Comparison of standardized uptake values measured on 18F-NaF PET/CT scans using three different tube current intensities

Objective: To analyze standardized uptake values (SUVs) using three different tube current intensities for attenuation correction on 18FNaF PET/CT scans. Materials and Methods: A total of 254 18F-NaF PET/CT studies were analyzed using 10, 20 and 30 mAs. The SUVs were calculated in volumes of interest (VOIs) drawn on three skeletal regions, namely, right proximal humeral diaphysis (RH), right proximal femoral diaphysis (RF), and first lumbar vertebra (LV1) in a total of 712 VOIs. The analyses covered 675 regions classified as normal (236 RH, 232 RF, and 207 LV1). Results: Mean SUV for each skeletal region was 3.8, 5.4 and 14.4 for RH, RF, and LV1, respectively. As the studies were grouped according to mAs value, the mean SUV values were 3.8, 3.9 and 3.7 for 10, 20 and 30 mAs, respectively, in the RH region; 5.4, 5.5 and 5.4 for 10, 20 and 30 mAs, respectively, in the RF region; 13.8, 14.9 and 14.5 for 10, 20 and 30 mAs, respectively, in the LV1 region. Conclusion: The three tube current values yielded similar results for SUV calculation.

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18F-fluoride PET/CT for bone scanning

Nuklearmedizin ◽

10.3413/nukmed-0433-11-10 ◽

2012 ◽

Vol 51 (03) ◽

pp. 84-87 ◽

Cited By ~ 4

Author(s):

T. Dannat ◽

V. Hartung ◽

A. Bockisch ◽

S. Rosenbaum-Krumme ◽

J. Nagarajah

Keyword(s):

Attenuation Correction ◽

Ct Scans ◽

Bone Lesions ◽

Bone Scanning ◽

Promising Tool ◽

Standardized Uptake Values ◽

Pet Ct ◽

Open Question ◽

Attenuation Corrected ◽

18F Fluoride

Summary Aim: 18F-fluoride PET/CT is a promising tool for bone scanning. Recently, guidelines concerning the conduct of 18F-fluoride PET/CT have been published. One open question of the German guideline was the necessity of attenuation correction for 18F-fluoride PET/CT. We evaluated the need for a CT-based attenuation correction in 18F-fluoride PET/CT scans for the detection of bone lesions. Patients and methods: We retrospectively analyzed wholebody 18F-Fluoride PET/CT scans of 59 cancer patients. The lesions were categorized as malignant, benign or inconclusive. This assignment was performed for every lesion in both: attenuation corrected (AC) and non-attenuation- corrected (NAC) images. The maximum standardized uptake values (SUVmax) of the lesion in the AC images were also determined. Results: All bone lesions were detected in both image modalities. The AC images revealed 201 lesions categorized as malignant, 114 as benign and 35 as inconclusive. Without an AC, the results were 209, 116 and 25, respectively (p > 0.05). 10/35 lesions categorized as inconclusive in the AC images were categorized as malignant in the NAC images, whereas 8 lesions were confirmed after comparison with other imaging modalities and follow-up data and 2 lesions were categorized as benign. The SUVmax for lesions identified as malignant showed a broad overlap with the SUV max of benign lesions and can consequently not be used for differentiation. Conclusion: An AC is not necessary for detecting bone lesions on 18F-fluoride PET/CT scans as the detection capability is identical for NAC imaging and lesion assignment was even better than with AC imaging. SUVmax seems not to improve the differentiation between malignant and benign bone lesions.

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Validation of MR-Based Attenuation Correction of a Newly Released Whole-Body Simultaneous PET/MR System

BioMed Research International ◽

10.1155/2019/8213215 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

Guobing Liu ◽

Tuoyu Cao ◽

Lingzhi Hu ◽

Jiaxu Zheng ◽

Lifang Pang ◽

...

