Cerebral microbleeds: Causes, clinical relevance, and imaging approach - A narrative review.

With advances in magnetic resonance imaging (MRI) sequences, there has been increased identification of microbleed/microhemorrhage across different population ages, but more commonly in the older age group. These are defined as focal areas of signal loss on gradient echo MRI sequences (T2* and susceptibility-weighted images), which are usually <5 mm in size representing hemosiderin deposition with wide ranges of etiologies. Susceptibility-weighted imaging (SWI) has become a routine MRI sequence for practices across the globe resulting in better identification of these entities. Over the past decade, there has been a better understanding of the clinical significance of microbleeds including their prognostic value in ischemic and hemorrhagic stroke. Cerebral amyloid angiopathy and hypertension are the two most common causes of microbleeds following peripheral and central pattern, respectively. In the younger age group, microbleeds are more common due to familial conditions or a wide range of hypercoagulable states. This review outlines the pathophysiology, prevalence, and clinical implications of cerebral microhemorrhage along with a brief discussion about the technical considerations of SWI.

High-Grade Astrocytoma with Piloid Features: A Dual Institutional Review of Imaging Findings of a Novel Entity.

High-grade astrocytoma with piloid features (HGAP) is a recently identified brain tumor characterized by a distinct DNA methylation profile. Predominantly located in the posterior fossa of adults, HGAP is notably prevalent in individuals with neurofibromatosis type 1. We present an image-centric review of HGAP and explore the association between HGAP and neurofibromatosis type 1. Data were collected from 8 HGAP patients treated at two tertiary care institutions between January 2020 and October 2023. Demographic details, clinical records, management, and tumor molecular profiles were analyzed. Tumor characteristics, including location and imaging features on MR imaging, were reviewed. Clinical or imaging features suggestive of neurofibromatosis 1 or the presence of NF1 gene alteration were documented. The mean age at presentation was 45.5 years (male/female = 5:3). Tumors were midline, localized in the posterior fossa (n = 4), diencephalic/thalamic (n = 2), and spinal cord (n = 2). HGAP lesions were T1 hypointense, T2-hyperintense, mostly without diffusion restriction, predominantly peripheral irregular enhancement with central necrosis (n = 3) followed by mixed heterogeneous enhancement (n = 2). Two NF1 mutation carriers showed signs of neurofibromatosis type 1 before HGAP diagnosis, with one diagnosed during HGAP evaluation, strengthening the HGAP-NF1 link, particularly in patients with posterior fossa masses. All tumors were IDH1 wild-type, often with ATRX, CDKN2A/B, and NF1 gene alteration. Six patients underwent surgical resection followed by adjuvant chemoradiation. Six patients were alive, and two died during the last follow-up. Histone H3 mutations were not detected in our cohort, such as the common H3K27M typically seen in diffuse midline gliomas, linked to aggressive clinical behavior and poor prognosis. HGAP lesions may involve the brain or spine and tend to be midline or paramedian in location. Underlying neurofibromatosis type 1 diagnosis or imaging findings are important diagnostic cues.

Cauda equina neuroendocrine tumors: A single institutional imaging review of cases over two decades.

Cauda Equina Neuroendocrine Tumors (CE-NET), previously referred to as paragangliomas are a rare subset of spinal tumors, with limited data on imaging. Herein, we present a retrospective review of clinical and imaging findings of CE-NETs in ten patients who were evaluated at our institution over the past two decades. All patients had well-defined intradural lesions in the lumbar spine which demonstrated slow growth. A review of imaging findings revealed the presence of an eccentric vascular pedicle along the dorsal aspect of the tumor in 8 of the 10 patients (eccentric vessel sign), a distinctive finding that has not previously been reported with this tumor and may help improve the accuracy of imaging-based diagnosis. In all cases, a gross-total resection was performed, with resolution of symptoms in most of the cases.

Newly Recognized Genetic Tumor Syndromes of the CNS in the 5th WHO Classification: Imaging Overview with Genetic Updates.

