Imaging Appearance Research Articles

The radiological features of HPV-positive vs HPV-negative OPSCC at a South African hospital

Background: Studies have found that, at presentation, human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) has a less advanced primary tumour, more advanced lymph node spread and commonly has cystic metastatic lymph nodes in comparison to HPV-negative OPSCC.Objectives: To compare the radiological features of HPV-positive and HPV-negative OPSCC in South African patients.Method: A retrospective cross-sectional study was conducted at a large South African hospital. Eligibility required a histologically proven OPSCC between 2007 and 2023; a p16 antigen test and, if positive, a confirmatory HPV DNA PCR test and a baseline pre-treatment contrast enhanced neck CT scan. All eligible HPV-positive OPSCC patients and a random sample of eligible HPV-negative OPSCC patients were enrolled.Results: Twenty-one HPV-positive and 55 HPV-negative OPSCC patients were recruited. There was no statistically significant difference in the tumour epicentre location, local advancement (≥ T3 in 67% and 71%, respectively, p = 0.54), mean primary tumour size (41 mm vs. 39 mm, p = 0.73), lymph node spread (bilateral or more in 67% vs. 82%, p = 0.22) or morphologically cystic lymph nodes (10% and 4%, p = 0.61).Conclusion: There was no statistically significant difference in the CT imaging appearances of HPV-positive and HPV-negative OPSCC in the studied sample of South African patients.Contribution: This study documents the radiological features of OPSCC in a small South African sample population, where HPV-positive and HPV-negative OPSCC could not be distinguished on CT criteria and did not display the classic features described in the literature.

EGS SO31 - Does in-hospital delay in appendicectomy lead to complicated appendicitis and affect post operative outcome - a single centre study

Abstract Background Acute appendicitis is one of the most common reasons for emergency general surgical admissions in the U.K. The standard treatment for acute appendicitis is emergency appendicectomy. However, the urgency to operate on patients admitted to hospital with acute appendicitis has been widely debated, with no current standard guideline to follow. The aim of this study was to identify the effect of in-hospital delay in appendicectomy on intra operative findings of complicated appendicitis. The secondary outcome measures were the requirement of a surgical drain, overall length of stay, post-operative complications and re-admission rates. Method This was a single centre retrospective study. All patients who underwent an emergency appendicectomy, between 01/09/2023 and 30/11/2023 were included in this study. Hospital electronic patient records were screened to record the time of decision to operate, surgical start time, the delay between decision to operate and surgical start, intra-operative findings, and post-operative course. A total of 105 patients were included. These were divided into two sub-groups based on the delay between decision to operate and surgical start time; patients who had surgery within 12-hours (early) and those who had surgery after 12-hours (delayed) from the decision to operate time. Results Surgery was performed within 12-hours in 42% cases. The remaining 68% had more than a 12-hour delay, with almost 1 in 4 cases (26 /105) delayed over 24 hours. 15% cases (16) with uncomplicated appearance on pre-op imaging and delayed more than 12-hours progressed to complicated appendicitis intra-operatively. Surgical drains were required in 10% delayed cases and 6% early cases. The median length of stay was 2-days in delayed, compared to 1 day in cases performed early. Post-operative complications were higher in cases early. Although majority of these had complicated appearance in pre-op imaging. Both groups had same readmission rate. Conclusion Our study found that in-hospital delay in appendicectomy can potentially result in increased length of stay, higher rate of requirement of surgical drains and progression from imaging severity. This needs better prioritisation and theatre allocation.

PATH-27. MOLECULAR, IMAGING, AND SURVIVAL MANIFESTATIONS IN MOLECULAR GLIOBLASTOMAS: INSIGHTS FROM A MULTI-NATIONAL STUDY

