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1.
Eur J Nucl Med Mol Imaging ; 51(5): 1451-1461, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38133687

RESUMO

PURPOSE: To evaluate if a machine learning prediction model based on clinical and easily assessable imaging features derived from baseline breast [18F]FDG-PET/MRI staging can predict pathologic complete response (pCR) in patients with newly diagnosed breast cancer prior to neoadjuvant system therapy (NAST). METHODS: Altogether 143 women with newly diagnosed breast cancer (54 ± 12 years) were retrospectively enrolled. All women underwent a breast [18F]FDG-PET/MRI, a histopathological workup of their breast cancer lesions and evaluation of clinical data. Fifty-six features derived from positron emission tomography (PET), magnetic resonance imaging (MRI), sociodemographic / anthropometric, histopathologic as well as clinical data were generated and used as input for an extreme Gradient Boosting model (XGBoost) to predict pCR. The model was evaluated in a five-fold nested-cross-validation incorporating independent hyper-parameter tuning within the inner loops to reduce the risk of overoptimistic estimations. Diagnostic model-performance was assessed by determining the area under the curve of the receiver operating characteristics curve (ROC-AUC), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy. Furthermore, feature importances of the XGBoost model were evaluated to assess which features contributed most to distinguish between pCR and non-pCR. RESULTS: Nested-cross-validation yielded a mean ROC-AUC of 80.4 ± 6.0% for prediction of pCR. Mean sensitivity, specificity, PPV, and NPV of 54.5 ± 21.3%, 83.6 ± 4.2%, 63.6 ± 8.5%, and 77.6 ± 8.1% could be achieved. Histopathological data were the most important features for classification of the XGBoost model followed by PET, MRI, and sociodemographic/anthropometric features. CONCLUSION: The evaluated multi-source XGBoost model shows promising results for reliably predicting pathological complete response in breast cancer patients prior to NAST. However, yielded performance is yet insufficient to be implemented in the clinical decision-making process.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/terapia , Fluordesoxiglucose F18 , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons , Aprendizado de Máquina
2.
Eur Radiol ; 34(8): 5276-5286, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38189981

RESUMO

OBJECTIVES: This study investigates the influence of normal cohort (NC) size and the impact of different NCs on automated MRI-based brain atrophy estimation. METHODS: A pooled NC of 3945 subjects (NCpool) was retrospectively created from five publicly available cohorts. Voxel-wise gray matter volume atrophy maps were calculated for 48 Alzheimer's disease (AD) patients (55-82 years) using veganbagel and dynamic normal templates with an increasing number of healthy subjects randomly drawn from NCpool (initially three, and finally 100 subjects). Over 100 repeats of the process, the mean over a voxel-wise standard deviation of gray matter z-scores was established and plotted against the number of subjects in the templates. The knee point of these curves was defined as the minimum number of subjects required for consistent brain atrophy estimation. Atrophy maps were calculated using each NC for AD patients and matched healthy controls (HC). Two readers rated the extent of mesiotemporal atrophy to discriminate AD/HC. RESULTS: The maximum knee point was at 15 subjects. For 21 AD/21 HC, a sufficient number of subjects were available in each NC for validation. Readers agreed on the AD diagnosis in all cases (Kappa for the extent of atrophy, 0.98). No differences in diagnoses between NCs were observed (intraclass correlation coefficient, 0.91; Cochran's Q, p = 0.19). CONCLUSION: At least 15 subjects should be included in age- and sex-specific normal templates for consistent brain atrophy estimation. In the study's context, qualitative interpretation of regional atrophy allows reliable AD diagnosis with a high inter-reader agreement, irrespective of the NC used. CLINICAL RELEVANCE STATEMENT: The influence of normal cohorts (NCs) on automated brain atrophy estimation, typically comparing individual scans to NCs, remains largely unexplored. Our study establishes the minimum number of NC-subjects needed and demonstrates minimal impact of different NCs on regional atrophy estimation. KEY POINTS: • Software-based brain atrophy estimation often relies on normal cohorts for comparisons. • At least 15 subjects must be included in an age- and sex-specific normal cohort. • Using different normal cohorts does not influence regional atrophy estimation.