The nervous system is commonly involved in a wide range of genetic tumor-predisposition syndromes. The classification of genetic tumor syndromes has evolved during the past years; however, it has now become clear that these syndromes can be categorized into a relatively small number of major mechanisms, which form the basis of the new 5th edition of the World Health Organization book (beta online version) on genetic tumor syndromes. For the first time, the World Health Organization has also included a separate chapter on genetic tumor syndromes in the latest edition of all the multisystem tumor series, including the 5th edition of CNS tumors. Our understanding of these syndromes has evolved rapidly since the previous edition (4th edition, 2016) with recognition of 8 new syndromes, including the following: Elongator protein complex-medulloblastoma syndrome, BRCA1-associated protein 1 tumor-predisposition syndrome, DICER1 syndrome, familial paraganglioma syndrome, melanoma-astrocytoma syndrome, Carney complex, Fanconi anemia, and familial retinoblastoma. This review provides a description of these new CNS tumor syndromes with a focus on imaging and genetic characteristics.

Maple Syrup Urine Disease: An Uncommon Cause of Neonatal Febrile Seizures.

Maple syrup urine disease (MSUD) is a rare autosomal-recessive disorder. An enzyme complex called branched-chain alpha-keto acid dehydrogenase (BCKAD) metabolizes branched-chain amino acids (BCAAs), such as leucine, isoleucine, and valine, in the body. The deficiency of this enzyme causes the accumulation of BCAAs in cerebrospinal fluid, plasma, and urine. This metabolic illness is defined by abnormal levels of BCAAs. The pathognomonic illness marker alloisoleucine is produced in the absence of the BCKAD enzyme, which is part of a metabolic pathway involving three BCAAs and gets accumulated in the body. Classically, affected neonates present with feeding problems, vomiting, lethargy, and irritability, leading to seizures, coma, and death if left untreated. Blood and urine analysis reveals an accumulation of BCAAs in the plasma and urine. Here, we report the case of a neonate on day 10 of life with febrile seizures and non-acceptance of feeds, who was diagnosed with the classical form of MSUD. This is a classic case of MSUD which was evaluated exhaustively and revealed all classic features clinically and on investigations.

Validation of a Deep Learning Model for Detecting Chest Pathologies from Digital Chest Radiographs.

Purpose: Manual interpretation of chest radiographs is a challenging task and is prone to errors. An automated system capable of categorizing chest radiographs based on the pathologies identified could aid in the timely and efficient diagnosis of chest pathologies. Method: For this retrospective study, 4476 chest radiographs were collected between January and April 2021 from two tertiary care hospitals. Three expert radiologists established the ground truth, and all radiographs were analyzed using a deep-learning AI model to detect suspicious ROIs in the lungs, pleura, and cardiac regions. Three test readers (different from the radiologists who established the ground truth) independently reviewed all radiographs in two sessions (unaided and AI-aided mode) with a washout period of one month. Results: The model demonstrated an aggregate AUROC of 91.2% and a sensitivity of 88.4% in detecting suspicious ROIs in the lungs, pleura, and cardiac regions. These results outperform unaided human readers, who achieved an aggregate AUROC of 84.2% and sensitivity of 74.5% for the same task. When using AI, the aided readers obtained an aggregate AUROC of 87.9% and a sensitivity of 85.1%. The average time taken by the test readers to read a chest radiograph decreased by 21% (p < 0.01) when using AI. Conclusion: The model outperformed all three human readers and demonstrated high AUROC and sensitivity across two independent datasets. When compared to unaided interpretations, AI-aided interpretations were associated with significant improvements in reader performance and chest radiograph interpretation time.

A deep learning approach for automated diagnosis of pulmonary embolism on computed tomographic pulmonary angiography.