Abstract Apart from the traditional definition of IDH-wildtype GBM based on histological characteristics, IDH-wildtype diffuse gliomas previously assigned to histological grade 2 or 3 are now defined as IDH-wildtype GBM in the presence of qualifying molecular markers (TERTp mutation, EGFR amplification, or chromosome +7/-10) (“molecular GBM”) in the 2021 WHO classification. However, the clinical significance of molecular GBM is unrevealed. This collaboration aims to comprehensively evaluate the clinical, molecular, imaging characteristics, and prognosis of molecular GBMs in a multi-national dataset and stratify survival. Retrospective chart and imaging review was performed in 258 molecular GBM patients from eight centers across three continents. Clinical, molecular, imaging, and survival characteristics were analyzed. The median age of molecular GBM patients was 58 years (range: 23-83) with 139 males, with TERTp mutation (83 of 214 [38.8%]), EGFR amplification (160 of 204 [78.4%]), and chromosome +7/-10 (82 of 143 patients [57.3%]). The majority of tumors were located at the frontal and temporal lobes (48.4%) and exhibited non-contrast-enhancing (CE) tumors (73.7%). Gliomatosis cerebri pattern was shown with 27 patients (12.4%). The median OS was 28.1 months (95% confidence interval 22.1-34.1). There was significantly shorter survival in patients with high Ki-67 index (> 20) compared to those with low Ki-67 index (median OS 19.3 vs. 31.5 months, log-rank test P = 0.002), while no survival differences were found according to histological grade or molecular diagnostics. Survival was significantly shorter in patients with infiltrative imaging appearance compared to those without (median OS 24.7 vs 41.0 months, log-rank test P = 0.014). In conclusion, survival within molecular GBM patients may be heterogeneous and associated with Ki-67 index and infiltrative imaging appearance.

Spondylodiscitis and Its Mimickers: A Pictorial Review

Spondylodiscitis is an infection of the intervertebral disc, the adjacent vertebral body, and/or contiguous structures due to the introduction of infectious agent, usually by the hematogenous route. Imaging is crucial in assessing bacterial and tubercular spondylodiscitis, as well as their associated complications. Magnetic resonance imaging in particular can clearly depict osteo-structural changes in the vertebral body and the associated disc, as well as any soft-tissue complications, such as paravertebral abscess and/or epidural abscess, improving disease characterization and helping to recognize the agent involved. Nevertheless, other non-infectious diseases may mimic imaging appearances of spondylodiscitis and one should be aware of these conditions when interpreting MR images, which include Modic type I degenerative changes, ankylosing spondylitis, acute Schmorl’s node, porotic fractures, and spinal neuropathy arthropathy. This pictorial review aims at describing imaging findings of bacterial and non-bacterial spondylodiscitis, complications, and those pathologies that mimic these infections.

Find the haystacks, then look for needles: The rate of strongly lensed supernovae in galaxy-galaxy strong gravitational lenses

Abstract The time delay between appearances of multiple images of a gravitationally lensed supernova (glSN) is sensitive to the Hubble constant, H0. As well as time delays, a lensed host galaxy is needed to enable precise inference of H0. In this work we investigate the connection between discoverable lensed transients and their host galaxies. We find that the Legacy Survey of Space and Time (LSST) will discover at least 90 glSNe per year, of which 54% will also have a strongly lensed host. The rates are uncertain by approximately 30 % depending primarily on the choice of the unlensed SN population and uncertainties in the redshift evolution of the deflector population, but the fraction of glSNe with a lensed host is consistently around a half. LSST will discover around 20 glSNe per year in systems that could plausibly have been identified by Euclid as galaxy-galaxy lenses before the discovery of the glSN. Such systems have preferentially longer time delays and therefore are well suited for cosmography. We define a golden sample of glSNe Ia with time delays over 10 days, image separations greater than 0.8 arcseconds, and a multiply imaged host. For this golden sample, we find $91\%$ occur in systems that should already be discoverable as galaxy-galaxy lenses in Euclid. For cosmology with glSNe, monitoring Euclid lenses is a plausible alternative to searching the entire LSST alert stream.

A Large Calf Mass in a Patient with Rheumatoid Arthritis: Giant Pannus Filling Baker’s Cyst

Abstract Rheumatoid arthritis (RA) presents a significant challenge among autoimmune diseases, affecting millions globally with diverse clinical manifestations, primarily targeting joints and inducing inflammation, pain, and deformities. In some cases, it leads to the formation of Bakers cysts, fluid-filled bursae in the popliteal region, resulting from chronic inflammation of the synovial membrane and subsequent pannus growth. Our case, a young female patient with RA, presenting with calf mass, highlights this complex interplay. She presented with large swelling and pain in her left calf region which on high-frequency ultrasound revealed a large, well-defined heteroechoic mass lesion distending bursa between the medial head of the gastrocnemius and semimembranosus muscle, measuring 25 cm craniocaudally, without any color Doppler abnormality. Ultrasound-guided biopsy was performed to rule out the possibility of sarcoma and it revealed inflammatory changes. Final diagnosis of excessive pannus formation within the Baker’s cyst forming large mass was made, with RA identified as the underlying cause. The differential diagnosis of masses in the popliteal fossa includes synovial/meniscal/ganglion cysts, lipomas, vascular pathologies, and neoplastic conditions. High-resolution ultrasound is an important diagnostic modality for evaluating popliteal fossa masses. Magnetic resonance imaging is typically performed to assess for neoplastic causes and internal derangement of the knee. Our case of a massive pannus filling a Baker’s cyst in the context of RA emphasizes the intricate nature of the disease and its diverse clinical expressions. It is important for the radiologist to be aware of this imaging appearance for timely diagnosis and management.

