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1.
J Neurol Neurosurg Psychiatry ; 95(7): 663-670, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38212059

RESUMEN

BACKGROUND: With expanding neurosurgical options in epilepsy, it is important to characterise each options' risk for postoperative cognitive decline. Here, we characterise how patients' preoperative white matter (WM) networks relates to postoperative memory changes following different epilepsy surgeries. METHODS: Eighty-nine patients with temporal lobe epilepsy with T1-weighted and diffusion-weighted imaging as well as preoperative and postoperative verbal memory scores (prose recall) underwent either anterior temporal lobectomy (ATL: n=38) or stereotactic laser amygdalohippocampotomy (SLAH; n=51). We computed laterality indices (ie, asymmetry) for volume of the hippocampus and fractional anisotropy (FA) of two deep WM tracts (uncinate fasciculus (UF) and inferior longitudinal fasciculus (ILF)). RESULTS: Preoperatively, left-lateralised FA of the ILF was associated with higher prose recall (p<0.01). This pattern was not observed for the UF or hippocampus (ps>0.05). Postoperatively, right-lateralised FA of the UF was associated with less decline following left ATL (p<0.05) but not left SLAH (p>0.05), while right-lateralised hippocampal asymmetry was associated with less decline following both left ATL and SLAH (ps<0.05). After accounting for preoperative memory score, age of onset and hippocampal asymmetry, the association between UF and memory decline in left ATL remained significant (p<0.01). CONCLUSIONS: Asymmetry of the hippocampus is an important predictor of risk for memory decline following both surgeries. However, asymmetry of UF integrity, which is only severed during ATL, is an important predictor of memory decline after ATL only. As surgical procedures and pre-surgical mapping evolve, understanding the role of frontal-temporal WM in memory networks could help to guide more targeted surgical approaches to mitigate cognitive decline.


Asunto(s)
Lobectomía Temporal Anterior , Epilepsia del Lóbulo Temporal , Hipocampo , Trastornos de la Memoria , Sustancia Blanca , Humanos , Epilepsia del Lóbulo Temporal/cirugía , Epilepsia del Lóbulo Temporal/diagnóstico por imagen , Masculino , Femenino , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología , Adulto , Trastornos de la Memoria/etiología , Persona de Mediana Edad , Lobectomía Temporal Anterior/efectos adversos , Hipocampo/cirugía , Hipocampo/patología , Hipocampo/diagnóstico por imagen , Complicaciones Posoperatorias , Procedimientos Neuroquirúrgicos/efectos adversos , Procedimientos Neuroquirúrgicos/métodos , Adulto Joven , Amígdala del Cerebelo/cirugía , Amígdala del Cerebelo/patología , Amígdala del Cerebelo/diagnóstico por imagen
2.
Magn Reson Med ; 90(6): 2400-2410, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37526017

RESUMEN

PURPOSE: To integrate 3D CEST EPI with an unevenly segmented RF irradiation module and preliminarily demonstrate it in the clinical setting. METHODS: A CEST MRI with unevenly segmented RF saturation was implemented, including a long primary RF saturation to induce the steady-state CEST effect, maintained with repetitive short secondary RF irradiation between readouts. This configuration reduces relaxation-induced blur artifacts during acquisition, allowing fast 3D spatial coverage. Numerical simulations were performed to select parameters such as flip angle (FA), short RF saturation duration (Ts2), and the number of readout segments. The sequence was validated experimentally with data from a phantom, healthy volunteers, and a brain tumor patient. RESULTS: Based on the numerical simulation and l-carnosine gel phantom experiment, FA, Ts2, and the number of segments were set to 20°, 0.3 s, and the range from 4 to 8, respectively. The proposed method minimized signal modulation in the human brain images in the kz direction during the acquisition and provided the blur artifacts-free CEST contrast over the whole volume. Additionally, the CEST contrast in the tumor tissue region is higher than in the contralateral normal tissue region. CONCLUSIONS: It is feasible to implement a highly accelerated 3D EPI CEST imaging with unevenly segmented RF irradiation.


Asunto(s)
Neoplasias Encefálicas , Imagen por Resonancia Magnética , Humanos , Estudios de Factibilidad , Imagen por Resonancia Magnética/métodos , Neoplasias Encefálicas/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Fantasmas de Imagen
3.
J Digit Imaging ; 36(3): 1189-1197, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36596936

RESUMEN

In recent years, the quantity and complexity of medical imaging acquisition and processing have increased tremendously. The explosion in volume and need for advanced imaging analysis have led to the creation of numerous software programs, which have begun to be incorporated into clinical practice for indications such as automated stroke assessment, brain tumor perfusion processing, and hippocampal volume analysis. Despite these advances, there remains a need for specialized, custom-built software for advanced algorithms and new areas of research that is not widely available or adequately integrated in these "out-of-the-box" solutions. The purpose of this paper is to describe the implementation of an image-processing pipeline that is versatile and simple to create, which allows for rapid prototyping of image analysis algorithms and subsequent testing in a clinical environment. This pipeline uses a combination of Orthanc server, custom MATLAB code, and publicly available FMRIB Software Library and RestNeuMap tools to automatically receive and analyze resting-state functional MRI data collected from a custom filter on the MR scanner output. The processed files are then sent directly to Picture Archiving and Communications System (PACS) without the need for user input. This initial experience can serve as a framework for those interested in simple implementation of an automated pipeline customized to clinical needs.


