Clinical Imaging Features Research Articles

A Comparative Study on the Diagnostic Performance of Multiple Radiomics Models in Differentiating PGL and MIA in Pulmonary Ground-Glass Nodules

Rationale and ObjectivesHistological subtypes of lung cancers are critical for clinical treatment decision. The aim of this study is to compare the diagnostic performance of multiple radiomics models in differentiating PGL and MIA in pulmonary GGN, in order to identify the most optimal diagnostic model. Materials and methodsPatients presenting with GGNs on lung CT, confirmed as PGL or MIA through surgical pathology between October 2015 and June 2023, were included. The GGNs were randomly divided into training and validation sets at a 7:3 ratio. Clinical imaging characteristics were analyzed by univariate and multivariate logistic regression to identify independent risk factors for predicting MIA, leading to the development of a clinical model. ITK-SNAP and Pyradiomics were employed for segmentation and radiomics feature extraction. Subsequently, radiomics and combined models were established. The diagnostic performance of the three models was compared using ROC curves and quantitatively assessed by AUC, accuracy, specificity, and sensitivity. ResultsA total of 116 cases of GGNs with pathologically confirmed PGLs and MIAs were included. The clinical model identified three independent predictors. The radiomics model identified seven distinct radiomic features. A combined model was constructed by integrating clinical imaging features with radiomic features. In the training set, the combined model demonstrated a higher AUC than the radiomics model, with AUCs of 0.87 and 0.85 respectively. In the validation set, the radiomics model outperformed the combined model with an AUC of 0.83 versus 0.82. Notably, the radiomics model achieved the highest accuracy and specificity, while the combined model demonstrated the highest sensitivity. However, both models performed significantly better than the clinical model. ConclusionThe independent radiomics model can serve as a rapid, non-invasive diagnostic tool for differentiating between the PGL and MIA.

A machine-learning model based on dynamic contrast-enhanced MRI for preoperative differentiation between hepatocellular carcinoma and combined hepatocellular–cholangiocarcinoma

To establish a machine-learning model based on dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) to differentiate combined hepatocellular-cholangiocarcinoma (cHCC-CC) from hepatocellular carcinoma (HCC) before surgery. Clinical and MRI data of 194 patients with histopathologically diagnosed cHCC-CC (n=52) or HCC (n=142) were analysed retrospectively. ITK-SNAP software was used to delineate three-dimensional (3D) lesions and extract high-throughput features. Feature selection was carried out based on Pearson's correlation coefficient and least absolute shrinkage and selection operator (LASSO) regression analysis. A radiomics model (radiomics features), a clinical model (i.e., clinical-image features), and a fusion model (i.e., radiomics features+clinical-image features) were established using six machine-learning classifiers. The performance of each model in distinguishing between cHCC-CC and HCC was evaluated with the receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC), sensitivity, and specificity. Significant differences in liver cirrhosis, tumour number, shape, edge, peritumoural enhancement in the arterial phase, and lipid were identified between cHCC-CC and HCC patients (p<0.05). The AUC of the fusion model based on logistic regression was 0.878 (95% CI: 0.766-0.949) in the arterial phase in the test set, and the sensitivity/specificity was 0.844/0.714; however, the AUC of the clinical and radiomics models was 0.759 (95% CI: 0.663-0.861) and 0.838 (95% CI: 0.719-0.921) in the test set, respectively. The fusion model based on DCE-MRI in the arterial phase can significantly improve the diagnostic rate of cHCC-CC and HCC as compared with conventional approaches.