Assuntos
Doença de Alzheimer , Atrofia , Encéfalo , Imageamento por Ressonância Magnética , Humanos , Idoso , Atrofia/patologia , Feminino , Masculino , Pessoa de Meia-Idade , Imageamento por Ressonância Magnética/métodos , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Estudos Retrospectivos , Valores de Referência , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Voluntários Saudáveis , Reprodutibilidade dos Testes
3.
Neurocrit Care ; 39(1): 125-134, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36802010

RESUMO

BACKGROUND: Early computed tomography perfusion (CTP) is frequently used to predict delayed cerebral ischemia following aneurysmatic subarachnoid hemorrhage (aSAH). However, the influence of blood pressure on CTP is currently controversial (HIMALAIA trial), which differs from our clinical observations. Therefore, we aimed to investigate the influence of blood pressure on early CTP imaging in patients with aSAH. METHODS: We retrospectively analyzed the mean transit time (MTT) of early CTP imaging within 24 h after bleeding prior to aneurysm occlusion with respect to blood pressure shortly before or after the examination in 134 patients. We correlated the cerebral blood flow with the cerebral perfusion pressure in the case of patients with intracranial pressure measurement. We performed a subgroup analysis of good-grade (World Federation of Neurosurgical Societies [WFNS] I-III), poor-grade (WFNS IV-V), and solely WFNS grade V aSAH patients. RESULTS: Mean arterial pressure (MAP) significantly correlated inversely with the mean MTT in early CTP imaging (R = - 0.18, 95% confidence interval [CI] - 0.34 to - 0.01, p = 0.042). Lower mean blood pressure was significantly associated with a higher mean MTT. Subgroup analysis revealed an increasing inverse correlation when comparing WFNS I-III (R = - 0.08, 95% CI - 0.31 to 0.16, p = 0.53) patients with WFNS IV-V (R = - 0.2, 95% CI - 0.42 to 0.05, p = 0.12) patients, without reaching statistical significance. However, if only patients with WFNS V are considered, a significant and even stronger correlation between MAP and MTT (R = - 0.4, 95% CI - 0.65 to 0.07, p = 0.02) is observed. In patients with intracranial pressure monitoring, a stronger dependency of cerebral blood flow on cerebral perfusion pressure is observed for poor-grade patients compared with good-grade patients. CONCLUSIONS: The inverse correlation between MAP and MTT in early CTP imaging, increasing with the severity of aSAH, suggests an increasing disturbance of cerebral autoregulation with the severity of early brain injury. Our results emphasize the importance of maintaining physiological blood pressure values in the early phase of aSAH and preventing hypotension, especially in patients with poor-grade aSAH.


Assuntos
Hipotensão , Hemorragia Subaracnóidea , Humanos , Hemorragia Subaracnóidea/complicações , Pressão Sanguínea , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Imagem de Perfusão , Homeostase
4.
HNO ; 71(5): 319-322, 2023 May.
Artigo em Alemão | MEDLINE | ID: mdl-37000225

RESUMO

A 50-year-old patient with confirmed monkeypox infection presented with odynophagia and nocturnal dyspnea. Clinically, there was a lesion on the tongue without any skin lesions and fibrinous plaques on the right tonsil with asymmetry of the palatoglossal arch. Due to a suggested abscess in the CT scan, a tonsillectomy à chaud was performed. By pan-orthopox-specific polymerase chain reaction (PCR) the monkeypox infection was also confirmed in the tonsil tissue. Isolated oral findings may represent a monkeypox infection and should be considered as a currently important differential diagnosis, especially for patients at risks.


Assuntos
Transtornos de Deglutição , Monkeypox virus , Mpox , Tonsila Palatina , Mpox/complicações , Mpox/diagnóstico , Mpox/tratamento farmacológico , Transtornos de Deglutição/diagnóstico , Transtornos de Deglutição/virologia , Tonsila Palatina/diagnóstico por imagem , Tonsila Palatina/patologia , Tonsila Palatina/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Monkeypox virus/isolamento & purificação , Tonsilectomia , Dor/diagnóstico , Tomografia Computadorizada por Raios X
5.
HNO ; 71(Suppl 1): 50-52, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37306746

RESUMO

A 50-year-old patient with confirmed monkeypox infection presented with odynophagia and nocturnal dyspnea. Clinically, there was a lesion on the tongue without any skin lesions and fibrinous plaques on the right tonsil with asymmetry of the palatoglossal arch. Due to a suggested abscess in the CT scan, a tonsillectomy à chaud was performed. By pan-orthopox-specific polymerase chain reaction (PCR) the monkeypox infection was also confirmed in the tonsil tissue. Isolated oral findings may represent a monkeypox infection and should be considered as a currently important differential diagnosis, especially for patients at risks.


