Polymethyl Methacrylate (Perspex) Line Pattern Phantom : A New Gamma Camera Test Pattern for Assessment of Extrinsic Resolution and Linearity
Journal Title: Sultan Qaboos University Medical Journal - Year 2001, Vol 3, Issue 1
Abstract
Objective: To evaluate the newly designed polymethyl methacrylate (Perspex) line pattern phantom (PLPP) for testing extrinsic resolution and linearity of gamma camera. Method: The phantom was made of 10 mm thick Perspex in which tubes of 1 mm external diameter and 0.5 mm internal diameter were inserted in 1 mm deep grooves, which had been machined in a particular pattern. The final arrangement of lines divided the phantom into four similar quadrants, which encompassed the whole surface of the gamma camera head. Such an arrangement permitted full detection of any change in the linearity and resolution. The tube was filled with technetium-99m (99mTc). Tests were performed on the only two single-headed gamma cameras available in Oman. Results: It was possible to resolve two lines as close as 6 mm. Using the line spread function (LSF) facility, the estimated full width half maximum height (FWHM) value was 4.1 mm. In addition, any distortion in the shape of the lines, used to measure linearity, could be easily detected over the entire surface of the camera head. Conclusion: Data obtained from the PLPP are in agreement with those obtained using the conventional four-quadrant bar pattern phantom (FQBP). The generally accepted relationship that the line profile FWHM is equal to approximately twice the minimal resolvable bar spacing does not apply to the PLPP. However, PLPP gives multi-direction linearity in any one quadrant. In addition, it does not need a flood source for imaging, thus minimizing the test cost.
Authors and Affiliations
Fadhil M Salih| Department of Clinical and Biomedical Physics, College of Medicine, Sultan Qaboos University, P.0.Box 35, AI-Khod 123, Muscat, Sultanate of Oman, Afkar N Al-Farsi| Department of Clinical and Biomedical Physics, College of Medicine, Sultan Qaboos University, P.0.Box 35, AI-Khod 123, Muscat, Sultanate of Oman
The Pattern of Female Nuptiality in Oman
Objectives: Te purpose of this study was to examine Omani patterns of female nuptiality, including the timing of marriage and determinants of age at a woman’s frst marriage. Methods: Te study utilised data from the 2...
Adrenocorticotropic Hormone-Dependent Cushing’s Syndrome Use of an octreotide trial to distinguish between pituitary or ectopic sources
Objectives: Adrenocorticotropic hormone (ACTH) overproduction is usually due to a pituitary tumour which is often not visible on magnetic resonance imaging (MRI). However, ACTH overproduction may be due to an ectopic s...
Genotypes and allele frequencies of angiotensin converting enzyme (ACE) insertion/deletion polymorphism among Omanis
Objective: To describe the angiotensin converting enzyme (ACE) genotype frequencies among Omani Arabs. Method: A polymerase chain reaction (PCR) test, based on separation of different size DNA fragments, was developed t...
A Combined Surgical and Prosthetic Approach for the Successful Management of a Mutilated Eye Socket A case report
Facial disfgurement through the loss of an eye due to a road trafc accident can be devastating for the patient and may leave few options for an ophthalmologist, especially if the situation demands urgency. In the prese...
Safety and Complications of Double-Lumen Tunnelled Cuffed Central Venous Dialysis Catheters Clinical and radiological perspective from a tertiary centre in Oman
Objectives: Tis study aimed to assess the technical success, safety and immediate and delayed complications of double-lumen tunnelled cuffed central venous catheters (TVCs) at the Sultan Qaboos University Hospital (SQ...