The value of computed tomography texture analysis in identifying chronic subdural hematoma patients with a good response to polytherapy

This study aimed to investigate the predictive factors of therapeutic efficacy for chronic subdural hematoma (CSDH) patients receiving atorvastatin combined with dexamethasone therapy by using clinical imaging characteristics in conjunction with computed tomography (CT) texture analysis (CTTA). Clinical imaging characteristics and CT texture parameters at admission were retrospectively investigated in 141 CSDH patients who received atorvastatin combined with dexamethasone therapy from June 2019 to December 2022. The patients were divided into a training set (n = 81) and a validation set (n = 60). Patients in the training data were divided into two groups based on the effectiveness of the treatment. Univariate and multivariate analyses were performed to assess the potential factors that could indicate the prognosis of CSDH patients in the training set. The receiver operating characteristic (ROC) curve was used to analyze the predictive efficacy of the significant factors in predicting the prognosis of CSDH patients and was validated using a validation set. The multivariate analysis showed that the hematoma density to brain parenchyma density ratio, singal min (minimum) and singal standard deviation of the pixel distribution histogram, and inhomogeneity were independent predictors for the prognosis of CSDH patients based on atorvastatin and dexamethasone therapy. The area under the ROC curve between the two groups was between 0.716 and 0.806. As determined by significant factors, the validation's accuracy range was 0.816 to 0.952. Clinical imaging characteristics in conjunction with CTTA could aid in distinguishing patients with CSDH who responded well to atorvastatin combined with dexamethasone.

Abstract TP179: Reversible Cerebral Vasoconstriction Syndrome (RCVS): A Retrospective Analysis of 79 Cases

Background: RCVS is characterized by severe thunderclap headaches often triggered by medications or sexual activity. Convexity subarachnoid hemorrhage, and less commonly, ischemic stroke and intracerebral hemorrhage can occur. There are few studies of the clinical-imaging features of RCVS (Singhal, 2011; Ducros, 2007). The pathogenesis is yet to be understood, and further studies looking into various triggers and outcomes, such as our present one, is essential to characterize the condition and develop targeted treatments. Methods: We performed an EMR search (2012-2023) for patients over 18Y of age with a diagnosis of RCVS in inpatient and outpatient settings. We retrospectively analyzed clinical (demographics, triggers, and discharge mRS)) and imaging features (CTA, MRA, DSA, and transcranial doppler (TCD)) to confirm RCVS diagnosis. RCVS score was calculated. Discharge mRS was inferred from EMR. Diagnosis adjudication was performed by RSM. Student t-test and Chi-square test were used to analyze outcomes. Results: Seventy-nine patients were identified (mean age 40±11.5Y, 91% women). The most common triggers were medications (39%), sexual activity (11.4%), and marijuana use (5%). One-third (35%) had chronic headache history (migraines 22%). Twenty-nine (37%) were postpartum (n=19) or pregnant (n=10). Fourteen had concurrent pre-eclampsia (17%). Twelve (15%) also had imaging features of posterior reversible encephalopathy syndrome (PRES). Vasoconstriction was seen on DSA (n=15), CTA (n=25), and MRA (n=23); In 14 patients, vasoconstriction was evident only on TCD. SAH occurred in 26 (33%), ischemic stroke in 8, and ICH in 9. Median RCVS score was 7 (IQR 6-9, range 4-10). CSF profile (n=19) was normal, aside from mildly elevated lymphocyte count (n=2, range 10-13 cells) or protein (n=5, range 50-80 mg/dL). Discharge mRS was 0-1 in 83%. Patients without RCVS trigger (n= 40) had higher ischemic stroke or hemorrhage occurrence ( χ2 = 3.8, P=0.05 ). RCVS scores in pregnant/postpartum patients were similar to others ( t = 2.01, P = 0.06). Conclusion: In this case series, absence of an RCVS trigger was associated with occurrence of stroke or hemorrhage. Most patients had favorable prognosis. These findings need to be confirmed in prospective studies.

The Diagnostic Value of a Nomogram Based on Clinical Imaging and MRIBased Radiomic Features in Triple-Negative Breast Cancer.