Assuntos
Mpox , Tonsilectomia , Tonsilite , Humanos , Pessoa de Meia-Idade , Tonsilite/cirurgia , Mpox/diagnóstico , Mpox/patologia , Tonsila Palatina/patologia , Abscesso/patologia , Dor/patologia
6.
J Radiol Prot ; 42(2)2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35130526

RESUMO

To implement typical doses (TD) and typical values (TV) for fluoroscopic diagnostic and interventional procedures. A total of 3811 fluoroscopic procedures performed within 34 months on three devices were included in this retrospective study. Dose-, patient- and procedure-related information were extracted using the institutional dose management system (DMS). TD/TV were defined as median dose and calculated for the five most frequent procedures per device for dose area product (DAP), cumulative air kerma (CAK) and fluoroscopy time (FT). National diagnostic reference levels and other single facility studies were compared to our results. Additionally, the five procedures with the highest doses of each device were analysed. To evaluate the data coverage of the DMS compared to the picture archiving and communication system (PACS), procedure lists were extracted from the PACS and compared to the procedure information extracted from the DMS. TD/TV for 15 procedures were implemented. Among all devices, TD for DAP ranged between 0.6 Gycm2for port catheter control (n= 64) and 145.9 Gycm2for transarterial chemoembolisation (n= 84). TD for CAK ranged between 5 mGy for port catheter control and 1397 mGy for aneurysm treatment (n= 129) and TV for FT ranged between 0.3 min for upper cavography (n= 67) and 51.4 min for aneurysm treatment. TD for DAP and CAK were lower or within the range of other single facility studies. The five procedures with the highest median DAP per device were identified, 6 of 15 procedures were also found to be among the most frequent procedures. Data coverage of the DMS compared to the PACS ranged between 71% (device 2, stroke treatment) and 78% (device 1, lower limb angiography) for the most common procedure per device. Thus, in 22%-29% of cases dose data of the performed procedure was not transferred into the DMS. We implemented TD/TV for fluoroscopic diagnostic and interventional procedures which enable a comprehensive dose analysis and comparison with previously published values.


Assuntos
Radiografia Intervencionista , Fluoroscopia , Humanos , Doses de Radiação , Estudos Retrospectivos
7.
Eur Radiol ; 31(2): 1043-1048, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32852588

RESUMO

OBJECTIVES: An automated workflow for age- and sex-specific estimation of regional brain volume changes from structural MRI relative to a standard population is presented and evaluated for feasibility. METHODS: T1w MRI scans are preprocessed in a standardized way comprising gray matter (GM) segmentation, normalization, modulation, and spatial smoothing. Resulting GM images are then compared to precomputed age- and sex-specific GM templates derived from the population-based Nathan Kline Institute Rockland Sample, and voxel-wise z-maps are compiled. z-maps are color-coded and fused with the subject's T1w images. The rate of technical success of the proposed workflow was evaluated in 1330 subjects of the Alzheimer's Disease Neuroimaging Initiative (ADNI). Furthermore, medial temporal atrophy (MTA) was assessed using the color-coded maps and with the MTA visual rating scale in these subjects. Sensitivities and specificity of color-coded maps and MTA scale were compared using McNemar's test. RESULTS: One test dataset was excluded due to severe motion artifacts. Out of the remaining 1329 datasets, atrophy map generation was successful in 1323 ADNI subjects (99.5%). Sensitivity for AD diagnosis (71.4 % vs. 53.3%, p < 0.0001 for left; 70.4% vs. 55.3%, p < 0.0001 for right hemisphere) and for MCI (45.4% vs. 17.4, p < 0.0001 for left; 43.5% vs. 14.6%, p < 0.0001 for right hemisphere) based on medial temporal atrophy assessment in color-coded maps was significantly higher than for MTA visual rating scale, while specificity was lower (78.4% vs. 93.8%, p < 0.0001 for left; 79.4% vs. 95.8%, p < 0.0001 for right hemisphere). The workflow is named veganbagel and is published as open-source software with an integrated PACS interface. CONCLUSIONS: Automated brain volume change estimation with the proposed workflow is feasible and technically dependable. It provides high potential for radiologic assessment of brain volume changes and neurodegenerative diseases. KEY POINTS: • A workflow combining techniques from voxel-based morphometry and population-based neuroimaging data is feasible and technically highly dependable. • The workflow is provided as open-source software, named veganbagel. • Sensitivity of medial temporal atrophy assessment in atrophy maps from veganbagel exceeds the sensitivity of MTA visual rating scale for the diagnosis of Alzheimer's disease.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Atrofia/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Estudos de Viabilidade , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Doenças Neurodegenerativas/diagnóstico por imagem , Doenças Neurodegenerativas/patologia , Fluxo de Trabalho
8.
Neuroradiology ; 63(12): 2073-2085, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34019112