Asunto(s)
Imagen por Resonancia Magnética , Sistemas de Información Radiológica , Humanos , Programas Informáticos , Algoritmos , Procesamiento de Imagen Asistido por Computador/métodos
4.
J Digit Imaging ; 36(2): 450-457, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36352165

RESUMEN

Automated co-registration and subtraction techniques have been shown to be useful in the assessment of longitudinal changes in multiple sclerosis (MS) lesion burden, but the majority depend on T2-fluid-attenuated inversion recovery sequences. We aimed to investigate the use of a novel automated temporal color complement imaging (CCI) map overlapped on 3D double inversion recovery (DIR), and to assess its diagnostic performance for detecting disease progression in patients with multiple sclerosis (MS) as compared to standard review of serial 3D DIR images. We developed a fully automated system that co-registers and compares baseline to follow-up 3D DIR images and outputs a pseudo-color RGB map in which red pixels indicate increased intensity values in the follow-up image (i.e., progression; new/enlarging lesion), blue-green pixels represent decreased intensity values (i.e., disappearing/shrinking lesion), and gray-scale pixels reflect unchanged intensity values. Three neuroradiologists blinded to clinical information independently reviewed each patient using standard DIR images alone and using CCI maps based on DIR images at two separate exams. Seventy-six follow-up examinations from 60 consecutive MS patients who underwent standard 3 T MR brain MS protocol that included 3D DIR were included. Median cohort age was 38.5 years, with 46 women, 59 relapsing-remitting type MS, and median follow-up interval of 250 days (interquartile range: 196-394 days). Lesion progression was detected in 67.1% of cases using CCI review versus 22.4% using standard review, with a total of 182 new or enlarged lesions using CCI review versus 28 using standard review. There was a statistically significant difference between the two methods in the rate of all progressive lesions (P < 0.001, McNemar's test) as well as cortical progressive lesions (P < 0.001). Automated CCI maps using co-registered serial 3D DIR, compared to standard review of 3D DIR alone, increased detection rate of MS lesion progression in patients undergoing clinical brain MRI exam.


Asunto(s)
Esclerosis Múltiple , Humanos , Femenino , Lactante , Esclerosis Múltiple/diagnóstico por imagen , Esclerosis Múltiple/patología , Imagenología Tridimensional/métodos , Imagen por Resonancia Magnética/métodos , Aumento de la Imagen , Neuroimagen
5.
Epilepsy Behav ; 130: 108659, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35339067

RESUMEN

Outcomes of treating low-grade epilepsy-associated tumors (LEATs) in the temporal lobe with MRI-guided laser interstitial thermal therapy (MRgLITT) remain poorly characterized. This study aimed to compare the safety and effectiveness of treating temporal lobe LEATs with MRgLITT versus open resection in a consecutive single-institution series. We reviewed all adult patients with epilepsy that underwent surgery for temporal lobe LEATs at our institution between 2002 and 2019, during which time we switched from open surgery to MRgLITT. Surgical outcome was categorized by Engel classification at >12mo follow-up and Kaplan-Meir analysis of seizure freedom. We recorded hospital length of stay, adverse events, and available neuropsychological results. Of 14 total patients, 7 underwent 9 open resections, 6 patients underwent MRgLITT alone, and 1 patient underwent an open resection followed by MRgLITT. Baseline group demographics differed and were notable for preoperative duration of epilepsy of 9.0 years (range 1-36) for open resection versus 14.0 years (range 2-34) for MRgLITT. Median length of stay was one day shorter for MRgLITT compared to open resection (p=<.0001). There were no major adverse events in the series, but there were fewer minor adverse events following MRgLITT. At 12mo follow-up, 50% (5/10) of patients undergoing open resection and 57% (4/7) of patients undergoing MRgLITT were free of disabling seizures (Engel I). When comparing patients who underwent similar procedures in the dominant temporal lobe, patients undergoing MRgLITT had fewer and milder material-specific neuropsychological declines than patients undergoing open resections. In this small series, MRgLITT was comparably safe and effective relative to open resection of temporal lobe LEATs.


Asunto(s)
Epilepsia Refractaria , Epilepsia del Lóbulo Temporal , Epilepsia , Terapia por Láser , Neoplasias , Adulto , Epilepsia Refractaria/cirugía , Epilepsia/etiología , Epilepsia/patología , Epilepsia/cirugía , Epilepsia del Lóbulo Temporal/complicaciones , Epilepsia del Lóbulo Temporal/patología , Epilepsia del Lóbulo Temporal/cirugía , Humanos , Terapia por Láser/métodos , Rayos Láser , Lóbulo Temporal/patología , Lóbulo Temporal/cirugía , Resultado del Tratamiento
6.
J Stroke Cerebrovasc Dis ; 31(9): 106644, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35849917

