scholarly journals Comparison between planar and single-photon computed tomography images for radiation intensity quantification in iodine-131 scintigraphy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yusuke Iizuka ◽  
Tomohiro Katagiri ◽  
Minoru Inoue ◽  
Kiyonao Nakamura ◽  
Takashi Mizowaki

AbstractThis study aimed to evaluate the feasibility of quantifying iodine-131 (131I) accumulation in scintigraphy images and compare planar and single-photon emission computed tomography (SPECT) images to estimate 131I radioactivity in patients receiving radioactive iodine therapy for thyroid cancer. We evaluated 72 sets of planar and SPECT images acquired between February 2017 and December 2018. Simultaneously, we placed a reference 131I capsule next to the patient during image acquisition. We evaluated the correlation between the intensity of the capsule in the images and the capsule dose and estimated the radiation dose at the thyroid bed. The mean capsule dose was 2.14 MBq (range, 0.63–4.31 MBq). The correlation coefficients (p-value) between capsule dose and maximum and mean intensities in both planar and SPECT images were 0.93 (p < 0.01), 0.96 (p < 0.01), 0.60 (p < 0.01), and 0.47 (p < 0.01), respectively. The mean intensities of planar images show the highest correlation coefficients. Based on a regression equation, the average radiation dose in the thyroid bed was 5.9 MBq. In conclusion, planar images reflected the radiation dose more accurately than SPECT images. The regression equation allows to determine the dose in other regions, such as the thyroid bed or sites of distant metastasis.

2021 ◽  
Author(s):  
Yusuke Iizuka ◽  
Tomohiro Katagiri ◽  
Minoru Inoue ◽  
Kiyonao Nakamura ◽  
Takashi Mizowaki

Abstract This study aimed to evaluate the feasibility of quantifying iodine-131 (131I) accumulation in scintigraphy images and compare planar and single-photon emission computed tomography (SPECT) images to estimate 131I radioactivity in patients receiving radioactive iodine therapy for thyroid cancer. We evaluated 72 sets of planar and SPECT images acquired between February 2017 and December 2018. Simultaneously, we placed a reference 131I capsule next to the patient during image acquisition. We evaluated the correlation between the intensity of the capsule in the images and the capsule dose and estimated the radiation dose at the thyroid bed. The mean capsule dose was 2.14 MBq (range, 0.63–4.31 MBq). The correlation coefficients (p-value) between capsule dose and maximum and mean intensities in both planar and SPECT images were 0.93 (p < 0.01), 0.96 (p < 0.01), 0.60 (p < 0.01), and 0.47 (p < 0.01), respectively. The mean intensities of planar images show the highest correlation coefficients. Based on a regression equation, the average radiation dose in the thyroid bed was 5.9 MBq. In conclusion, planar images reflected the radiation dose more accurately than SPECT images. The regression equation allows to determine the dose in other regions, such as the thyroid bed or sites of distant metastasis.


Diagnostics ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 57
Author(s):  
Ji Lee ◽  
Hee-Sung Song ◽  
Jae Choi ◽  
Chang Hyun ◽  
Sang Lee ◽  
...  

Technetium (Tc)-99m-methoxyisobutylisonitrile (MIBI) single photon-emission computed tomography/computed tomography (SPECT/CT) is now being used increasingly for preoperative localization of parathyroid adenomas. Tc-99m-MIBI scintigraphy in a 52-year-old man with a diagnosis of primary hyperparathyroidism revealed two focal areas with retention of radioactivity in the left lobe of the thyroid gland on the delayed phase of MIBI SPECT/CT but no significant focal radioactive uptake on MIBI planar images. The patient subsequently underwent left partial parathyroidectomy. Histological analysis identified one lesion to be thyroid hyperplasia and the other to be parathyroid adenoma. This case demonstrates the value of MIBI SPECT/CT for localization of a parathyroid lesion when compared with planar images and that false-positive findings can lead to misdiagnosis in a patient with coexisting thyroid disease. An appropriate diagnostic work-up that includes Tc-99m MIBI SPECT/CT in addition to ultrasonography is helpful for an accurate diagnosis in patients with concomitant thyroid disease.


2020 ◽  
Author(s):  
Young-Sil An ◽  
Do Young Park ◽  
Byoung-Hyun Min ◽  
Joon-Kee Yoon