RESUMO

PURPOSE: Parkinson's disease (PD) is primarily defined by motor symptoms and is associated with alterations of sensorimotor areas. Evidence for network changes of the sensorimotor network (SMN) in PD is inconsistent and a systematic evaluation of SMN in PD yet missing. We investigate functional connectivity changes of the SMN in PD, both, within the network, and to other large-scale connectivity networks. METHODS: Resting-state fMRI was assessed in 38 PD patients under long-term dopaminergic treatment and 43 matched healthy controls (HC). Independent component analysis (ICA) into 20 components was conducted and the SMN was identified within the resulting networks. Functional connectivity within the SMN was analyzed using a dual regression approach. Connectivity between the SMN and the other networks from group ICA was investigated with FSLNets. We investigated for functional connectivity changes between patients and controls as well as between medication states (OFF vs. ON) in PD and for correlations with clinical parameters. RESULTS: There was decreased functional connectivity within the SMN in left inferior parietal and primary somatosensory cortex in PD OFF. Across networks, connectivity between SMN and two motor networks as well as two visual networks was diminished in PD OFF. All connectivity decreases partially normalized in PD ON. CONCLUSION: PD is accompanied by functional connectivity losses of the SMN, both, within the network and in interaction to other networks. The connectivity changes in short- and long-range connections are probably related to impaired sensory integration for motor function in PD. SMN decoupling can be partially compensated by dopaminergic therapy.


Assuntos
Doença de Parkinson , Córtex Sensório-Motor , Mapeamento Encefálico , Humanos , Imageamento por Ressonância Magnética , Vias Neurais/diagnóstico por imagem , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/tratamento farmacológico , Córtex Sensório-Motor/diagnóstico por imagem
9.
Neurol Sci ; 41(11): 3165-3173, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32350674

RESUMO

BACKGROUND: Endovascular treatment (EVT) is an established procedure in patients with acute ischemic stroke due to occlusion of the proximal M1-segment of middle cerebral artery. The assessment of distal thrombectomy in daily clinical routine has not yet been sufficiently evaluated. METHODS: Patients with M2-segment-occlusions treated by EVT in the local department (January 2012-December 2017) were included (n = 57, mean National-Institutes-of-Health-Stroke-Scale of 11, range 0-20). Patients were grouped according to localization of M2-occlusion (Cohort A (n = 14): central region only, B (n = 24): central region and involvement of frontal vessels, C (n = 19): parietal, occipital, and/or temporal vessels). Differences in proximal (M2-trunk, n = 34) and distal (M2-branches, n = 23) occlusions were also examined. Reperfusion (Thrombolysis-In-Cerebral-Infarction (TICI)), early clinical outcome at discharge (modified Rankin Scale (mRS)), and complications (hemorrhage, new emboli) were noted. RESULT: Successful reperfusion (TICI2b-3) was found in 49 patients (86.0%). Favorable early clinical outcome (mRS0-2) was achieved in n = 19 (37.7%). Compared to admission, mRS at discharge improved significantly (median (admission) 5 vs. median (discharge) 4, p < 0.001). Early clinical outcome was more favorable in patients with better reperfusion (TICI2b-3: mean mRS 3 ± 1.7 vs. TICI0-2a: mean mRS 4.4 ± 1.4, p = 0.037). Six (10.5%) patients suffered from symptomatic intracranial hemorrhage during treatment or hospitalization. Four patients died (7.0%). No significant differences in favorable clinical outcome (mRS ≤ 2: Cohort A 42.9%, B 50.0%, C 16.7%, p = 0.4; χ2-test) or periinterventional complications were found with regard to vessel involvement. CONCLUSION: EVT in patients with acute M2-occlusion is safe and leads to a significant clinical improvement at discharge. No significant differences in clinical outcome or complications were found with regard to the localization of the M2-occlusion.


Assuntos
Isquemia Encefálica , Procedimentos Endovasculares , Acidente Vascular Cerebral , Isquemia Encefálica/complicações , Isquemia Encefálica/terapia , Humanos , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Infarto da Artéria Cerebral Média/cirurgia , Artéria Cerebral Média/diagnóstico por imagem , Artéria Cerebral Média/cirurgia , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/cirurgia , Trombectomia , Resultado do Tratamento
11.
Eur Radiol ; 29(7): 3705-3713, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30783785