RESUMEN

OBJECTIVES: Diffusion weighted imaging hyperintensity (DWI-H) has been described in the retina and optic nerve during acute central retinal artery occlusion (CRAO). We aimed to determine whether DWI-H can be accurately identified on standard brain magnetic resonance imaging (MRI) in non-arteritic CRAO patients at two tertiary academic centers. MATERIALS AND METHODS: Retrospective cross-sectional study that included all consecutive adult patients with confirmed acute non-arteritic CRAO and brain MRI performed within 14 days of CRAO. At each center, two neuroradiologists masked to patient clinical data reviewed each MRI for DWI-H in the retina and optic nerve, first independently then together. Statistical analysis for inter-rater reliability and correlation with clinical data was performed. RESULTS: We included 204 patients [mean age 67.9±14.6 years; 47.5% females; median time from CRAO to MRI 1 day (IQR 1-4.3); 1.5 T in 127/204 (62.3%) and 3.0 T in 77/204 (37.7%)]. Inter-rater reliability varied between centers (κ = 0.27 vs. κ = 0.65) and was better for retinal DWI-H. Miss and error rates significantly differed between neuroradiologists at each center. After consensus review, DWI-H was identified in 87/204 (42.6%) patients [miss rate 117/204 (57.4%) and error rate 11/87 (12.6%)]. Significantly more patients without DWI-H had good visual acuity at follow-up (p = 0.038). CONCLUSIONS: In this real-world case series, differences in agreement and interpretation accuracy among neuroradiologists limited the role of DWI-H in diagnosing acute CRAO on standard MRI. DWI-H was identified in 42.6% of patients and was more accurately detected in the retina than in the optic nerve. Further studies are needed with standardized novel MRI protocols.


Asunto(s)
Oclusión de la Arteria Retiniana , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Imagen de Difusión por Resonancia Magnética , Femenino , Humanos , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética , Masculino , Persona de Mediana Edad , Nervio Óptico/diagnóstico por imagen , Reproducibilidad de los Resultados , Retina/patología , Oclusión de la Arteria Retiniana/diagnóstico por imagen , Oclusión de la Arteria Retiniana/terapia , Estudios Retrospectivos
7.
AJR Am J Roentgenol ; 216(5): 1378-1386, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33729880

RESUMEN

OBJECTIVE. This article aimed to assess changing use of brain imaging tests among patients with Alzheimer disease and vascular dementia who visited U.S. emergency departments (EDs) between 2006 and 2014. MATERIALS AND METHODS. Using the largest publicly available all-payer ED database, the Nationwide Emergency Department Sample, we identified a weighted cohort of 427,705 individuals with Alzheimer disease and 33,743 individuals with vascular dementia who visited U.S. EDs between 2006 and 2014. Logistic regression analyses were performed to identify factors associated with use. RESULTS. Between 2006 and 2014, ED visits among patients with Alzheimer disease and vascular dementia declined by 24.7% and 20.3%, respectively. However, there was a significant increase in utilization rates of head CT (from 4.4% to 11.1% in patients with Alzheimer disease and from 1.5% to 2.9% in patients with vascular dementia) and brain MRI (from 0.04% to 0.5% in patients with Alzheimer disease and 0.0% to 0.1% in those with vascular dementia) in the same time period. Among patients with Alzheimer disease, age, median income in patient ZIP code, day of the week of the ED visit, hospital teaching status, and hospital geographic region were significant predictors of imaging use. Among patients with vascular dementia, insurance type and hospital classification (urban vs rural) were significant predictors of imaging use. CONCLUSION. Despite declining ED visits, ED brain imaging in patients with Alzheimer disease and vascular dementia has increased. Various patient-specific and hospital-specific factors contribute to differential utilization rates.


Asunto(s)
Demencia/diagnóstico por imagen , Servicio de Urgencia en Hospital/estadística & datos numéricos , Neuroimagen/métodos , Anciano , Anciano de 80 o más Años , Encéfalo/diagnóstico por imagen , Estudios de Cohortes , Femenino , Humanos , Masculino , Estudios Retrospectivos , Estados Unidos
8.
AJR Am J Roentgenol ; 217(6): 1401-1416, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34259036

RESUMEN

Recent successful trials of thrombectomy launched a shift to imaging-based patient selection for stroke intervention. Many centers have adopted CT perfusion imaging (CTP) as a routine part of stroke workflow, and the demand for emergent CTP interpretation is growing. Fully automated CTP postprocessing software that rapidly generates standardized color-coded CTP summary maps with minimal user input and with easy accessibility of the software output is increasingly being adopted. Such automated postprocessing greatly streamlines clinical workflow and CTP interpretation for radiologists and other frontline physicians. However, the straightforward interface overshadows the computational complexity of the underlying postprocessing workflow, which, if not carefully examined, predisposes the interpreting physician to diagnostic errors. Using case examples, this article aims to familiarize the general radiologist with interpreting automated CTP software data output in the context of contemporary stroke management, providing a discussion of CTP acquisition and postprocessing, a stepwise guide for CTP quality assurance and troubleshooting, and a framework for avoiding clinically significant pitfalls of CTP interpretation in commonly encountered clinical scenarios. Interpreting radiologists should apply the outlined approach for quality assurance and develop a comprehensive search pattern for the identified pitfalls, to ensure accurate CTP interpretation and optimize patient selection for reperfusion.


