Analysis of position-dependent Compton scatter in scintimammography with mild compression

Williams, Mark B.; Narayanan, Deepa; Moré, M.J.; Goodale, P.J.; Majewski, S.A.; Kieper, D.

doi:10.1109/tns.2003.817297

Cited by 16 publications

(13 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This lower scatter content, as compared to the high scatter and torso contribution near the chest wall, corresponds to lower image noise, which would enhance SNR. This finding agrees with some literature related to the scatter distribution of nuclear breast images and the importance of energy resolution (Pani et al 1998, Williams et al 2000, Williams et al 2003). However, with the enhancement only observed with deep-seated tumours, a case for ER offering little to no benefit to breast imaging can also be made (Hruska and O’Connor 2006, Hruska and O’Connor 2008).…”

Section: Discussionsupporting

confidence: 93%

Simulation study comparing high-purity germanium and cadmium zinc telluride detectors for breast imaging

Campbell¹,

Peterson²

2014

Phys. Med. Biol.

View full text Add to dashboard Cite

We conducted simulations to compare the potential imaging performance for breast cancer detection with High-Purity Germanium (HPGe) and Cadmium Zinc Telluride (CZT) systems with 1% and 3.8% energy resolution at 140 keV, respectively. Using the Monte Carlo N-Particle (MCNP5) simulation package, we modelled both 5 mm-thick CZT and 10 mm-thick HPGe detectors with the same parallel-hole collimator for the imaging of a breast/torso phantom. Simulated energy spectra were generated, and planar images were created for various energy windows around the 140-keV photopeak. Relative sensitivity and scatter and the torso fractions were calculated along with tumour contrast and signal-to-noise ratios (SNR). Simulations showed that utilizing a ±1.25% energy window with an HPGe system better suppressed torso background and small-angle scattered photons than a comparable CZT system using a −5%/+10% energy window. Both systems provided statistically similar contrast and SNR, with HPGe providing higher relative sensitivity. Lowering the counts of HPGe images to match CZT count density still yielded equivalent contrast between HPGe and CZT. Thus, an HPGe system may provide equivalent breast imaging capability at lower injected radioactivity levels when acquiring for equal imaging time.

show abstract

Section: Discussionsupporting

confidence: 93%

Simulation study comparing high-purity germanium and cadmium zinc telluride detectors for breast imaging

Campbell¹,

Peterson²

2014

Phys. Med. Biol.

View full text Add to dashboard Cite

show abstract

“…Although that schedule was not always availchest wall edge of the compression paddle. Gamma imaging can be performed in list mode to permit postacquisition scatter correction ( 35 ) and/or extraction of information about tracer dynamics, if desired. MBI tomosynthesis reconstruction is performed by using an expectation maximization algorithm.…”

Section: Dmt Scanner Descriptionmentioning

confidence: 99%

Dual-Modality Breast Tomosynthesis

Williams¹,

Judy²,

Gunn³

et al. 2010

Radiology

View full text Add to dashboard Cite

Purpose:To evaluate the clinical performance of a hybrid scanner that uses dual-modality tomosynthesis (DMT) and technetium 99m sestamibi to provide coregistered anatomic and functional breast images in three dimensions. Materials and Methods:A prospective pilot evaluation of the scanner was performed in women scheduled to undergo breast biopsy after institutional review board approval and informed consent were obtained. All subject data were handled in compliance with the rules and regulations concerning the privacy and security of protected health information under HIPAA. The study included 17 women (mean age, 53 years; age range, 44-67 years) and 21 biopsy-sampled lesions. Results of DMT scanning were compared with histopathologic results for the 21 lesions. Results:Of the 21 lesions, seven were malignant, and 14 were benign. Among the 13 subjects with one lesion each, three had positive biopsy results, and 10 had negative biopsy results. Among the four subjects with two lesions, the biopsy results were as follows: bilateral in one, both negative; bilateral in one, both positive; unilateral in two, one positive and one negative. The sensitivity, specifi city, positive predictive value, negative predictive value, and accuracy of DMT scanning were 86%, 100%, 100%, 93%, and 95%, respectively. Conclusion:Pilot clinical evaluation of the DMT scanner suggests that it is a feasible and accurate method with which to detect and diagnose breast cancer. Systems such as the DMT scanner that are designed specifi cally for three-dimensional multimodality breast imaging could make possible some of the advances in tumor detection, localization, and characterization of breast cancer that are now being observed with whole-body three-dimensional hybrid systems, such as positron emission tomography/computed tomography (CT) or single photon emission computed tomography/CT.q RSNA, 2010

