Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 3 de 3
Filter
Add more filters










Database
Language
Publication year range
1.
Clin Radiol ; 72(9): 800.e1-800.e6, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28476245

ABSTRACT

AIM: To investigate whether time-resolved imaging with interleaved stochastic trajectories (TWIST)-volumetric interpolated breath-hold examination (VIBE) hepatic arterial phase imaging technique improves image quality in patients experiencing transient severe motion (TSM) during abdominal magnetic resonance imaging (MRI) with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA). MATERIALS AND METHODS: This retrospective study compares TSM in MRI images from 28 patients with focal liver lesions imaged with gadopentetic acid (Gd-DTPA) and 28 patients with focal liver lesions imaged with Gd-EOB-DTPA. Images were taken during the precontrast phase, five hepatic arterial phases acquired with a single breath-hold, portal venous phase, and late dynamic phase. RESULTS: There was a significant difference in the mean motion scores for the arterial phase in Gd-EOB-DTPA cohort before, and after, enhancement (p<0.001); however, there was no significant difference in the Gd-DTPA cohort for the same (p<0.05). The mean motion scores in the five hepatic arterial phases in the Gd-EOB-DTPA cohort after enhancement were significantly higher than that in the Gd-DTPA cohort (p<0.001). TSM occurred significantly more frequently in the Gd-EOB-DTPA cohort (64.2%) than in the Gd-DTPA cohort (3.5%, p<0.001). The highest motion score in Gd-EOB-DTPA cohort occurred during the fourth arterial phase, which was significantly higher than the other four arterial phases after enhancement (p<0.001). Moderate and severe TSM (motion score ≥3) occurred mainly in the mid and mid-late arterial phase. All patients with arterial phase images affected by TSM (motion scores ≥3) had at least one arterial phase image with TSM score <3, which was of adequate image quality for diagnostic purposes. CONCLUSION: The TWIST-VIBE hepatic arterial phase imaging technique can be used to acquire arterial images at abdominal MRI with Gd-EOB-DTPA, and these images have adequate quality for diagnosis in patients who are affected by TSM.


Subject(s)
Contrast Media/administration & dosage , Gadolinium DTPA/administration & dosage , Liver Neoplasms/diagnostic imaging , Magnetic Resonance Imaging/methods , Adult , Aged , Aged, 80 and over , Artifacts , Female , Humans , Image Enhancement/methods , Male , Middle Aged , Movement , Retrospective Studies
2.
Psychol Med ; 45(16): 3467-79, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26189512

ABSTRACT

BACKGROUND: Converging evidence has revealed both functional and structural abnormalities in adolescents with early-onset conduct disorder (EO-CD). The neurological abnormalities underlying EO-CD may be different from that of adolescent-onset conduct disorder (AO-CD) patients. However, the cortical structure in AO-CD patients remains largely unknown. The aim of the present study was to investigate the cortical alterations in AO-CD patients. METHOD: We investigated T1-weighted brain images from AO-CD patients and age-, gender- and intelligence quotient-matched controls. Cortical structures including thickness, folding and surface area were measured using the surface-based morphometric method. Furthermore, we assessed impulsivity and antisocial symptoms using the Barratt Impulsiveness Scale (BIS) and the Antisocial Process Screening Device (APSD). RESULTS: Compared with the controls, we found significant cortical thinning in the paralimbic system in AO-CD patients. For the first time, we observed cortical thinning in the precuneus/posterior cingulate cortex (PCC) in AO-CD patients which has not been reported in EO-CD patients. Prominent folding abnormalities were found in the paralimbic structures and frontal cortex while diminished surface areas were shown in the precentral and inferior temporal cortex. Furthermore, cortical thickness of the paralimbic structures was found to be negatively correlated with impulsivity and antisocial behaviors measured by the BIS and APSD, respectively. CONCLUSIONS: The present study indicates that AO-CD is characterized by cortical structural abnormalities in the paralimbic system, and, in particular, we highlight the potential role of deficient structures including the precuneus and PCC in the etiology of AO-CD.


Subject(s)
Conduct Disorder/etiology , Conduct Disorder/physiopathology , Gyrus Cinguli/abnormalities , Parietal Lobe/abnormalities , Adolescent , Anxiety , Case-Control Studies , Depression , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Psychiatric Status Rating Scales , Self Report , Severity of Illness Index
3.
Appl Opt ; 53(27): G95-104, 2014 Sep 20.
Article in English | MEDLINE | ID: mdl-25322141

ABSTRACT

With the advancement of computing and optical technologies, it is now possible to capture digital holograms of real-life object scenes. Theoretically, through the analysis of a hologram, the three-dimensional (3D) objects coded on the hologram can be identified. However, being different from an optical image, a hologram is composed of complicated fringes that cannot be analyzed easily with traditional computer vision methods. Over the years, numerous important research investigations have been attempted to provide viable solutions to this problem. The aim of this work is three-fold. First, we provide a quick walkthrough on the overall development of holographic-based 3D object recognition (H3DOR) in the past five decades, from film-based approaches to digital-based innovation. Second, we describe in more detail a number of selected H3DOR methods that are introduced at different timelines, starting from the late sixties and then from the seventies, where viable digital holographic-based 3D recognition methods began to emerge. Finally, we present our work on digital holographic, pose-invariant 3D object recognition that is based on a recently introduced virtual diffraction plane framework. As our method has not been reported elsewhere, we have included some experimental results to demonstrate the feasibility of the approach.

SELECTION OF CITATIONS
SEARCH DETAIL
...