Asunto(s)
Angiografía por Tomografía Computarizada/métodos , Imagen de Perfusión/métodos , Garantía de la Calidad de Atención de Salud/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Triaje/métodos , Encéfalo/diagnóstico por imagen , Humanos , Accidente Cerebrovascular Isquémico , Guías de Práctica Clínica como Asunto
9.
Neuroradiology ; 63(7): 1071-1078, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33415349

RESUMEN

PURPOSE: Reduced gray-white matter contrast along the central sulcus has been described on T1- and T2-weighted magnetic resonance imaging (MRI). The purpose of this study was to assess the gray-white matter contrast of the motor cortex on double inversion recovery (DIR), a sequence with superior gray-white matter differentiation. METHODS: The gray-white matter signal on DIR was retrospectively compared to T1-weighted magnetization-prepared rapid gradient echo (T1-MPRAGE) using normal (n = 25) and abnormal (n = 25) functional MRI (fMRI) exams. Quantitative gray-white matter contrast ratios (CR) of the precentral and adjacent gyri were obtained on normal exams. Two neuroradiologists qualitatively rated reduced gray-white matter contrast of the hemispheres of both normal and abnormal exams. Hand motor functional mapping was used as a reference. RESULTS: In normal hemispheres (n = 50), the mean CR was significantly lower on DIR (0.44) vs T1-MPRAGE (0.63, p < 0.001). Reduced gray-white matter contrast was categorized as "definitely present" more frequently on DIR than T1-MPRAGE by reviewers in both normal (n = 50; reviewer 1 DIR 88% and MPRAGE 68%, p = 0.02; reviewer 2 DIR 86% and T1-MPRAGE 64%; p=0.01) and abnormal hemispheres (n = 50; reviewer 1 DIR 80% and T1-MPRAGE 38%, p < 0.001; reviewer 2 DIR 74% and T1-MPRAGE 46%, p = 0.005). CONCLUSION: Reduced gray-white matter contrast of the motor cortex is more pronounced on DIR compared to T1-MPRAGE on quantitative and qualitative assessments of normal MRI exams. In abnormal cases, reviewers more definitively identified the motor cortex on DIR. In cases with distorted brain anatomy, DIR may be a useful adjunct sequence to localize the motor cortex.


Asunto(s)
Corteza Motora , Sustancia Blanca , Encéfalo , Humanos , Imagenología Tridimensional , Imagen por Resonancia Magnética , Corteza Motora/diagnóstico por imagen , Estudios Retrospectivos , Sustancia Blanca/diagnóstico por imagen
10.
Epilepsia ; 61(8): 1723-1734, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32777090

RESUMEN

OBJECTIVE: Magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy (MRg-LITT) is an alternative to open epilepsy surgery. We assess safety and effectiveness of MRg-LITT for extratemporal lobe epilepsy (ETLE) in patients who are considered less favorable for open resection. METHODS: We retrospectively reviewed sequential cases of patients with focal ETLE who underwent MRg-LITT between 2012 and 2019. Epileptogenic zones were determined from standard clinical and imaging data ± stereoelectroencephalography (SEEG). Standard stereotactic techniques, MRI thermometry, and a commercial laser thermal therapy system were used for ablations. Anatomic MRI was used to calculate ablation volumes. Clinical outcomes were determined longitudinally. RESULTS: Thirty-five patients with mean epilepsy duration of 21.3 ± 12.2 years underwent MRg-LITT for focal ETLE at a mean age 36.4 ± 12.7 years. A mean 2.59 ± 1.45 trajectories per patient were used to obtain ablation volumes of 8.8 ± 7.5 cm3 . Mean follow-up was 27.3 ± 19.5 months. Of 32 patients with >12 months of follow-up, 17 (53%) achieved good outcomes (Engel class I + II) of whom 14 (44%) were Engel class I. Subgroup analysis revealed better outcomes for patients with lesional ETLE than for those who were nonlesional, multifocal, or who had failed prior interventions (P = .02). Of 13 patients showing favorable seizure-onset patterns (localized low voltage fast activity or rhythmic spiking on SEEG) prior to ablation, 9 (69%) achieved good outcomes, whereas only 3 of 11 (27%) who show other slower onset patterns achieved good outcomes. Minor adverse events included six patients with transient sensorimotor neurologic deficits and four patients with asymptomatic hemorrhages along the fiber tract. Major adverse events included one patient with a brain abscess that required stereotactic drainage and one patient with persistent hypothalamic obesity. Three deaths-two seizure-associated and one suicide-were unrelated to surgical procedures. SIGNIFICANCE: MRI-guided laser interstitial thermal therapy (or MRg-LITT) was well-tolerated and yielded good outcomes in a heterogeneous group of ETLE patients. Lesional epilepsy and favorable seizure-onset patterns on SEEG predicted higher likelihoods of success.


