Evaluation of the quantitative accuracy of a commercially available positron emission mammography scanner

Springer, A.; Mawlawi, Osama

doi:10.1118/1.3560881

Cited by 20 publications

(16 citation statements)

References 29 publications

(27 reference statements)

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“…Between-plane resolution degrades as detector separation increases, so this PEM design is well-suited to hand imaging where the detector separation is only 4.5 – 6 cm. Springer et al determined that applying corrections for count rate, attenuation and scatter was essential for the PEM Flex Solo II system, with the least attenuation effects seen in phantoms of thickness 4 cm [43]. A dedicated small-parts system like PEM has high spatial resolution, and in breast applications, has been shown to have comparable sensitivity and specificity to MRI for breast lesions [44].…”

Section: Discussionmentioning

confidence: 99%

18F-FDG PET of the hands with a dedicated high-resolution PEM system (arthro-PET): correlation with PET/CT, radiography and clinical parameters

Mhlanga

Carrino

Lodge

et al. 2014

Eur J Nucl Med Mol Imaging

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Purpose The aim of this study was to prospectively determine the feasibility and compare the novel use of a positron emission mammography (PEM) scanner with standard PET/CT for evaluating hand osteoarthritis (OA) with 18F-FDG. Methods Institutional review board approval and written informed consent were obtained for this HIPAA-compliant prospective study in which 14 adults referred for oncological 18F-FDG PET/CT underwent dedicated hand PET/CT followed by arthro-PET using the PEM device. Hand radiographs were obtained and scored for the presence and severity of OA. Summed qualitative and quantitative joint glycolytic scores for each modality were compared with the findings on plain radiography and clinical features. Results Eight patients with clinical and/or radiographic evidence of OA comprised the OA group (mean age 73±7.7 years). Six patients served as the control group (53.7±9.3 years). Arthro-PET quantitative and qualitative joint glycolytic scores were highly correlated with PET/CT findings in the OA patients (r=0.86. p =0.007; r=0.94, p=0.001). Qualitative arthro-PET and PET/CT joint scores were significantly higher in the OA patients than in controls (38.7±6.6 vs. 32.2±0.4, p=0.02; 37.5±5.4 vs. 32.2±0.4, p=0.03, respectively). Quantitative arthro-PET and PET/CT maximum SUV-lean joint scores were higher in the OA patients, although they did not reach statistical significance (20.8±4.2 vs. 18±1.8, p= 0.13; 22.8±5.38 vs. 20.1±1.54, p=0.21). By definition, OA patients had higher radiographic joint scores than controls (30.9±31.3 vs. 0, p=0.03). Conclusion Hand imaging using a small field of view PEM system (arthro-PET) with FDG is feasible, performing comparably to PET/CT in assessing metabolic joint activity. Arthro-PET and PET/CT showed higher joint FDG uptake in OA. Further exploration of arthro-PET in arthritis management is warranted.

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Section: Discussionmentioning

confidence: 99%

18F-FDG PET of the hands with a dedicated high-resolution PEM system (arthro-PET): correlation with PET/CT, radiography and clinical parameters

Mhlanga

Carrino

Lodge

et al. 2014

Eur J Nucl Med Mol Imaging

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“…Broadening the application of the PEM beyond the breast to use PUV as a quantitative metric must address several new considerations, namely the PEM uptake value's lack of standardization or correction. A phantom study found that quantitative accuracy of the PEM (based on administered dose) was affected by thickness of the phantom[10] if this finding were reproducible in vivo, then we would see variations in the correlation between SUV and PUV in smaller objects of interest such as the hands versus larger objects such as the thigh. Although our sample size was too small to appreciate such differences in a statistically significant way, this finding would be interesting to evaluate in a larger study.…”

Section: Discussionmentioning

confidence: 99%

Correlation of PUV and SUV in the extremities while using PEM as a high-resolution positron emission scanner

et al. 2014

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Intro Due to its unique configuration of two adjustable plate detectors Positron Emission Mammography, or PEM, could theoretically also function as a high resolution positron emission scanner for the extremities or neck. PEM quantitates its activity via a “PEM Uptake Value,” or PUV, and although its relationship to the Standardized Uptake Value, or SUV, has been demonstrated in the breasts, to our knowledge there are no studies validating PUV in other sites such as the extremities. Materials/Methods Thi s was a retrospective chart review of two separate protocols of a total of 15 patients. The patients all had hypermetabolic lesions in the extremities or neck on imaging with PET/CT and were sent after their PET/CT to PEM for further imaging. Due to the se quential nature of these exams no additional radiotracer was administered. Results A spearman rank order correlation was calculated between the PUV max obtained from PEM images, and the SUVmax for all. The spearman rank order correlation for all sites wa s 0.42 which is not significantly different from 0 (p=0.13). When neck lesions were excluded from the group, there was a strong and statistically significant correlation between PUVmax and SUVmax, with a spearman rank correlation of 0.73 and significantly different from 0 (p=0.0068). Discussion The correlation of PUV and SUV in the extremities indicates the potential use of PEM as a semiquantitative, high resolution positron emission scanner and warrants further investigation especially in the realm of dis ease processes that often present in the extremities such as melanoma, osteomyelitis and arthritis as well as playing a role in the imaging of patients with metallic hardware post limb salvage surgery.

