Breast tumour imaging using incomplete circular orbit pinhole SPET

Scarfone, Christopher; Rj, Jaszczak; Li, Jian; Ms, Soo; Smith, Michelle D.; Kl, Greer; Re, Coleman

doi:10.1097/00006231-199711000-00012

Cited by 35 publications

(15 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[1]- [8], and pinhole, e.g. [9]- [17], SPECT breast imaging. Three prominent considerations in designing SPECT systems specifically for breast imaging are (i) to limit the distance, averaged over the entire SPECT scan, between the collimator and the breast and other nearby tissue of interest (in order to improve spatial resolution), (ii) to limit the average amount of attenuating tissue between the collimator and the breast and other nearby tissue of interest, and (iii) to satisfy sampling requirements, so that the SPECT acquisition provides sufficient information with which to reconstruct the volume of interest.…”

Section: Introductionmentioning

confidence: 99%

“…Here we consider pinhole trajectories which can meet the above three considerations (shortened distance, lessened attenuation, sufficient sampling) for clinician-specified volumes ranging from the breast alone to surrounding tissue in the axilla and upper chest. Many of the dedicated SPECT breast imaging methods that have been proposed can be classified as either predominantly vertical axis of rotation (VAOR) [1]- [6][15] [16] or predominantly horizontal axis of rotation (HAOR) [9][10] [12]- [14] [17]. (The labels VAOR and HAOR are nominal, indicating the predominant motion.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Pinhole Trajectories for SPECT Imaging of the Breast, Axilla, and Upper Chest

Bowsher

Roper

Peter

et al. 2006

2006 IEEE Nuclear Science Symposium Conference Record

View full text Add to dashboard Cite

Several methods have been proposed for dedicated SPECT imaging of the breast. Two key characteristics achieved by these methods are shortened distance and lessened attenuation between the SPECT collimator and the breast. However, many of these methods are unable to image the important regions of the axilla and upper chest. Partial-Circle pinhole trajectories can image into the axilla, but only over a narrow axial range. Here we propose X and X-Line trajectories that can effectively image a broad axial range of the breast, axilla, and upper chest. The X and X-Line trajectories provide a third dimension of pinhole displacement, which is key to expanding the range of sufficient sampling. In order to investigate spatial variations in the imaging characteristics of different pinhole trajectories, phantoms were constructed with hot lesions and Defrise slabs distributed throughout the breast and torso. Projection data were computer simulated, and images were reconstructed by OSEM. These studies indicate that all three trajectories can sample activity well into the axilla. However, the axial range of good sampling is narrow with the Partial-Circle trajectory. The X and X-Line trajectories provide good sampling well into the axilla and over a broad axial range. The convex hulls of the X and X-Line trajectories encompass the breast and much of the axilla and upper chest, thereby satisfying Tuy's condition for sufficient sampling of those regions, truncation issues aside. The spatial extent of the convex hull is tunable. At the same time, the X and X-Line trajectories achieve two other key characteristics of dedicated SPECT breast imaging: Shortened average distance and lessened average attenuation between the collimator, i.e. the pinhole, and the breast and other nearby tissue of interest.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Pinhole Trajectories for SPECT Imaging of the Breast, Axilla, and Upper Chest

Bowsher

Roper

Peter

et al. 2006

2006 IEEE Nuclear Science Symposium Conference Record

View full text Add to dashboard Cite

show abstract

“…Pinhole collimation has been used to improve resolution in small organ and small animal single-photon emission tomography (SPET) studies [1,2,3,4,5]. However, reconstruction artefacts due to data truncation, an insufficient amount of projection data for exact reconstruction and the utilisation of filtered backprojection (FBP)-based reconstruction methods have limited the clinical use of pinhole SPET [6].…”

Section: Introductionmentioning

confidence: 99%

Pinhole single-photon emission tomography reconstruction based on median root prior

Sohlberg

Kuikka

Ruotsalainen

2003

Eur J Nucl Med Mol Imaging

View full text Add to dashboard Cite

The maximum likelihood expectation maximisation (ML-EM) algorithm can be used to reduce reconstruction artefacts produced by filtered backprojection (FBP) methods in pinhole single-photon emission tomography (SPET). However, ML-EM suffers from noise propagation along iterations, which leads to quantitatively unpleasant reconstruction results. To avoid this increase in noise, the median root prior (MRP) algorithm for pinhole SPET was implemented. Projection data of a line source and Picker's thyroid phantom were collected using a single-head gamma camera with a pinhole collimator. MRP was added to existing pinhole ML-EM reconstruction algorithm and the phantom studies were reconstructed using MRP, ML-EM and FBP for comparison. Coefficients of variation, contrasts and full-widths at half-maximum were calculated and showed a clear reduction in noise without significant loss of resolution or decrease in contrast when MRP was applied. MRP also produced visually pleasing images even with high iteration numbers, free of the checkerboard-type noise patterns which are typical of ML-EM images.

show abstract

“…INTRODUCTION Parallel hole collimation [1] and pinhole collimation [2,3] have been employed for scintimammography with standard gamma cameras. Pinhole collimation with object magnification permits image resolution that is better than the intrinsic resolution of the detector.…”

mentioning

confidence: 99%

Optimizing pinhole and parallel hole collimation for scintimammography with compact pixellated detectors

Smith

Kieper

Majewski

et al. 2003

IEEE Trans. Nucl. Sci.

View full text Add to dashboard Cite

Abstract-The relative advantages of pinhole and parallel hole collimators for scintimammography with compact, pixellated gamma detectors were investigated using analytic models of resolution and sensitivity. Collimator design was studied as follows. A desired object resolution was specified for a pixellated detector with a given crystal size and intrinsic spatial resolution and for a given object-to-collimator distance. Using analytic formulas, pinhole and parallel hole collimator parameters were calculated that satisfy this object resolution with optimal geometric sensitivity. Analyses were performed for 15 cm x 20 cm field of view detectors with crystal elements 1.0, 2.0 and 3.0 mm on a side and 140 keV incident photons. The sensitivity for a given object resolution was greater for pinhole collimation at smaller distances, a s expected. The object distance at which the pinhole and parallel hole sensitivity curves cross each other is important. The crossover distances increased with larger crystal size for a constant object resolution and increased as the desired object resolution decreases for a constant crystal size. For example, for 4 mm object resolution these distances were 5.5 cm, 6.5 cm and 8 cm for the 1 mm, 2 mm and 3 mm crystal detectors, respectively. The results suggest a strategy of parallel hole collimation for whole breast imaging and pinhole collimation for imaging focal uptake. This could be accomplished with a dual detector system with a different collimator type on each head or a single head system equipped with two collimators and a rapid switching mechanism. Multipinhole collimators have the potential to increase sensitivity yet maintain high image resolution. An experimental SPECT phantom study with a four-pinhole collimator was acquired with a pixellated detector. The iterative maximum-likelihood expectationmaximization (MLEM) reconstruction of a hot sphere in a warm cylinder showed the potential of multipinhole collimation to improve sensitivity for tomographic pinhole scintimammography.

show abstract

Breast tumour imaging using incomplete circular orbit pinhole SPET

Cited by 35 publications

References 0 publications

Pinhole Trajectories for SPECT Imaging of the Breast, Axilla, and Upper Chest

Pinhole Trajectories for SPECT Imaging of the Breast, Axilla, and Upper Chest

Pinhole single-photon emission tomography reconstruction based on median root prior

Optimizing pinhole and parallel hole collimation for scintimammography with compact pixellated detectors

Contact Info

Product

Resources

About