The purpose of this study was to evaluate a new commercial image processing technique (MicroPure; Toshiba America Medical Systems, Tustin, CA) for identifying breast microcalcifications compared to gray scale ultrasound imaging (US) using mammography as the reference standard.
Twenty women, with breast calcifications identified mammographically, underwent gray scale US and MicroPure examinations of the breast. Still images and digital clips of the target area were acquired using gray scale US and MicroPure (at 3 different sensitivity levels: 0, 1, and 2). The images were analyzed by 4 independent and blinded readers (2 radiologists and 2 physicists) to determine the number of calcifications as well as to score image quality and artifacts.
For all 4 readers, there were significantly more calcifications seen with MicroPure (at the 2 highest sensitivity levels) compared to gray scale US (P < .009). Agreement between readers consistently increased from gray scale US to MicroPure imaging (gray scale intraclass correlation coefficient, 0.02-0.44; versus MicroPure intraclass correlation coefficient, 0.34-0.71). The agreement improved between mammography and MicroPure (13.2%-28.3%) when compared with mammography and gray scale US (1.7%-5.2%); the 2 radiologists saw a bigger improvement. Two readers preferred the MicroPure image quality over gray scale US (P < .001) and vice versa for the other 2 readers(P < .001). All 4 readers saw fewer artifacts with MicroPure (at level 2) than with gray scale US (P < .02).
MicroPure imaging identified significantly more breast microcalcifications than gray scale US.
[Show abstract][Hide abstract] ABSTRACT: Background
We presented the photoacoustic imaging (PAI) tool and to evaluate whether microcalcifications in breast tissue can be detected on photoacoustic (PA) images.
We collected 21 cores containing microcalcifications (n = 11, microcalcification group) and none (n = 10, control group) in stereotactic or ultrasound (US) guided 8-gauge vacuum-assisted biopsies. Photoacoustic (PA) images were acquired through ex vivo experiments by transmitting laser pulses with two different wavelengths (700 nm and 800 nm). The presence of microcalcifications in PA images were blindly assessed by two radiologists and compared with specimen mammography. A ratio of the signal amplitude occurring at 700 nm to that occurring at 800 nm was calculated for each PA focus and was called the PAI ratio.
Based on the change of PA signal amplitude between 700 nm and 800 nm, 10 out of 11 specimens containing microcalcifications and 8 out of 10 specimens without calcifications were correctly identified on blind review; the sensitivity, specificity, accuracy, positive predictive and negative predictive values of our blind review were 90.91%, 80.0%, 85.71%, 83.33% and 88.89%. The PAI ratio in the microcalcification group was significantly higher than that in the control group (the median PAI ratio, 2.46 versus 1.11, respectively, P = .001). On subgroup analysis in the microcalcification group, neither malignant diagnosis nor the number or size of calcification-foci was proven to contribute to PAI ratios.
Breast microcalcifications generated distinguishable PA signals unlike breast tissue without calcifications. So, PAI, a non-ionizing and non-invasive hybrid imaging technique, can be an alternative in overcoming the limitations of conventional US imaging.
PLoS ONE 08/2014; 9(8):e105878. DOI:10.1371/journal.pone.0105878 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A new commercial image processing technique (MicroPure, Toshiba America Medical Systems, Tustin, CA, USA) that identifies breast microcalcifications was evaluated at the time of patients' annual screening mammograms. Twenty women scheduled for annual screening mammography were enrolled in the study. Patients underwent bilateral outer-upper-quadrant real-time dual gray scale ultrasound and MicroPure imaging using an Aplio XG scanner (Toshiba). MicroPure combines non-linear imaging and speckle suppression to mark suspected calcifications as white spots in a blue overlay image. Four independent and blinded readers analyzed digital clips to determine the presence or absence of microcalcifications and artifacts. The presence of microcalcifications determined by readers was not significantly different from that of mammography (p = 0.57). However, the accuracy was low overall (52%) and also in younger women (<50 years, 54%). In conclusion, although microcalcifications can be identified using MicroPure imaging, this method is not currently appropriate for a screening population and should be used in more focused applications.
Ultrasound in Medicine & Biology 09/2014; 40(9). DOI:10.1016/j.ultrasmedbio.2014.04.008 · 2.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Thyroid nodules are extremely common and the vast majority are non-malignant; therefore the accurate discrimination of a benign lesion from malignancy is challenging. Ultrasound (US) characterisation has become the key component of many thyroid nodule guidelines and is primarily based on the detection of key features by high-resolution US. The thyroid imager should be familiar with the strengths and limitations of this modality and understand the technical factors that create and alter the imaging characteristics. Specific advances in high-resolution US are discussed with reference to individual features of thyroid cancer and benign disease. Potential roles for three-dimensional thyroid ultrasound and computer-aided diagnosis are also considered. The second section provides an overview of current evidence regarding thyroid ultrasound elastography (USE). USE is a novel imaging technique that quantifies tissue elasticity (stiffness) non-invasively and has potential utility because cancers cause tissue stiffening. In recent years, there has been much research into the value of thyroid USE for distinguishing benign and malignant nodules. Preliminary findings from multiple pilot studies and meta-analyses are promising and suggest that USE can augment the anatomical detail provided by high-resolution US. However, a definite role remains controversial and is discussed.
• High-resolution US characterises thyroid nodules by demonstration of specific anatomical features • Technical advances heavily influence the key US features of thyroid nodules • Most papillary carcinomas appear stiffer than benign thyroid nodules on US elastography (USE) • Thyroid USE is controversial because of variation in the reported accuracies for malignancy • Combined grey-scale US/USE may lower the FNAC rate in benign nodules.
Insights into Imaging 03/2015; 6(2). DOI:10.1007/s13244-015-0398-9
Note: This list is based on the publications in our database and might not be exhaustive.
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