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“…The impact of the anisotropic resolution on our results, and potential benefits of isotropic resolution for lesion detection, are not clear. Another consequence of tomosynthesis is that image quantification of tracer uptake is typically compromised (26), although there are approaches to overcome this limitation (27). PET detectors that completely surround the breast provide much higher photon detection sensitivity than scanning-detector systems, and as a result, lower image noise would be expected from such systems for a given acquisition protocol.…”

Section: Discussionmentioning

confidence: 99%

Positron Emission Mammography Image Interpretation for Reduced Image Count Levels

et al. 2015

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We studied the effects of reduced 18 F-FDG injection activity on interpretation of positron emission mammography (PEM) images and compared image interpretation between 2 postinjection imaging times. Methods: We performed a receiver-operating-characteristic (ROC) study using PEM images reconstructed with different count levels expected from injected activities between 23 and 185 MBq. Thirty patients received 2 PEM scans at postinjection times of 60 and 120 min. Half of the patients were scanned with a standard protocol; the others received one-half of the standard activity. Images were reconstructed using 100%, 50%, and 25% of the total counts acquired. Eight radiologists used a 5-point confidence scale to score 232 PEM images for the presence of up to 3 malignant lesions. Paired images were analyzed with conditional logistic regression and ROC analysis to investigate changes in interpretation.Results: There was a trend for increasing lesion detection sensitivity with increased image counts: odds ratios were 2.2 (P 5 0.01) and 1.9 (P 5 0.04) per doubling of image counts for 60-and 120-min uptake images, respectively, without significant difference between time points (P 5 0.7). The area under the ROC curve (AUC) was highest for the 100%-count, 60-min images (0.83 vs. 0.75 for 50%-counts, P 5 0.02). The 120-min images had a similar trend but did not reach statistical significance (AUC 5 0.79 vs. 0.73, P 5 0.1). Our data did not yield significant trends between specificity and image counts. Lesion-to-background ratios increased between 60-and 120-min scans (P , 0.001). Conclusion: Reducing the image counts relative to the standard protocol decreased diagnostic accuracy. The increase in lesion-to-background ratio between 60-and 120-min uptake times was not enough to improve detection sensitivity in this study, perhaps in part due to fewer counts in the later scan. Mot ivated by remaining challenges in diagnosis, staging, and management of breast cancer, small, high-resolution PET scanners dedicated to breast imaging have been investigated since the 1990s (1-13). Dedicated breast PET systems (positron emission mammography [PEM]) have spatial resolutions better than whole-body (WB) PET scanners by factors of 2-4 and are much smaller than WB PET scanners, allowing placement of the detectors close to the breast, thus increasing geometric detection efficiency for annihilation photons relative to WB PET. In theory, increased detector efficiency allows for lower injected activities or shorter scan times while maintaining a fixed image noise level.Increased detector efficiency adds to the number of detected coincidence counts during a scan, which is the underlying metric determining inherent image noise. The activity injected into the patient (A inj ), uptake time (T up ), scan duration (T s ), and detector efficiency are the primary factors determining the number of PEM scan counts. The PEM Flex Solo II scanner (PEM Flex; CMR Naviscan) consists of 2 bar detectors (6 · 16 cm imaging area) that scan in unison along the 6-cm ...

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Evaluation of the quantitative accuracy of a commercially available positron emission mammography scanner

Abstract: Applying corrections for count rate effects, attenuation, and scatter will be essential for the PEM Flex Solo II to be able to produce quantitatively accurate images.

Cited by 20 publications

References 29 publications

18F-FDG PET of the hands with a dedicated high-resolution PEM system (arthro-PET): correlation with PET/CT, radiography and clinical parameters

18F-FDG PET of the hands with a dedicated high-resolution PEM system (arthro-PET): correlation with PET/CT, radiography and clinical parameters

Correlation of PUV and SUV in the extremities while using PEM as a high-resolution positron emission scanner

Positron Emission Mammography Image Interpretation for Reduced Image Count Levels

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