This study aimed to determine the utility of a radiomic nomogram combined with clinical imaging and radiomic features based on MRI for the diagnosis of triple-negative breast cancer. Multi-parametric MRI images of 136 breast cancer patients were retrospectively analyzed, 95 cases were stratified into the training cohort, and 41 cases were selected for the test group. According to the pathological molecular typing, the patients were divided into 23 cases of triple-negative breast cancer and 113 cases of non-triple-negative breast cancer. ITK software was used to manually delineate the lesion volume region of interest (VOI), and the Pyradiomics package was used to extract radiomic features for screening and model building. The platform was then used to analyze the clinical and imaging risk factors of breast cancer to build a characteristic model separately. Finally, a radiomic nomogram was constructed by integrating the radiomic and independent clinical image features. The diagnostic performance of the model was assessed using ROC curves. Univariate and multivariate analyses showed that the menstrual cycle, glandular density, and skin thickening were risk factors for clinical imaging characteristics of triple-negative breast cancer. The Area Under the Curve (AUC) was 0.839 and 0.826 for univariate and multivariate analysis, respectively. After screening, 11 radiomic features participated in the calculation of the radiomic score, and its AUC in the test set was 0.803. Combining it further with clinical models, the AUC improved to 0.899. The radiomic nomogram developed in this study has great value in the diagnosis of triple-negative breast cancer.

Prediction of postoperative reintervention risk for uterine fibroids using clinical-imaging features and T2WI radiomics before high-intensity focused ultrasound ablation

Objective To predict the risk of postoperative reintervention for uterine fibroids using clinical-imaging features and T2WI radiomics before high-intensity focused ultrasound (HIFU) ablation. Methods Among patients with uterine fibroids treated with HIFU from 2019 to 2021, 180 were selected per the inclusion and exclusion criteria (42 reintervention and 138 non-reintervention). All patients were randomly assigned to either the training (n = 125) or validation (n = 55) cohorts. Multivariate analysis was used to determine independent clinical-imaging features of reintervention risk. The Relief and LASSO algorithm were used to select optimal radiomics features. Random forest was used to construct the clinical-imaging model based on independent clinical-imaging features, the radiomics model based on optimal radiomics features, and the combined model incorporating the above features. An independent test cohort of 45 patients with uterine fibroids tested these models. The integrated discrimination index (IDI) was used to compare the discrimination performance of these models. Results Age (p < .001), fibroid volume (p = .001) and fibroid enhancement degree (p = .001) were identified as independent clinical-imaging features. The combined model had AUCs of 0.821 (95% CI: 0.712–0.931) and 0.818 (95% CI: 0.694–0.943) in the validation and independent test cohorts, respectively. The predictive performance of the combined model was 27.8% (independent test cohort, p < .001) and 29.5% (independent test cohort, p = .001) better than the clinical-imaging and radiomics models, respectively. Conclusion The combined model can effectively predict the risk of postoperative reintervention for uterine fibroids before HIFU ablation. It is expected to help clinicians to develop accurate, personalized treatment and management plans. Future studies will need to be prospectively validated.

Reversible cerebral vasoconstriction syndrome: A review of pathogenesis, clinical presentation, and treatment.

Reversible segmental narrowing of the intracranial arteries has been described since several decades in numerous clinical settings, using variable nosology. Twenty-one years ago, we tentatively proposed the unifying concept that these entities, based on similar clinical-imaging features, represented a single cerebrovascular syndrome. This "reversible cerebral vasoconstriction syndrome" or RCVS has now come of age. A new International Classification of Diseases code, (ICD-10, I67.841) has been established, enabling larger-scale studies. The RCVS2 scoring system provides high accuracy in confirming RCVS diagnosis and excluding mimics such as primary angiitis of the central nervous system. Several groups have characterized its clinical-imaging features. RCVS predominantly affects women. Recurrent worst-ever (thunderclap) headaches are typical at onset. While initial brain imaging is often normal, approximately one-third to half develop complications such as convexity subarachnoid hemorrhages, lobar hemorrhages, ischemic strokes located in arterial "watershed" territories and reversible edema, alone or in combination. Vasoconstriction evolves over hours to days, first affecting distal and then the more proximal arteries. An overlap between RCVS and primary thunderclap headache, posterior reversible encephalopathy syndrome, Takotsubo cardiomyopathy, transient global amnesia, and other conditions has been recognized. The pathophysiology remains largely unknown. Management is mostly symptomatic: headache relief with analgesics and oral calcium-channel blockers, removal of vasoconstrictive factors, and avoidance of glucocorticoids that can significantly worsen outcome. Intra-arterial vasodilator infusions provide variable success. Overall, 90-95% of admitted patients achieve complete or major resolution of symptoms and clinical deficits within days to weeks. Recurrence is exceptional, although 5% can later develop isolated thunderclap headaches with or without mild cerebral vasoconstriction.

