scholarly journals Methodology and hardware for assessing the quantitative characteristics of pet images in the study of dynamic objects

2021 ◽  
Vol 66 (4) ◽  
pp. 496-504
Author(s):  
E. V. Emelyanenko ◽  
M. N. Piatkevich ◽  
I. G. Tarutin
Keyword(s):  
Single Photon ◽  
Photon Emission ◽  
Reconstruction Algorithm ◽  
Recovery Coefficient ◽  
Pet Ct ◽  
Quantitative Characteristics ◽  
Dynamic Objects ◽  
The Difference ◽  
Computed Tomograph ◽  
Phantom Design

The description of the original phantom design for assessing the quantitative characteristics of PET images in the study of dynamic objects is given. The phantom movement is controlled by the breath synchronization system, which records the phantom movement amplitude and the duration of the movement cycle. A curve was obtained that simulates human breathing, the parameters of which (amplitude and period) correspond to those obtained in the study of the chest. The values of the ecovery coefficients and contrast are obtained taking into account the sizes of the spheres, as well as the static and dynamic types of movement of phantoms. An assessment of the discrepancy between the recovery coefficients and the contrast values for the spheres installed inside the phantom in the static and dynamic states has been made. With a decrease in the diameter (respectively, and volume) of the sphere, an increase in the difference in values (between the static and dynamic positions of the phantom) of the recovery coefficient is observed. The optimal values of the recovery coefficients obtained using the QClear reconstruction algorithm have been determined. Recommendations for the use of the developed device in the study of dynamic objects are described. It is advisable to use the installation presented in this work to control the quality of the qualitative and quantitative characteristics of diagnostic images obtained both on PET/CT scanners and during studies using SPECT/CT (single-photon emission tomograph combined with a computed tomograph).

Computerized Tomography (CT) Updates and Challenges in Diagnosis of Bone Metastases During Prostate Cancer

2020 ◽  
Vol 16 (5) ◽  
pp. 565-571
Author(s):  
Jinguo Zhang ◽  
Guanzhong Zhai ◽  
Bin Yang ◽  
Zhenhe Liu
Keyword(s):  
Prostate Cancer ◽  
Computed Tomography ◽  
Bone Metastases ◽  
Computerized Tomography ◽  
Single Photon ◽  
Photon Emission ◽  
Major Complication ◽  
Tracer Uptake ◽  
Emission Computed Tomography ◽  
Pet Ct

Prostate cancer is one of the most common cancers in men. This cancer is often associated with indolent tumors with little or no lethal potential. Some of the patients with aggressive prostate cancer have increased morbidity and early deaths. A major complication in advanced prostate cancer is bone metastasis that mainly results in pain, pathological fractures, and compression of spinal nerves. These complications in turn cause severe pain radiating to the extremities and possibly sensory as well as motor disturbances. Further, in patients with a high risk of metastases, treatment is limited to palliative therapies. Therefore, accurate methods for the detection of bone metastases are essential. Technical advances such as single-photon emission computed tomography/ computed tomography (SPECT/CT) have emerged after the introduction of bone scans. These advanced methods allow tomographic image acquisition and help in attenuation correction with anatomical co-localization. The use of positron emission tomography/CT (PET/CT) scanners is also on the rise. These PET scanners are mainly utilized with 18F-sodium-fluoride (NaF), in order to visualize the skeleton and possible changes. Moreover, NaF PET/CT is associated with higher tracer uptake, increased target-to-background ratio and has a higher spatial resolution. However, these newer technologies have not been adopted in clinical guidelines due to lack of definite evidence in support of their use in bone metastases cases. The present review article is focused on current perspectives and challenges of computerized tomography (CT) applications in cases of bone metastases during prostate cancer.

scholarly journals A Nordic survey of CT doses in hybrid PET/CT and SPECT/CT examinations

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Natalie A. Bebbington ◽  
Bryan T. Haddock ◽  
Henrik Bertilsson ◽  
Eero Hippeläinen ◽  
Ellen M. Husby ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Single Photon Emission ◽  
Positron Emission ◽  
Pet Ct ◽  
Clinical Purpose ◽  
Single Photon Emission Computed ◽  
Photon Emission Computed Tomography

