A comparative analysis of several transformations for enhancement and segmentation of magnetic resonance image scene sequences

Soltanian-Zadeh, Hamid; Windham, Joe P.; Peck, Donald J.; Yagle, A.E.

doi:10.1109/42.158934

Cited by 77 publications

(30 citation statements)

References 36 publications

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“…All image analysis tasks were performed on a Sun Ultra Sparc 2 workstation (Sun Microsystems Inc., Mountain View, Calif., USA) using the Eigentool image analysis software [34,35,36,37]. Eigentool has a comprehensive set of functions for displaying, restoring, enhancing and analyzing images.…”

Section: Methodsmentioning

confidence: 99%

Multiparametric Iterative Self-Organizing Data Analysis of Ischemic Lesions Using Pre- or Post-Gd T1 MRI

Soltanian-Zadeh

Bagher‐Ebadian²,

Ewing³

et al. 2006

Cerebrovasc Dis

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Background: The purpose of this work was to evaluate effects of Gd-diethylenetriaminepentacetic acid (DTPA) injection on T₁-weighted images of stroke and lesion segmentation and characterization results generated by our multiparametric iterative self-organizing data (ISODATA) method. The post-Gd image incorporates vasculature information into the analysis. Methods: Either a pre-Gd T₁-weighted image (T1WI) or a post-Gd T1WI was used along with diffusion-, T₂- and proton-density-weighted images in the analysis. ISODATA is a data-driven method that segments and characterizes tissue damage in stroke using multiparametric MRI. Results: Experimental results in both animal and human studies showed that the use of post-Gd T1WI modified the segmentation and characterization results on the periphery of the lesion. The peripheral region that changes with Gd-DTPA has a higher permeability compared to the rest of the lesion. Either of the data sets (including pre- or post-Gd T1WI) was used to estimate the tissue recovery and generated consistent results. Conclusions: This study shows that our multiparametric ISODATA approach consistently identifies and characterizes the core of the ischemic lesion. It also shows that the inclusion of post-Gd T1WI results in the segmentation and characterization of the lesion periphery if it has a higher permeability compared to the rest of the lesion. Finally, it confirms that the multiparametric ISODATA MRI characterizes tissue damage and recovery in stroke.

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Section: Methodsmentioning

confidence: 99%

Multiparametric Iterative Self-Organizing Data Analysis of Ischemic Lesions Using Pre- or Post-Gd T1 MRI

Soltanian-Zadeh

Bagher‐Ebadian²,

Ewing³

et al. 2006

Cerebrovasc Dis

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“…For timeresolved MRA, a detailed description for the use of correlation analysis and alternative techniques for background suppression is provided in (7). The correlationbased method for three-dimensional MRA addressed the issue of SNR loss relative to straightforward mask subtraction by using concepts from (8,9). Another correlation-based approach used pulsed injections to separate arterial and venous signal in pulmonary vessels in time-resolved MRA (10).…”

Section: Dramatic Increases In Contrast In Diagnostic Angiography Examentioning

confidence: 99%

Background suppression in time‐resolved MR angiography without mask acquisition or operator intervention

Arunachalam¹,

Thornton²,

Block³

2006

Magnetic Resonance Imaging

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Purpose: To suppress static and background tissue in time-resolved MRA studies of the full thorax or abdomen without the need of a mask image or operator intervention. Materials and Methods:The time course of each voxel is projected onto the orthogonal complement space of a matrix that spans static and linearly enhancing signal vectors. The norm of the solution, or the projection length, acts as a confidence measure for segmenting vascular and nonvascular tissue. Voxels whose confidence measures fall below an automatically detected threshold value are considered nonvascular. These voxels undergo an increasing level of suppression as the distance of the confidence measure from the threshold grows.Results: MIPs of processed volunteer studies were compared to the original unaltered studies to assess the improvement in clarity of vascular structures. Qualitative and quantitative comparisons of full body MIPs verify excellent suppression of nonvascular tissue in time-resolved threedimensional image volumes. Conclusion:Contrast increased by an average factor of 13 in five volunteer studies, quantitatively emphasizing the improvement in MIP processing achieved by this method. Improvement in the clarity of vascular structures in subvolume MIPs is also demonstrated to emphasize the significant increase in ease with which regions of interest can be identified. DRAMATIC INCREASES IN CONTRAST in diagnostic angiography exams have been achieved in numerousmodalities by subtracting a mask image acquired prior to the arrival of a contrast injection. Significant artifacts result from this subtraction if patient motion occurs between the mask acquisition and the scan with injected contrast. For this reason, angiography techniques using subtraction are applied when the acquisition time is less than the typical period over which motion can be considered insignificant. Thus using subtraction to improve contrast on angiography of the peripheral vessels or cerebral vasculature is relatively easy, while it is not used for coronary imaging. The improved contrast from the subtraction operation also results in a theoretical ͱ2 loss in signal-to-noise ratio (SNR) when the noise properties of the mask and acquisition are similar.The relatively slow speed of thoracic and abdominal contrast-enhanced magnetic resonance angiography (CE-MRA) normally allows only one three-dimensional image volume at high resolution with good anatomic coverage to be completed within a breath-hold. If a mask acquisition is acquired, it must be acquired under a separate breath-hold. The position of internal organs during breath-holds at end-exhalation has been shown to be reproducible, but positions at end-inspiration vary significantly. Therefore, breathhold feedback is required to enable optimal visualization of arteries in angiography exams (1). In the absence of this feedback, since patients can maintain much longer breath-holds at end-inspiration, most CE-MRA exams are performed this way. As misregistration between the mask and image volumes in thoracic and a...

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“…The method does not make the assumption that voxels consist of only two components; [see Refs. [2][3][4]. It generates an unbiased estimate of partial volumes from arbitrary set of images of the same anatomical cite, as long as the number of images in the sequence at least equals the number of tissues in partial volume voxels.…”

mentioning

confidence: 99%

Optimal partial volume estimation in MRI

Soltanian‐Zadeh

Windham

1999

Magn. Reson. Med.

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A comparative analysis of several transformations for enhancement and segmentation of magnetic resonance image scene sequences

Cited by 77 publications

References 36 publications

Multiparametric Iterative Self-Organizing Data Analysis of Ischemic Lesions Using Pre- or Post-Gd T1 MRI

Multiparametric Iterative Self-Organizing Data Analysis of Ischemic Lesions Using Pre- or Post-Gd T1 MRI

Background suppression in time‐resolved MR angiography without mask acquisition or operator intervention

Optimal partial volume estimation in MRI

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