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Quantifying the quality of medical x-ray images. An evaluation based on normal anatomy for lumbar spine and chest radiography.

Tingberg, Anders LU (2000)
Abstract (Swedish)
Popular Abstract in Swedish

Det är sedan länge känt att för samma bildkvalitet kan patientstråldosen variera kraftigt mellan två olika sjukhus för en och samma röntgenundersökning. Det finns ett stort utrymme för sänkning av patientstråldosen utan att undersökningens kvalitet påverkas. Vid optimering inom röntgendiagnostik balanseras patientstråldos mot bildkvalitet. Optimeringen kräver att man har noggranna metoder för bestämning av patientstråldos och klinisk bildkvalitet. Det finns säkra metoder för bestämning av patientstråldos, men fortfarande finns det utrymme för att förbättra metoderna för att bestämma klinisk bildkvalitet. Tidigare metoder har byggt på detektion av patologiska strukturer. Dessa metoder är objektiva... (More)
Popular Abstract in Swedish

Det är sedan länge känt att för samma bildkvalitet kan patientstråldosen variera kraftigt mellan två olika sjukhus för en och samma röntgenundersökning. Det finns ett stort utrymme för sänkning av patientstråldosen utan att undersökningens kvalitet påverkas. Vid optimering inom röntgendiagnostik balanseras patientstråldos mot bildkvalitet. Optimeringen kräver att man har noggranna metoder för bestämning av patientstråldos och klinisk bildkvalitet. Det finns säkra metoder för bestämning av patientstråldos, men fortfarande finns det utrymme för att förbättra metoderna för att bestämma klinisk bildkvalitet. Tidigare metoder har byggt på detektion av patologiska strukturer. Dessa metoder är objektiva och väl beprövade men de är både besvärliga att förbereda och tidskrävande att genomföra.



Denna avhandling är inriktad mot att utveckla enkla, snabba och säkra metoder för att bestämma klinisk bildkvalitet i röntgenbilder av ländrygg och lungor. Metoderna bygger på visuell bedömning av synbarheten hos definierade anatomiska strukturer. Med hjälp av ett poängsystem kan man få en siffra på hur en bra röntgenbild är för diagnos. Vi har visat att med de nya enkla metoderna kan man få lika goda resultat som med de gamla metoderna, samtidigt som de nya metoderna är mycket enklare och snabbare att förbereda och genomföra. (Less)
Abstract
Optimisation in diagnostic radiology requires accurate methods for determination of patient absorbed dose and clinical image quality. Simple methods for evaluation of clinical image quality are at present scarce and this project aims at developing such methods. Two methods are used and further developed; fulfilment of image criteria (IC) and visual grading analysis (VGA). Clinical image quality descriptors are defined based on these two methods: image criteria score (ICS) and visual grading analysis score (VGAS), respectively. For both methods the basis is the Image Criteria of the “European Guidelines on Quality Criteria for Diagnostic Radiographic Images”. Both methods have proved to be useful for evaluation of clinical image quality.... (More)
Optimisation in diagnostic radiology requires accurate methods for determination of patient absorbed dose and clinical image quality. Simple methods for evaluation of clinical image quality are at present scarce and this project aims at developing such methods. Two methods are used and further developed; fulfilment of image criteria (IC) and visual grading analysis (VGA). Clinical image quality descriptors are defined based on these two methods: image criteria score (ICS) and visual grading analysis score (VGAS), respectively. For both methods the basis is the Image Criteria of the “European Guidelines on Quality Criteria for Diagnostic Radiographic Images”. Both methods have proved to be useful for evaluation of clinical image quality. The two methods complement each other: IC is an absolute method, which means that the quality of images of different patients and produced with different radiographic tech-niques can be compared with each other. The separating power of IC is, however, weaker than that of VGA. VGA is the best method for comparing images produced with different radiographic techniques and has strong separating power, but the re-sults are relative, since the quality of an image is compared to the quality of a refer-ence image.