Clinical-imaging features of the institutional cohort of young patients with stroke

Stroke in younger adults is a less common event in comparison to older ones, but there have been registered a negative trend and an earlier onset of stroke in the past decades. Stroke in younger adults represents an emerging public health issue that needs strengthening, prevention, early diagnosis, and management. The aim of the present research is to investigate the clinical features, risk factors and other diagnostic findings of the young population that developed stroke.

Clinical Image Feature Analysis and Diagnostic Efficacy Evaluation of Pulmonary Ultrasound in the Diagnosis of Congenital Pulmonary Airway Malformations in Children: Based on a Single Center, Retrospective Cohort Study.

Objective A single center, retrospective cohort study was conducted to analyze the clinical image features and diagnostic efficiency of pulmonary ultrasound in the diagnosis of congenital pulmonary airway malformations (CPAMs) in children. Methods The starting and ending time of this study is from May 2019 to December 2021. This study included 200 children with CPAM diagnosed by prenatal ultrasound and postpartum CT imaging (aged from 1 hour to 3 years), including 103 males and 97 females. All of them were diagnosed by fetal ultrasound and were examined by chest X-ray (CXR), chest CT, and lung ultrasound (LUS). The clinical image characteristics and diagnostic efficiency of CXR, chest CT, and LUS in the diagnosis of CPAM in children were analyzed. Results 200 lesions were limited to single lung, and the most common were right lower lobe, right lower lobe in 80 cases (40.0%), left lower lobe in 60 cases (30.0%), right upper lobe in 30 cases (15.0%), left upper lobe in 20 cases (10.0%), and right middle lobe in 10 cases (5.0%). Among the 200 cases of preoperative CT examination, 196 cases (98.00%) showed lesions and confirmed diagnosis, and 4 cases were missed. Chest X-ray showed multiple focal circular low-density shadow in the right lung, and the heart shadow and mediastinum moved slightly to the left. CXR showed multiple cystic transparent shadows in the left lower lung and slightly to the right of the mediastinum and heart. CXR showed multiple balloon cavities of different sizes in the right lung field, and the mediastinum and heart shadow shifted to the left. The direct signs of LUS (including single or multiple cystic lesions) were not significantly different from those of CXR, but the indirect signs were significantly higher than those of CXR. Conclusion The most common CT findings of CPAM in children are cystic lesions, especially polycystic lesions, while LUS images of CPAM in children are various. LUS is a noninvasive and nonradiological examination method, which is easy to operate and repeat. LUS can be used for preliminary qualitative screening of CPAM in children, and the diagnostic value of indirect signs of LUS is better than that of CXR.

Clinical imaging characteristics of inpatients with coronavirus disease-2019 in Heilongjiang Province, China: a retrospective study.

Objective: To investigate the clinical, laboratory, and radiological characteristics of patients with coronavirus disease-2019 (COVID-19) in Heilongjiang Province.Results: Patients in the ICU group were older and their incidence of cardiovascular disease was higher than those in the non-ICU group. Lymphocyte levels were lower and neutrophil and D-dimer levels were higher in the ICU than that in the non-ICU group. Compared to the non-ICU group, the incidence of pulmonary consolidation and ground-glass opacity with consolidation was significantly higher in the ICU group, all lung lobes were more likely to be involved, with higher number of lung lobes and areas surrounding the bronchi. Of the 59 patients with COVID-19 in this group, 15 received mechanical ventilation. All intubated patients involved lung lobes, and a large number of lesions were observed in the area around the bronchial vessels.Conclusion: Significant differences were observed in clinical symptoms, laboratory tests, and computed tomography features between the ICU and non-ICU groups.Methods: A total of 59 patients with COVID-19, comprising 44 patients in the intensive care unit (ICU) and 15 in the non-ICU, were retrospectively analyzed. Characteristics of the two groups of patients were compared.