Keyword(s):

Soft Tissue ◽

Attenuation Correction ◽

Whole Body ◽

Bone Lesions ◽

Soft Tissue Lesions ◽

Standardized Uptake Values ◽

Positron Emission ◽

Pet Ct ◽

The Mean ◽

Relative Differences

The aim of this study was to validate quantitative performance of a newly released simultaneous positron emission tomography (PET)/magnetic resonance imaging (MRI) scanner, by using MR-based attenuation correction (MRAC), both in phantom study and in patient study. PET/MRI image uniformities of a phantom under different hardware configurations were tested and compared. Thirty patients were examined with 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) PET/computed tomography (CT) and subsequent PET/MRI. PET images from PET/MRI were corrected with MRAC (PETMR), CT-based attenuation maps (μ-maps, PETCT), and segmented CT μ-maps (PETCTSeg) derived from PET/CT. Standardized uptake values (SUVs) were compared among the 3 sets of PET in main organs (bone, liver and lung) and in 52 FDG-avid lesions, including soft-tissue lesions and bone lesions. The result showed that PET imaging uniformities of PET/MRI under different configurations were good (<8.8%). The SUV differences among the 3 sets of PET varied with organs and lesion types. In detail, the mean relative differences of SUV between PETMR and PETCT were as follows: −18.8%, bone (SUVmean); −8.0%, liver (SUVmean); −12.2%, lung (SUVmean); −18.1%, bone lesions (SUVmean); −13.3%, bone lesions (SUVmax); −8.2%, soft-tissue lesions (SUVmean); and −7.3%, soft-tissue lesions (SUVmax). The mean relative differences between PETMR and PETCTSeg were as follows: −19.0%, bone (SUVmean); −3.5%, liver (SUVmean); −3.3%, lung (SUVmean); −19.3%, bone lesions (SUVmean); −17.5%, bone lesions (SUVmax); −5.5%, soft-tissue lesions (SUVmean); and −4.4%, soft-tissue lesions (SUVmax). The differences of SUV between PETMR and PETCT were larger than those between PETMR and PETCTSeg, in both soft tissue and soft-tissue lesions (P<0.001), but not in bone or bone lesions. In conclusion, MRAC in the newly released PET/MR system is accurate in most tissues, with SUV deviations being generally less than 10%, compared to PET/CT. In bone, however, underestimations can be substantial, which may be partially attributed to segmentation of the MR-based μ-maps.

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An Investigation of the Required MR Bone Attenuation Correction for Quantitative Whole-Body PET/MR Imaging Using Clinical NaF PET/CT Studies

International Journal of Medical Physics Clinical Engineering and Radiation Oncology ◽

10.4236/ijmpcero.2018.73023 ◽

2018 ◽

Vol 07 (03) ◽

pp. 273-295

Author(s):

Hua A. Ai ◽

Osama Mawlawi ◽

R. Jason Stafford ◽

Jim Bankson ◽

Yiping Shao ◽

...

Keyword(s):

Mr Imaging ◽

Attenuation Correction ◽

Whole Body ◽

Pet Ct ◽

Ct Studies

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18f-Fludeoxyglucose and 11c-Methionine PET/CT Scans in Patients with Multiple Myeloma Following Autologous Stem-Cell Transplantation (auto-HSCT)

Blood ◽

10.1182/blood-2018-99-112886 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 3433-3433

Author(s):

Maxim V. Solovev ◽

Larisa P. Mendeleeva ◽

Maiia V. Firsova ◽

Irakly P. Aslanidi ◽

Olga V. Mukhortova ◽

...

Keyword(s):

