organ, but most commonly involves liver parenchyma. Complications like rupture/infection can further complicate the scenario. Familiarity with variable imaging appearances of HD is very helpful in making the diagnosis. This may also aid in diagnosis of difficult or atypical cases. We retrospectively reviewed radiologic findings of HD in 11 patients, who presented to our department in last 1 year. There was involvement of the lung, pleura, mediastinum, liver, abdominal cavity, pelvic cavity, ovary, splenic parenchyma, renal parenchyma, spinal cord, and brain, with variable imaging features.

Automated Detection of Normal Pressure Hydrocephalus Using CT Imaging for Calculating the Ventricle-to-Subarachnoid Volume Ratio.

Normal pressure hydrocephalus (NPH) is a diagnostic challenge because its clinical symptoms and imaging appearance resemble normal aging and other forms of dementia. Identifying NPH is essential so that patients can receive timely treatment to improve gait distortion and quality of life. An automated marker of NPH was developed and evaluated on clinical CT images, and its utility was assessed in a large patient cohort. A retrospective review was conducted of CT images from 306 tap test-responsive patients with NPH between January 2015 and January 2022. Control CT images were obtained from patients in the emergency department who were evaluated for headache and had unremarkable CT findings between June 2021 and August 2022. The ventricle-to-subarachnoid volume ratio (VSR) was automatically calculated by the imaging software and used as a predictor of NPH in linear regression modeling with adjustment for age and sex. The correlations of VSR with age, sex, and the receiver operating characteristic were computed. VSR was significantly greater in patients with NPH than controls (P < .001). Importantly, VSR was not significantly correlated with age (P = .56, R2 = 0.001). VSR identifies NPH with a sensitivity and specificity of 94.1% and 92.5%, respectively, with an area under the receiver operating characteristic curve of 0.99 (95% CI 0.975-0.995). Automated assessment of the VSR on head CT images identified probable NPH with 93% accuracy. The assessment of a large cohort of patients with NPH supports the generalizability of clinical screening of CT images. Moreover, the results support the utility of ventricle-to-sulcal concordance often used by radiologists but not currently a part of the accepted guidelines for imaging markers of NPH.

Diaphyseal aneurysmal bone cyst: A case report

Aneurysmal bone cyst (ABC) is benign lesion of long bone metaphysis, but it can also become locally aggressive lesion. ABC affects mostly medullary region of long bone metaphysis that predominantly affects children and young adults. Meta-diaphysis of the long bones and posterior elements of the vertebrae are the most common sites of involvement. ABCs can involve every skeletal site, but the most common locations are the metaphysis of the long bones, followed by the spine. However, diaphyseal lesions may occur. Patients with ABCs typically present with insidious onset of pain, swelling or a palpable mass. The imaging appearance of ABC is variable; however, a lytic and expansile lesion with fluid-fluid levels is the most common presentation. Although incidence of intracortical variety of ABCs is rare but surgeons might evaluate its severity in view of aggressive benign or malignant lesions of diaphysis. We present the case of a 11-year-old female with left shaft ulna ABC.

Osteomyelitis of the Jaw Bones and Its Mimics: Resolving the Diagnostic Enigma

AbstractJaw osteomyelitis is a severe inflammatory condition affecting the maxilla or mandible, posing diagnostic and therapeutic challenges. An early and accurate diagnosis is crucial to initiating appropriate treatment and preventing potential complications. Radiological imaging plays a pivotal role in diagnosing and evaluating jaw osteomyelitis, providing valuable insights into the extent of the disease and aiding clinicians in making informed decisions. One of the most important aspects of imaging is to differentiate them from the noninfectious mimics, which can closely mimic their imaging appearance. This article aims to present a comprehensive overview of imaging in jaw osteomyelitis, focusing on the critical clinical and imaging markers that distinguish it from its noninfectious imitators.

A New Contrastive Learning-Based Vision Transformer for Sentiment Analysis Using Scene Text Images

Sentiment analysis using scene text images is complex and challenging because it has an arbitrary background, and the method should rely on only visual features. Unlike most existing methods that use either text or images or both, this study uses only scene text images for sentiment analysis. The intuition to use only scene text images is that sometimes users express their feelings and emotions or convey their messages by writing text in different shapes with diverse background designs. It is noted that the existing methods ignore such vital cues for sentiment analysis. This work explores a vision transformer to extract visual features that represent contextual information about the appearance of the text image. Further, to strengthen the visual features, the proposed work introduces contrastive learning which maximizes the gap between inter-classes and minimizes the gap between intra-classes of positive, negative, and neutral. To demonstrate the effectiveness of the proposed method, it is tested on our own constructed dataset and benchmark dataset. A comparative study of our method with the existing method shows the proposed method is superior in the classification of positive, negative, and neutral scene text images.

Cystic Neutrophilic Granulomatous Mastitis: Imaging Features With Histopathologic Correlation.

Cystic neutrophilic granulomatous mastitis (CNGM) is a rare type of granulomatous lobular mastitis (GLM) with a distinct histologic pattern characterized on histopathology by clear lipid vacuoles lined by peripheral neutrophils ("suppurative lipogranulomas"), often containing gram-positive bacilli and strongly associated with Corynebacterial infection (in particular, Corynebacterium kroppenstedtii). Cystic neutrophilic granulomatous mastitis has a distinct histopathologic appearance, but the imaging appearance is less well described and has been limited to case reports and small case series published primarily in pathology literature. Mammographic findings of CNGM include focal asymmetry, skin thickening, and irregular or oval masses. Sonographic findings of CNGM include irregular mass, complex collection/abscess, dilated ducts with intraductal debris, axillary lymphadenopathy, and skin thickening with subcutaneous edema. The imaging features of CNGM are nonspecific, and biopsy is required. Identifying a causative organism, when possible, requires a Gram stain, microbiological culture, and, potentially, molecular analysis. Although therapeutic options exist for CNGM, including antibiotics, steroids, and surgical intervention, there is no current consensus on optimal treatment.

Research on a High-Efficiency Goat Individual Recognition Method Based on Machine Vision.

Accurate identification of individual goat identity is necessary for precision farming. Previous studies have primarily focused on using front face images for goat identification, leaving the potential of other appearances and multi-source appearance fusion unexplored. In this study, we used a self-developed multi-view appearance image acquisition platform to capture five different appearances (left face, right face, front face, back body, and side body) from 54 Wanlin white goats. The recognition ability of different goat appearance images and its multi-source appearance fusion for its identity recognition was then systematically examined based on the four basic network models, namely, MobileNetV3, MobileViT, ResNet18, and VGG16, and the best combination of goat appearance and network was screened. When only one kind of goat appearance image was used, the combination of side body image and MobileViT was the best, with an accuracy of 99.63%; under identity recognition based on multi-source image appearance fusion, all recognition models after outlook fusion of two viewpoints generally outperformed single viewpoint appearance identity recognition models in recognizing the identity of individual goats; when three or more kinds of goat appearance images were utilized for fusion, any of the four models were capable of identifying the identity of an individual goat with 100% accuracy. Based on these results, a goat individual identity recognition strategy was proposed that balances accuracy, computation, and time, providing new ideas for goat individual identity recognition in complex farming contexts.