Isolated Upper Limb Weakness From Ischemic Stroke: Mechanisms and Outcome

ObjectiveTo characterize isolated upper extremity (UE) weakness from stroke. MethodsIn our Get with the Guidelines-Stroke dataset (n = 7643), 87 patients (1.14%) had isolated UE weakness and underwent thorough stroke evaluation with diffusion-weighted magnetic resonance imaging and good-quality arterial imaging. We analyzed clinical-imaging features, etiology, management, and outcome. Since isolated UE weakness is typically associated with contralateral hand-knob area infarcts, patients were classified into Group-A (motor strip infarct) or Group-B (non-motor strip infarct). ResultsThe mean age was 68 years; 66% were male, 72% had hypertension, 22% diabetes, 53% hyperlipidemia, and 16% were smokers. In Group-A (n = 71), 18 patients had single and 53 had multiple infarcts involving the contralateral motor strip. In Group-B (n = 16), 6 patients had contralateral subcortical white matter infarcts, 9 had bihemispheric infarcts and 1 had a brainstem infarct. Compared to Group-B, patients in Group-A more often had carotid artery stenosis or irregular plaque (84.5% versus 50%, P = .006) and large-artery atherosclerosis mechanism (46% versus 19%, P = .05), and less often cardioembolic mechanism (13% versus 44%, P = .008). Among 36 patients with large-artery mechanism, 27 had less than 70% stenosis including 19 with plaque ulceration/thrombus. Recurrent strokes occurred in 10 patients (11.5%), including 5 with mild-moderate carotid stenosis and plaque ulceration/thrombosis, over 1515 days follow-up. ConclusionStroke mechanism in acute isolated UE weakness is variable. Contralateral motor-strip infarcts are associated with carotid stenosis, often with plaque ulceration (“vulnerable carotid plaque”), and infarcts in other locations with cardioembolism. Recurrent stroke risk is high especially with mild-moderate carotid artery stenosis and plaque ulceration/thrombus.

Childhood Nasopharyngeal Carcinoma (NPC): A Review of Clinical-Imaging Features and Recent Trends in Management

Introduction: Nasopharyngeal carcinoma (NPC) in children and adolescents is a relatively rare yet highly malignant disease. Clinical presentation of NPC in this age group is non-specific and varied leading to a predominantly late diagnosis. The objective of this paper is to explore and clarify the tumour’s ambiguity and assess the precision of imaging in mapping its morphology and loco-regional extension and possible distant metastases. Treatment regimes that minimize adverse radio-therapeutic effects on surrounding structures will be highlighted. Method: Retrospective analysis and observations of literature (in English) between 2004 to December 2017 was performed. A search was performed using the Medline data-base. The following are the search terms: “children”, “nasopharyngeal carcinoma”, “symptoms’, “imaging” and “therapy”. Material: Of the 43 papers found on the primary search only 36 satisfied the search criteria. Four review papers of the primary search were retained as sources of reference. The core material comprised 22 papers on NPC’s clinical presentation and the role of imaging in diagnosis and prognostication. There were three papers on advanced imaging in adults. The rest of the seven comprised selected articles on chemo-radiation, radiotherapy and related late toxicities. Results: The clinical presentations range from nasal stuffiness, otalgia to unilateral or bilateral neck masses. Symptoms can last from a few weeks to 6 months; by then disease can be advanced. A WHO high-grade undifferentiated squamous cell carcinoma is the commonest lesion in clinical practice. Data from magnetic resonance imaging (MRI) focusing on tumour extensions and tumour volume are markers of long-term prognosis. Diffusion weighted MRI by assessing microscopic changes of NPC can determine the ultimate outlook of adults afflicted with NPC. Treatment of paediatric NPC consists of induction chemotherapy followed by radiotherapy with dosage up to 65-70 Gy. Morphologically, the main mimicker of childhood NPC is an embryonic parameningeal rhabdomyosarcoma arising from the pharyngeal and nasal space. Both have inclination to invade the skull base. Conclusion: Despite NPC’s varied and nonspecific presentations, the clinician must be vigilant because treatment of the disease in different stages of severity has a higher response rate than its adult counterpart. Contrast MRI and computed tomography (CT) are precise in showing skull base invasion, loco-regional and distant metastases. The application of diffusion weighted MRI has a role in determining the tumour’s microscopic contents and long-term prognosis. Use of intensity modulated radiation therapy (IMRT) in addition to induction chemotherapy and irradiation treatment regime has decreased the incidence of the dreaded late sequelae.

