RESUMEN
PURPOSE: While amyloid-ß deposition in the cerebral cortex for Alzheimer's disease (AD) is often evaluated by amyloid positron emission tomography (PET), amyloid-ß-related iron can be detected using phase difference enhanced (PADRE) imaging; however, no study has validated the association between PADRE imaging and amyloid PET. This study investigated whether the degree of hypointense areas on PADRE imaging correlated with the uptake of amyloid PET. METHODS: PADRE imaging and amyloid PET were performed in 8 patients with AD and 10 age-matched normal controls. ROIs in the cuneus, precuneus, superior frontal gyrus (SFG), and superior temporal gyrus (STG) were automatically segmented. The degree of hypointense areas on PADRE imaging in each ROI was evaluated using 4-point scaling of visual assessment or volumetric semiquantitative assessment (the percentage of hypointense volume within each ROI). The mean standardized uptake value ratio (SUVR) of amyloid PET in each ROI was also calculated. The Spearman's correlation coefficient between the 4-point scale of PADRE imaging and SUVR of amyloid PET or between the semiquantitative hypointense volume percentage and SUVR in each ROI was evaluated. RESULTS: In the precuneus, a significant positive correlation was identified between the 4-point scale of PADRE imaging and SUVR of amyloid PET (Rs = 0.5; P = 0.034) in all subjects. In the cuneus, a significant positive correlation was identified between the semiquantitative volume percentage of PADRE imaging and SUVR of amyloid PET (Rs = 0.55; P = 0.02) in all subjects. CONCLUSION: Amyloid-ß-enhancing PADRE imaging can be used to predict the SUVR of amyloid PET, especially in the cuneus and precuneus, and may have the potential to be used for diagnosing AD by detecting amyloid deposition.
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Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/patología , Tomografía de Emisión de Positrones/métodos , Péptidos beta-Amiloides/metabolismo , Imagen por Resonancia Magnética/métodos , Corteza CerebralRESUMEN
We evaluated cerebral gyri (CG) on phase difference enhanced imaging (PADRE) of corticobasal syndrome (CBS), progressive supranuclear palsy (PSP), and Parkinson's disease (PD) patients to determine whether it is possible to discriminate among them on an individual basis. Two radiologists reviewed appearance of the normal CG and that of CBS patients on PADRE, and deviations from the appearance of the normal CG were recorded. Next, based on the CG abnormalities, two other reviewers reviewed PADRE images from 12 CBS, 14 PSP, and 30 PD patients. In healthy subjects on the PADRE images, the signal intensity (SI) of the gray matter (GM) was homogeneously, slightly hyperintense to the subcortical white matter (SCWM), and the SI of the SCWM was homogeneously hypointense. In CBS patients, hypointense layer in superficial GM and disappearance of hypointense in SCWM. The frequency of the abnormal findings on PADRE in the blinded manner by two readers was 100% (12/12), 3% (1/30), and 29% (4/14 in Reader 1) or 36% (5/14 in Reader 2) in CBS PD, and PSP patients, respectively. Laterality of the PADRE findings was showed in 12 (100%) CBS patients and 3 (21%) PSP, but not in any PD patients. The previously reported typical findings in CBS on conventional magnetic resonance image (MRIs) were observed in only 42% (5/12) of CBS patients. In conclusion, the abnormal findings in CG on PADRE appears more useful than conventional MRI findings for discriminating CBS from PD on an individual basis.
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Enfermedad de Parkinson , Parálisis Supranuclear Progresiva , Sustancia Blanca , Corteza Cerebral/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/diagnóstico por imagen , Parálisis Supranuclear Progresiva/diagnóstico por imagen , Sustancia Blanca/diagnóstico por imagenRESUMEN
PURPOSE: The purpose of this study was to evaluate the delineation of nerve fiber bundles in the brainstem and optic radiation in infants associated with aging on T1WI, T2WI, and phase difference-enhanced (PADRE) images. MATERIALS AND METHODS: We retrospectively reviewed 21 consecutive subjects < 2 years old who underwent brain MRI without abnormal imaging findings. Two neuroradiologists evaluated the eight nerve fiber bundles in the brainstem and optic radiation using a 3-point scale focused on the contrast to surrounding brain parenchyma. We also evaluated the signal ratio of the optic radiation to surrounding white matter on PADRE for each month age. RESULTS: T2WI was able to delineate nerve fiber bundles better than T1WI at 1 month old, and the images gradually became unclear with aging. On PADRE, almost all nerve fiber bundles were unclear or invisible at 1 month old but gradually became clearer with aging. There was a significant negative correlation between age and the signal ratio of the optic radiation to surrounding white matter. CONCLUSIONS: The PADRE imaging was able to delineate the nerve fiber bundles in infants, and the delineation gradually became clearer with aging. The combination of PADRE, T1WI, and T2WI would be useful for evaluation of nerve fiber bundles in infants.
