oru.sePublikationer
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Low-dose computed tomography of the abdomen and lumbar spine
Örebro University, School of Health Sciences.ORCID iD: 0000-0003-0137-9991
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Radiography is a common radiologic investigation despite abundant evidence of its limited diagnostic value. On the other hand, computed tomography (CT) has a high diagnostic value and is widely considered to be among the most important advances in medicine. However, CT exposes patients to a higher radiation dose and it might therefore not be acceptable simply to replace radiography with CT, despite the powerful diagnostic value of this technique. At the expense of reduced CT image quality, which could be adjusted to the diagnostic needs, low-dose CT of abdomen and lumbar spine can be performed at similar dose to radiography. The aim of the current thesis project was to evaluate low-dose CT of the abdomen and lumbar spine and to compare it with radiography. The hypothesis was that CT would give better image quality and diagnostic information compared to radiography at similar dose levels. Firstly, the diagnostic accuracy of low-dose CT of the abdomen was evaluated. Results showed that low-dose CT of abdomen has a high sensitivity and specificity compared to radiography, i.e., it has higher diagnostic accuracy. Similar results were obtained from our systematic review. Secondly, in a phantom study, an ovine phantom was scanned at various CT settings. The image quality was evaluated to obtain a protocol for the optimal settings for low-dose CT of lumbar spine at 1 mSv. This new protocol was then used in a clinical study to assess the image quality of low-dose CT of the lumbar spine and compare it to radiography. Results showed that low-dose CT has significantly better image quality than radiography. Finally, the impact of Iterative reconstruction (IR) on image quality of lumbar spine CT was tested. Iterative reconstruction is a recent CT technique aimed to reduce radiation dose and/or improve image quality. The results showed that the use of medium strength IR levels in the reconstruction of CT image improves image quality compared to filtered back projection. In conclusion, low-dose CT of the abdomen and lumbar spine, at about 1 mSv, has better image quality and gives diagnostic information compared to radiography at similar dose levels and it could therefore replace radiography.

Place, publisher, year, edition, pages
Örebro: Örebro university , 2016. , 87 p.
Series
Örebro Studies in Medicine, ISSN 1652-4063 ; 137
Keyword [en]
Tomography, X-Ray Computed, Radiography, Radiation Dosage, Abdomen, Spine, Lumbosacral Region, Regression Analysis
National Category
Surgery
Research subject
Surgery
Identifiers
URN: urn:nbn:se:oru:diva-48242ISBN: 978-91-7529-104-8 (print)OAI: oai:DiVA.org:oru-48242DiVA: diva2:903226
Public defence
2016-04-08, Universitetssjukhuset, Bohmanssonsalen, Södra Grev Rosengatan, Örebro, 13:00 (English)
Opponent
Supervisors
Available from: 2016-02-15 Created: 2016-02-15 Last updated: 2016-12-05Bibliographically approved
List of papers
1. Diagnostic accuracy of low-dose CT compared with abdominal radiography in non-traumatic acute abdominal pain: prospective study and systematic review
Open this publication in new window or tab >>Diagnostic accuracy of low-dose CT compared with abdominal radiography in non-traumatic acute abdominal pain: prospective study and systematic review
Show others...
2016 (English)In: European Radiology, ISSN 0938-7994, E-ISSN 1432-1084, Vol. 26, no 6, 1766-1774 p.Article in journal (Refereed) Published
Abstract [en]

Objectives: Abdominal radiography is frequently used in acute abdominal non-traumatic pain despite the availability of more advanced diagnostic modalities. This study evaluates the diagnostic accuracy of low-dose CT compared with abdominal radiography, at similar radiation dose levels.

Methods: Fifty-eight patients were imaged with both methods and were reviewed independently by three radiologists. The reference standard was obtained from the diagnosis in medical records. Sensitivity and specificity were calculated. A systematic review was performed after a literature search, finding a total of six relevant studies including the present.