Immunodeficiency-Associated Burkitt’s lymphoma in pediatric patients: a clinical case report

Burkitt’s lymphoma, a form of non-Hodgkin lymphoma, is a neoplastic monoclonal proliferation of lymphoid cells in areas of the immune system. It can occur in HIV-positive patients, as AIDS is related to the development of non- Hodgkin lymphoma. Burkitt's lymphoma is a rare subtype, highly prevalent in patients with AIDS. Incisional biopsy, in situ hybridization and computerized axial tomography are the appropriate tests to determine the characterize of the lesions. The case of a 4-year-old HIV-positive patient, who developed Burkitt’s lymphoma of the oral cavity, is reported in this paper. The aim of this case report is to describe the course of the pathology, taking into account its clinical imaging characteristics and treatment.

Phenylketonuria: Our Experience in Nine Years at a Tertiary-level Referral Institute.

Introduction:Phenyl ketonuria is an inborn error of amino acid metabolism resulting in excessive phenyl alanine levels in blood resulting in a spectrum of neurological defects.Patients and Methods:We retrospectively went through the records of patients diagnosed as Phenyl ketonuria in the last nine years in our team and patients who's data could be accessed were analyzed in detail. Details of laboratory tests, imaging clinical features, course were recorded.Observation:A total of 32 patients were identified in nine years of which data was available only for 15 patients. Age at diagnosis varied from 2.5 years to 7 years. 73% were males. Global developmental delay, Microcephaly. Seizures blond hair, spasticity, regression, Ocular Hypertelorism, low set ears, Seborrhea, Hypotonia, Family history of mental retardation and Consanguinity was common one patient showed a large hypo pigmented area in left arm with eczematous rash.Results of Lab Tests:Urine ferric chloride test and DNPH was positive in all cases. Tandem mass spectroscopy showed elevated phenyl alanine, normal tyrosine and elevated PHE tyrosine ratio in all cases. MRI showed symmetrical Flair hyperintensities in T2 weighted images in the parieto occipital region hypo on T1 with no diffusion restriction in 11 cases and MRS was normal. Genetic testing showed one non consanguineous family having carrier state. Follow up is from 1 year to 5 years. Seizures controlled in all. Regular fallow up shows change in hair color and gain of mile stones. There was no mortality.Conclusion:Phenyl ketonuria is a controllable metabolic disease. However there is considerable delay before diagnosis resulting in persistence of sequelae in children with PKU as well as normal children born to PKU mothers which needs attention to prevent these complications.

Abstract 112: Recrudescence of Neurological Deficits After Stroke: Clinical-imaging Phenotype, Triggers and Risk Factors