BACKGROUND: Computed tomographic pulmonary angiography (CTPA) is the diagnostic standard for confirming pulmonary embolism (PE). Since PE is a life-threatening condition, early diagnosis and treatment are critical to avoid PE-associated morbidity and mortality. However, PE remains subject to misdiagnosis. METHODS: We retrospectively identified 251 CTPAs performed at a tertiary care hospital between January 2018 to January 2021. The scans were classified as positive (n = 55) and negative (n = 196) for PE based on the annotations made by board-certified radiologists. A fully anonymized CT slice served as input for the detection of PE by the 2D segmentation model comprising U-Net architecture with Xception encoder. The diagnostic performance of the model was calculated at both the scan and the slice levels. RESULTS: The model correctly identified 44 out of 55 scans as positive for PE and 146 out of 196 scans as negative for PE with a sensitivity of 0.80 [95% CI 0.68, 0.89], a specificity of 0.74 [95% CI 0.68, 0.80], and an accuracy of 0.76 [95% CI 0.70, 0.81]. On slice level, 4817 out of 5183 slices were marked as positive for the presence of emboli with a specificity of 0.89 [95% CI 0.88, 0.89], a sensitivity of 0.93 [95% CI 0.92, 0.94], and an accuracy of 0.89 [95% CI 0.887, 0.890]. The model also achieved an AUROC of 0.85 [0.78, 0.90] and 0.94 [0.936, 0.941] at scan level and slice level, respectively for the detection of PE. CONCLUSION: The development of an AI model and its use for the identification of pulmonary embolism will support healthcare workers by reducing the rate of missed findings and minimizing the time required to screen the scans.

Observer performance evaluation of the feasibility of a deep learning model to detect cardiomegaly on chest radiographs.

Background: Cardiothoracic ratio (CTR) is the ratio of the diameter of the heart to the diameter of the thorax. An abnormal CTR (>0.55) is often an indicator of an underlying pathological condition. The accurate prediction of an abnormal CTR chest X-rays (CXRs) aids in the early diagnosis of clinical conditions. Purpose: We propose a deep learning (DL)-based model for automatic CTR calculation to assist radiologists with rapid diagnosis of cardiomegaly and thus optimise the radiology flow. Material and Methods: The study population included 1012 posteroanterior CXRs from a single institution. The Attention U-Net DL architecture was used for the automatic calculation of CTR. An observer performance test was conducted to assess the radiologist's performance in diagnosing cardiomegaly with and without artificial intelligence assistance. Results: U-Net model exhibited a sensitivity of 0.80 [95% CI: 0.75, 0.85], specificity >99%, precision of 0.99 [95% CI: 0.98, 1], and a F1 score of 0.88 [95% CI: 0.85, 0.91]. Furthermore, the sensitivity of the reviewing radiologist in identifying cardiomegaly increased from 40.50% to 88.4% when aided by the AI-generated CTR. Conclusion: Our segmentation-based AI model demonstrated high specificity (>99%) and sensitivity (80%) for CTR calculation. The performance of the radiologist on the observer performance test improved significantly with provision of AI assistance. A DL-based segmentation model for rapid quantification of CTR can therefore have significant potential to be used in clinical workflows by reducing radiologists' burden and alerting to an abnormal enlarged heart early on.

Utility of 3D-T2 space MRI sequence in diagnosing a rare cause of lower backache: horseshoe cord and meningocoele manqué in a case of composite split cord malformation.

Diastematomyelia is the asymmetric or symmetric lateral duplication of the spinal cord into two hemicords. Pang divided it into three types: type-1, type-2 and composite split cord malformation (SCM). Composite SCMs are uncommon and are defined by the coexistence of multiple types of split cord with normal cord in between. When partially bridged, they are called a horseshoe cord. We report a case of a young woman who presented with backache and was diagnosed with composite SCM with horseshoe cord and type-2 SCM with intervening normal cord. In our case, 3D-SPACE due to its superior topographical evaluation, allowed us to visualise and characterise the thin meningocoele manque bands and detect horseshoe cords, asymmetric cords and demarcate the precise extent of syrinx, which were suboptimally imaged on isolated T2 and T1WI sequences. If left untreated during surgery, bands can be the potential cause for persistent backache.

Evaluating the Association Between Comorbidities and COVID-19 Severity Scoring on Chest CT Examinations Between the Two Waves of COVID-19: An Imaging Study Using Artificial Intelligence.