Giant benign mesenteric cysts (mesothelioma and lymphangioma): A report of two cases

Introduction and importanceMesenteric cysts are a rare group of intra-abdominal tumors located in the mesentery or omentum, most of this lesion are asymptomatically but occasionally presents with non-specific symptoms, which makes diagnosis difficult. Case presentationWe present two cases of giant mesenteric cyst in our Institution, the first case is a women of 23 years with previous gynecologic surgery with chronic abdominal pain and large abdominal mass CT showed a giant intraabdominal 30 × 25 × 15 cm, the patient went to laparotomy and a large mesenteric tumor found. The Histopathology reported a Benign cyst mesothelioma (BCM). The second case is a 47 year male with intermittent abdominal pain and abdominal CT shows a 20x21x15 cm tumor. Laparotomy was performed. Histopathology reported a large lymphangioma. Clinical discussionBCM tumors are rare intrabdominal lesions often diagnosed in premenopausal women. Its etiopathogenesis is still unclear, associated risk factors are endometriosis, pelvic inflammatory disease and previous pelvic surgery. Lymphangiomas are an infrequent cyst tumors. It results from a failure in the evolutionary development of the lymphatic system, often localized in the head and neck and its localization in the abdomen is even rare. The definitive diagnosis is made by histopathology. ConclusionMesenteric cysts diagnosis if often challenge due to nonspecific symptoms and significant overlap in imaging appearance between the different entities, its diagnosis should be in mind when encounter a cystic abdominal tumor, surgical complete removal of this tumors is the optimal treatment to prevent recurrence and complications.

Temporal development of subdural collections in infants with confessed abusive head trauma: a forensic neuroimaging study.

Estimating the age of injury in pediatric abusive head trauma (AHT) is a challenging task but potentially valuable for the identification of perpetrators. The aims of the study are (1) to describe the temporal development of different imaging features of subdural collections (SDCs), and (2) to provide novel age-diagnostic reference data for forensic-radiological expert reports. Using a multi-center approach and a 10-year study period, serial neuroimaging studies of 13 comprehensively investigated AHT cases (8 CT and 26 MRI scans) were analyzed regarding several subdural imaging parameters (SDC appearances, entities, components, and associated findings). Due to confessions by perpetrators, the time points of the trauma were presumed unique and known in all cases facilitating correlation of imaging findings with time. Hyperdense SDCs in CT were found up to 9 d post-injury (p.i.), CSF-like SDCs in CT or MRI as early as from the 3rd hour p.i., and subdural membrane formation as late as from day 283. The heterogeneous variant of the subdural hematohygroma was observed to be the dominant SDC entity between 3 h and 22 d p.i. The tadpole sign was detected in MRI between 3 h and 46 d p.i. Certain subdural imaging findings may be helpful for estimating the age of injury in AHT. Subdural membrane formation is demonstrated to be a late finding and the tadpole sign is an early phenomenon p.i. The data corroborated that the sediment but not the supernatant has the potential for being valuable for age-diagnostic aspects. Question Reliable evidence-based data on the development of SDCs is sparse but required for expert opinions on pediatric AHT. Findings Reference data on the evolution of the imaging appearance of SDCs and associated phenomena in confirmed cases of AHT are provided. Clinical relevance As there is a great need for estimating the age of injury in criminal and civil proceedings, many clinical radiologists are confronted with the diagnostic and forensic aspects of AHT that are addressed in the present study.

A practical approach to the post esophagectomy CT: expected postoperative anatomy and anatomical approach to associated complication.

This pictorial review aims to provide a structured approach to the interpretation of post esophagectomy CT by reviewing the major esophagectomy surgeries and conduit reconstructions, along with their associated complications at key anatomical landmarks. This paper combines an image rich experience and evidence-based approach to common and rare complications. The paper begins with an overview of the conventional Ivor Lewis esophagectomy and the expected postoperative imaging appearance (with separate detailed tables on additional surgical reconstructions), followed by a focused review of various complications at specific anatomical sites in a systematic fashion. By the conclusion of this review, radiologists will be equipped to employ a systematic approach to post-esophagectomy CT interpretation, confidently identifying both common and uncommon complications.

