Influence of cold walls on PET image quantification and volume segmentation: a phantom study.

Abstract:

PURPOSE:Commercially available fillable plastic inserts used in positron emission tomography phantoms usually have thick plastic walls, separating their content from the background activity. These "cold" walls can modify the intensity values of neighboring active regions due to the partial volume effect, resulting in errors in the estimation of standardized uptake values. Numerous papers suggest that this is an issue for phantom work simulating tumor tissue, quality control, and calibration work. This study aims to investigate the influence of the cold plastic wall thickness on the quantification of 18F-fluorodeoxyglucose on the image activity recovery and on the performance of advanced automatic segmentation algorithms for the delineation of active regions delimited by plastic walls. METHODS:A commercial set of six spheres of different diameters was replicated using a manufacturing technique which achieves a reduction in plastic walls thickness of up to 90%, while keeping the same internal volume. Both sets of thin- and thick-wall inserts were imaged simultaneously in a custom phantom for six different tumor-to-background ratios. Intensity values were compared in terms of mean and maximum standardized uptake values (SUVs) in the spheres and mean SUV of the hottest 1 ml region (SUVmax, SUVmean, and SUVpeak). The recovery coefficient (RC) was also derived for each sphere. The results were compared against the values predicted by a theoretical model of the PET-intensity profiles for the same tumor-to-background ratios (TBRs), sphere sizes, and wall thicknesses. In addition, ten automatic segmentation methods, written in house, were applied to both thin- and thick-wall inserts. The contours obtained were compared to computed tomography derived gold standard ("ground truth"), using five different accuracy metrics. RESULTS:The authors' results showed that thin-wall inserts achieved significantly higher SUVmean, SUVmax, and RC values (up to 25%, 16%, and 25% higher, respectively) compared to thick-wall inserts, which was in agreement with the theory. This effect decreased with increasing sphere size and TBR, and resulted in substantial (>5%) differences between thin- and thick-wall inserts for spheres up to 30 mm diameter and TBR up to 4. Thinner plastic walls were also shown to significantly improve the delineation accuracy for the majority of the segmentation methods tested, by increasing the proportion of lesion voxels detected, although the errors in image quantification remained non-negligible. CONCLUSIONS:This study quantified the significant effect of a 90% reduction in the thickness of insert walls on SUV quantification and PET-based boundary detection. Mean SUVs inside the inserts and recovery coefficients were particularly affected by the presence of thick cold walls, as predicted by a theoretical approach. The accuracy of some delineation algorithms was also significantly improved by the introduction of thin wall inserts instead of thick wall inserts. This study demonstrates the risk of errors deriving from the use of cold wall inserts to assess and compare the performance of PET segmentation methods.

journal_name

Med Phys

journal_title

Medical physics

authors

Berthon B,Marshall C,Edwards A,Evans M,Spezi E

doi

10.1118/1.4813302

subject

Has Abstract

pub_date

2013-08-01 00:00:00

pages

082505

issue

8

eissn

0094-2405

issn

2473-4209

journal_volume

40

pub_type

杂志文章
  • Image reconstruction algorithm for a rotating slat collimator.

    abstract::A slat collimator in single photon emission computed tomography consists of a set of parallel slats. As the collimator spins, the detector measures a one-dimensional projection data set. A complete data set can be obtained by rotating the detector/collimator assembly around the object (patient) while the collimator sp...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.1485057

    authors: Zeng GL,Gagnon D,Matthews CG,Kolthammer JA,Radachy JD,Hawkins WG

    更新日期:2002-07-01 00:00:00

  • Automated registration of large deformations for adaptive radiation therapy of prostate cancer.

    abstract::Available deformable registration methods are often inaccurate over large organ variation encountered, for example, in the rectum and bladder. The authors developed a novel approach to accurately and effectively register large deformations in the prostate region for adaptive radiation therapy. A software tool combinin...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3095777

    authors: Godley A,Ahunbay E,Peng C,Li XA

    更新日期:2009-04-01 00:00:00

  • Technical Note: On maximizing Cherenkov emissions from medical linear accelerators.

    abstract:PURPOSE:Cherenkov light during MV radiotherapy has recently found imaging and therapeutic applications but is challenged by relatively low fluence. Our purpose is to investigate the feasibility of increasing Cherenkov light production during MV radiotherapy by increasing photon energy and applying specialized beam-hard...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1002/mp.12927

    authors: Shrock Z,Yoon SW,Gunasingha R,Oldham M,Adamson J

    更新日期:2018-07-01 00:00:00

  • SU-E-T-459: Radiobiological Evaluation of Implant Duration and Radionuclide Selection for COMS Eye Plaque Brachytherapy Using an Objective Function.