Multiple Myeloma ◽

Ct Scan ◽

Mean Value ◽

Disease Stage ◽

Ct Scans ◽

Pet Ct ◽

Abnormal Accumulation ◽

The Mean ◽

18F Fdg ◽

Pet Ct Scan

Abstract Introduction: Over the past years, possible use of PET/CT scan for diagnosis of multiple myeloma has been intensively studied; there is evidence that the use of 11C-methionine instead of 18F-fludeoxyglucose (18F-FDG) in multiple myeloma patients promotes the decrease in false negative PET/CT scan results. Comparative evaluation of the efficacy of detection of residual tumor lesions in MM patients following auto-HSCT using different radiopharmaceuticals for PET/CT scans is an important task. Goal of the study: To compare the results of tumor imaging using 18F-FDG and 11C-methionine PET/CT scan in MM patients following auto-HSCT. Materials and methods: Over the period from December 2016 to March 2018, 27 MM patients (8 males and 19 females) aged 32 to 64 years (median=57) were enrolled into a prospective study designed to evaluate efficacy of detection of tumor lesions using PET/CT scan technique. The disease stage according to the International Staging System (ISS) was I, II and III in 10, 7 and 10 patients, respectively. The onset of myeloma cast nephropathy was diagnosed in 4 (18%) patients, intraosseous plasmacytomas were found in 18 (67%) patients, extramedullary brain lesions was observed in 1 case. All patients received induction therapy with bortezomib; immunomodulatory drugs were used in 6 cases. Mobilization of CD34+ blood cells was carried out according to the regimen Cyclophosphamide 4 g/m2 + G-CSF. While using high-dose melphalan (200 mg/m2), a single (n=21) or tandem (n=6) auto-HSCT was conducted. On Day 100 after the initiation of auto-HSCT, PET/CT scan with two radiopharmaceuticals - 18F-FDG and 11C-methionine was performed. The obtained images were evaluated by visual inspection and semi-quantitative analysis. There were foci of increased accumulation of each agent (areas of hypermetabolism) not related to its physiological distribution. For each of the radiopharmaceuticals, the standardized uptake value (SUVmax) in the lesions was estimated automatically. The results of PET/CT and anti-tumor response achieved following auto-HSCT were compared according to the criteria developed by the International Myeloma Working Group. Statistical analysis was performed using Statistica 10 software. The quantitative values were expressed as the mean value ± standard deviation or the median value. Comparison of the respective measurements was carried out using the Student's t-test. To compare frequencies of data between independent groups, the Fisher's exact test or chi-square test were used. Results: Following auto-HSCT, 60% of patients demonstrated complete remission (CR). When using 18F-FDG, abnormal accumulation was observed in 37% (n=10) cases, PET-negative results were obtained in 63% (n=17) patients. Following administration of 11C-methionine, hypermetabolic foci were revealed in 67% (n=18) cases, lack of accumulation was observed in 33% (n=9) patients (Fig. 1). When using 11C-methionine, MM patients were found 1.8 times more likely to demonstrate abnormal accumulation of the radiopharmaceutical (p<0.02). Following administration of 18F-FDG, PET/CT scans of MM patients demonstrated 1 to 6 (mean value = 1±1.5) foci of abnormal fixation, while the use of 11C-methionine allowed revealing 1 to 12 (mean value=2.5±3.1) lesions. When using 11C-methionine, the number of lesions demonstrating abnormal accumulation of the radiopharmaceutical was 2.5 times that of 18F-FDG (p<0.05). Mean value of SUVmax for 18F-FDG was 1.02±1.6, while the mean value of SUVmax for 11C-methionine was 2.29±2.04. When using 11C-methionine, the values of SUVmax significantly exceeded the respective parameter associated with the use of 18F-FDG (p=0.02). Discussion: The results of our study have demonstrated a significant role of 11C-methionine for detection of tumor lesions in MM patients following auto-HSCT. The use of 11C-methionine PET/CT scan allows improving the accuracy of diagnosis of tumor lesions in MM patients following auto-HSCT. Disclosures No relevant conflicts of interest to declare.

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Impact of the Noise Penalty Factor on Quantification in Bayesian Penalized Likelihood (Q.Clear) Reconstructions of 68Ga-PSMA PET/CT Scans

Diagnostics ◽

10.3390/diagnostics11050847 ◽

2021 ◽

Vol 11 (5) ◽

pp. 847

Author(s):

Sjoerd Rijnsdorp ◽

Mark J. Roef ◽

Albert J. Arends

Keyword(s):