Asunto(s)
Epilepsia Refractaria/cirugía , Epilepsias Parciales/cirugía , Terapia por Láser/métodos , Imagen por Resonancia Magnética/métodos , Adulto , Epilepsia del Lóbulo Frontal/cirugía , Femenino , Giro del Cíngulo/cirugía , Humanos , Hipotálamo/cirugía , Masculino , Persona de Mediana Edad , Lóbulo Occipital/cirugía , Lóbulo Parietal/cirugía , Técnicas Estereotáxicas , Cirugía Asistida por Computador/métodos , Adulto Joven
11.
Radiology ; 290(1): 179-186, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30375929

RESUMEN

Purpose To compare dual-energy CT with iodine quantification to single-energy CT for evaluation of the spot sign for intracranial hematoma expansion. Materials and Methods In this retrospective study, 42 patients (mean age, 66 years ± 15 [standard deviation]; 19 women) were referred for dual-energy CT assessment of intracranial hemorrhage from October 2014 to January 2017. A machine learning approach (naive Bayes classifier) was used to identify iodine markers of extravasation for risk of hematoma expansion. Specificity and sensitivity of these markers were then independently validated in 65 new patients from February 2017 to February 2018. Results Analysis of dual-energy CT images identified two features of iodine extravasation: total iodine concentration within the hematoma (Ih) and focal iodine concentration in the brightest spot in the hematoma (Ibs) as predictors of expansion. The I2 score derived from these features provided a measure of expansion probability. Optimal classification threshold was an I2 score of 20 (95% confidence interval [CI]: 18, 23), leading to correct identification of 39 of 46 (85%; 95% CI: 71%, 94%) of the hematomas on the training set (sensitivity of 79% [11 of 14; 95% CI: 57%, 100%] and specificity of 88% [28 of 32; 95% CI: 76%, 99%]), and 62 of 70 (89%; 95% CI: 79%, 95%) of the hematomas on the validation set (sensitivity of 71% [10 of 14; 95% CI: 48%, 95%] and specificity of 93% [52 of 56; 95% CI: 86%, 100%]). Sensitivity, specificity, and accuracy of conventional spot sign were, respectively, 57% (eight of 14), 90% (29 of 32), and 80% (37 of 46) on the training set and 57% (eight of 14), 83% (47 of 56), and 75% (53 of 70) on the validation set. Conclusion This study identified two quantitative markers of intracranial hemorrhage expansion at dual-energy CT of the brain. The I2 score derived from these markers highlights the utility of dual-energy CT measurements of iodine content for high sensitivity risk assessment. © RSNA, 2018 Online supplemental material is available for this article.


Asunto(s)
Hemorragia Cerebral/diagnóstico por imagen , Hemorragia Cerebral/patología , Tomografía Computarizada por Rayos X/métodos , Anciano , Anciano de 80 o más Años , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
12.
J Magn Reson Imaging ; 50(1): 175-182, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30390367

RESUMEN

BACKGROUND: Oxygen extraction fraction (OEF) elevation predicts increased ischemic stroke incidence among patients with carotid steno-occlusive disease, and can be estimated from quantitative susceptibility mapping (QSM) MRI. PURPOSE: To explore QSM oximetry during acetazolamide (ACZ) challenge, hypothesizing that detectable OEF alterations will reflect hemodynamic compromise in unilateral cerebrovascular disease (CVD) patients. STUDY TYPE: Retrospective. SUBJECTS: Fourteen unilateral CVD patients, and 24 healthy controls (HC). FIELD STRENGTH/SEQUENCE: Multiecho gradient echo (GRE) and T1 -weighted images at 3T. ASSESSMENT: We constructed QSM images and R2* maps from multiecho GRE images. QSM-OEF maps were generated from the susceptibility difference between venous blood and background brain tissue. Intrasubject diseased/contralateral hemisphere OEF ratios in the middle cerebral artery (MCA) territories were calculated. Intravascular susceptibility in the straight sinus (SS) and MCA was also measured. STATISTICAL TESTS: The result significance was determined using t-tests and Pearson's correlation. RESULTS: Mean and standard deviation for the patient diseased/contralateral OEF ratios were 1.15 ± 0.14 at baseline and 1.23 ± 0.17 post-ACZ. Disease group R2* ratios were 0.95 ± 0.05 at baseline and 1.03 ± 0.08 post-ACZ. Left/right OEF and R2* ratios for the HC group were 0.98 ± 0.06 and 0.99 ± 0.038, respectively. Susceptibility (ppb) in the SS and MCA in patients was 162.63 ± 35.4 and -22.33 ± 13.70, respectively, at baseline, 124.56 ± 37.43 and -19.27 ± 23.14 post-ACZ. The HC group SS and MCA susceptibility was 146.10 ± 24.79 and -19.59 ± 12.37, respectively. Patient group OEF ratios were greater than 1.0 before and after ACZ challenge (P < 0.01 and < 0.001, respectively, one-sample t-test), and were greater than HC ratios (P < 0.001 unpaired t-test). OEF and R2* ratios increased from baseline to post-ACZ (P = 0.024, 0.004, respectively, paired t-test). Detectable blood oxygenation change was confirmed by finding SS susceptibility decreased from baseline to post-ACZ (P < 0.001, paired t-test), while MCA susceptibility did not change significantly (P = 0.67, paired t-test). DATA CONCLUSION: These results suggest QSM is sensitive to dynamic OEF modulation during hemodynamic augmentation. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;50:175-182.