Abstract Background Computed tomography (CT) scans are routinely performed in positron emission tomography (PET) and single photon emission computed tomography (SPECT) examinations globally, yet few surveys have been conducted to gather national diagnostic reference level (NDRL) data for CT radiation doses in positron emission tomography/computed tomography (PET/CT) and single photon emission computed tomography/computed tomography (SPECT/CT). In this first Nordic-wide study of CT doses in hybrid imaging, Nordic NDRL CT doses are suggested for PET/CT and SPECT/CT examinations specific to the clinical purpose of CT, and the scope for optimisation is evaluated. Data on hybrid imaging CT exposures and clinical purpose of CT were gathered for 5 PET/CT and 8 SPECT/CT examinations via designed booklet. For each included dataset for a given facility and scanner type, the computed tomography dose index by volume (CTDIvol) and dose length product (DLP) was interpolated for a 75-kg person (referred to as CTDIvol,75kg and DLP75kg). Suggested NDRL (75th percentile) and achievable doses (50th percentile) were determined for CTDIvol,75kg and DLP75kg according to clinical purpose of CT. Differences in maximum and minimum doses (derived for a 75-kg patient) between facilities were also calculated for each examination and clinical purpose. Results Data were processed from 83 scanners from 43 facilities. Data were sufficient to suggest Nordic NDRL CT doses for the following: PET/CT oncology (localisation/characterisation, 15 systems); infection/inflammation (localisation/characterisation, 13 systems); brain (attenuation correction (AC) only, 11 systems); cardiac PET/CT and SPECT/CT (AC only, 30 systems); SPECT/CT lung (localisation/characterisation, 12 systems); bone (localisation/characterisation, 30 systems); and parathyroid (localisation/characterisation, 13 systems). Great variations in dose were seen for all aforementioned examinations. Greatest differences in DLP75kg for each examination, specific to clinical purpose, were as follows: SPECT/CT lung AC only (27.4); PET/CT and SPECT/CT cardiac AC only (19.6); infection/inflammation AC only (18.1); PET/CT brain localisation/characterisation (16.8); SPECT/CT bone localisation/characterisation (10.0); PET/CT oncology AC only (9.0); and SPECT/CT parathyroid localisation/characterisation (7.8). Conclusions Suggested Nordic NDRL CT doses are presented according to clinical purpose of CT for PET/CT oncology, infection/inflammation, brain, PET/CT and SPECT/CT cardiac, and SPECT/CT lung, bone, and parathyroid. The large variation in doses suggests great scope for optimisation in all 8 examinations.

scholarly journals A geometric based preprocessing for weighted ray transforms with applications in SPECT

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Fedor Goncharov
Keyword(s):  
Single Photon ◽  
Photon Emission ◽  
Reconstruction Algorithm ◽  
Emission Computed Tomography ◽  
Radon Transforms ◽  
Single Photon Emission Computed ◽  
Ray Transforms ◽  
Straight Lines ◽  
The Impact ◽  
Photon Emission Computed Tomography

AbstractIn this work we investigate numerically the reconstruction approach proposed in [F. O. Goncharov and R. G. Novikov, An analog of Chang inversion formula for weighted Radon transforms in multidimensions, Eurasian J. Math. Comput. Appl. 4 2016, 2, 23–32] for weighted ray transforms (weighted Radon transforms along oriented straight lines) in 3D. In particular, the approach is based on a geometric reduction of the data modeled by weighted ray transforms to new data modeled by weighted Radon transforms along two-dimensional planes in 3D. Such reduction could be seen as a preprocessing procedure which could be further completed by any preferred reconstruction algorithm. In a series of numerical tests on modelized and real SPECT (single photon emission computed tomography) data we demonstrate that such procedure can significantly reduce the impact of noise on reconstructions.

scholarly journals Assessing Response UsingTc99m-MIBI Early after Interstitial Chemotherapy with Carmustine-Loaded Polymers in Glioblastoma Multiforme: Preliminary Results

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
D. Cecchin ◽  
I. Schiorlin ◽  
A. Della Puppa ◽  
G. Lombardi ◽  
P. Zucchetta ◽  
...  
Keyword(s):  
Glioblastoma Multiforme ◽  
Single Photon ◽  
Statistical Significance ◽  
Photon Emission ◽  
Single Photon Emission ◽  
Volume Of Interest ◽  
Effect Of Treatment ◽  
The Difference ◽  
Photon Emission Tomography

Introduction. Early signs of response after applying wafers of carmustine-loaded polymers (gliadel) are difficult to assess with imaging because of time-related imaging changes.Tc99m-sestamibi (MIBI) brain single-photon emission tomography (SPET) has reportedly been used to reveal areas of cellularity distinguishing recurrent neoplasm from radionecrosis. Our aim was to explore the role of MIBI SPET in assessing response soon after gliadel application in glioblastoma multiforme (GBM).Methods. We retrospectively reviewed the charts on 28 consecutive patients with a radiological diagnosis of GBM who underwent MIBI SPET/CT before surgery (with intracavitary gliadel placement in 17 patients), soon after surgery, and at 4 months. The area of uptake was selected using a volume of interest that was then mirrored contralaterally to obtain a semiquantitative ratio.Results. After adjusting for ratio at the baseline, the effect of treatment (gliadel versus non-gliadel) was not statistically significant. Soon after surgery, however, 100% of patients treated with gliadel had a decreased ratio, as opposed to 62.5% of patients in the non-gliadel groupP=0.0316. The difference between ratios of patients with radical versus partial resection reached statistical significance by a small marginP=0.0528.Conclusions. These data seem to suggest that the MIBI ratio could be a valuable tool for monitoring the effect of gliadel early after surgery.

scholarly journals Tc-99m HYNIC-TOC scintigraphy in dedifferentiated thyroid cancer

2019 ◽  
Vol 12 (4) ◽  
pp. e227910
Author(s):  
Kanhaiyalal Agrawal ◽  
P Sai Sradha Patro ◽  
C Preetam
Keyword(s):  
Thyroid Cancer ◽  
Single Photon ◽  
Somatostatin Receptor ◽  
Photon Emission ◽  
Peptide Receptor Radionuclide Therapy ◽  
Ct Imaging ◽  
Whole Body ◽  
Emission Computed Tomography ◽  
Serum Thyroglobulin ◽  
Pet Ct