RESUMO

OBJECTIVES: To evaluate machine learning (ML) to detect chest CT examinations with dose optimization potential for quality assurance in a retrospective, cross-sectional study. METHODS: Three thousand one hundred ninety-nine CT chest examinations were used for training and testing of the feed-forward, single hidden layer neural network (January 2016-December 2017, 60% male, 62 ± 15 years, 80/20 split). The model was optimized and trained to predict the volumetric computed tomography dose index (CTDIvol) based on scan patient metrics (scanner, study description, protocol, patient age, sex, and water-equivalent diameter (DW)). The root mean-squared error (RMSE) was calculated as performance measurement. One hundred separate, consecutive chest CTs were used for validation (January 2018, 60% male, 63 ± 16 years), independently reviewed by two blinded radiologists with regard to dose optimization, and used to define an optimal cutoff for the model. RESULTS: RMSE was 1.71, 1.45, and 1.52 for the training, test, and validation dataset, respectively. The scanner and DW were the most important features. The radiologists found dose optimization potential in 7/100 of the validation cases. A percentage deviation of 18.3% between predicted and actual CTDIvol was found to be the optimal cutoff: 8/100 cases were flagged as suboptimal by the model (range 18.3-53.2%). All of the cases found by the radiologists were identified. One examination was flagged only by the model. CONCLUSIONS: ML can comprehensively detect CT examinations with dose optimization potential. It may be a helpful tool to simplify CT quality assurance. CT scanner and DW were most important. Final human review remains necessary. A threshold of 18.3% between the predicted and actual CTDIvol seems adequate for CT quality assurance. KEY POINTS: • Machine learning can be integrated into CT quality assurance to improve retrospective analysis of CT dose data. • Machine learning may help to comprehensively detect dose optimization potential in chest CT, but an individual review of the results by an experienced radiologist or radiation physicist is required to exclude false-positive findings.


Assuntos
Aprendizado de Máquina , Tomografia Computadorizada Multidetectores/normas , Garantia da Qualidade dos Cuidados de Saúde , Lesões por Radiação/prevenção & controle , Radiografia Torácica/normas , Doenças Torácicas/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doses de Radiação , Estudos Retrospectivos , Adulto Jovem
12.
Neurol Sci ; 40(7): 1443-1451, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30949780

RESUMO

BACKGROUND AND PURPOSE: The Aperio thrombectomy device (Aperio) is a stent retriever designed to achieve rapid and substantial flow restoration in acute ischemic stroke due to large-vessel occlusions (LVOs). We evaluated the safety and efficacy of the Aperio device and compared it with published data of established stent retrievers. METHODS: We retrospectively analyzed institutional data of consecutive stroke procedures in patients with LVO in the anterior circulation that were treated between January 2017 and December 2017 with the Aperio. Reperfusion rate regarding to the extended thrombolysis in cerebral infarction scale (eTICI), procedural times, early clinical outcome, and complications were documented. RESULTS: Eighty-two patients were treated by using the Aperio in LVO in the anterior circulation. Median age was 77 (± 12) years (w = 59.8%). Median Baseline National Institutes of Health Stroke Scale (NIHSS) score was 14. Fifty-three (64.6%) patients received intravenous thrombolysis. Successful recanalization (eTICI≥2b) was achieved in 85.3%. Mean time from groin puncture to final recanalization was 52.3 ± 34.8 min. Embolization to new territories occurred in one case. Symptomatic intracranial hemorrhage within 24 h was observed in six patients (7.3%). Twenty-eight (41.2%) out of 68 patients available for assessment of functional outcome at 3 months achieved favorable outcome (mRS 0-2). CONCLUSION: The Aperio stent retriever mechanical thrombectomy device demonstrated high rates of successful reperfusion and a good safety profile in patients with acute ischemic stroke due to LVO in the anterior circulation.


Assuntos
Isquemia Encefálica/cirurgia , Acidente Vascular Cerebral/cirurgia , Trombectomia/instrumentação , Idoso , Isquemia Encefálica/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Complicações Pós-Operatórias/epidemiologia , Reperfusão , Estudos Retrospectivos , Stents , Acidente Vascular Cerebral/epidemiologia , Trombectomia/efeitos adversos , Resultado do Tratamento
13.
J Stroke Cerebrovasc Dis ; 28(3): 640-648, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30579732

RESUMO

INTRODUCTION: The benefit of the direct aspiration thrombectomy (ADAPT) technique for the treatment of ischemic stroke due to large vessel occlusion are challenged after publishing of the ASTER trial that failed to show superiority of ADAPT compared to stent retriever. Aim of the present single-center study was a retrospective evaluation of the ADAPT technique comparing our results with literature. MATERIAL/METHODS: We retrospectively analyzed institutional data of stroke procedures in patients with mainstem occlusion of the middle cerebral artery treated between November 2016 and December 2017 with an initial attempt of manual thrombaspiration. Reperfusion rate (thrombolysis in cerebral infarction), procedural times, early clinical outcome and complications were recorded. RESULTS: Forty patients were treated by using direct thrombaspiration in middle cerebral artery mainstem occlusion. Median age was 67.5 (±17.8) years (m = 27.5%). Median Baseline National Institutes of Health Stroke Scale score was 12 (IQR 7) preintervention and 3 (IQR 11) postintervention. Twenty-eight (70%) patients received intravenous thrombolysis. Successful recanalization (modified thrombolysis in cerebral infarction ≥ 2b) could be achieved in 85% with direct aspiration alone. Mean time from groin puncture to recanalization was 25.2 ± 14.3 minutes. Embolization to new territories occurred in 1 of 40 (2.5%) cases and symptomatic intracranial hemorrhage in 3 of 40 (7.5%). Nineteen of 40 (47.5%) patients achieved favorable outcome (modified Rankin scale 0-2) at discharge. CONCLUSIONS: The ADAPT technique presented as a safe and efficient first-line recanalization strategy with good clinical outcome for treatment of acute ischemic stroke resulting from large vessel occlusions in this single-center study and review of the literature. However, the concept of ADAPT as an equivalent first-line approach to stent retriever thrombectomy has to be proven by future randomized studies.