Background Coronavirus disease 2019 (COVID-19) has accounted for over 352 million cases and five million deaths globally. Although it affects populations across all nations, developing or transitional, of all genders and ages, the extent of the specific involvement is not very well known. This study aimed to analyze and determine how different were the first and second waves of the COVID-19 pandemic by assessing computed tomography severity scores (CT-SS). Methodology This was a retrospective, cross-sectional, observational study performed at a tertiary care Institution. We included 301 patients who underwent CT of the chest between June and October 2020 and 1,001 patients who underwent CT of the chest between February and April 2021. All included patients were symptomatic and were confirmed to be COVID-19 positive. We compared the CT-SS between the two datasets. In addition, we analyzed the distribution of CT-SS concerning age, comorbidities, and gender, as well as their differences between the two waves of COVID-19. Analysis was performed using the SPSS version 22 (IBM Corp., Armonk, NY, USA). The artificial intelligence platform U-net architecture with Xception encoder was used in the analysis. Results The study data revealed that while the mean CT-SS did not differ statistically between the two waves of COVID-19, the age group most affected in the second wave was almost a decade younger. While overall the disease had a predilection toward affecting males, our findings showed that females were more afflicted in the second wave of COVID-19 compared to the first wave. In particular, the disease had an increased severity in cases with comorbidities such as hypertension, diabetes mellitus, bronchial asthma, and tuberculosis. Conclusions This assessment demonstrated no significant difference in radiological severity score between the two waves of COVID-19. The secondary objective revealed that the two waves showed demographical differences. Hence, we iterate that no demographical subset of the population should be considered low risk as the disease manifestation was heterogeneous.

Analysing the Insights and Assessing the Impact of a Digital Mammography and Tomosynthesis Based 2-year Long Prospective Breast Screening Programme Organised in Western India.

BACKGROUND: While the past decades have seen a rise in the number of cases diagnosed with cancer, breast cancer in particular has become the most frequently diagnosed cancer in women over the past decade. The figures for associated mortality are on a decline in most Western and developed nations, but in contrast they continue to remain high in transitional nations like India. MATERIALS AND METHODS: After receiving approval by IEC and IRB, we set-up a prospective 2-year long screening programme combined with outreach camps to ensure representation of the larger population and include urban, rural and tribal population. Strict screening criteria were enforced and trained female paramedical staff were assigned to the camp  for patient counselling and breast cancer awareness. Investigation was performed at the tertiary care institute utilising both full-field digital breast mammography and tomosynthesis. Biopsy was advised for highly suspicious lesions. RESULTS: The study encompassed n=1017 Indian women and revealed that 39% (n=397) of them belonged to 41-50 years age group. BIRADS categorisation of the lesions revealed that while majority (57%; n=580) women had no detectable abnormality, nearly 22% (n=224) had lesions suspected to be benign while 10% (n=99) of them had lesions with a suspicion of high index of malignancy. 43% (n=437) of the populace had dense breasts (type-C). Most of the BIRADS-5 lesions (36/38) were confirmed as malignant on histopathology. CONCLUSION: We propose a model for screening mammography and also presents the results of this programme which we implemented to screen populace from a large and densely populated geographic region. The model was successful in being self-sustainable and received a good turnout on the back of community outreach breast awareness camps and by incentivizing the women by performing mammograms completely free of cost and also providing them reports.

Real-world analysis of artificial intelligence in musculoskeletal trauma.

Musculoskeletal trauma accounts for a large percentage of emergency room visits and is amongst the top causes of unscheduled patient visits to the emergency room. Musculoskeletal trauma results in expenditure of billions of dollars and protracted losses of quality-adjusted life years. New and innovative methods are needed to minimise the impact by ensuring quick and accurate assessment. However, each of the currently utilised radiological procedures, such as radiography, ultrasonography, computed tomography, and magnetic resonance imaging, has resulted in implosion of medical imaging data. Deep learning, a recent advancement in artificial intelligence, has demonstrated the potential to analyse medical images with sensitivity and specificity at par with experts. In this review article, we intend to summarise and showcase the various developments which have occurred in the dynamic field of artificial intelligence and machine learning and how their applicability to different aspects of imaging in trauma can be explored to improvise our existing reporting systems and improvise on patient outcomes.