Asunto(s)
Acetazolamida/farmacología , Arterias Carótidas/diagnóstico por imagen , Hemodinámica , Imagen por Resonancia Magnética , Oximetría , Oxígeno/química , Adulto , Anciano , Encéfalo/irrigación sanguínea , Circulación Cerebrovascular , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Estudios Retrospectivos
14.
J Neuroophthalmol ; 39(1): 35-40, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-29554002

RESUMEN

BACKGROUND: Optic nerve sheath tortuosity is a previously reported, but incompletely characterized, finding in idiopathic intracranial hypertension (IIH). We hypothesized that optic nerve angle (ONA), as a quantitative measure of tortuosity, would change dynamically with cerebrospinal fluid (CSF) pressure status of patients with IIH immediately before and after lumbar puncture (LP). METHODS: Consecutive patients with suspected IIH referred for MRI and diagnostic LP were prospectively enrolled in this single institution, institutional review board-approved study. Each patient underwent a pre-LP MRI, diagnostic LP with opening pressure (OP) and closing pressure (CP), and then post-LP MRI all within 1 session. Sagittal and axial ONAs were measured on multiplanar T2 SPACE images by 2 neuroradiologists on pre- and post-LP MRI. Effects of measured pressure and CSF volume removal on changes in ONA were analyzed as was interrater reliability for ONA measurement. RESULTS: Ten patients with IIH were included {all female, median age 29 (interquartile range [IQR] 25-32)}. All patients had elevated OP (median 37, IQR 34-41 cm H2O), and significantly reduced CP (median 18, IQR 16-19 cm H2O, P < 0.001) after CSF removal (IQR 13-16 mL). Within patients, mean ONAs (sagittal and axial) were significantly lower before (162 ± 9°, 163 ± 10°) than after (168 ± 7°, 169 ± 5°) LP (P = 0.001, 0.008, respectively). Interrater reliability was higher with sagittal ONA measurements (0.89) than axial (0.72). CONCLUSIONS: ONA changes with short-term CSF pressure reduction in patients with IIH, establishing optic nerve tortuosity as a dynamic process related to CSF status.


Asunto(s)
Presión Intracraneal/fisiología , Imagen por Resonancia Magnética/métodos , Nervio Óptico/patología , Seudotumor Cerebral/terapia , Punción Espinal/métodos , Adulto , Femenino , Estudios de Seguimiento , Humanos , Masculino , Estudios Prospectivos , Seudotumor Cerebral/diagnóstico , Seudotumor Cerebral/fisiopatología , Reproducibilidad de los Resultados
15.
Neurosurg Focus ; 47(6): E20, 2019 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-31786554

RESUMEN

Intracranial aneurysms confer the risk of subarachnoid hemorrhage (SAH), a potentially devastating condition, though most aneurysms will remain asymptomatic for the lifetime of the patient. Imaging is critical to all stages of patient care for those who harbor an unruptured intracranial aneurysm (UIA), including to establish the diagnosis, to determine therapeutic options, to undertake surveillance in patients who elect not to undergo treatment or whose aneurysm(s) portends such a low risk that treatment is not indicated, and to perform follow-up after treatment. Neuroimaging is equally as important in patients who suffer an SAH. DSA remains the reference standard for imaging of intracranial aneurysms due to its high spatial and temporal resolution. As noninvasive imaging technology, such as CTA and MRA, improves, the diagnostic accuracy of such tests continues to increasingly approximate that of DSA. In cases of angiographically negative SAH, imaging protocols are necessary not only for diagnosis but also to search for an initially occult vascular lesion, such as a thrombosed, ruptured aneurysm that might be detected in a delayed fashion. Given the crucial role of neuroimaging in all aspects of care for patients with UIAs and SAH, it is incumbent on those who care for these patients, including cerebrovascular neurosurgeons, interventional neurologists and neuroradiologists, and diagnostic radiologists and neurointensivists, to understand the role of imaging in this disease and how individual members of the multispecialty team use imaging to ensure best practices to deliver cutting-edge care to these often complex cases. This review expounds on the role of imaging in the management of UIAs and ruptured intracranial aneurysms and in the workup of angiographically negative subarachnoid hemorrhage.


Asunto(s)
Angiografía Cerebral/métodos , Aneurisma Intracraneal/diagnóstico por imagen , Neuroimagen/métodos , Hemorragia Subaracnoidea/diagnóstico por imagen , Cuidados Posteriores/métodos , Aneurisma Roto/diagnóstico por imagen , Aneurisma Roto/cirugía , Angiografía de Substracción Digital/métodos , Enfermedades Asintomáticas , Calcinosis/diagnóstico por imagen , Angiografía por Tomografía Computarizada , Humanos , Imagenología Tridimensional/métodos , Aneurisma Intracraneal/cirugía , Angiografía por Resonancia Magnética/métodos , Tamizaje Masivo , Diseño de Software , Hemorragia Subaracnoidea/cirugía , Evaluación de Síntomas
16.
Pain Med ; 19(4): 686-692, 2018 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-29177411

