Physical quantities useful for quality control of quantitative SPECT/CT imaging

Summary Aim: To gather information on clinical operations, quality control (QC) standards and adoption of guidelines for FDG-PET/CT imaging in Austrian PET/CT centres. Methods: A written survey composed of 68 questions related to A) PET/CT centre and installation, B) standard protocol parameters for FDG-PET/CT imaging of oncology patients, and C) standard QC procedures was conducted between November and December 2013 among all Austrian PET/CT centres. In addition, a NEMA-NU2 2012 image quality phantom test was performed using standard whole-body imaging settings on all PET/CT systems with a lesion-to- background ratio of 4. Recovery coefficients (RC) were calculated for each lesion and PET/ CT system. Resu lts: A) 13 PET/CT systems were installed in 12 nuclear medicine departments at public hospitals. B) Average fasting prior to FDG-PET/CT was 7.6 (4-12) h. All sites measured blood glucose levels while using different cut-off levels (64%: 150 mg/dl). Weight- based activity injection was performed at 83% sites with a mean FDG activity of 4.1 MBq/kg. Average FDG uptake time was 55 (45-75) min. All sites employed CT contrast agents (variation from 1 %-95% of the patients). All sites reported SUV-max. C) Frequency of QC tests varied significantly and QC phantom measurements revealed significant differences in RCs. Conclusion: Significant variations in FDG-PET/CT protocol parameters among all Austrian PET/CT users were observed. subsequently, efforts need to be put in place to further standardize imaging protocols. At a minimum clinical PET/CT operations should ensure compliance with existing guidelines. Further, standardized QC procedures must be followed to improve quantitative accuracy across PET/CT centres.

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An alternative method for radioactivity measurement in quantitative bone SPECT/CT imaging

Science Progress ◽

10.1177/00368504211028363 ◽

2021 ◽

Vol 104 (3) ◽

pp. 003685042110283

Author(s):

Masaru Ishihara ◽

Yasuaki Kato ◽

Masahisa Onoguchi ◽

Takayuki Shibutani

Keyword(s):

Computed Tomography ◽

Analytical Methods ◽

Measurement Method ◽

Ct Imaging ◽

Emission Computed Tomography ◽

Post Injection ◽

Quantitative Spect ◽

Quantitative Parameters ◽

Alternative Method ◽

Bone Spect

Bone scintigraphy with combined single-photon emission computed tomography (SPECT) and computed tomography (CT) has become widely used for the detection of bone metastases. However, calculation of the semi-quantitative standardized uptake value (SUV) requires measurement of the pre- and post-injection radioactivity of the radiopharmaceutical. This study aimed to compare measured and fixed input radioactivity values for quantitative SPECT/CT bone imaging to examine whether the fixed measurement method of radiopharmaceutical radioactivity could be used as an alternative method. Four different methods were used to quantify the Tc-99m hydroxymethylene diphosphonate input radioactivity: (A) measured pre- and post-injection radioactivity values; (B) measured pre-injection and fixed post-injection radioactivity values; (C) fixed pre-injection and measured post-injection radioactivity values; (D) fixed pre- and post-injection radioactivity values. All SPECT/CT acquisitions were analyzed using bone SPECT analysis software, and the semi-quantitative parameters (SUVpeak and SUVmean) were recorded and compared for each analytical method. Two semi-quantitative parameters showed significant differences between analytical methods A and B, A and D, and C and D. However, an additional subgroup analysis performed on patients whose median post-injection measured radioactivity value was <1.5 MBq showed no significant differences in parameters between all analytical methods. Measurement of the radiopharmaceutical radioactivity can be an alternative method because it reduces the volume of radioactivity post-injection. The simplified fixed measurement method of radiopharmaceutical radioactivity can be used as an alternative method in cases when measuring the radioactivity in quantitative bone SPECT/CT imaging is missed.