    abstract:PURPOSE:The biologically effective dose (BED) of temporary brachytherapy treatments is a function of both chosen radionuclide (R) and implant duration (T). This study endeavored to evaluate BED delivered to the tumor volume and surrounding ocular structures as a function of plaque position (P), prescription dose, R, an...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4735548

    authors: Gagne N,Rivard M

    更新日期:2012-06-01 00:00:00

  • Monte Carlo and experimental dosimetry of an 1251 brachytherapy seed.

    abstract::We have performed a comprehensive dosimetric characterization of the Oncura model 6711 125I seed using both experimental [LiF thermoluminscent dosimetry (TLD)] and theoretical (Monte Carlo photon transport) methods. In addition to determining the dosimetric parameters of the 6711, this report quantified: (1) the angul...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.2388158

    authors: Dolan J,Lia Z,Williamson JF

    更新日期:2006-12-01 00:00:00

  • Cascaded-systems analyses and the detective quantum efficiency of single-Z x-ray detectors including photoelectric, coherent and incoherent interactions.

    abstract:PURPOSE:Theoretical models of the detective quantum efficiency (DQE) of x-ray detectors are an important step in new detector development by providing an understanding of performance limitations and benchmarks. Previous cascaded-systems analysis (CSA) models accounted for photoelectric interactions only. This paper des...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4794495

    authors: Yun S,Tanguay J,Kim HK,Cunningham IA

    更新日期:2013-04-01 00:00:00

  • Automatic treatment planning based on three-dimensional dose distribution predicted from deep learning technique.

    abstract:PURPOSE:To develop an automated treatment planning strategy for external beam intensity-modulated radiation therapy (IMRT), including a deep learning-based three-dimensional (3D) dose prediction and a dose distribution-based plan generation algorithm. METHODS AND MATERIALS:A residual neural network-based deep learning...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1002/mp.13271

    authors: Fan J,Wang J,Chen Z,Hu C,Zhang Z,Hu W

    更新日期:2019-01-01 00:00:00

  • SU-E-I-103: Detecting Anomalous Pixels and Correlated Artifacts in Digital Detectors from Flat-Field Images.

    abstract:PURPOSE:Anomalous pixels may be defined as those pixels whose exposure response relationship is deviant from the typical, expected or calibrated response. A group of anomalous pixels may Result in visible correlated artifacts. Here we demonstrate an approach to identify anomalous pixels and correlated artifacts using f...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4734820

    authors: Dave J,Gingold E,Yorkston J,Bercha I,Goldman L,Walz-Flannigan A,Willis C

    更新日期:2012-06-01 00:00:00

  • SU-E-T-619: A Network-Flow Solution Approach to VMAT Treatment Plan Optimization.

    abstract:PURPOSE:To add mathematical rigor to the merging phase of the recently published two-stage VMAT optimization method called VMERGE. Using an exact merging method, we are able to better characterize the tradeoff between delivery efficiency and dose quality. METHODS:VMERGE begins with an IMRT plan that uses 180 equi-spac...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4735709

    authors: Salari E,Craft D

    更新日期:2012-06-01 00:00:00

  • Advanced statistical techniques applied to comprehensive FTIR spectra on human colonic tissues.

    abstract:PURPOSE:Colon cancer is a major public health problem due to its high disease rate and death toll worldwide. The use of FTIR microscopy in the field of cancer diagnosis has become attractive over the past 20 years. In the present study, the authors investigated the potential of FTIR microscopy to define spectral change...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3298013

    authors: Zwielly A,Mordechai S,Sinielnikov I,Salman A,Bogomolny E,Argov S

    更新日期:2010-03-01 00:00:00

  • SU-E-T-126: Non-Reference Condition Correction Factor KNR of Typical Radiation Detectors for the Dosimetry of High-Energy Photons.

    abstract:PURPOSE:To correct for the deviations of the detector response when typical radiation detectors are used under non-reference conditions, factor kNR was calculated from the known energy dependence of the detector response at photon energies from 10 keV upwards and from clinical photon spectra within a large water phanto...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4735184

    authors: Chofor N,Poppe B,Harder D

    更新日期:2012-06-01 00:00:00

  • Eddy current disruption: effect on nuclear magnetic resonance coil impedance and power loss.

    abstract::We present a theoretical development and experimental verification of a description of power loss and sample resistance for a lossy sample in a nuclear magnetic resonance radio frequency coil for a sample geometry where the eddy current streamlines are disrupted from their usually assumed circular paths. Specifically ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.596336

    authors: Harpen MD

    更新日期:1989-09-01 00:00:00

  • Technical Note: Introduction of variance component analysis to setup error analysis in radiotherapy.