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Envejecimiento/fisiología , Encéfalo/anatomía & histología , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Fibras Nerviosas/fisiología , Adulto , Encéfalo/fisiología , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Estudios RetrospectivosRESUMEN
PURPOSE: To test the feasibility of the phase difference enhanced (PADRE) imaging for differentiation between Alzheimer disease (AD) patients and control subjects on 3T MR imaging. MATERIALS AND METHODS: Fifteen patients with AD and 10 age-matched control subjects underwent two-dimensional fast field echo imaging to obtain PADRE images on a 3T MR scanner. A double Gaussian distribution model was used to determine the threshold phase value for differentiation between the physiologic and non-physiologic iron in the cerebral cortices, and PADRE images were processed with the threshold. Using a 4-point grading system, two readers independently assessed the signal of the four cerebral cortices on PADRE images: the cuneus, precuneus, superior frontal gyrus, and superior temporal gyrus. The difference in the signals in each cortex between the AD patients and age-matched control subjects was determined by using Mann-Whitney U test. Inter-rater reliability was determined by Kappa analysis. We also evaluated the correlation between Mini-Mental State Examination (MMSE) score and the hypointense grade, and between disease duration and the hypointense grade using the Spearman rank correlation test. RESULTS: The threshold phase value for differentiation between the physiologic and non-physiologic iron was -4.6% π (radian). The mean grades of the cuneus, precuneus, and superior temporal gyrus were significantly higher for the AD patients than for the control subjects (P = 0.002). Excellent inter-rater reliability was seen in the precuneus (kappa = 0.93), superior temporal gyrus (kappa = 0.94), and superior frontal gyrus (kappa = 0.93); good inter-rater reliability was observed in the cuneus (kappa = 0.75). We found a statistical correlation between MMSE score and the hypointense grade in superior temporal gyrus (STG) (P = 0.008), and no correlation between disease duration and the hypointense grade in any gyrus. CONCLUSION: Our results suggest the feasibility of PADRE imaging at 3T for differentiation between AD patients and control subjects.
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Enfermedad de Alzheimer/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Estudios de Casos y Controles , Estudios de Factibilidad , HumanosRESUMEN
INTRODUCTION: In Parkinson's disease (PD) patients, magnetic resonance (MR) imaging studies using phase difference enhanced imaging (PADRE) and susceptibility-weighted imaging (SWI) showed the obscuration of the boundary between the crural fibers and substantia nigra, and the absence of dorsolateral nigral hyperintensity, respectively. PADRE images have not been evaluated in other types of neurodegenerative parkinsonism, and PADRE and SWI images have not been compared. Here we evaluated PADRE and SWI images in patients with progressive supranuclear palsy (PSP), multiple system atrophy (MSA), or PD and controls, and we compared the diagnostic values. METHODS: PADRE and SWI-like MR images were visually assessed focusing on the substantia nigra in 39 PD patients, eight with PSP, 13 with MSA, and 34 normal controls. RESULTS: The obscuration of the boundary between the crural fibers and substantia nigra on PADRE was observed in: the PD group, 62%; PSP, 100%; MSA, 60%, and controls, 19%. The overall collect classification for neurodegenerative parkinsonism was 74%. The absence of dorsolateral nigral hyperintensity on SWI-like images was present in: PD, 97%; PSP, 100%; MSA, 67%; and controls, 6%, resulting in the overall correct classification of 96%. CONCLUSIONS: The MR feature on PADRE was observed not only in PD but also in other neurodegenerative parkinsonism, especially in PSP with high sensitivity. The finding in substantia nigra on SWI had greater discrimination power than that of PADRE in neurodegenerative parkinsonism, especially in PD.