Results: Overall sensitivity with 95 % CI for CT was 75 % (66-83 %) and 46 % (37-56 %) for radiography. Specificity was 87 % (77-94 %) for both methods. In the systematic review the overall sensitivity for CT varied between 75 and 96 % with specificity from 83 to 95 % while the overall sensitivity for abdominal radiography varied between 30 and 77 % with specificity 75 to 88 %.

Conclusions: Based on the current study and available evidence, low-dose CT has higher diagnostic accuracy than abdominal radiography and it should, where logistically possible, replace abdominal radiography in the workup of adult patients with acute non-traumatic abdominal pain.

Key points: • Low-dose CT has a higher diagnostic accuracy than radiography. • A systematic review shows that CT has better diagnostic accuracy than radiography. • Radiography has no place in the workup of acute non-traumatic abdominal pain.

Place, publisher, year, edition, pages
New York: Springer, 2016
Keyword
X-ray computed tomography, abdominal radiography, sensitivity and specificity, abdominal pain, abdomen, acute
National Category
Radiology, Nuclear Medicine and Medical Imaging
Research subject
Radiology
Identifiers
urn:nbn:se:oru:diva-47089 (URN)10.1007/s00330-015-3984-9 (DOI)000376100100030 ()26385800 (PubMedID)2-s2.0-84942013953 (Scopus ID)
Note

Funding Agency:

Region Örebro County

Available from: 2015-12-16 Created: 2015-12-16 Last updated: 2017-03-14Bibliographically approved
2. Low-dose computed tomography of the lumbar spine: a phantom study on imaging parameters and image quality
Open this publication in new window or tab >>Low-dose computed tomography of the lumbar spine: a phantom study on imaging parameters and image quality
2014 (English)In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 55, no 7, 824-832 p.Article in journal (Refereed) Published
Abstract [en]

Background: Lumbar spine radiography has limited diagnostic value but low radiation dose compared with computed tomography (CT). The average effective radiation dose from lumbar spine radiography is about 1.1 mSv. Low-dose lumbar spine CT may be an alternative to increase the diagnostic value at low radiation dose, around 1 mSv.

Purpose: To determine the optimal settings for low-dose lumbar spine CT simultaneously aiming for the highest diagnostic image quality possible.

Material and Methods: An ovine lower thoracic and lumbar spine phantom, with all soft tissues around the vertebrae preserved except the skin, was placed in a 20 L plastic container filled with water. The phantom was scanned repeatedly with various technical settings; different tube potential, reference mAs, and with different convolution filters. Five radiologists evaluated the image quality according to a modification of the European guidelines for multislice computed tomography (MSCT) quality criteria for lumbar spine CT 2004. In a visual comparison the different scans were also ranked subjectively according to perceived image quality. Image noise and contrast were measured.

Results: A tube potential of 120 kV with reference mAs 30 and medium or medium smooth convolution filter gave the best image quality at a sub-millisievert dose level, i.e. with an effective dose comparable to that from lumbar spine radiography.

Conclusion: Low-dose lumbar spine CT thus opens a possibility to substitute lumbar spine radiography with CT without obvious increase in radiation dose.

Keyword
conventional radiography; CT; spine; structures; techniques
National Category
Radiology, Nuclear Medicine and Medical Imaging
Research subject
Radiology
Identifiers
urn:nbn:se:oru:diva-38243 (URN)10.1177/0284185113509615 (DOI)000342575300008 ()2-s2.0-84907878366 (Scopus ID)
Available from: 2014-11-03 Created: 2014-10-30 Last updated: 2017-03-26Bibliographically approved
3. Low dose CT of the lumbar spine compared with radiography: a study on image quality with implications for clinical practice
Open this publication in new window or tab >>Low dose CT of the lumbar spine compared with radiography: a study on image quality with implications for clinical practice
Show others...
2016 (English)In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 57, no 5, 602-611 p.Article in journal (Refereed) Published
Abstract [en]

Background: Lumbar spine radiography is often performed instead of CT for radiation dose concerns.