There is literature evidence showing utility of somatostatin receptor (SSTR) positron emission tomography-CT (PET-CT) imaging in differentiated thyroid cancer with Thyroglobulin Elevated and Negative Iodine Scan (TENIS). These patients are less benefited with I-131 therapy and surgery remains only curable option if disease could be localised. If surgery is not feasible, other therapeutic options are not promising. However, if these patients show strongly positive SSTR imaging, then possibility of peptide receptor radionuclide therapy may be explored. As SSTR PET-CT imaging is expensive and not widely available, Technetium-99m (Tc-99m) hydrazinonicotinyl-Tyr3-octreotide (HYNIC-TOC), which is a Single photon emission computed tomography (SPECT) tracer, can be used. We are documenting a case of raised serum thyroglobulin antibody and negative I-131 whole body scan with disease recurrence localised on Tc-99m HYNIC-TOC scan.

scholarly journals EANM dosimetry committee series on standard operational procedures: a unified methodology for 99mTc-MAA pre- and 90Y peri-therapy dosimetry in liver radioembolization with 90Y microspheres

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Carlo Chiesa ◽  
Katarina Sjogreen-Gleisner ◽  
Stephan Walrand ◽  
Lidia Strigari ◽  
Glenn Flux ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Single Photon ◽  
Photon Emission ◽  
Absorbed Dose ◽  
Calibration Method ◽  
Emission Computed Tomography ◽  
Pet Ct ◽  
Improve Calculation ◽  
Voxel Dosimetry ◽  
Lung Shunt

AbstractThe aim of this standard operational procedure is to standardize the methodology employed for the evaluation of pre- and post-treatment absorbed dose calculations in 90Y microsphere liver radioembolization. Basic assumptions include the permanent trapping of microspheres, the local energy deposition method for voxel dosimetry, and the patient–relative calibration method for activity quantification.The identity of 99mTc albumin macro-aggregates (MAA) and 90Y microsphere biodistribution is also assumed. The large observed discrepancies in some patients between 99mTc-MAA predictions and actual 90Y microsphere distributions for lesions is discussed. Absorbed dose predictions to whole non-tumoural liver are considered more reliable and the basic predictors of toxicity. Treatment planning based on mean absorbed dose delivered to the whole non-tumoural liver is advised, except in super-selective treatments.Given the potential mismatch between MAA simulation and actual therapy, absorbed doses should be calculated both pre- and post-therapy. Distinct evaluation between target tumours and non-tumoural tissue, including lungs in cases of lung shunt, are vital for proper optimization of therapy. Dosimetry should be performed first according to a mean absorbed dose approach, with an optional, but important, voxel level evaluation. Fully corrected 99mTc-MAA Single Photon Emission Computed Tomography (SPECT)/computed tomography (CT) and 90Y TOF PET/CT are regarded as optimal acquisition methodologies, but, for institutes where SPECT/CT is not available, non-attenuation corrected 99mTc-MAA SPECT may be used. This offers better planning quality than non dosimetric methods such as Body Surface Area (BSA) or mono-compartmental dosimetry. Quantitative 90Y bremsstrahlung SPECT can be used if dedicated correction methods are available.The proposed methodology is feasible with standard camera software and a spreadsheet. Available commercial or free software can help facilitate the process and improve calculation time.

scholarly journals The Role of Imaging Techniques to Define a Peri-Prosthetic Hip and Knee Joint Infection: Multidisciplinary Consensus Statements

2020 ◽  
Vol 9 (8) ◽  
pp. 2548 ◽  
Author(s):  
Carlo Luca Romanò ◽  
Nicola Petrosillo ◽  
Giuseppe Argento ◽  
Luca Maria Sconfienza ◽  
Giorgio Treglia ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Single Photon ◽  
Imaging Techniques ◽  
Joint Infection ◽  
Photon Emission ◽  
Clinical Signs ◽  
Added Value ◽  
Emission Tomography ◽  
Pet Ct ◽  
Consensus Statements

Diagnosing a peri-prosthetic joint infection (PJI) remains challenging despite the availability of a variety of clinical signs, serum and synovial markers, imaging techniques, microbiological and histological findings. Moreover, the one and only true definition of PJI does not exist, which is reflected by the existence of at least six different definitions by independent societies. These definitions are composed of major and minor criteria for defining a PJI, but most of them do not include imaging techniques. This paper highlights the pros and cons of available imaging techniques—X-ray, ultrasound, computed tomography (CT), Magnetic Resonance Imaging (MRI), bone scintigraphy, white blood cell scintigraphy (WBC), anti-granulocyte scintigraphy, and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT), discusses the added value of hybrid camera systems—single photon emission tomography/computed tomography (SPECT/CT), PET/CT and PET/MRI and reports consensus answers on important clinical questions that were discussed during the Third European Congress on Inflammation/Infection Imaging in Rome, December 2019.

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