Background: Re-emergence of prior stroke-related deficits or post-stroke recrudescence ( PSR ) has not been adequately studied. Methods: Using preliminary criteria for PSR (transient recurrence or worsening of residual post-stroke deficits; chronic brain infarct or hemorrhage but no acute vascular lesion on MRI including DWI; no severe ipsilateral cerebral artery stenosis; no evidence for seizure), we identified 153 patients (145 prior infarcts, 8 hypertensive ICH) with 164 admissions for PSR from 2000-2015. Clinical-imaging features of PSR were characterized. Triggers of PSR were identified by comparing PSR admissions to adjacent admissions without PSR (n=65). Risk factors for PSR were identified by comparing PSR cases to 1861 controls without PSR in our prospective institutional stroke registry. Results: PSR occurred 3.9±0.6y after stroke, lasted 18.4±20.4 hrs, and 69% resolved on Day 1. Mean age 67±16y, 60% women. Neuro-worsening was usually abrupt, mild, with motor-sensory or language dysfunction. No patient had isolated gaze paresis, hemianopia or neglect. During PSR the NIHSS worsened by mean 2.5±1.9 points; deficits were limited to a single subscale NIHSS item in 38%. The underlying chronic strokes were variably-sized, predominantly affected white-matter tracts, and 73% involved the MCA territory. Infection, hypotension, hyponatremia, insomnia/stress and benzodiazepine use were higher (p&lt;0.05) during PSR as compared to adjacent admissions without PSR. As compared to the ischemic stroke registry controls, the subgroup of 145 cases with PSR after ischemic stroke had more women, African-American and Other races, diabetes, dyslipidemia, smoking, and more severe NIHSS scores at the time of index stroke (all p&lt;0.05). The PSR group had more small-vessel infarcts and more strokes from “other definite” causes. Six patients with PSR received iv tPA without hemorrhagic complications. Conclusion: This detailed characterization of PSR should enable prompt diagnosis and distinguish PSR from mimics such as TIA, migraine, Todd’s paralysis, Uhthoff’s phenomenon, and others. This is the first large comprehensive study of PSR. Prospective studies are required to validate our proposed diagnostic criteria and decipher underlying mechanisms.

Clinical-Imaging Features of Venous Strokes

Clinical-Imaging Features of Venous Strokes

Background based Gaussian mixture model lesion segmentation in PET.

Quantitative (18)F-fluorodeoxyglucose positron emission tomography is limited by the uncertainty in lesion delineation due to poor SNR, low resolution, and partial volume effects, subsequently impacting oncological assessment, treatment planning, and follow-up. The present work develops and validates a segmentation algorithm based on statistical clustering. The introduction of constraints based on background features and contiguity priors is expected to improve robustness vs clinical image characteristics such as lesion dimension, noise, and contrast level. An eight-class Gaussian mixture model (GMM) clustering algorithm was modified by constraining the mean and variance parameters of four background classes according to the previous analysis of a lesion-free background volume of interest (background modeling). Hence, expectation maximization operated only on the four classes dedicated to lesion detection. To favor the segmentation of connected objects, a further variant was introduced by inserting priors relevant to the classification of neighbors. The algorithm was applied to simulated datasets and acquired phantom data. Feasibility and robustness toward initialization were assessed on a clinical dataset manually contoured by two expert clinicians. Comparisons were performed with respect to a standard eight-class GMM algorithm and to four different state-of-the-art methods in terms of volume error (VE), Dice index, classification error (CE), and Hausdorff distance (HD). The proposed GMM segmentation with background modeling outperformed standard GMM and all the other tested methods. Medians of accuracy indexes were VE <3%, Dice >0.88, CE <0.25, and HD <1.2 in simulations; VE <23%, Dice >0.74, CE <0.43, and HD <1.77 in phantom data. Robustness toward image statistic changes (±15%) was shown by the low index changes: <26% for VE, <17% for Dice, and <15% for CE. Finally, robustness toward the user-dependent volume initialization was demonstrated. The inclusion of the spatial prior improved segmentation accuracy only for lesions surrounded by heterogeneous background: in the relevant simulation subset, the median VE significantly decreased from 13% to 7%. Results on clinical data were found in accordance with simulations, with absolute VE <7%, Dice >0.85, CE <0.30, and HD <0.81. The sole introduction of constraints based on background modeling outperformed standard GMM and the other tested algorithms. Insertion of a spatial prior improved the accuracy for realistic cases of objects in heterogeneous backgrounds. Moreover, robustness against initialization supports the applicability in a clinical setting. In conclusion, application-driven constraints can generally improve the capabilities of GMM and statistical clustering algorithms.

Clinical-Imaging Features And Surgical Considerations in a Pediatric Dental Patient With Osteogenesis Imperfecta Treated With Bisphosphonate

Osteogenesis imperfecta (OI) is a rare autosomal dominant disorder caused by mutations in the genes COL1A1 or COL1A2 associated with changes in type I collagen metabolism. Patients with OI may have blue sclerae, hearing loss, dentinogenesis imperfecta (DI), growth deficiency, ligamentous laxity, or a combination of these. Bisphosphonate therapy is reported to improve mobility and bone density and to reduce pain and the incidence of fracture. However, it may also favor the development of maxillary osteonecrosis, especially after dental surgery.