Purpose: To compare image quality and diagnostic information from low dose lumbar spine CT at an effective dose of about 1 mSv with lumbar spine radiography.

Material and Methods: Fifty-one patients were examined by both methods. Five reviewers scored all examinations on eight image quality criteria using a five-graded scale and also assessed three common pathologic changes.

Results: Low dose CT scored better than radiography on the following: sharp reproduction of disc profile and vertebral end-plates (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3-2.5), intervertebral foramina and pedicles (OR, 4.3; 95% CI, 3.1-5.9), intervertebral joints (OR, 139; 95% CI, 59-326), spinous and transverse processes (OR, 7.0; 95% CI, 4.3-11.2), sacro-iliac joints (OR, 4.2; 95% CI, 3.2-5.7), reproduction of the adjacent soft tissues (OR, 2.9; 95% CI, 2.1-4.0), and absence of any obscuring superimposed gastrointestinal gas and contents (OR, 188; 95% CI, 66-539). Radiography scored better on sharp reproduction of cortical and trabecular bone (OR, 0.3; 95% CI, 0.2-0.4). The reviewers visualized disk degeneration, spondylosis/diffuse idiopathic skeletal hyperostosis (DISH) and intervertebral joint osteoarthritis more clearly and were more certain with low dose CT. Mean time to review low dose CT was 204 s (95% CI, 194-214 s.), radiography 152 s (95% CI, 146-158 s.). The effective dose for low dose CT was 1.0-1.1 mSv, for radiography 0.7 mSv.

Conclusion: Low dose lumbar spine CT at about 1 mSv has superior image quality to lumbar spine radiography with more anatomical and diagnostic information.

Place, publisher, year, edition, pages
London, United Kingdom: Sage Publications, 2016
Keyword
Radiation dose, radiography, tomography, X-ray computed, axial skeleton
National Category
Radiology, Nuclear Medicine and Medical Imaging
Research subject
Radiology
Identifiers
urn:nbn:se:oru:diva-47090 (URN)10.1177/0284185115595667 (DOI)000374327600014 ()26221055 (PubMedID)
Available from: 2015-12-16 Created: 2015-12-16 Last updated: 2017-03-13Bibliographically approved
4. Impact of iterative reconstruction on image quality of low-dose CT of the lumbar spine
Open this publication in new window or tab >>Impact of iterative reconstruction on image quality of low-dose CT of the lumbar spine
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Surgery
Research subject
Surgery
Identifiers
urn:nbn:se:oru:diva-49423 (URN)
Available from: 2016-03-17 Created: 2016-03-17 Last updated: 2016-03-17Bibliographically approved

Open Access in DiVA

Spikblad(112 kB)26 downloads
File information
File name SPIKBLAD01.pdfFile size 112 kBChecksum SHA-512
7261acdbb59910ca55a06136c1db3f617932631c09f1e9ab0e4be761db315c4ba8645e173f4e302a6823a8aa7ae980afe6897407f5bf720543a585ffc59d1aec
Type spikbladMimetype application/pdf
Cover(128 kB)32 downloads
File information
File name COVER01.pdfFile size 128 kBChecksum SHA-512
71a8658fa37b8e21850eab3b760131d8ba3a904a0158a70abb793196f124dd747408f465a7d59b9dad80b801307f6cc2c298b376c16e4b5e734c72e41feaf727
Type coverMimetype application/pdf
Introductory chapter(12507 kB)116 downloads
File information
File name FULLTEXT01.pdfFile size 12507 kBChecksum SHA-512
0ee1f459cb58d636da174c5e2e32317e6be64e6075195b063a5ed95116c913b2618cca3ee8eb8fba5276397ecaa269f834778907df2cad28f014bdb677cacca3
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Alshamari, Muhammed
By organisation
School of Health Sciences
Surgery

Search outside of DiVA

GoogleGoogle Scholar
Total: 116 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 1686 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf