@article{MPeikari2012,

title = {Characterization of ultrasound elevation beamwidth artifacts for prostate brachytherapy needle insertion},

author = {Mohammad Peikari and Thomas K. Chen and Andras Lasso and Tamas Heffter and E. Clif Burdette and Gabor Fichtinger},

url = {http://online.medphys.org/resource/1/mphya6/v39/i1/p246_s1

https://labs.cs.queensu.ca/perklab/wp-content/uploads/sites/3/2024/02/MPeikari2012.pdf},

doi = {10.1118/1.3669488},

issn = {0094-2405},

year  = {2012},

date = {2012-01-01},

urldate = {2012-01-01},

journal = {Medical Physics},

volume = {39},

pages = {246-256},

abstract = {<p>Purpose: Ultrasound elevation beamwidth leads to image artefacts and uncertainties in localizing objects (such as a surgical needle) in ultrasound images. We examined the clinical significance of errors caused by elevation beamwidth artefacts and imaging parameters in needle insertion procedures. Method: Beveled prostate brachytherapy needles were inserted through all holes of a grid template under real-time transrectal ultrasound (TRUS) guidance. The needle tip position as indicated by the TRUS image was compared to their observed physical location. A new device was developed to measure the ultrasound elevation beamwidth. Result: Imaging parameters of the TRUS scanner have direct impact on the localization error ranging from 0.5 mm upto 4 mm. The smallest localization error was observed laterally close to the center of the grid template, and axially within the beam’s focal zone. Largest localization error occurs laterally around both sides of the grid template, and axially within the beam’s far field. we also found that the localization errors vary with both lateral and elevation offsets. Conclusion: We found properly adjusting the TRUS imaging settings to lower the ultrasound gain and power effectively minimized the appearance of elevation beamwidth artefacts and in turn reduced the localization errors of the needle tip.</p>},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{fichtinger2011p,

title = {Effects of ultrasound section-thickness on brachytherapy needle tip localization error},

author = {Mohammad Peikari and Thomas Kuiran Chen and Andras Lasso and Tamas Heffter and Gabor Fichtinger},

url = {https://link.springer.com/chapter/10.1007/978-3-642-23623-5_38},

year  = {2011},

date = {2011-01-01},

pages = {299-306},

publisher = {Springer Berlin Heidelberg},

abstract = {Purpose: Ultrasound section-thickness is the out-of-plane beamwidth causing major roles in creating image artifacts normally appearing around the anechoic areas. These artifacts can introduce errors in localizing the needle tips during any ultrasound-guided procedure. To study how section-thickness and imaging parameters can affect observing and localizing needle tips, we have conducted a typical calibration setup experiment. Method: Multiple needles were inserted orthogonal to the axial image plane, at various distances from the transducer. The experiment was conducted on a brachytherapy stepper for a curvilinear transrectal-ultrasound probe. Result: Experiments demonstrated that the imaging parameters have direct impacts on observing needle tips at different axial locations. They suggest specific settings to minimize the imaging artifacts. Conclusion: The ultrasound section-thickness …},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{fichtinger2011u,

title = {Section-thickness profiling for brachytherapy ultrasound guidance},

author = {Mohammad Peikari and Thomas Kuiran Chen and Everette C Burdette and Gabor Fichtinger},

url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/7964/79640R/Section-thickness-profiling-for-brachytherapy-ultrasoundguidance/10.1117/12.877993.short},

year  = {2011},

date = {2011-01-01},

volume = {7964},

pages = {226-233},

publisher = {SPIE},

abstract = {Purpose 

Ultrasound (US) elevation beamwidth causes a certain type of image artifact around the anechoic areas of the tissue. It is generally assumed that the US image is of zero thickness, which contradicts the fact that the acoustic beam can only be mechanically focused at a depth resulting in a finite, non-uniformed elevation beamwidth. We suspect that elevation beamwidth artifacts contribute to target reconstruction error in computer-assisted interventions. This paper introduces a method for characterization of the beamwidth for transrectal ultrasound (TRUS) used in prostate brachythyerapy. In particular, we measure how the US sectionthickness varies along the beam's axial depth. 

Method 

We developed a beam-profiling device (a TRUS-bridge phantom) specifically tailored for standard brachytherapy ultrasound imaging systems to generate a complete section-thickness profile of a given TRUS transducer. The …},

keywords = {},

pubstate = {published},

tppubtype = {article}

}