Utility of Constructive Interference in Steady-State Sequence in Detecting Thin Pituitary Stalk in Pituitary Stalk Interruption Syndrome.

Pituitary stalk interruption syndrome (PSIS) is a rare congenital anomaly, causing hypothalamic-pituitary malfunction. It is characterized by hypoplastic anterior pituitary, absent or thin infundibulum, and absent or ectopic posterior pituitary. Its early recognition is important in disease management. MRI plays a pivotal role in early diagnosis. We report a case of a 13-year-old male child, presenting with stunting of growth and discrepancy between chronological and bone age of four years. A subsequent MRI revealed a small anterior pituitary, hypoplastic pituitary stalk, and an absence of visualization of the bright pituitary gland signal in the sella. The posterior pituitary gland was present ectopically in the midline along the floor of the third ventricle near the median eminence.

Evaluation of Changes in Condylar Cartilage Thickness Using MRI and Ultrasound Imaging in Patients Treated by Mandibular Advancement With Myofunctional Appliance: An In-Vivo Pilot Study.

Introduction The changes occurring due to growth modulation of the condylar cartilage act as an important mechanism for mandibular advancement using myofunctional appliance therapy. So this study aims to evaluate the condylar cartilage thickness by using MRI and USG in patients undergoing myofunctional appliance therapy for mandibular advancement with the null hypothesis being that there are no changes seen in the thickness of condylar cartilage in growing children. Materials and methods A prospective evaluation of samples having skeletal Class-II malocclusion ranging between cervical vertebral maturation index (CVMI) stage II and III, requiring twin block functional therapy was performed. Ten patients were selected randomly who underwent MRI and USG in the open and close positions for the evaluation of condylar cartilage thickness and the dimensional changes in the width of the right and left condyle in mm at T0 and T1. Result There was no statistically significant difference between the values interpreted by MRI or USG imaging when compared at T0 and T1 and in the open and closed mouth on the left and right sides. At T0, the mean thickness noted was 0.49 mm and 0.48 mm during opening and closing on the left side and 0.52 mm in both positions on the right side. At T1, the mean thickness noted was 0.8 and 0.79mm during opening and closing on the left side, whereas it was 0.81 mm in both positions on the right side. Conclusion The condylar cartilage thickness increases significantly after twin block therapy suggestive of mandibular growth in skeletal class II malocclusion. It can be inferred that both MRI and USG carry equal diagnostic interpretation, as there was no statistically significant difference between the two imaging modalities.

Heterotaxy Syndrome: Discordant Growth.

Heterotaxy syndrome implies a discordance between placement of thoracic organs with respect to abdominal organs. A large number of these have associated congenital heart defects. This syndrome is unique as every patient is different and can have any permutation and combination of symptoms. In our case, the five-year-old male child presented with complaints of abdominal distension, fever, and bluish discoloration of limbs with even mild exertion. Radiological evaluation was diagnosed with a large atrial septal defect, cardiomegaly, partial pulmonary venous circulation, multiple small spleens on the right side of body, a large midline liver, malrotated bowel, inferiorly displaced kidneys, and two hemiazygos veins. The echocardiography and electrocardiogram too were consistent with atrial septal defect and right ventricular strain pattern. The reasons for this highly variable pattern are rooted in the genetically complicated process of lateralization with a strong link to the copy number variations. Due to the variable patterns, it is more efficient to report all the findings utilizing a step-by-step process of commenting on each and every individual organ, instead of classifying them under different categories based on atrial isomerism. This is important as any other way of classification predisposes to a certain bias.

Comparison of Tracheal Diameter Measurements on Radiograph Versus Computed Tomography at a Tertiary Care Hospital in Pune, Central India.