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Process Fingerprint in Micro-EDM Drilling

Micromachines ◽

10.3390/mi10040240 ◽

2019 ◽

Vol 10 (4) ◽

pp. 240 ◽

Cited By ~ 5

Author(s):

Mattia Bellotti ◽

Jun Qian ◽

Dominiek Reynaerts

Keyword(s):

Quality Control ◽

Electrical Discharge ◽

Electrical Discharge Machining ◽

Processing Parameters ◽

Micro Edm ◽

Manufacturing Tolerance ◽

Micro Electrical Discharge Machining ◽

Line Process ◽

Physical Quantities ◽

Edm Drilling

The micro electrical discharge machining (micro-EDM) process is extensively used in aerospace, automotive, and biomedical industries for drilling small holes in difficult-to-machine materials. However, due to the complexity of the electrical discharge phenomena, optimization of the processing parameters and quality control are time-consuming operations. In order to shorten these operations, this study investigates the applicability of a process fingerprint approach in micro-EDM drilling. This approach is based on the monitoring of a few selected physical quantities, which can be controlled in-line to maximize the drilling speed and meet the manufacturing tolerance. A Design of Experiments (DoE) is used to investigate the sensitivity of four selected physical quantities to variations in the processing parameters. Pearson’s correlation is used to evaluate the correlation of these quantities to some main performance and hole quality characteristics. Based on the experimental results, the potential of the process fingerprint approach in micro-EDM drilling is discussed. The results of this research provide a foundation for future in-line process optimization and quality control techniques based on machine learning.

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Quantitative SPECT/CT Imaging of 177Lu with In Vivo Validation in Patients Undergoing Peptide Receptor Radionuclide Therapy

Molecular Imaging and Biology ◽

10.1007/s11307-014-0806-4 ◽

2014 ◽

Vol 17 (4) ◽

pp. 585-593 ◽

Cited By ~ 26

Author(s):

J. C. Sanders ◽

T. Kuwert ◽

J. Hornegger ◽

P. Ritt

Keyword(s):

Radionuclide Therapy ◽

Peptide Receptor Radionuclide Therapy ◽

Ct Imaging ◽

Quantitative Spect ◽

Peptide Receptor ◽

In Vivo Validation

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An automated voxelized dosimetry tool for radionuclide therapy based on serial quantitative SPECT/CT imaging

Medical Physics ◽

10.1118/1.4824318 ◽

2013 ◽

Vol 40 (11) ◽

pp. 112503 ◽

Cited By ~ 34

Author(s):

Price A. Jackson ◽

Jean-Mathieu Beauregard ◽

Michael S. Hofman ◽

Tomas Kron ◽

Annette Hogg ◽

...

Keyword(s):

Radionuclide Therapy ◽

Ct Imaging ◽

Quantitative Spect

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What validation tests can be done by the clinical medical physicist while waiting for the standardization of quantitative SPECT/CT imaging?

10.21203/rs.3.rs-118913/v1 ◽

2020 ◽

Author(s):

Hanna Piwowarska-Bilska ◽

Aleksandra Supińska ◽

Bożena Birkenfeld

Keyword(s):

Nuclear Medicine ◽

Activity Concentration ◽

Total Activity ◽

Ct Imaging ◽

Calibration Factor ◽

Recovery Coefficient ◽

Quantitative Spect ◽

Gamma Cameras ◽

Reconstruction Methods ◽

Accuracy Of Measurements

Abstract Objective The aim of the study was to assess the accuracy of quantitative SPECT/CT imaging in a clinical setting and to compare test results from two nuclear medicine departments.Methods Phantom studies were carried out with two gamma cameras manufactured by GE Healthcare: Discovery NM/CT 670 and NM/CT 850, used in two nuclear medicine departments.Results The convergence of activity concentration recovery was validated for the two gamma cameras operating in two medical centres using a homogeneous 3D phantom. The comparison of results revealed a 5% difference in the calibration factor Bg. cal; 6% difference in COV, and a 0.6% difference in total activity deviation ∆Atot.Recovery coefficients (RCmax) for activity concentration in spheres of the anthropomorphic phantom was measured for different image reconstruction techniques. RCmax was in the range of 0.2-0.4 for the smallest sphere (ϕ10 mm), and 1.3-1.4 for the largest sphere (ϕ37 mm). Conversion factors for SUVmax and SUVmean for the gamma camera systems used were 0.99 and 1.13, respectively.Conclusions 1) Measurements taken in our study confirmed the clinical suitability of 5 parameters of image quality (Bg. cal- background calibration factor, ∆Atot- total activity deviation, COV- noise level estimation, QH- hot contrast, AM-accuracy of measurements or RC- recovery coefficient) for the validation of SPECT/CT system performance in terms of correct quantitative acquisitions of images. 2) This work shows that absolute SPECT/CT quantification is achievable in clinical nuclear medicine centers. Results variation of quantitative analyzes between centers is mainly related to the use of different reconstruction methods. 3) It is necessary to standardize the technique of measuring the SUV conversion factor obtained with different SPECT/CT scanners.

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