    abstract:PURPOSE:The purpose of this technical note is to introduce variance component analysis to the estimation of systematic and random components in setup error of radiotherapy. METHODS:Balanced data according to the one-factor random effect model were assumed. RESULTS:Analysis-of-variance (anova)-based computation was ap...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4961397

    authors: Matsuo Y,Nakamura M,Mizowaki T,Hiraoka M

    更新日期:2016-09-01 00:00:00

  • Comparison of x ray computed tomography number to proton relative linear stopping power conversion functions using a standard phantom.

    abstract:PURPOSE:Adequate evaluation of the results from multi-institutional trials involving light ion beam treatments requires consideration of the planning margins applied to both targets and organs at risk. A major uncertainty that affects the size of these margins is the conversion of x ray computed tomography numbers (XCT...

    journal_title:Medical physics

    pub_type: 杂志文章,多中心研究

    doi:10.1118/1.4870956

    authors: Moyers MF

    更新日期:2014-06-01 00:00:00

  • The accuracy and reproducibility of a global method to correct for geometric image distortion in the x-ray imaging chain.

    abstract::A method to correct for geometric image distortion in the x-ray imaging chain, so-called dewarping, has been developed. A global two-dimensional polynomial model of which the degree is optimized is used. The performance of the method has been tested in a number of experiments using images of a plate with a 1 cm spaced...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.598101

    authors: Gronenschild E

    更新日期:1997-12-01 00:00:00

  • Calculation of the biological effective dose for piecewise defined dose-rate fits.

    abstract::An algorithmic solution to the biological effective dose (BED) calculation from the Lea-Catcheside formula for a piecewise defined function is presented. Data from patients treated for metastatic thyroid cancer were used to illustrate the solution. The Lea-Catcheside formula for the G-factor of the BED is integrated n...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3070587

    authors: Hobbs RF,Sgouros G

    更新日期:2009-03-01 00:00:00

  • Characteristics of sensitometric curves of radiographic films.

    abstract::A new type of radiographic film, EDR (extended dose range) film, has been recently become available for film dosimetry. It is particularly attractive for composite isodose verification of intensity modulated radiation therapy because of its low sensitivity relative to the more common Kodak XV film. For XV film, the re...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.1568979

    authors: Zhu XR,Yoo S,Jursinic PA,Grimm DF,Lopez F,Rownd JJ,Gillin MT

    更新日期:2003-05-01 00:00:00

  • Theoretical investigation of the count rate capabilities of in-pixel amplifiers for photon counting arrays based on polycrystalline silicon TFTs.

    abstract:PURPOSE:Photon counting arrays (PCAs), capable of measuring the spectral information of individual x-ray photons and recording that information digitally, provide a number of advantages compared to conventional, energy-integrating active matrix flat-panel imagers - such as reducing the undesirable effects of electronic...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1002/mp.13128

    authors: Liang AK,Koniczek M,Antonuk LE,El-Mohri Y,Zhao Q

    更新日期:2018-10-01 00:00:00

  • Compensator quality control with an amorphous silicon EPID.

    abstract::The calibration and quality control of compensators is conventionally performed with an ion chamber in a water-equivalent phantom. In our center, the compensator factor and four off-axis fluence ratios are measured to verify the central axis beam modulation and orientation of the compensator. Here we report the invest...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.1584040

    authors: Menon GV,Sloboda RS

    更新日期:2003-07-01 00:00:00

  • Model-based optoacoustic inversion with arbitrary-shape detectors.

    abstract:PURPOSE:Optoacoustic imaging enables mapping the optical absorption of biological tissue using optical excitation and acoustic detection. Although most image-reconstruction algorithms are based on the assumption of a detector with an isotropic sensitivity, the geometry of the detector often leads to a response with spa...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3589141

    authors: Rosenthal A,Ntziachristos V,Razansky D

    更新日期:2011-07-01 00:00:00

  • The role of humidity and other correction factors in the AAPM TG-21 dosimetry protocol.

    abstract::A detailed derivation is presented of the formulas required to determine Ngas and Dmed in the AAPM TG-21 dosimetry protocol. This protocol specifies how to determine the absorbed dose in an electron or photon beam when using exposure or absorbed dose calibrated ion chambers. It is shown that the expression given in TG...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.596292

    authors: Rogers DW,Ross CK

    更新日期:1988-01-01 00:00:00

  • A comparison of the physical imaging properties of Fuji ST-V, ST-VA, and ST-VN computed radiography image plates.