Background Variations in tracheal diameter with respect to factors like age and gender are one of the major factors affecting the size of the endotracheal tube (ETT) preferred in a patient. It is important to pre-determine this figure because a tube of a larger size predisposes the patient for tracheal mucosal ischemia, while one of a smaller size may not ensure adequate oxygen saturation in the patient. Purpose We undertook this study to assess the accuracy of radiograph versus computed tomography (CT) and comment on whether a CT should be carried out mandatorily in all patients where intubation is needed. Materials and methods The study was undertaken at Dr DY Patil Medical College, Hospital, and Research Center, a tertiary care institute in Pune, India. A total of 217 patients in whom both chest radiograph and chest CT were performed were enrolled in the study and measurements were performed at suitable landmarks which correspond to the position of endotracheal tubes. Results The males had a mean age of 44.2 years and females of 41.7 years. The mean X-ray transverse diameter was 15.4 ± 3.2 (SD) mm, mean CT axial transverse diameter was 15.3 ± 3.4 (SD) mm, mean CT sagittal diameter was 14.8 ± 3.7 (SD) mm, and the mean CT coronal diameter was 15.2 ± 3.5(SD)mm. Conclusions There was a significant difference in mean X-ray transverse diameter (Low kV), CT axial transverse diameter, CT sagittal diameter, and CT coronal diameter between males and females. Mean values were significantly higher in males as compared to females. There was a significant difference in tracheal diameters for different age groups, irrespective of the modality. Bland-Altman analysis revealed no significant difference between chest radiograph and CT for tracheal diameter measurement.

Painful Abdominal Lump in the Pediatric Age Group: A Diagnostic Dilemma.

Any cystic lesion occurring in the mesentery which may or may not extend into the retroperitoneum is referred to as a mesenteric cyst; they have an infrequent incidence rate in the pediatric age group. Definitive etiology of the cystic lymphatic malformations is still not known but there are multiple hypotheses. A young male child presented with acute onset abdominal pain and palpable intra-abdominal mass and ultrasonography revealed presence of two lesions, one of them as an encysted turbid fluid collection in the right lumbar region and the other as a dilated, tortuous, intercalated structure. On CT, the first one was identified definitively as a mesenteric cyst while the other as a possible neoplastic mass in close proximity to the first one. Histopathology confirmed the diagnosis as a cystic lymphatic malformation of the mesenteric cyst. The limited awareness of its existence along with its usually asymptomatic nature, are the likely reasons that it still remains an elusive diagnosis. Based on our case we discuss, the use of a multi-modality approach towards diagnosing cystic malformation disorders and how the use of MRI is under-utilised when it could prove decisive.

CT as a Diagnostic Tool for Emphysematous Pyelitis: A Case Report.

Gas forming infections of the renal collecting system occurs because of organisms like Escherichia coli, Klebsiella, and Proteus. If the gas is restricted to the collecting system, without causing involvement of the cortex, it is called emphysematous pyelitis; whereas, invasion and penetration of the cortex imply a more gruesome diagnosis of emphysematous pyelonephritis. A 59-year-old male patient, previously diagnosed with a large right renal calculus and having multiple co-morbidities presented to the surgery department with right flank pain; Double J (DJ) stenting was done to relieve the pain from colic due to obstructive renal calculi; the patient subsequently discharged without any post-procedural complications. The patient came back a month later with similar complaints and multiple spikes of fever. Blood and urine culture revealed growth of Escherichia coli. The first line radiological investigations, like X-ray and ultrasonography, were suggestive of the presence of air in the pelvis, ureter, bladder; confirmation by CT revealed the presence of air in the collecting system, including the calyx. This air was seen invading focally into the anterior renal cortex. Also, the DJ stent had migrated into the proximal ureter.  The patient had developed emphysematous pyelitis predominantly, which had developed an overlapping component of pyelonephritis. The aetiology for air in the renal system was infection by Escherichia coli. CT proved to be diagnostic in differentiating both of them, as the presence of air entering the renal cortex was detected only on CT. Subsequently, prominent initiation of antibiotic therapy and replacement of DJ stent was carried out, following which the patient recovered fully within two weeks.