Amputation and limb-sparing surgery in childhood sarcoma: Post-operative imaging appearances and complications.

Limb-sparing surgery and amputation are common surgical techniques used to achieve local tumour control in childhood primary bone and soft tissue malignancy of the limbs. The interpretation of post-operative limb imaging in these frequently complex cases is assisted by knowledge of the surgical techniques employed. This review discusses the rationale underpinning the most common surgical techniques used for these patients as well as their expected post-operative imaging appearance and complications. Amputation, long bone resection, endoprosthetic reconstruction, allograft reconstruction, the use of fibular autografts, allograft-prosthetic composite reconstruction and arthrodesis are discussed.

Low field magnetic resonance imaging of palmar osteochondral fragmentation of the distal phalanx

SummaryBackgroundThe presence of palmar osteochondral fragments of the distal phalanx is a newly recognised cause of foot lameness with only a few cases having been reported.ObjectivesTo describe the low field magnetic resonance imaging (MRI) appearance of palmar articular fragmentation of the distal phalanx and concurrent abnormalities of the distal interphalangeal joint (DIPJ); to investigate the prevalence of these fragments in a population of sports and pleasure horses and their potential clinical significance.Study designRetrospective descriptive case series.MethodsThis is a retrospective descriptive case series in which all Sports and Pleasure horses undergoing standing low‐field MRI of the feet between 2015 and 2023 were reviewed. Appearance, location and number of palmar articular fragments were recorded. When a palmar fragment was present, abnormal findings of the DIPJ were graded.ResultsA total of 855 horses underwent MRI examination of one or both front feet. Palmar osteochondral fragmentation of the distal phalanx was identified in four horses (0.4% prevalence), three Lusitanos and one Warmblood. The age range was 4–17 years old. All fragments were located along the palmarolateral margin of the glenoid of the distal phalanx in front feet. Concurrent imaging abnormalities of the joint were present in all four horses.Main limitationsLack of histopathology.ConclusionsThe prevalence of palmar articular fragments of the distal phalanx was low in this population of horses. Palmar osteochondral fragmentation must be considered when evaluating lameness localised to the foot, since it was identified only in lame limbs and associated with other imaging abnormalities of the DIPJ.

Comprehensive Review of Post-treatment Imaging in Head and Neck Cancers: From expected to unexpected and beyond.

Head and neck cancer management requires multidisciplinary approach in which radical surgery with or without flap reconstructions and neck dissection, along with radiotherapy (RT)/chemoradiotherapy (CRT) serve as the key components. Neoadjuvant chemotherapy (NACT) and immunotherapy are used in selected cases based on the institutional preference. Knowledge of expected posttreatment changes on imaging is essential to differentiate it from recurrence. In addition, awareness of various posttreatment complications is imperative for their early detection on imaging. Distorted anatomy after treatment poses diagnostic challenge, hence, proper choice of imaging modality and appropriate timing of scan is pertinent for accurate posttreatment evaluation. In this article, we have provided a comprehensive review on expected imaging appearances post RT/CRT and after major types of head and neck squamous cell carcinoma (HNSCC) surgeries. In addition, we have extensively reviewed the imaging appearances of various posttreatment complications, and recurrences at the primary and lymph nodal sites. We have also delved into the patterns of recurrence in human papillomavirus (HPV) positive HNSCC in this article. Furthermore, we have provided flowcharts and discussed recommendations on the site-specific and treatment related imaging modalities to be used along with their appropriate timing, for adequate evaluation of HNSCC after treatment. We have also reviewed posttreatment reporting of imaging findings using Neck Imaging Reporting and Data Systems (NIRADS) and Hopkins criteria. In addition, we have also touched upon the role of advanced imaging techniques for posttreatment HNSCC evaluation.

Pituitary gland duplication syndrome - An international imaging analysis.