Assuntos
Infarto da Artéria Cerebral Média/terapia , Trombectomia/métodos , Idoso , Idoso de 80 Anos ou mais , Circulação Cerebrovascular , Avaliação da Deficiência , Feminino , Humanos , Infarto da Artéria Cerebral Média/diagnóstico , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Trombectomia/efeitos adversos , Terapia Trombolítica , Fatores de Tempo , Resultado do Tratamento
14.
Eur Radiol ; 28(12): 4949-4958, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29948072

RESUMO

OBJECTIVES: The pathogenesis leading to poor functional outcome after aneurysmal subarachnoid haemorrhage (aSAH) is multifactorial and not fully understood. We evaluated a machine learning approach based on easily determinable clinical and CT perfusion (CTP) features in the course of patient admission to predict the functional outcome 6 months after ictus. METHODS: Out of 630 consecutive subarachnoid haemorrhage patients (2008-2015), 147 (mean age 54.3, 66.7% women) were retrospectively included (Inclusion: aSAH, admission within 24 h of ictus, CTP within 24 h of admission, documented modified Rankin scale (mRS) grades after 6 months. Exclusion: occlusive therapy before first CTP, previous aSAH, CTP not evaluable). A random forests model with conditional inference trees was optimised and trained on sex, age, World Federation of Neurosurgical Societies (WFNS) and modified Fisher grades, aneurysm in anterior vs. posterior circulation, early external ventricular drainage (EVD), as well as MTT and Tmax maximum, mean, standard deviation (SD), range, 75th quartile and interquartile range to predict dichotomised mRS (≤ 2; > 2). Performance was assessed using the balanced accuracy over the training and validation folds using 20 repeats of 10-fold cross-validation. RESULTS: In the final model, using 200 trees and the synthetic minority oversampling technique, median balanced accuracy was 84.4% (SD 0.7) over the training folds and 70.9% (SD 1.2) over the validation folds. The five most important features were the modified Fisher grade, age, MTT range, WFNS and early EVD. CONCLUSIONS: A random forests model trained on easily determinable features in the course of patient admission can predict the functional outcome 6 months after aSAH with considerable accuracy. KEY POINTS: • Features determinable in the course of admission of a patient with aneurysmal subarachnoid haemorrhage (aSAH) can predict the functional outcome 6 months after the occurrence of aSAH. • The top five predictive features were the modified Fisher grade, age, the mean transit time (MTT) range from computed tomography perfusion (CTP), the WFNS grade and the early necessity for an external ventricular drainage (EVD). • The range between the minimum and the maximum MTT may prove to be a valuable biomarker for detrimental functional outcome.


Assuntos
Aneurisma Intracraniano , Hemorragia Subaracnóidea , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/fisiopatologia , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Admissão do Paciente/estatística & dados numéricos , Valor Preditivo dos Testes , Estudos Retrospectivos , Hemorragia Subaracnóidea/diagnóstico por imagem , Hemorragia Subaracnóidea/fisiopatologia
16.
Cerebrovasc Dis ; 43(5-6): 272-282, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28319953