RESUMEN

Objective: Correlation between radiologic structural abnormalities and clinical symptoms in low back pain patients is poor. There is an unmet clinical need to image inflammation in pain conditions to aid diagnosis and guide treatment. Ferumoxytol, an ultrasmall superparamagnetic iron oxide (USPIO) nanoparticle, is clinically used to treat iron deficiency anemia and showed promise in imaging tissue inflammation in human. We explored whether ferumoxytol can be used to identify tissue and nerve inflammation in pain conditions in animals and humans. Methods: Complete Freud's adjuvant (CFA) or saline was injected into mice hind paws to establish an inflammatory pain model. Ferumoxytol (20 mg/kg) was injected intravenously. Magnetic resonance imaging (MRI) was performed prior to injection and 72 hours postinjection. The changes in the transverse relaxation time (T2) before and after ferumoxytol injection were compared between mice that received CFA vs saline injection. In the human study, we administered ferumoxytol (4 mg/kg) to a human subject with clinical symptoms of lumbar radiculopathy and compared the patient with a healthy subject. Results: Mice that received CFA exhibited tissue inflammation and pain behaviors. The changes in T2 before and after ferumoxytol injection were significantly higher in mice that received CFA vs saline (20.8 ± 3.6 vs 2.2 ± 2.5, P = 0.005). In the human study, ferumoxytol-enhanced MRI identified the nerve root corresponding to the patient's symptoms, but the nerve root was not impinged by structural abnormalities, suggesting the potential superiority of this approach over conventional structural imaging techniques. Conclusions: Ferumoxytol-enhanced MRI can identify tissue and nerve inflammation and may provide a promising diagnostic tool in assessing pain conditions in humans.


Asunto(s)
Medios de Contraste , Diagnóstico por Imagen/métodos , Óxido Ferrosoférrico , Inflamación/diagnóstico por imagen , Dolor/diagnóstico por imagen , Radiculopatía/diagnóstico por imagen , Adulto , Animales , Humanos , Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Magnética/métodos , Masculino , Nanopartículas del Metal , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad
17.
AJR Am J Roentgenol ; 209(1): 176-181, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28379730

RESUMEN

OBJECTIVE: Spinal epidural abscess (SEA) is a serious infection requiring prompt treatment and potential neurosurgical intervention. Although contrast-enhanced spine MRI is the mainstay for diagnosis of SEA, unenhanced MRI is typically performed for patients with nonspecific symptoms or insufficient clinical information. We evaluated the sensitivity and specificity of imaging features suggestive of SEA at unenhanced spine MRI. MATERIALS AND METHODS: We searched our database for contrast-enhanced lumbar spine MRI examinations from January 1, 2000, through August 1, 2014, with "epidural abscess" in the report. We included 68 patients older than 18 years with an enhancing epidural collection at MRI and surgical (60%), microbiologic (15%), or clinical (25%) confirmation of SEA. Sixty-eight age- and sex-matched control subjects without SEA were also selected. Three readers scored unenhanced MR images on the degree of psoas and paraspinal muscle edema, extent of bone marrow edema, and abnormal disk signal. RESULTS: Paraspinal edema was highly sensitive (97%) for SEA, with lower sensitivities for psoas (54%), bone marrow (65%), and disk edema (66%). Each of these markers was highly significant in univariate analysis (p < 0.001). A multivariate logistic regression model adjusting for age and sex found that paraspinal (p < 0.001) and bone marrow edema (p = 0.006) were significant independent predictors of SEA (odds ratio, 58; p < 0.001), with a trend toward significance for psoas edema and abnormal disk signal. Psoas muscle edema was the most specific (96%) finding for the presence of SEA. CONCLUSION: Paraspinal edema is highly sensitive for SEA. Familiarity with the findings for SEA at unenhanced MRI could help expedite further definitive evaluation when contrast agent is not administered.


Asunto(s)
Edema/diagnóstico por imagen , Absceso Epidural/diagnóstico por imagen , Vértebras Lumbares/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Medios de Contraste , Diagnóstico Diferencial , Absceso Epidural/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad
18.
Oncologist ; 21(2): 214-9, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26834160

RESUMEN

BACKGROUND: Recurrent mutations in the isocitrate dehydrogenase 1 (IDH1) and IDH2 genes, which are frequent in gliomas, result in marked accumulation of the metabolic by-product 2-hydroxyglutarate (2-HG) within tumors. In other malignancies, such as acute myeloid leukemia, presence of IDH mutation is associated with elevated 2-HG levels in serum or urine compartments. Circulating 2-HG in patients with glial malignancies has not been thoroughly investigated. METHODS: In this study, we analyzed 2-HG levels in the serum and urine of a large set of patients with IDH-mutant and IDH-wild-type glioma, and the cerebrospinal fluid (CSF) from a subset of this cohort. RESULTS: We found that 2-HG was elevated in the urine of patients with IDH-mutant versus IDH-wild-type glioma, although no significant differences in 2-HG levels were observed in the serum or the small set of CSF samples obtained. Among patients with IDH-mutant glioma, 2-HG levels did not differ based on the histopathologic grade, genetic subtype (TP53 mutant or 1p/19q codeleted), presence of a canonical (IDH1 R132H) or noncanonical (any other IDH variant) mutation, or treatment type. CONCLUSION: Our finding suggests that urinary 2-HG is increased among patients with IDH-mutant gliomas, and may represent a future surrogate, noninvasive biomarker to aid in diagnosis, prognosis, and management. IMPLICATIONS FOR PRACTICE: Patients with glioma who harbor mutations in isocitrate dehydrogenase genes showed selective elevation of the oncometabolite 2-hydroxyglutarate in the urine. Similar elevations were not identified in the serum or cerebrospinal fluid. 2-Hydroxyglutarate may serve as a useful, noninvasive biomarker to stratify patients newly diagnosed with glioma with regard to prognosis and management.