Duplication of the pituitary gland is a rare developmental anomaly. Multiple associated craniofacial malformations have previously been reported with the largest series to date consisting of five patients. In this multi-institutional series of ten patients, we present a detailed review of the imaging features and discuss a possible overarching pathogenesis that would explain most of the detected malformations. Inclusion criteria for this retrospective imaging review were the presence of a pituitary stalk and gland duplication and the characteristic appearance of the hypothalamic ventral midline. In addition to the clinical presentation, we recorded the imaging findings of ten patients (9 female) through onsite and online reviews. Genetic analysis was available for six patients. The duplicated pituitary stalk and gland showed normal imaging appearances in all patients. Mammillary bodies were clearly identified lateral to the characteristic prominence of the hypothalamic ventral midline. Strands of tissue extending to the anterior dura ("limited ventral myeloschisis") were noted at the medulla oblongata in 10, and at the cervical spinal cord in 7 patients. The medulla oblongata showed a "butterfly" appearance on axial images in 9 patients. Ten patients had cervical segmentation anomalies ("zipper"-like), 9 anterior-posterior brainstem patterning defects (small pons, elongated medulla), and corpus callosum measurements were abnormal in all patients. Three patients each presented with diencephalic-mesencephalic junction abnormalities and 4 with an anterior mesencephalic "cap". An oropharyngeal teratoma was present in four patients. Genetics was normal in three of the six patients studied; the remainder were found to have mutations in EFNB1 and a gene variant of GIT1, two copies of 7. And 8. exon of SMN1 gene, and 2.126 megabase duplication at bands q11.1 and q11.2 of one chromosome 15, respectively. Duplication of the pituitary gland presents as well-defined craniofacial and cervical spine malformation phenotype. Axial mesoderm duplication generating an excess of Sonic Hedgehog may be the primary embryological driver leading to this condition. CFNS＝ Craniofrontonasal Syndrome; DPG＝ Duplication of the Pituitary Gland; SHH＝ Sonic Hedgehog.

Risk-benefit analysis of a multi-site radiographer comment model for emergency departments.

Critical/urgent X-ray findings are not always communicated in an appropriate time frame to ED physicians. The practice of radiographers alerting referrers to clinically significant image findings (verbally, via image flags or written comment) is noted internationally but risk assessment data is unavailable in the literature. A hybrid radiographer comment and alert model was piloted in New South Wales and a risk-benefit assessment conducted for timely and safe communication of abnormal X-ray appearances to ED physicians. Radiographer comments (n = 1102) were provided to five New South Wales EDs by 69 radiographers for a period of 3-12 months. Site auditors classified comments as true positive (TP), false positive (FP) or indeterminate (ID) with respect to the radiology report. FP comments were investigated with ED referrers and a low-medium-high-risk assessment was provided by two independent reviewers. A total of 42 FP (3.9%; 95% confidence interval [CI] 2.9-5.3) comments were analysed for any adverse outcomes. Risk assessments demonstrated 37 low, 5 low-moderate and no high-risk cases. A total of 282 direct or potential patient benefits were identified (26.4%; 95% CI 23.8-29.1). A total of 42 radiology report discrepancies were incidentally found: (3.9%; 95% CI 2.9-5.3). Audit results demonstrated areas where the radiographer comment could mitigate risk. The provision of radiographer alerts with a written comment for ED was found to be low risk to patients in the pilot study. Radiographers communicating directly with the emergency team when abnormal image appearances are detected can reduce diagnostic error and improve patient safety and health outcomes.

Diagnostic imaging findings in lame Warmblood horses with bone injuries of the medial proximal phalanx glenoid cavity.

This retrospective study aims to describe baseline and follow-up imaging findings in subchondral and trabecular bone damage occurring outside of the sagittal groove in the proximal phalanx (P1) glenoid in a case series of lame Warmblood horses. Thirteen lame horses (16 forelimbs) with standing magnetic resonance imaging (sMRI) evidence of nonsagittal groove glenoid subchondral and trabecular bone injury of P1 as the main lesion were included. All injuries were located at the medial aspect of the P1 glenoid. At sMRI, changes included subchondral bone plate thickening and trabecular sclerosis, bone marrow edema-like signal, subchondral bone resorption (11/16), and new bone production (8/16). Subchondral bone resorption in the transverse plane was linear (8/11), round (2/11), or ill-defined (1/11). Sclerosis, bone resorption, and new bone production were seen radiographically in 10, 4, and 5 limbs, respectively. All limbs had concurrent metacarpal condyle sMRI imaging abnormalities, osteophytosis, and joint effusion. Follow-up sMRIs were obtained in 8 of 16 limbs, five of which showing progression of the resorptive lesion. One horse encountered a comminuted fracture of the affected P1 18 months after the follow-up sMRI examination. The imaging appearance of the medial glenoid bone injuries of P1 in this case series is consistent with chronic bone overload. The linear configuration of bone resorption seen in eight lesions suggests short, incomplete stress fractures, which is supported by the ultimate catastrophic fracture occurring in one case.