    abstract::The physical imaging performance of ST-V, ST-VA, and ST-VN computed radiography image plates, read with a Philips AC3 acquisition system, was investigated at 70 kVp with 0.5 mm of copper beam filtration for four different entrance air kerma values: 0.5, 2.6, 26, and 260 micro Gy. Measurements included characteristic r...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.598412

    authors: Kengyelics SM,Davies AG,Cowen AR

    更新日期:1998-11-01 00:00:00

  • A scintillator-based approach to monitor secondary neutron production during proton therapy.

    abstract:PURPOSE:The primary objective of this work is to measure the secondary neutron field produced by an uncollimated proton pencil beam impinging on different tissue-equivalent phantom materials using organic scintillation detectors. Additionally, the Monte Carlo code mcnpx-PoliMi was used to simulate the detector response...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4963813

    authors: Clarke SD,Pryser E,Wieger BM,Pozzi SA,Haelg RA,Bashkirov VA,Schulte RW

    更新日期:2016-11-01 00:00:00

  • Mineralization in calcified plaque is like that of cortical bone--further evidence from ultrashort echo time (UTE) magnetic resonance imaging of carotid plaque calcification and cortical bone.

    abstract:PURPOSE:This study aims to investigate carotid plaque calcification (CPC) using two-dimensional (2D) and 3D ultrashort echo time (UTE) magnetic resonance imaging (MRI) sequences and compare T1, T2*, water concentration, and bone mineral density (BMD) of CPC with those of cortical bone. METHODS:Twelve carotid plaque sp...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4819944

    authors: Du J,Peterson M,Kansal N,Bydder GM,Kahn A

    更新日期:2013-10-01 00:00:00

  • A Dirichlet process mixture model for automatic (18)F-FDG PET image segmentation: Validation study on phantoms and on lung and esophageal lesions.

    abstract:PURPOSE:The aim of this study was to implement a Dirichlet process mixture (DPM) model for automatic tumor edge identification on (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) images by optimizing the parameters on which the algorithm depends, to validate it experimentally, and to test its robus...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4947123

    authors: Giri MG,Cavedon C,Mazzarotto R,Ferdeghini M

    更新日期:2016-05-01 00:00:00

  • Innovative methodology for intercomparison of radionuclide calibrators using short half-life in situ prepared radioactive sources.

    abstract:PURPOSE:An original radionuclide calibrator method for activity determination is presented. The method could be used for intercomparison surveys for short half-life radioactive sources used in Nuclear Medicine, such as(99m)Tc or most positron emission tomography radiopharmaceuticals. METHODS:By evaluation of the resul...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4884035

    authors: Oliveira PA,Santos JA

    更新日期:2014-07-01 00:00:00

  • Fast IMRT with narrow high energy scanned photon beams.

    abstract:PURPOSE:Since the first publications on intensity modulated radiation therapy (IMRT) in the early 1980s almost all efforts have been focused on fairly time consuming dynamic or segmental multileaf collimation. With narrow fast scanned photon beams, the flexibility and accuracy in beam shaping increases, not least in co...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3615059

    authors: Andreassen B,Strååt SJ,Holmberg R,Näfstadius P,Brahme A

    更新日期:2011-08-01 00:00:00

  • A novel computer-aided lung nodule detection system for CT images.

    abstract:PURPOSE:The paper presents a complete computer-aided detection (CAD) system for the detection of lung nodules in computed tomography images. A new mixed feature selection and classification methodology is applied for the first time on a difficult medical image analysis problem. METHODS:The CAD system was trained and t...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3633941

    authors: Tan M,Deklerck R,Jansen B,Bister M,Cornelis J

    更新日期:2011-10-01 00:00:00

  • Performance characteristics of an orthovoltage x-ray therapy machine.

    abstract::Performance characteristics sufficient to provide physical data base specific to the Siemen's Stabilipan 2 orthovoltage x-ray therapy machine are presented. Operating conditions covering the working range of the unit from 100 to 300 kVp are selected. Beam quality, output, the central axis depth dose, relative output f...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.596016

    authors: Niroomand-Rad A,Gillin MT,Lopez F,Grimm DF

    更新日期:1987-09-01 00:00:00

  • AAPM Task Group 329: Reference dose specification for dose calculations: Dose-to-water or dose-to-muscle?

    abstract::Linac calibration is done in water, but patients are comprised primarily of soft tissue. Conceptually, and specified in NRG/RTOG trials, dose should be reported as dose-to-muscle to describe the dose to the patient. Historically, the dose-to-water of the linac calibration was often converted to dose-to-muscle for pati...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1002/mp.13995

    authors: Kry SF,Feygelman V,Balter P,Knöös T,Charlie Ma CM,Snyder M,Tonner B,Vassiliev ON

    更新日期:2020-03-01 00:00:00