Low contrast detectability and spatial resolution with model-based Iterative reconstructions of MDCT images: a phantom and cadaveric study

Millon, Domitille; Vlassenbroek, Alain; Maanen, Aline G. Van; Cambier, Samantha E; Coche, Emmanuel

doi:10.1007/s00330-016-4444-x

Cited by 37 publications

(21 citation statements)

References 22 publications

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“…Its value for organ recognition (segmentation), lesion detection, and lesion characterization has been explored (11) and its ability to detect and reduce the image noise has been demonstrated (12À16). Unlike the conventional noise reduction methods, which involve a trade-off between spatial resolution and noise reduction (6,17), deep learning lowers the image noise and increases spatial resolution simultaneously (9). In this phantom study we examined the noise characteristics, spatial resolution, and task-based detectability of DLR images.…”

Section: Introductionmentioning

confidence: 99%

Deep Learning Reconstruction at CT: Phantom Study of the Image Characteristics

et al. 2020

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Section: Introductionmentioning

confidence: 99%

Deep Learning Reconstruction at CT: Phantom Study of the Image Characteristics

et al. 2020

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“…However, some researchers have reported that peak shifts, like that present in the ADMIRE NPS, did not influence to diagnostic performance and instead improved low-contrast detectability. 4 As IIR mostly maintains the spatial resolution of FBP and reduces the NPS over the entire frequency range, its SP is uniformly better than that of FBP, thus resembling the properties achieved by dose increase. As the SP 2 at 2.5, 5, and 10 mGy with IIR were comparable to those at 5, 10, and 20 mGy with FBP, respectively, the dose reduction with IIR was estimated at approximately 50%.…”

Section: Discussionmentioning

confidence: 90%

“…F I G . However, some researchers have reported that peak shifts, like that present in the ADMIRE NPS, did not influence to diagnostic performance and instead improved low-contrast detectability 4. Images processed with (left column) FBP and (middle column) IIR, and corresponding subtraction images (right column), for the rod object for the TTF measurement, a bar-pattern phantom, and a clinical abdomen image.…”

mentioning

confidence: 99%

“…reconstruction (IR) algorithms for CT dose reduction, noise mitigation, and delivering a suitable image quality for clinical use. [2][3][4] Although IR allows dose reduction in the most recent CT systems, some systems are not endowed with such techniques, and the benefits of dose reduction cannot be obtained for patients who are examined using these systems. To overcome this limitation, an image-based IR system (IIR) (SafeCT, Medic Vision Imaging Solutions Ltd., Tirat Carmel, Israel), has been recently developed for clinical use and offers a vendor-neutral technique for processing filtered back projection (FBP) images from CT scanners.…”

mentioning

confidence: 99%

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Quality evaluation of image‐based iterative reconstruction for CT: Comparison with hybrid iterative reconstruction

Kawashima

Ichikawa

Matsubara

et al. 2019

J Applied Clin Med Phys

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The purpose of this study is to evaluate the physical image quality of a commercially available image‐based iterative reconstruction (IIR) system for two object contrasts to resemble a soft tissue (60 HU) and an enhanced vessel (270 HU), and compare the results with those of filtered back projection (FBP) and iterative reconstruction (IR). A 192‐slice computed tomography (CT) scanner was used for data acquisitions. IIR images were processed from the FBP images. Task‐based in‐plane transfer function (TTF) and slice sensitivity profile (SSPtask) were measured from rod objects inside of a 25‐cm diameter water phantom at four dose levels (2.5, 5, 10, and 20 mGy). Noise power spectrum (NPS) was measured from the water‐only part. System performance (SP) function was calculated as TTF2/NPS over FBP, IR, and IIR for comparison. In addition, an image subtraction was performed using images of rod objects, a bar‐pattern phantom, and a clinical abdomen case to observe the noise reduction performance of IIR. As a results, IIR mostly preserved TTF and SSPtask of FBP, whereas IR exhibited enhanced TTF at 10 and 20 mGy for 60 HU contrast and at all doses for 270 HU contrast. SP of IIR at 2.5, 5, 10 mGy (half doses) were similar to those of FBP at 5, 10, 20 mGy, respectively. IR exhibited enhanced SP at medium to high frequencies. The subtracted images showed weak remained edge signals in the bar‐pattern and abdominal images. In conclusion, IIR uniformly improved the task‐based image quality of FBP over the entire frequency range, whereas IR improved the characteristics over medium to high frequencies. The dose reduction potential of IIR estimated from SP is approximately 50%, when allowing the slight signal reductions.

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“…Therefore, scatter radiation is normally corrected by mathematical algorithms [50, 51], which may not equally correct for scatter induced artifacts in every situation. On the other hand, iterative reconstruction algorithms of the MDCT decrease image noise and alter the image impression [52, 53], which was not available or applied in CBCT. Due to the reasons given above, a direct comparison between different CBCT devices or CBCT and MDCT machines is further complicated regarding objective, and especially subjective image quality.…”

Section: Discussionmentioning

confidence: 99%

Surface radiation dose comparison of a dedicated extremity cone beam computed tomography (CBCT) device and a multidetector computed tomography (MDCT) machine in pediatric ankle and wrist phantoms

et al. 2017

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ObjectivesTo evaluate and compare surface doses of a cone beam computed tomography (CBCT) and a multidetector computed tomography (MDCT) device in pediatric ankle and wrist phantoms.MethodsThermoluminescent dosimeters (TLD) were used to measure and compare surface doses between CBCT and MDCT in a left ankle and a right wrist pediatric phantom. In both modalities adapted pediatric dose protocols were utilized to achieve realistic imaging conditions. All measurements were repeated three times to prove test-retest reliability. Additionally, objective and subjective image quality parameters were assessed.ResultsAverage surface doses were 3.8 ±2.1 mGy for the ankle, and 2.2 ±1.3 mGy for the wrist in CBCT. The corresponding surface doses in optimized MDCT were 4.5 ±1.3 mGy for the ankle, and 3.4 ±0.7 mGy for the wrist. Overall, mean surface dose was significantly lower in CBCT (3.0 ±1.9 mGy vs. 3.9 ±1.2 mGy, p<0.001). Subjectively rated general image quality was not significantly different between the study protocols (p = 0.421), whereas objectively measured image quality parameters were in favor of CBCT (p<0.001).ConclusionsAdapted extremity CBCT imaging protocols have the potential to fall below optimized pediatric ankle and wrist MDCT doses at comparable image qualities. These possible dose savings warrant further development and research in pediatric extremity CBCT applications.

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Low contrast detectability and spatial resolution with model-based Iterative reconstructions of MDCT images: a phantom and cadaveric study

Cited by 37 publications

References 22 publications

Deep Learning Reconstruction at CT: Phantom Study of the Image Characteristics

Deep Learning Reconstruction at CT: Phantom Study of the Image Characteristics

Quality evaluation of image‐based iterative reconstruction for CT: Comparison with hybrid iterative reconstruction

Surface radiation dose comparison of a dedicated extremity cone beam computed tomography (CBCT) device and a multidetector computed tomography (MDCT) machine in pediatric ankle and wrist phantoms

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