The usefulness of the two methods has been verified by comparing the results from both of them with results from a generally accepted method for evaluation of clinical image quality, receiver operating characteristics (ROC). The results of the comparison between the two methods based on visibility of anatomical structures and the method based on detection of pathological structures (free-response forced error) indicate that the former two methods can be used for evaluation of clinical image quality as efficiently as the method based on ROC. More studies are, however, needed for us to be able to draw a general conclusion, including studies of other organs, using other radiographic techniques, etc.



The results of the experimental evaluation of clinical image quality are compared with physical quantities calculated with a theoretical model based on a voxel phantom, and correlations are found. The results demonstrate that the computer model can be a useful tool in planning further experimental studies. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Ass. Prof Persliden, Jan, Örebro Hospital
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Clinical physics, normal anatomy, free response forced error (FFE), receiver operating characteristics (ROC), visual grading analysis (VGA), European image criteria, quantifying clinical image quality, radiology, tomography, medical instrumentation, Klinisk fysiologi, radiologi, tomografi, medicinsk instrumentering
pages
54 pages
publisher
Department of Radiation Physics, Lund university
defense location
Malmö University Hospital (entrance no. 59, MFC Lilla aulan )
defense date
2000-06-09 09:15
external identifiers
  • other:ISRN: LUNDFD6/NFRF 00/1013 -- SE ISRN LUMEDW/MEMR 00/1013 -- SE
ISBN
91-628-4225-0
language
English
LU publication?
yes
id
e246cd1c-2512-428c-933e-49f061c1a9f2 (old id 40610)
date added to LUP
2007-07-31 12:43:00
date last changed
2016-09-19 08:45:05
@phdthesis{e246cd1c-2512-428c-933e-49f061c1a9f2,
  abstract     = {Optimisation in diagnostic radiology requires accurate methods for determination of patient absorbed dose and clinical image quality. Simple methods for evaluation of clinical image quality are at present scarce and this project aims at developing such methods. Two methods are used and further developed; fulfilment of image criteria (IC) and visual grading analysis (VGA). Clinical image quality descriptors are defined based on these two methods: image criteria score (ICS) and visual grading analysis score (VGAS), respectively. For both methods the basis is the Image Criteria of the “European Guidelines on Quality Criteria for Diagnostic Radiographic Images”. Both methods have proved to be useful for evaluation of clinical image quality. The two methods complement each other: IC is an absolute method, which means that the quality of images of different patients and produced with different radiographic tech-niques can be compared with each other. The separating power of IC is, however, weaker than that of VGA. VGA is the best method for comparing images produced with different radiographic techniques and has strong separating power, but the re-sults are relative, since the quality of an image is compared to the quality of a refer-ence image.<br/><br>
<br/><br>
The usefulness of the two methods has been verified by comparing the results from both of them with results from a generally accepted method for evaluation of clinical image quality, receiver operating characteristics (ROC). The results of the comparison between the two methods based on visibility of anatomical structures and the method based on detection of pathological structures (free-response forced error) indicate that the former two methods can be used for evaluation of clinical image quality as efficiently as the method based on ROC. More studies are, however, needed for us to be able to draw a general conclusion, including studies of other organs, using other radiographic techniques, etc.<br/><br>
<br/><br>
The results of the experimental evaluation of clinical image quality are compared with physical quantities calculated with a theoretical model based on a voxel phantom, and correlations are found. The results demonstrate that the computer model can be a useful tool in planning further experimental studies.},
  author       = {Tingberg, Anders},
  isbn         = {91-628-4225-0},
  keyword      = {Clinical physics,normal anatomy,free response forced error (FFE),receiver operating characteristics (ROC),visual grading analysis (VGA),European image criteria,quantifying clinical image quality,radiology,tomography,medical instrumentation,Klinisk fysiologi,radiologi,tomografi,medicinsk instrumentering},
  language     = {eng},
  pages        = {54},
  publisher    = {Department of Radiation Physics, Lund university},
  school       = {Lund University},
  title        = {Quantifying the quality of medical x-ray images. An evaluation based on normal anatomy for lumbar spine and chest radiography.},
  year         = {2000},
}