Iterative reconstruction algorithms in nuclear medicine

Vandenberghe, Stefaan; D’Asseler, Yves; Walle, Rik Van de; Kauppinen, Tomi; Koole, Michel; Bouwens, Luc; Laere, Koen Van; Lemahieu, Ignace; Dierckx, Rudi

doi:10.1016/s0895-6111(00)00060-4

Cited by 95 publications

(55 citation statements)

References 55 publications

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“…On the down side, the time required for one iteration of the iterative reconstruction is approximately 2-3 times more than that of the FBP, and depending on the algorithm settings and convergence criterion, 10-100 iterations are used for one reconstruction [16]. To address this issue, a few algorithms have been proposed [33,34] to speed up the reconstruction process of the iterative schemes.…”

Section: Iterative Reconstructionmentioning

confidence: 99%

“…Imaging was performed on an L-band (1.2 GHz) EPRI system with a volume resonator with a diameter of 12.6 mm and a useable height of 12 mm. Spectrometer settings were: incident power, 4 mW; scan time per projection, 5.24 s; field of view, 25×25 mm 2 ; gradient strengths, 3.5 and 6 G/cm; modulation amplitudes, 220, 120, 40, 20, 10 mG (with the corresponding measured SNR of 200, 100, 27,16,8). Since spectral shape varies with the modulation amplitude, a separate spectral shape was observed for each modulation amplitude.…”

Section: Epri Experimentsmentioning

confidence: 99%

“…For FBP, all the projections are deconvolved using the previously proposed [13] two-step deblurring procedure before applying back projection. For the iterative reconstruction [14][15][16], we have proposed an analogous two-step deblurring procedure in which the first step is the same, i.e., each projection is deconvolved by the conventional noniterative procedure, but the second step (iterative deconvolution), to suppress the blurring introduced by the lowpass filtering in the first step, is not performed explicitly but is rather merged with the iterative reconstruction procedure itself. The iterative reconstruction algorithm used in this research is multiplicative simultaneous iterative reconstruction technique (MSIRT) [17], and we expect similar results for the other iterative reconstruction techniques.…”

Section: Introductionmentioning

confidence: 99%

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Enhanced resolution for EPR imaging by two-step deblurring

Ahmad

Clymer

Vikram

et al. 2007

Journal of Magnetic Resonance

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The broad spectrum of spin probes used for electron paramagnetic resonance imaging (EPRI) result in poor spatial resolution of the reconstructed images. Conventional deconvolution procedures can enhance the resolution to some extent but obtaining high resolution EPR images is still a challenge. In this work, we have implemented and analyzed the performance of a postacquisition deblurring technique to enhance the spatial resolution of the EPR images. The technique consists of two steps; noniterative deconvolution followed by iterative deconvolution of the acquired projections which are then projected back using filtered backprojection (FBP) to reconstruct a high resolution image. Further, we have proposed an analogous technique for the iterative reconstruction algorithms such as multiplicative simultaneous iterative reconstruction technique (MSIRT) which can be a method of choice for many applications. The performance of the suggested deblurring approach is evaluated using computer simulations and EPRI experiments. Results suggest that the proposed procedure is superior to the standard FBP and standard iterative reconstruction algorithms in terms of meansquare-error (MSE), spatial resolution, and visual judgment. Although the procedure is described for 2D imaging, it can be readily extended to 3D imaging.

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Section: Iterative Reconstructionmentioning

confidence: 99%

Section: Epri Experimentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Enhanced resolution for EPR imaging by two-step deblurring

Ahmad

Clymer

Vikram

et al. 2007

Journal of Magnetic Resonance

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“…Our method utilizes an inverse form of back‐projection used in CT reconstruction. The first CT reconstruction in history was accomplished by iteratively reducing the deviations of the predicted detector signal from the measured signal, using the algebraic reconstruction technique 20 , 21 . In IMRT optimization, we search for a configuration of beam intensities that deliver the prescribed dosimetry.…”

Section: Introductionmentioning

confidence: 99%

Direct aperture optimization using an inverse form of back‐projection

Zhu

Cullip

Tracton

et al. 2014

J Applied Clin Med Phys

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Direct aperture optimization (DAO) has been used to produce high dosimetric quality intensity‐modulated radiotherapy (IMRT) treatment plans with fast treatment delivery by directly modeling the multileaf collimator segment shapes and weights. To improve plan quality and reduce treatment time for our in‐house treatment planning system, we implemented a new DAO approach without using a global objective function (GFO). An index concept is introduced as an inverse form of back‐projection used in the CT multiplicative algebraic reconstruction technique (MART). The index, introduced for IMRT optimization in this work, is analogous to the multiplicand in MART. The index is defined as the ratio of the optima over the current. It is assigned to each voxel and beamlet to optimize the fluence map. The indices for beamlets and segments are used to optimize multileaf collimator (MLC) segment shapes and segment weights, respectively. Preliminary data show that without sacrificing dosimetric quality, the implementation of the DAO reduced average IMRT treatment time from 13 min to 8 min for the prostate, and from 15 min to 9 min for the head and neck using our in‐house treatment planning system PlanUNC. The DAO approach has also shown promise in optimizing rotational IMRT with burst mode in a head and neck test case.PACS number: 87.55.D‐

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“…Recently, iterative reconstruction techniques for CT have been introduced to decrease image noise as an alternative to the standard filtered back-projection (FBP) method. [7][8][9][10][11] Earlier versions of iterative reconstruction algorithms required a high amount of computational calculating time and could not be used in this form for emergency radiologic procedures. 12 The second generation of iterative reconstruction processes, sinogram-affirmed iterative reconstruction (SAFIRE), is now commercially available.…”

mentioning

confidence: 99%

Acute Intracranial Hemorrhage in CT: Benefits of Sinogram-Affirmed Iterative Reconstruction Techniques

Bodelle

Klein

Naguib

et al. 2013

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE:Acute intracranial hemorrhage represents a severe and time critical pathology that requires precise and quick diagnosis, mainly by performing a CT scan. The purpose of this study was to compare image quality and intracranial hemorrhage conspicuity in brain CT with sinogram-affirmed iterative reconstruction and filtered back-projection reconstruction techniques at standard (340 mAs) and low-dose tube current levels (260 mAs).

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Iterative reconstruction algorithms in nuclear medicine

Cited by 95 publications

References 55 publications

Enhanced resolution for EPR imaging by two-step deblurring

Enhanced resolution for EPR imaging by two-step deblurring

Direct aperture optimization using an inverse form of back‐projection

Acute Intracranial Hemorrhage in CT: Benefits of Sinogram-Affirmed Iterative Reconstruction Techniques

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