Abstract Background: This study attempted to compare the radiopharmaceutical uptake findings of planar bone scintigraphy (BS) and single photon emission computed tomography (SPECT)/computed tomography (CT) performed on knee joints.Methods: We retrospectively included 104 patients who underwent bone SPECT/CT and BS 4 hours after the intravenous administration of technetium-99m-hydroxymethylene diphosphonate (99mTc-HDP) for pain in the knee joint. The uptake degree of each of the knee regions (medial femoral, lateral femoral, medial tibial, lateral tibial, and patellar area) in planar images and SPECT/CT were evaluated by visual (grades 0 to 2) and quantitative analyses (uptake counts for planar image and standardized uptake values [SUVs] for SPECT/CT). Results: The uptake grades assessed visually on the planar images differed significantly from the uptake grades on SPECT/CT images in all areas of the knee (all p < 0.001), and SPECT/CT imaging revealed a larger number of uptake lesions than those noted in planar imaging for each patient (3.3 ± 2.0 versus 2.4 ± 2.3, p < 0.0001). In all regions of the knee, all of the quantitative values, including uptake counts obtained from the planar image as well as the maximum SUV (SUVmax) and mean SUV (SUVmean) obtained from SPECT/CT, showed statistically higher values as their visual grades increased (all p <0.001). However, when analyzed for each area, only the SUVmax showed a significant difference by grade in all knee regions. Quantitative uptake values obtained from planar images were moderately correlated with SUVs of SPECT/CT images (r = 0.58 for SUVmean and r = 0.53 for SUVmax, all p <0.001) in the total knee regions. Looking at each area, there was a significant but low correlation between the uptake counts of the planar images and the SUVs on SPECT/CT in the right lateral tibial region (r = 0.45 for SUVmean, r = 0.31 for SUVmax, all p <0.001).Conclusions: In assessing knee joints, the findings of planar images and SPECT/CT images differ both visually and quantitatively, and more lesions can be found in SPECT/CT than in the planar images.


2020 ◽  
Vol 34 (11) ◽  
pp. 799-806
Author(s):  
Koichiro Abe ◽  
Makoto Hosono ◽  
Takayuki Igarashi ◽  
Takashi Iimori ◽  
Masanobu Ishiguro ◽  
...  

Abstract The diagnostic reference levels (DRLs) are one of several effective tools for optimizing nuclear medicine examinations and reducing patient exposure. With the advances in imaging technology and alterations of examination protocols, the DRLs must be reviewed periodically. The first DRLs in Japan were established in 2015, and since 5 years have passed, it is time to review and revise the DRLs. We conducted a survey to investigate the administered activities of radiopharmaceuticals and the radiation doses of computed tomography (CT) in hybrid CT accompanied by single photon emission computed tomography (SPECT)/CT and positron emission tomography (PET)/CT. We distributed a Web-based survey to 915 nuclear medicine facilities throughout Japan and survey responses were provided by 256 nuclear medicine facilities (response rate 28%). We asked for the facility's median actual administered activity and median radiation dose of hybrid CT when SPECT/CT or PET/CT was performed for patients with standard habitus in the standard protocol of the facility for each nuclear medicine examination. We determined the new DRLs based on the 75th percentile referring to the 2015 DRLs, drug package inserts, and updated guidelines. The 2020 DRLs are almost the same as the 2015 DRLs, but for the relatively long-lived radionuclides, the DRLs are set low due to the changes in the Japanese delivery system. There are no items set higher than the previous values. Although the DRLs determined this time are roughly equivalent to the DRLs used in the US, overall they tend to be higher than the European DRLs. The DRLs of the radiation dose of CT in hybrid CT vary widely depending on each imaging site and the purpose of the examination.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Young-Sil An ◽  
Do Young Park ◽  
Byoung-Hyun Min ◽  
Su Jin Lee ◽  
Joon-Kee Yoon

Abstract Background This study attempted to compare the radiopharmaceutical uptake findings of planar bone scintigraphy (BS) and single photon emission computed tomography (SPECT)/computed tomography (CT) performed on knee joints. Methods We retrospectively included 104 patients who underwent bone SPECT/CT and BS 4 h after the intravenous administration of technetium-99m-hydroxymethylene diphosphonate (99mTc-HDP) for pain in the knee joint. The uptake degree of each of the knee regions (medial femoral, lateral femoral, medial tibial, lateral tibial, and patellar area) in planar images and SPECT/CT were evaluated by visual (grades 0 to 2) and quantitative analyses (uptake counts for planar image and standardized uptake values [SUVs] for SPECT/CT). Results The uptake grades assessed visually on the planar images differed significantly from the uptake grades on SPECT/CT images in all areas of the knee (all p < 0.001), and SPECT/CT imaging revealed a larger number of uptake lesions than those noted in planar imaging for each patient (3.3 ± 2.0 vs 2.4 ± 2.3, p < 0.0001). In all regions of the knee, all of the quantitative values, including uptake counts obtained from the planar image as well as the maximum SUV (SUVmax) and mean SUV (SUVmean) obtained from SPECT/CT, showed statistically higher values as their visual grades increased (all p < 0.001). However, when analyzed for each area, only the SUVmax showed a significant difference by grade in all knee regions. Quantitative uptake values obtained from planar images were moderately correlated with SUVs of SPECT/CT images (r = 0.58 for SUVmean and r = 0.53 for SUVmax, all p < 0.001) in the total knee regions. Looking at each area, there was a significant but low correlation between the uptake counts of the planar images and the SUVs on SPECT/CT in the right lateral tibial region (r = 0.45 for SUVmean, r = 0.31 for SUVmax, all p < 0.001). Conclusions In assessing knee joints, the findings of planar images and SPECT/CT images differ both visually and quantitatively, and more lesions can be found in SPECT/CT than in the planar images. The SUVmax could be a reliable value to evaluate knee joint uptake activity.


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