Modified PET / SPECT Cylindrical Phantom

Sayed, Inayatullah Shah; Shah, Ayaz Ali

doi:10.1007/978-3-540-36841-0_414

Cited by 3 publications

(2 citation statements)

References 2 publications

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“…We employed an acrylic cylindrical phantom [15] with insert of holes drilled in a solid acrylic block mimicking the hot regions in a cold background (22.6, 18.1, 14.5, 11.6, 9.4, 7.5, 6.1, and 4.9 mm diameter), and solid circular rods simulating cold regions in a hot background with various diameters (22.5, 18.0, 14.4, 11.5, 9.3, 7.4, 6.0, and 4.8 mm), as shown in Figure 1. The advantage of this specific design provided similar transaxial views of hot and cold regions.…”

Section: Data Acquisition and Image Reconstructionmentioning

confidence: 99%

Comparison of Low-Pass Filters for SPECT Imaging

Sayed

Ismail

2020

International Journal of Biomedical Imaging

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In single photon emission computed tomography (SPECT) imaging, the choice of a suitable filter and its parameters for noise reduction purposes is a big challenge. Adverse effects on image quality arise if an improper filter is selected. Filtered back projection (FBP) is the most popular technique for image reconstruction in SPECT. With this technique, different types of reconstruction filters are used, such as the Butterworth and the Hamming. In this study, the effects on the quality of reconstructed images of the Butterworth filter were compared with the ones of the Hamming filter. A Philips ADAC forte gamma camera was used. A low-energy, high-resolution collimator was installed on the gamma camera. SPECT data were acquired by scanning a phantom with an insert composed of hot and cold regions. A Technetium-99m radioactive solution was homogenously mixed into the phantom. Furthermore, a symmetrical energy window (20%) centered at 140 keV was adjusted. Images were reconstructed by the FBP method. Various cutoff frequency values, namely, 0.35, 0.40, 0.45, and 0.50 cycles/cm, were selected for both filters, whereas for the Butterworth filter, the order was set at 7. Images of hot and cold regions were analyzed in terms of detectability, contrast, and signal-to-noise ratio (SNR). The findings of our study indicate that the Butterworth filter was able to expose more hot and cold regions in reconstructed images. In addition, higher contrast values were recorded, as compared to the Hamming filter. However, with the Butterworth filter, the decrease in SNR for both types of regions with the increase in cutoff frequency as compared to the Hamming filter was obtained. Overall, the Butterworth filter under investigation provided superior results than the Hamming filter. Effects of both filters on the quality of hot and cold region images varied with the change in cutoff frequency.

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Section: Data Acquisition and Image Reconstructionmentioning

confidence: 99%

Comparison of Low-Pass Filters for SPECT Imaging

Sayed

Ismail

2020

International Journal of Biomedical Imaging

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“…A new insert (as shown in Figure 1) of hot and cold regions for emission computed tomography (ECT) resolution test phantom was scanned [13]. is 208 mm.…”

Section: Spect Data Collectionmentioning

confidence: 99%

Effect of Cut-Off Frequency of Butterworth Filter on Detectability and Contrast of Hot and Cold Regions in Tc-99m SPECT

Sayed¹,

Nasrudin²

2016

IJMPCERO

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In SPECT, noise is one of the major limitations that degrade image quality. To suppress the noisy signals in an image, digital filters are most commonly applied. However, in SPECT image reconstruction, selection of an appropriate filter and its functions has always remained a difficult task. In this work an attempt was made to investigate the effects of varying cut-off frequencies and in keeping the order of Butterworth filter constant on detectability and contrast of hot and cold regions images. A new insert simulating hot and cold regions which provides similar views in a reconstructed image was placed in the phantom's cylindrical source tank and imaged. Tc-99m radionuclide was distributed uniformly in the phantom. SPECT data were collected in a 20% energy window centered at 140 keV by a Philips ADAC Forte dual head gamma camera mounted with a LEHR collimator. Images were generated by using the filtered backprojection technique. A Butterworth filter of order 5 with cut-off frequencies 0.35 and 0.45 cycles•cm −1 was applied. Images were examined in terms of hot and cold regions, detectability and contrast. Results show that the hot and cold regions' detectability and contrast vary with the change of cut-off frequency. With a 0.45 cycles•cm −1 cut-off frequency, a significant enhancement in contrast of cold regions was achieved as compared to a 0.35 cycles•cm −1 cut-off frequency. Furthermore, the detectability of hot and cold regions improved with the use of a 0.45 cycles•cm −1 cut-off frequency. In conclusion, image quality of hot and cold regions affected in a different way with a change of cut-off frequency. Thus, care should be taken in selecting the filter cut-off frequency prior to reconstruction of images; particularly, when both types of regions are expected in the reconstructed image.

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Emission Computed Tomography Test Phantoms: A Review

Sayed

Rahim

2018

2018 IEEE 5th International Conference on Engineering Technologies and Applied Sciences (ICETAS)

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It is vital to assess the performance of emission computed tomography (ECT) systems prior to their use for clinical examinations. Generally, performance tests of ECT systems are time-consuming, expensive and require more than one phantom to scan and then analyse the data. There is nonavailability of such type of phantoms that can provide all necessary data for performance of some quality control (QC) tests from a single scan data. In this paper, commercially available emission computed tomography (ECT) phantoms are thoroughly reviewed. It is concluded that, there is a need of designing and construction of a time-saving and cost-effective new compact ECT phantom .

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Modified PET / SPECT Cylindrical Phantom

Cited by 3 publications

References 2 publications

Comparison of Low-Pass Filters for SPECT Imaging

Comparison of Low-Pass Filters for SPECT Imaging

Effect of Cut-Off Frequency of Butterworth Filter on Detectability and Contrast of Hot and Cold Regions in Tc-99m SPECT

Emission Computed Tomography Test Phantoms: A Review

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