Abstract WP431: Distinguishing RCVS-associated Subarachnoid Hemorrhage From Cryptogenic and Aneurysmal Subarachnoid Hemorrhage

Background: Reversible cerebral vasoconstriction syndrome (RCVS) is a self-limited entity with usually benign outcome. Over 30% RCVS patients develop subarachnoid hemorrhage (SAH). We aimed to identify features that differentiate RCVS-SAH from more ominous causes of SAH, i.e. aneurysmal SAH (aSAH) and cryptogenic ‘angio-negative’ SAH (cSAH). Methods: We compared the clinical-imaging features of 38 consecutive RCVS-SAH patients, to 515 aSAH and 93 cSAH patients consecutively admitted to Massachusetts General Hospital. Results: As compared to aSAH and cSAH, the RCVS-SAH group was significantly younger, more women, and higher frequency of migraine, depression, chronic obstructive pulmonary disease (COPD), alcohol and drug exposure, and prior antidepressant use. The distribution of Hunt-Hess (HH) grade and Fisher group were different between groups, with median values highest in the aSAH group. The RCVS-SAH group had more hypodense lesions on 1st head CT and earlier, more severe and widespread vasoconstriction on cerebral angiography. Discharge mRS scores were lowest in the RCVS-SAH group. To avoid overfitting, multivariate logistic regression (Firth’s method) was performed using separate models for clinical and radiological variables given small "N". Predictors of RCVS-SAH vs. aSAH [model 1]: age (O.R. 0.9, 95% C.I. 0.9-0.96), prior headache disorder (O.R. 9.3, 95% C.I. 3.9-22.4), depression (O.R. 5.6, 95% C.I. 1.8-17.6), and COPD (O.R. 7.6, 95% C.I. 2.9-20.1), and [model 2]: HH grade (O.R. 0.4, 95% C.I. 0.2-0.7), Fisher group (O.R. 0.2, 95% C.I. 0.07-0.4), and the number of constricted arteries (O.R. 1.6, 95% C.I. 1.4-1.9). Predictors of RCVS-SAH vs. cSAH [model 1]: age (O.R. 0.9, 95%C.I. 0.9-0.97), prior headache (O.R. 10.3, 95% C.I. 4.3-24.9), depression (O.R. 6.9, 95% C.I. 2.1-22.4), and alcohol use (O.R. 5.1, 95% C.I. 2.0-12.9), and [model 2]: Fisher group (O.R. 0.01, 95% C.I. 0.0-0.6), vasospasm severity (O.R. 9.1, 95% C.I. 1.4-57.2), and the number of constricted arteries (O.R. 2.0, 95% C.I. 1.2-3.1). Conclusion: Several clinical-imaging features distinguish RCVS-SAH from aSAH and cSAH. These data should prove useful to improve the diagnostic accuracy, management, and resource utilization in patients with SAH.

Quantification and Discrimination of Abnormal Sulcal Patterns in Polymicrogyria

Polymicrogyria (PMG) is a malformation of cortical development characterized by an irregular gyral pattern and its diagnosis and severity have been qualitatively judged by visual inspection of imaging features. We aimed to provide a quantitative description of abnormal sulcal patterns for individual PMG brains using our sulcal graph-based analysis and examined the association with language impairment. The sulcal graphs were constructed from magnetic resonance images in 26 typical developing and 18 PMG subjects and the similarity between sulcal graphs was computed by using their geometric and topological features. The similarities between typical and PMG groups were significantly lower than the similarities measured within the typical group. Furthermore, more lobar regions were determined to be abnormal in most patients when compared with the visual diagnosis of PMG involvement, suggesting that PMG may have more global effects on cortical folding than previously expected. Among the PMG, the group with intact language development showed sulcal patterns more closely matched with the typical than the impaired group in the left parietal lobe. Our approach shows the potential to provide a quantitative means for detecting the severity and extent of involvement of cortical malformation and a greater understanding of genotype-phenotype and clinical-imaging features correlations.