Sarcoma or haematoma? If only it was that simple! Part 2

Introduction: Imaging appearances and clinical presentation of soft tissue sarcoma and soft tissue haematomas are similar. It is imperative that sarcoma is differentiated from benign soft tissue lesions due to the poor outcomes and high morbidity associated with sarcoma. Topic Description: Part 2 of this pictorial review summarises the key ultrasound appearances of soft tissue sarcoma and soft tissue haematomas and some differential diagnoses. Discussion: Ultrasound is the first line test in the investigation of soft tissue masses. With the overlapping ultrasound appearances of soft tissue sarcoma and soft tissue haematomas, it is essential that practitioners are aware of key ultrasound appearances and understand when to escalate cases for further investigation. Conclusion: Sound knowledge of the clinical and sonographic features of soft tissue haematomas and soft tissue sarcoma as well as recognising potential differential diagnoses is fundamental to ensuring an accurate diagnosis, timely management and improved patient outcomes.

Groundnut (ARACHIS HYPOGAEA L.) seed defect classification using ensemble deep learning techniques

Groundnut is an oil seed cash crop, that can be consumed directly by humans and animals. It is also used as an intelligence in the industrial production of butter and other products. However, Groundnut seeds can become infected with fungi, viruses, pests, physical damage, and high heat, which can negatively impact crop yield, quality, and economic value, and pose health hazards. To address these challenges, computer vision technology detects and classifies defects. This study introduced an ensemble deep learning defected classification model that combines VGG16 and InceptionV3 using seed images. To enhance model performance, collected images are preprocessed using novel techniques tailored to different image types. Preprocessing techniques are chosen based on image-quality evaluation metrics. Watershed segmentation is applied followed by detecting the region of interest in the image using YOLOv3. The image dataset is augmented and balanced using a Generative Adversarial Network (GAN). The model development involves a combination of classical and deep-based features, comparing features extracted with (HOG and GLCM) to those extracted with InceptionV3 and VGG16. The ensemble model achieves an accuracy of 96.25 % with a split ratio of 10 % for testing, 10 % for validation, and 80 % for training set. This research benefits farmers looking to improve yield, consumers of groundnut products, and researchers studying seed defects. The work provides valid insights for future researchers regarding dataset creation, augmentation, methods, and feature selection for modeling. However, the model experienced misclassifications due to the similar appearance of sample images in different classes. Future researchers should address these challenges and consider factors such as oil content and defect grading.

Microsaccadic suppression of peripheral perceptual detection performance as a function of foveated visual image appearance.

Microsaccades are known to be associated with a deficit in perceptual detection performance for brief probe flashes presented in their temporal vicinity. However, it is still not clear how such a deficit might depend on the visual environment across which microsaccades are generated. Here, and motivated by studies demonstrating an interaction between visual background image appearance and perceptual suppression strength associated with large saccades, we probed peripheral perceptual detection performance of human subjects while they generated microsaccades over three different visual backgrounds. Subjects fixated near the center of a low spatial frequency grating, a high spatial frequency grating, or a small white fixation spot over an otherwise gray background. When a computer process detected a microsaccade, it presented a brief peripheral probe flash at one of four locations (over a uniform gray background) and at different times. After collecting full psychometric curves, we found that both perceptual detection thresholds and slopes of psychometric curves were impaired for peripheral flashes in the immediate temporal vicinity of microsaccades, and they recovered with later flash times. Importantly, the threshold elevations, but not the psychometric slope reductions, were stronger for the white fixation spot than for either of the two gratings. Thus, like with larger saccades, microsaccadic suppression strength can show a certain degree of image dependence. However, unlike with larger saccades, stronger microsaccadic suppression did not occur with low spatial frequency textures. This observation might reflect the different spatiotemporal retinal transients associated with the small microsaccades in our study versus larger saccades.

Magnetic resonance imaging spectrum of intracranial meningiomas: An institutional review of common and uncommon imaging appearances

Magnetic resonance imaging spectrum of intracranial meningiomas: An institutional review of common and uncommon imaging appearances

MRI Imaging Appearance in Mullerian Duct Anomalies.

MRI Imaging Appearance in Mullerian Duct Anomalies.