Penalized Likelihood ◽

Ct Scans ◽

Ct Scanner ◽

Scan Time ◽

Standardized Uptake Values ◽

Positron Emission ◽

Penalty Factor ◽

Psma Pet ◽

Pet Ct ◽

Voxel Grid

Functional imaging with 68Ga prostate-specific membrane antigen (PSMA) and positron emission tomography (PET) can fulfill an important role in treatment selection and adjustment in prostate cancer. This article focusses on quantitative assessment of 68Ga-PSMA-PET. The effect of various parameters on standardized uptake values (SUVs) is explored, and an optimal Bayesian penalized likelihood (BPL) reconstruction is suggested. PET acquisitions of two phantoms consisting of a background compartment and spheres with diameter 4 mm to 37 mm, both filled with solutions of 68Ga in water, were performed with a GE Discovery 710 PET/CT scanner. Recovery coefficients (RCs) in multiple reconstructions with varying noise penalty factors and acquisition times were determined and analyzed. Apparent recovery coefficients of spheres with a diameter smaller than 17 mm were significantly lower than those of spheres with a diameter of 17 mm and bigger (p < 0.001) for a tumor-to-background (T/B) ratio of 10:1 and a scan time of 10 min per bed position. With a T/B ratio of 10:1, the four largest spheres exhibit significantly higher RCs than those with a T/B ratio of 20:1 (p < 0.0001). For spheres with a diameter of 8 mm and less, alignment with the voxel grid potentially affects the RC. Evaluation of PET/CT scans using (semi-)quantitative measures such as SUVs should be performed with great caution, as SUVs are influenced by scanning and reconstruction parameters. Based on the evaluation of multiple reconstructions with different β of phantom scans, an intermediate β (600) is suggested as the optimal value for the reconstruction of clinical 68Ga-PSMA PET/CT scans, considering that both detectability and reproducibility are relevant.

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PET/CT Scan as a Surrogate for Treatment Outcomes in Pulmonary Sarcoidosis

10.21203/rs.3.rs-39748/v1 ◽

2020 ◽

Author(s):

Nidah Shabbir Khakoo ◽

Safayeth Jabeen Isma ◽

Mehdi Mirsaeidi

Keyword(s):

Treatment Outcomes ◽

Pulmonary Sarcoidosis ◽

Ct Scans ◽

Serum Angiotensin Converting Enzyme ◽

Reactive Protein ◽

Multiple Organs ◽

Pet Ct ◽

The Mean ◽

One Year ◽

The University

Abstract Background: One of the challenges in treating sarcoidosis is that there is currently no reliable modality to measure disease activity and prognosis. This study was conducted to determine if PET/CT scans could be used to evaluate clinical response to sarcoidosis treatment. Methods: In a retrospective cohort study, subjects with symptomatic pulmonary sarcoidosis followed by the University of Miami Sarcoidosis program from 2015 through 2018 were assessed. Inclusion criteria were subjects ≥18 years who had histologically-confirmed pulmonary sarcoidosis for ≥2 years. Subjects that had PET/CT scans completed prior to starting treatment and approximately one year later were enrolled. Demographics, circulatory blood biomarkers, subjective symptoms, and medications were recorded at baseline (T0) and a year later (T1). Results: Ten subjects with symptomatic pulmonary sarcoidosis were enrolled. All subjects had at least one organ affected by sarcoidosis and a highest of five organs involved (mean 2.75, SD 1.21). Mean serum angiotensin-converting enzyme (ACE) level was 56.0 U/L (SD 43.08), mean lysozyme was 7.78 µg/mL (SD 3.78), and mean C-reactive protein (CRP) was 0.73 mg/dL (SD 0.85) at T0. Further, mean number of positive lesions was 4.27 (SD 2.65) and mean highest SUV was 5.59 (SD 3.59), with a highest of 14.5 at T0. After one year of therapy, a significant improvement in measured outcomes was noted. Dyspnea was absent in all subjects at T1 and only 1 (10%) reported cough at T1. The mean ACE was 42.17 U/L (SD 20.24), mean lysozyme was 6.24 µg/mL (SD 0.80), and mean CRP was 1.67 mg/dL (SD 1.60) at T1. Furthermore, five (50%) subjects were receiving a reduced dose of their respective medication at T1. In terms of PET/CT findings, the mean number of positive lesions decreased at T1 to 1.73 (SD 2.87) and the mean highest SUV decreased to 2.18 (SD 3.3). Conclusion: PET/CT scans can be used as a surrogate modality to help guide treatments in those subjects affected by sarcoidosis, as shown by significant reductions in the involvement of multiple organs. Further studies with larger sample sizes are necessary to explore the potential PET/CT scans have to influence treatment outcomes in sarcoidosis.

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18F-FDOPA PET/CT Uptake Parameters Correlate with Catecholamine Secretion in Human Pheochromocytomas

Neuroendocrinology ◽

10.1159/000491578 ◽

2018 ◽

Vol 107 (3) ◽

pp. 228-236 ◽

Cited By ~ 2

Author(s):

Sophie Moog ◽

Sébastien Houy ◽

Elodie Chevalier ◽

Stéphane Ory ◽

Georges Weryha ◽

...