Asunto(s)
Biomarcadores de Tumor/orina , Glioma/orina , Glutaratos/orina , Isocitrato Deshidrogenasa/genética , Adulto , Anciano , Femenino , Genotipo , Glioma/sangre , Glioma/genética , Glioma/patología , Glutaratos/sangre , Humanos , Masculino , Persona de Mediana Edad , Mutación
19.
Radiology ; 280(1): 177-83, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27322974

RESUMEN

Purpose To evaluate the ability of dual-energy (DE) computed tomography (CT) to differentiate calcification from acute hemorrhage in the emergency department setting. Materials and Methods In this institutional review board-approved study, all unenhanced DE head CT examinations that were performed in the emergency department in November and December 2014 were retrospectively reviewed. Simulated 120-kVp single-energy CT images were derived from the DE CT acquisition via postprocessing. Patients with at least one focus of intraparenchymal hyperattenuation on single-energy CT images were included, and DE material decomposition postprocessing was performed. Each focal hyperattenuation was analyzed on the basis of the virtual noncalcium and calcium overlay images and classified as calcification or hemorrhage. Sensitivity, specificity, and accuracy were calculated for single-energy and DE CT by using a common reference standard established by relevant prior and follow-up imaging and clinical information. Results Sixty-two cases with 68 distinct intraparenchymal hyperattenuating lesions in which the reference standards were available were included in the study, of which 41 (60%) were confirmed as calcification and 27 (40%) were confirmed as hemorrhage. Sensitivity, specificity, and accuracy of DE CT for the detection of hemorrhage were 96% (95% confidence interval [CI]: 81%, 100%), 100% (95% CI: 91%, 100%), and 99% (95% CI: 92%, 100%) and those of single-energy CT were 74% (95% CI: 54%, 89%), 95% (95% CI: 83%, 99%), and 87% (95% CI: 76%, 94%), respectively. Six of 68 (9%) lesions were classified as indeterminate and three (4%) were misinterpreted with single-energy CT alone and were correctly classified with DE CT. Conclusion DE CT by using material decomposition enables accurate differentiation between calcification and hemorrhage in patients presenting for emergency head imaging and can be especially useful in problem-solving complex cases that are difficult to determine based on conventional CT appearance alone. (©) RSNA, 2016 Online supplemental material is available for this article.


Asunto(s)
Encefalopatías/diagnóstico por imagen , Calcinosis/diagnóstico por imagen , Servicio de Urgencia en Hospital , Hemorragia/diagnóstico por imagen , Imagen Radiográfica por Emisión de Doble Fotón/métodos , Tomografía Computarizada por Rayos X/métodos , Enfermedad Aguda , Anciano , Anciano de 80 o más Años , Encéfalo/diagnóstico por imagen , Calcinosis/complicaciones , Femenino , Hemorragia/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad
20.
Quant Imaging Med Surg ; 14(4): 2774-2787, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38617153

RESUMEN

Background: Magnetic resonance imaging (MRI) is a primary non-invasive imaging modality for tumor segmentation, leveraging its exceptional soft tissue contrast and high resolution. Current segmentation methods typically focus on structural MRI, such as T1-weighted post-contrast-enhanced or fluid-attenuated inversion recovery (FLAIR) sequences. However, these methods overlook the blood perfusion and hemodynamic properties of tumors, readily derived from dynamic susceptibility contrast (DSC) enhanced MRI. This study introduces a novel hybrid method combining density-based analysis of hemodynamic properties in time-dependent perfusion imaging with deep learning spatial segmentation techniques to enhance tumor segmentation. Methods: First, a U-Net convolutional neural network (CNN) is employed on structural images to delineate a region of interest (ROI). Subsequently, Hierarchical Density-Based Scans (HDBScan) are employed within the ROI to augment segmentation by exploring intratumoral hemodynamic heterogeneity through the investigation of tumor time course profiles unveiled in DSC MRI. Results: The approach was tested and evaluated using a cohort of 513 patients from the open-source University of Pennsylvania glioblastoma database (UPENN-GBM) dataset, achieving a 74.83% Intersection over Union (IoU) score when compared to structural-only segmentation. The algorithm also exhibited increased precision and localized predictions of heightened segmentation boundary complexity, resulting in a 146.92% increase in contour complexity (ICC) compared to the reference standard provided by the UPENN-GBM dataset. Importantly, segmenting tumors with the developed new approach uncovered a negative correlation of the tumor volume with the scores in the Karnofsky Performance Scale (KPS) clinically used for assessing the functional status of patients (-0.309), which is not observed with the prevailing segmentation standard. Conclusions: This work demonstrated that including hemodynamic properties of tissues from DSC MRI can improve existing structural or morphological feature-based tumor segmentation techniques with additional information on tumor biology and physiology. This approach can also be applied to other clinical indications that use perfusion MRI for diagnosis or treatment monitoring.

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