show abstract

“…Williams et al previously demonstrated the varying scatter contribution in the energy spectra as a function of distance from the chest wall. 17 Although not explored in this work, it may be beneficial to apply a standard energy window at the chest wall and the wider energy window for pixels away from the chest wall edge.…”

Section: Discussionmentioning

confidence: 99%

Proof of concept for low‐dose molecular breast imaging with a dual‐head CZT gamma camera. Part II. Evaluation in patients

et al. 2012

View full text Add to dashboard Cite

Purpose: Molecular breast imaging (MBI) has shown promise as an adjunct screening technique to mammography for women with dense breasts. The demonstration of reliable lesion detection with MBI performed at low administered doses of Tc-99 m sestamibi, comparable in effective radiation dose to screening mammography, is essential to adoption of MBI for screening. The concept of performing low-dose MBI with dual-head cadmium zinc telluride (CZT) gamma cameras has been investigated in phantoms in Part I. In this work, the objectives were to evaluate the impact of the count sensitivity improvement methods on image quality in patient MBI exams and to determine if adequate lesion detection could be achieved at reduced doses. Methods: Following the implementation of two count sensitivity improvement methods, registered collimation optimized for near-field imaging and energy acceptance window optimized for CZT, MBI exams were performed in the course of clinical care. Clinical image count density (counts/ cm 2 ) was compared between standard MBI [740 MBq (20 mCi) Tc-99 m sestamibi, standard collimation, standard energy window] and low-dose MBI [296 MBq (8 mCi) Tc-99 m sestamibi, optimized collimation, wide energy window] in a cohort of 50 patients who had both types of MBI exams performed. Lesion detection at low doses was evaluated in a separate cohort of 32 patients, in which low-dose MBI was performed following 296 MBq injection and acquired in dynamic mode, allowing the generation of images acquired for 2.5, 5, 7.5, and 10 min/breast view with proportionately reduced count densities. Diagnostic accuracy at each count density level was compared and kappa statistic was used to assess intrareader agreement between 10 min acquisitions and those at shorter acquisition durations. Results: In patient studies, low-dose MBI performed with 296 MBq Tc-99 m sestamibi and new optimal collimation/wide energy window resulted in an average relative gain in count density of 4.2 6 1.3 compared to standard MBI performed with 740 MBq. Interpretation of low-dose 296 MBq images with count densities corresponding to acquisitions of 2.5, 5, 7.5, and 10 min/view and median lesion size of 1.4 cm resulted in similar diagnostic accuracy across count densities and substantial to near-perfect intrareader agreement between full 10 min-views and lower count density views. Conclusions: Review of patient studies showed that registered optimized collimation and wide energy window resulted in a substantial gain in count sensitivity as previously indicated by phantom results. This proof of concept work indicates that MBI performed at administered doses of 296 MBq Tc-99 m sestamibi with the applied count sensitivity improvements permits the detection of small breast lesions in patients. Findings suggest that further reductions in acquisition duration or administered dose may be achievable.

show abstract

Analysis of position-dependent Compton scatter in scintimammography with mild compression

Cited by 16 publications

References 1 publication

Simulation study comparing high-purity germanium and cadmium zinc telluride detectors for breast imaging

Simulation study comparing high-purity germanium and cadmium zinc telluride detectors for breast imaging

Dual-Modality Breast Tomosynthesis

Proof of concept for low‐dose molecular breast imaging with a dual‐head CZT gamma camera. Part II. Evaluation in patients

Contact Info

Product

Resources

About