RESUMO

BACKGROUND: The invasiveness and risk of thromboembolic complications of catheter angiography underline the need for alternative imaging modalities in patients following intracranial aneurysm (IA) repair. However, the overall image quality of existing noninvasive imaging modalities, such as single-energy CT angiography (SE-CTA), compromises its value in this respect. OBJECTIVE: We prospectively investigated the value of a novel dual-energy CTA (DE-CTA) scanner and algorithm for assessing the degree of occlusion and parent vessel patency in patients following IA repair. METHODS: A prospective cohort of 17 patients underwent DE-CTA imaging following surgical or endovascular IA repair. This dataset was matched with an identical historical cohort of 17 patients, who underwent IA repair and SE-CTA imaging. Beam-hardening artifacts, as a measure for objective imaging quality were analyzed based on the volume of a prolate ellipsoid, whereas subjective imaging quality at the IA site and corresponding parent vessels was rated by 2 independent neuroradiologists on a scale from 4 (excellent, no artifacts) to 1 (poor, severe artifacts). RESULTS: Objective DE-CTA image quality was markedly higher, compared to SE-CTA in patients undergoing surgical (0.77 ± 0.23 vs. 10.91 ± 1.88 mL, respectively; p < 0.001) or endovascular (32.36 ± 10.62 vs. 107.63 ± 24.51 mL, respectively; p = 0.026) IA repair. Subjective image quality for DE-CTA was significantly improved compared to SE-CTA in the surgical group but not in the endovascular group. The calculated dose values for DE-CTA in our study remain markedly below the legally required radiation dose limits. CONCLUSION: The imaging quality of DE-CTA, especially for patients undergoing surgical IA repair, is distinctly superior, compared to SE-CTA imaging. Therefore, DE-CTA may serve as a noninvasive alternative for assessing the IA occlusion rate and parent vessel patency.


Assuntos
Angiografia Cerebral/métodos , Angiografia por Tomografia Computadorizada/métodos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/cirurgia , Tomografia Computadorizada Multidetectores/métodos , Adulto , Idoso , Algoritmos , Artefatos , Angiografia Cerebral/instrumentação , Circulação Cerebrovascular , Angiografia por Tomografia Computadorizada/instrumentação , Feminino , Humanos , Aneurisma Intracraniano/fisiopatologia , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores/instrumentação , Variações Dependentes do Observador , Valor Preditivo dos Testes , Estudos Prospectivos , Doses de Radiação , Exposição à Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Sistema de Registros , Reprodutibilidade dos Testes , Estudos Retrospectivos , Tomógrafos Computadorizados , Grau de Desobstrução Vascular
17.
J Neuroradiol ; 44(6): 371-376, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28687123

RESUMO

BACKGROUND AND PURPOSE: The pathogenesis of poor functional outcome after aneurysmal subarachnoid hemorrhage (aSAH) is not fully understood. Microcirculatory dysfunction, which can be indirectly measured by CT perfusion (CTP), is assumed to play a central role. We evaluated the predictive value of early changes in microcirculation for secondary critical perfusion changes. MATERIALS AND METHODS: Out of 351 consecutive aSAH patients, 166 patients with ≥1 CTP within 72h of ictus (early CTP) and ≥3 CTPs in total were included in the retrospective analysis (53.2±12.4years of age). Receiver-operating-characteristic (ROC) analysis was performed to identify the mean transit time (MTT) threshold in early CTP with the highest sensitivity and specificity for predicting secondary critical perfusion changes >72h after ictus. The odds ratio was calculated and the threshold for the highest odds ratio was determined. RESULTS: Secondary critical perfusion changes were observed in 67/166 patients (40.4%). An early MTT 1.3 times the mean normal MTT could predict those changes with an odds ratio of 2.67 (sensitivity 67.2%, specificity 56.6%). Shifting the threshold to 1.26 times the mean normal MTT resulted in an odds ratio of 3.56 (sensitivity 79.1%, specificity 48.5%). CONCLUSIONS: Early MTT is predictive of secondary critical perfusion changes, which could have applications for neuromonitoring and treatment.


Assuntos
Angiografia Cerebral/métodos , Angiografia por Tomografia Computadorizada/métodos , Microcirculação , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Circulação Cerebrovascular , Meios de Contraste , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
18.
Forensic Sci Med Pathol ; 13(2): 145-150, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28265799

RESUMO

The aim of this study was to evaluate the objective and subjective image quality of a novel computed tomography (CT) protocol with reduced radiation dose for body packing with 80 kVp and automated tube current modulation (ATCM) compared to a standard body packing CT protocol. 80 individuals who were examined between March 2012 and July 2015 in suspicion of ingested drug packets were retrospectively included in this study. Thirty-one CT examinations were performed using ATCM and a fixed tube voltage of 80 kVp (group A). Forty-nine CT examinations were performed using a standard protocol with a tube voltage of 120 kVp and a fixed tube current time product of 40 mAs (group B). Subjective and objective image quality and visibility of drug packets were assessed. Radiation exposure of both protocols was compared. Contrast-to-noise ratio (group A: 0.56 ± 0.36; group B: 1.13 ± 0.91) and Signal-to-noise ratio (group A: 3.69 ± 0.98; group B: 7.08 ± 2.67) were significantly lower for group A compared to group B (p < 0.001). Subjectively, image quality was decreased for group A compared to group B (2.5 ± 0.8 vs. 1.2 ± 0.4; p < 0.001). Attenuation of body packets was higher with the new protocol (group A: 362.2 ± 70.3 Hounsfield Units (HU); group B: 210.6 ± 60.2 HU; p = 0.005). Volumetric Computed Tomography Dose Index (CTDIvol) and Dose Length Product (DLP) were significantly lower in group A (CTDIvol 2.2 ± 0.9 mGy, DLP 105.7 ± 52.3 mGycm) as compared to group B (CTDIvol 2.7 ± 0.1 mGy, DLP 126.0 ± 9.7 mGycm, p = 0.002 and p = 0.01). The novel 80 kVp CT protocol with ATCM leads to a significant dose reduction compared to a standard CT body packing protocol. The novel protocol led to a diagnostic image quality and cocaine body packets were reliably detected due to the high attenuation.