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Imagen por Resonancia Magnética/métodos , Atrofia de Múltiples Sistemas/diagnóstico por imagen , Trastornos Parkinsonianos/diagnóstico por imagen , Parálisis Supranuclear Progresiva/diagnóstico por imagen , Anciano , Anciano de 80 o más Años , Progresión de la Enfermedad , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad , Estadísticas no Paramétricas , Sustancia NegraRESUMEN
Background The white matter in the Heschl's gyrus (HG-WM) may appear differently to the other gyri on phase difference enhanced imaging (PADRE), which can enhance the myelin density. Purpose To evaluate the signal intensity (SI) of HG-WM using the PADRE technique and to compare the images with susceptibility-weighted imaging (SWI)-like images. Material and Methods The participants included 19 normal controls (38 HGs; mean age, 60.1 years; age range, 28-80 years). Coronal PADRE and SWI-like images were acquired using a 3T magnetic resonance (MR) system. The SI of the HG-WM was classified into three grades based on a comparison with the SI of the superior temporal gyrus: Grade 1, isointense; Grade 2, slightly hypointense, and Grade 3, markedly hypointense. Results In the assessment of the SI of the HG-WM, the HG-WM appeared hypointense in all 38 sites of the 19 participants; the hypointensity corresponded to Grade 2 in 13 (34%) images and Grade 3 in 25 (66%) images. On the other hand, the HG-WM was classified as Grade 1 (isointense) in all of the SWI-like images. Conclusion The HG-WM appears hypointense on PADRE, which probably reflects the higher myelin content. PADRE may be useful for identifying the HG through the assessment of the SI of the HG-WM.
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Corteza Auditiva/diagnóstico por imagen , Imagen por Resonancia Magnética , Sustancia Blanca/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Aumento de la Imagen , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
PURPOSE: The medial medullary lamina (MML) separates the medial globus pallidus (GPm) from the lateral. The aim of this study was to assess the changes in appearance of MML related to age using the phase difference-enhanced (PADRE) imaging and to determine whether PADRE can depict the MML in the patients with Parkinson's disease (PD). MATERIALS AND METHODS: We enrolled 20 patients with PD and 50 normal control subjects (NC). First, for the visualization of the MML in the NC, we compared the PADRE, susceptibility-weighted imaging (SWI)-like images and T2 weighted imaging (WI) by using multiple comparison. The grading methods are as follows: grade 1; MML was not delineated, grade 2; less than half of MML was delineated, grade 3; more than half of MML was delineated and grade 4; whole MML was clearly delineated. We determined grade 3 and 4 as good depiction, delineating the GPm. Then, we evaluated patients with PD using the same method. RESULTS: In NC, the delineation of MML was good in 84% of cases on PADRE, but only 34% of cases showed a good depiction on SWI-like images (average grading score 3.31 vs 2.11, P < 0.05). No MML was delineated in all cases on T2 WI. Although younger subjects tended to show whole MML clearly, a part of MML tends to be obscured with age on PADRE. In patients with PD the depiction of MML on PADRE was also good in 90% of cases. CONCLUSION: The PADRE technique facilitates the depiction of the MML within globus pallidus (GP) on a broad range of age NC and patients with PD and it is superior to SWI-like images and T2 WI.
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Mapeo Encefálico/métodos , Globo Pálido/diagnóstico por imagen , Globo Pálido/patología , Aumento de la Imagen/métodos , Imagen por Resonancia Magnética/métodos , Enfermedad de Parkinson/diagnóstico por imagen , Enfermedad de Parkinson/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patologíaRESUMEN
Background The superficial white matter (SWM), which fills the space between the deep white matter and the cortex, has not been well characterized. Purpose To determine whether the assessment of the relative signal intensity (SI) of the SWM in the precentral and postcentral gyri on phase difference enhanced (PADRE) images contributes in establishing anatomical landmark. Material and Methods The study population consisted of 43 normal subjects (28 women, 15 men; mean age, 52.9 years; age range, 22-90 years). By the consensus of two observers, the precentral gyri, postcentral gyri, and superior frontal cortex (SFC) were identified based on the established anatomical methods. The SI of the SWM in the precentral and postcentral gyri on PADRE images was divided into three grades in comparison with that of the SFC: Grade I, isointense; Grade II, slightly hypointense; and Grade III, markedly hypointense. Results The SWM in the precentral and postcentral gyri showed hypointensity on PADRE images. In the SI analyses of the PADRE images, the Grade I, Grade II, and Grade III appearances were found in one (1%), 20 (23%), and 65 (76%) of the 86 precentral gyri (43 subjects), respectively, and in one (1%), 23 (27%), and 62 (72%) of the 86 postcentral gyri, respectively. Conclusion On PADRE images, the perirolandic SWM showed hypointensity compared to other cerebral cortices, which probably reflects differences in the concentrations of the nerve fibers, as well as the higher myelin content. PADRE may be useful for the identification of the central sulcus by assessing the SI of the SWM.