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  1. A low-cost phantom for simple routine testing of single photon emission computed tomography (SPECT) cameras
    Ng AH, Ng KH, Dharmendra H, Perkins AC
    Appl Radiat Isot, 2009 Oct;67(10):1864-8.
    PMID: 19049851 DOI: 10.1016/j.apradiso.2008.10.010
    A simple sphere test phantom has been developed for routine performance testing of SPECT systems in situations where expensive commercial phantoms may not be available. The phantom was based on a design with six universal syringe hubs set in the frame to support a circular array of six glass blown spheres of different sizes. The frame was then placed into a water-filled CT abdomen phantom and scanned with a triple head camera system (Philips IRIX, USA). Comparison was made with a commercially available phantom (Deluxe Jaszczak phantom). Whereas the commercial phantom demonstrates cold spot resolution, an important advantage of the sphere test phantom was that hot spot resolution could be easily measured using almost half (370MBq) of the activity recommended for use in the commercial phantom. Results showed that the contrast increased non-linearly with sphere volume and radionuclide concentration. The phantom was found to be suitable as an inexpensive option for daily performance tests.
    Matched MeSH terms: Tomography, Emission-Computed, Single-Photon/methods
  2. Diagnosis of pulmonary embolism: A comparison between ventilation/perfusion SPECT/CT and perfusion-only SPECT/CT
    Thanuja M, Maimanah M, Sara U
    Med J Malaysia, 2020 09;75(5):490-493.
    PMID: 32918415
    BACKGROUND: The role of nuclear medicine in diagnosing pulmonary embolism (PE) is continuously evolving owing to advancements in imaging methods. In recent years, ventilation/perfusion single photon emission computed tomography-computed tomography (V/Q SPECT/CT) has established a synergistic role over conventional V/Q planar scintigraphy and V/Q SPECT in diagnosing pulmonary embolism.

    OBJECTIVES: In this study, we aimed to assess the incremental value of V/Q SPECT/CT over conventional V/Q planar scintigraphy and V/Q SPECT, and to determine if Q only-SPECT/CT without the conventional ventilation component could replace the current imaging protocol in diagnosing pulmonary embolism.

    METHODS: We retrospectively assessed 73 patients with suspicion of pulmonary embolism who had undergone/Q planar scintigraphy, V/Q SPECT and V/Q SPECT/CT consecutively. Combination of clinical follow-up, laboratory test results and correlative imaging were used as reference standard. Q-only SPECT/CT datasets were then analysed separately without the V-planar, V-SPECT and V-SPECT/CT datasets.

    RESULTS: A total of 66 patients fulfilled our initial inclusion and exclusion criteria, with 23 patients as positive for PE and 43 patients ruled out of having PE based on the reference standard. Sensitivity and specificity for V/P planar scintigraphy, V/Q SPECT, and V/Q SPECT-CT were 86.9% and 39.5%, 91.3% and 55.8%, and 100% and 97.6% respectively. Overall, SPECT/CT resulted in significantly higher diagnostic accuracy than planar and SPECT imaging respectively (p<0.05). Q-only SPECT/CT significantly over diagnosed pulmonary embolism in 12 patients (p<0.05).

    CONCLUSION: Adding V/Q SPECT/CT to the algorithm of PE significantly improves the sensitivity and specificity. However, by eliminating the ventilation component, the diagnostic accuracy is significantly reduced.

    Matched MeSH terms: Tomography, Emission-Computed, Single-Photon/methods*
  3. Fulltext Wiener filter improves diagnostic accuracy of CAD SPECT images-comparison to angiography and CT angiography
    Masoomi MA, Al-Shammeri I, Kalafallah K, Elrahman HMA, Ragab O, Ahmed E, et al.
    Medicine (Baltimore), 2019 Jan;98(4):e14207.
    PMID: 30681596 DOI: 10.1097/MD.0000000000014207
    Many discrepancy in selection of proper filter and its parameters for individual cases exists. The authors investigate the impact of the most common filters on patient NM images with coronary artery disease (CAD), and compare the results with the computerized tomography (CT)-Angio and angiography for accuracy.The investigation initiated by performing various single photon emission computerized tomography (SPECT)/CT scan of the national electrical manufacturers association chest phantoms having hot and cold inserts. Data acquired on GE 670 PRO SPECT/CT; 360Ø, 64 frames, 60 seconds, low energy high resolution (LEHR) 128, low energy general purpose (LEGP) with CT attenuation (120 kV and 170 mA). The images reconstructed with filtered back projection and ITERATIVE ordered-subset expectation maximization utilizing filters; Hann, Butterworth, Metz, Hamming, and Wiener. The Image contrast was calculated to assess absolute nearness of the inserts. Based on the preliminary results, then scans of 92 patients with CAD; 64 males and 28 females, age 41 to 77 years old, who had been reported earlier reprocessed with the nominated filter and were reported by 2 NM expert. The results compared to the earlier reports and to the CT-Angio and angiography.The optimization suggested 3 filters; Wiener (Wi), Metz and Butterworth (But) provide the highest contrast (99- 66.4%) and (81- 32%) for the cold and hot inserts respectively, with the (Wi) filter to be the better option. The reprocessed patients scan with the (Wi) presented an elevated diagnostic accuracy, correlated well with the CT-Angio and angiography results (P 
    Matched MeSH terms: Tomography, Emission-Computed, Single-Photon/methods
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