Assuntos
Tráfico de Drogas , Doses de Radiação , Radiografia Abdominal , Tomografia Computadorizada por Raios X/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
19.
Eur J Nucl Med Mol Imaging ; 42(8): 1257-67, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25852011

RESUMO

PURPOSE: To compare the accuracy of different MR sequences in simultaneous PET/MR imaging for T staging in non-small-cell lung cancer in relation to histopathology. METHODS: The study included 28 patients who underwent dedicated thoracic PET/MR imaging before tumour resection. Local tumour staging was performed separately by three readers with each of the following MR sequences together with PET: transverse T2 BLADE, transverse non-enhanced and contrast-enhanced T1 FLASH, T1 3D Dixon VIBE in transverse and coronal orientation, coronal T2 HASTE, and coronal TrueFISP. The staging results were compared with histopathology after resection as the reference standard. Differences in the accuracy of T staging among the MR sequences were evaluated using McNemar's test. Due to multiple testing, Bonferroni correction was applied to prevent accumulation of α errors; p < 0.0024 was considered statistically significant. RESULTS: Compared with histopathology, T-staging accuracy was 69% with T2 BLADE, 68% with T2 HASTE, 59% with contrast-enhanced T1 FLASH, 57% with TrueFISP, 50 % with non-enhanced T1 FLASH, and 45% and 48% with T1 3D Dixon VIBE in transverse and coronal orientation, respectively. Staging accuracy with T2 BLADE was significantly higher than with non-enhanced T1 FLASH and with T1 3D Dixon VIBE in transverse and coronal orientations (p < 0.0024). T2 HASTE had a significantly higher T-staging accuracy than transverse T1 3D-Dixon-VIBE (p < 0.0024). CONCLUSION: Transverse T2 BLADE images provide the highest accuracy for local tumour staging and should therefore be included in dedicated thoracic PET/MR protocols. As T1 3D Dixon VIBE images acquired for attenuation correction performed significantly worse, this sequence cannot be considered sufficiently accurate for local tumour staging in the thorax.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Fluordesoxiglucose F18 , Neoplasias Pulmonares/diagnóstico por imagem , Imageamento por Ressonância Magnética , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Idoso , Carcinoma Pulmonar de Células não Pequenas/patologia , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Tomografia Computadorizada por Raios X
20.
Abdom Imaging ; 40(7): 2152-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26048697

RESUMO

PURPOSE: The aim of this study was to evaluate the impact of a reduced tube potential (100 kVp) for non-enhanced abdominal low-dose CT on radiation dose and image quality (IQ) in the detection of body packing. METHODS: This retrospective study was approved by the local research ethics committee of our clinic. From March 2012 to July 2014, 99 subjects were referred to our institute with suspected body packing. 50 CT scans were performed using a 120 kVp protocol (group A), and 49 CTs were performed using a low-dose protocol with a tube voltage of 100 kVp (group B). Subjective and objective IQ were assessed. DLP and CTDIvol were analyzed. RESULTS: All examinations were of diagnostic IQ. Objective IQ was not significantly different between the 120 kVp and 100 kVp protocol. Mean density of solid and liquid body packets was 210 ± 60.2 HU at 120 kVp and 250.6 ± 29.7 HU at 100 kVp. Radiation dose was significantly lower in group B as compared to group A (p < 0.05). In group A, body packs were detected in 16 (32%) of the 50 patients. In group B, packets were observed in 15 (31%) of 49 patients. Laboratory analysis detected cocaine in all smuggled body packs. CONCLUSIONS: Low-tube voltage 100 kVp MDCT with automated tube current modulation in screening of illegal drugs leads to a diagnostic IQ and significant dose reduction compared to 120 kVp low-tube voltage protocols. Despite lower radiation dose, liquid and solid cocaine containers retain high attenuation and are easily detected.


Assuntos
Cocaína , Embalagem de Medicamentos/métodos , Corpos Estranhos/diagnóstico por imagem , Tomografia Computadorizada Multidetectores , Doses de Radiação , Radiografia Abdominal , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Adulto Jovem
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