Keyword(s):

Tumor Volume ◽

Primary Cultures ◽

Nuclear Imaging ◽

Real Time Measurement ◽

Standardized Uptake Values ◽

Positron Emission ◽

Pet Ct ◽

Single Center Study ◽

The Mean ◽

First Time

Background: 18F-FDOPA positron emission tomography/computed tomography (PET/CT) is a sensitive nuclear imaging technology for the diagnosis of pheochromocytomas (PHEO). However, its utility in determining predictive factors for the secretion of catecholamines remains poorly studied. Methods: Thirty-nine histologically confirmed PHEO were included in this retrospective single-center study. Patients underwent 18F-FDOPA PET/CT before surgery, with an evaluation of several uptake parameters (standardized uptake values [SUVmax and SUVmean] and the metabolic burden [MB] calculated as follows: MB = SUVmean × tumor volume) and measurement of plasma and/or urinary metanephrine (MN), normetanephrine (NM), and chromogranin A. Thirty-five patients were screened for germline mutations in the RET, SDHx, and VHL genes. Once resected, primary cultures of 5 PHEO were used for real-time measurement of catecholamine release by carbon fiber amperometry. Results: The MB of the PHEO positively correlated with 24-h urinary excretion of NM (r = 0.64, p < 0.0001), MN (r = 0.49, p = 0.002), combined MN and NM (r = 0.75, p < 0.0001), and eventually plasma free levels of NM (r = 0.55, p = 0.006). In the mutated patients (3 SDHD, 2 SDHB, 3 NF1, 1 VHL, and 3 RET), a similar correlation was observed between MB and 24-h urinary combined MN and NM (r = 0.86, p = 0.0012). For the first time, we demonstrate a positive correlation between the PHEO-to-liver SUVmax ratio and the mean number of secretory granule fusion events of the corresponding PHEO cells revealed by amperometric spikes (p = 0.01). Conclusion: While the 18F-FDOPA PET/CT MB of PHEO strongly correlates with the concentration of MN, amperometric recordings suggest that 18F-FDOPA uptake could be enhanced by overactivity of catecholamine exocytosis.

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Risk of ionizing radiation exposure from CT scans in the Neuro ICU - a patient safety blind spot?

F1000Research ◽

10.12688/f1000research.9680.1 ◽

2016 ◽

Vol 5 ◽

pp. 2489

Author(s):

Avinash B. Kumar ◽

Roy C. Neeley

Keyword(s):

Mechanical Ventilation ◽

Patient Safety ◽

Ionizing Radiation ◽

Radiation Exposure ◽

Medical Center ◽

Academic Medical Center ◽

Ct Scans ◽

Academic Medical ◽

The Mean ◽

Ct Studies

Introduction: The exposure to ionizing radiation has increased significantly with the wide availability of computed tomography (CT) scans and portable imaging technology. We examine the pattern of use of inpatient diagnostic imaging and radiation exposure in the neuro-intensive care unit (Neuro ICU, N-ICU) patient population at a large academic medical center. Methods: We retrospectively evaluated all patients admitted to the Neuro ICU at our academic medical center from January 1 to December 31, 2013. The number and type of CT studies was collected, and the corresponding estimated radiation dose was calculated. We limited the evaluation to CT scans, which accounts for the majority of radiation exposure. Data were electronically collected and cross-referenced to the patients’ electronic medical records (EMR) and radiology records. Radiation dose estimates were calculated based on published reference values and conversion factors (CT head (2mSv)), CT angiography of the head and neck (7-10 mSv), Ct Chest /Abd/pelvis ( 10 mSv), CT cerebral perfusion analysis (3.3 mSv). Results: In the calendar year 2013, we had a total of 2353 admission encounters (F=1078). The mean age on admission was 56.55Y ± 16.7. The mean length of ICU stay was 6.3 days. Mechanical ventilation was initiated on 420 patients with a mean length on mechanical ventilation 5.09 days. 2028 CT scans were completed of which approximately 60% were head CT without contrast (n=1209). 379 patients had multiple CT studies. The mean number of studies was 3.8 ± 2. The number of patients with more thanthree3 studies during their ICU stay was 159. The maximum number of studies on a single patient was 21. Conclusion: Patients in the Neuro ICU are at a risk for significant exposure to ionizing radiation. Radiation exposure must be factored into the culture of quality and patient safety in the ICU.

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