PURPOSE: Breast ultrasonography (US) presents an alternative to mammography in young asymptomatic individuals and a complementary examination in screening of women with dense breasts. Handheld US is the standard-of-care, yet when used in whole-breast examination, no effort has been devoted to monitoring breast coverage and missed regions, which is the purpose of this study. METHODS: We introduce a computer-aided system assisting radiologists and US technologists in covering the whole breast with minimum alteration to the standard workflow. The proposed system comprises a standard US device, proprietary electromagnetic 3D tracking technology and software that combines US visual and tracking data to estimate a probe trajectory, total time spent in different breast segments, and a map of missed regions. A case study, which involved four radiologists (two junior and two senior) performing whole-breast ultrasound in 75 asymptomatic patients, was conducted to test the importance and relevance of the system. RESULTS: The mean process time per breast was [Formula: see text], with no statistically significant difference between the left and the right sides, and slightly longer examination time of junior radiologists. The process time density shows that central parts of the breast have better coverage compared to the periphery. Within the central part, missed regions of minimum detectable size of [Formula: see text] occur in [Formula: see text] of examinations, and non-negligible [Formula: see text] regions occur in [Formula: see text] of cases. CONCLUSION: The results of the case study indicate that missed regions are present in handheld whole-breast US, which renders the proposed system for tracking the probe position during examination a valuable tool for monitoring coverage.
- Klíčová slova
- Breast, Cancer, Coverage, Screening, Tracking, Ultrasound,
- MeSH
- design vybavení MeSH
- diagnóza počítačová * MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mamografie metody MeSH
- nádory prsu diagnostické zobrazování MeSH
- počítače do ruky MeSH
- počítačové systémy MeSH
- počítačové zpracování obrazu MeSH
- prsy diagnostické zobrazování MeSH
- reprodukovatelnost výsledků MeSH
- software MeSH
- ultrasonografie prsů metody MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE: Quantitative description of hepatic microvascular bed could contribute to understanding perfusion CT imaging. Micro-CT is a useful method for the visualization and quantification of capillary-passable vascular corrosion casts. Our aim was to develop and validate open-source software for the statistical description of the vascular networks in micro-CT scans. METHODS: Porcine hepatic microvessels were injected with Biodur E20 resin, and the resulting corrosion casts were scanned with 1.9-4.7 [Formula: see text] resolution. The microvascular network was quantified using newly developed QuantAn software both in randomly selected volume probes (n = 10) and in arbitrarily outlined hepatic lobules (n = 4). The volumes, surfaces, lengths, and numbers of microvessel segments were estimated and validated in the same data sets with manual stereological counting. Calculations of tortuosity, radius histograms, length histograms, exports of the skeletonized vascular network into open formats, and an assessment of the degree of their anisotropy were performed. RESULTS: Within hepatic lobules, the microvessels had a volume fraction of 0.13 [Formula: see text] 0.05, surface density of 21.0 [Formula: see text] 2.0 [Formula: see text], length density of 169.0 [Formula: see text] 40.2 [Formula: see text], and numerical density of 588.5 [Formula: see text] 283.1 [Formula: see text]. Sensitivity analysis of the automatic analysis to binary opening, closing, threshold offset, and aggregation radius of branching nodes was performed. CONCLUSION: The software QuantAn and its source code are openly available to researchers working in the field of stochastic geometry of microvessels in micro-CT scans or other three-dimensional imaging methods. The implemented methods comply with reproducible stereological techniques, and they were highly consistent with manual counting. Preliminary morphometrics of the classical hepatic lobules in pig were provided.
- Klíčová slova
- Liver, Microvessels, Pig, Porcine, Python, Stereology, X-ray microtomography,
- MeSH
- interpretace obrazu počítačem metody MeSH
- játra krevní zásobení diagnostické zobrazování MeSH
- koroze MeSH
- mikrocévy diagnostické zobrazování MeSH
- prasata MeSH
- rentgenová mikrotomografie metody MeSH
- software MeSH
- zobrazování trojrozměrné metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE: Thrombolytic therapy in patients with acute ischemic stroke is contraindicated when the infarction core exceeds a given threshold. To date, there are no standardized guidelines for computed tomography infarction core assessment. Current practice involves use of thresholding methods, where the results are further adjusted by an experienced physician. An automated method for infarction core delineation and volume measurement was developed and tested. MATERIALS AND METHODS: CT postprocessing software was developed for analysis of whole brain perfused blood volume (PBV) and cerebral blood volume (CBV) maps. The program was designed for potential use with mean transit time (MTT) or cerebral blood flow (CBF) maps. The proposed method was tested on a set of 12 patients on both PBV and CBV maps with whole brain coverage by comparison with the results of a simple thresholding method and with manually marked findings provided by two independent physicians. RESULTS: The proposed method produced a marked infarct core volume corresponding to 53 % of the manually delineated volumes. The simple thresholding method with the optimal threshold, using the same dataset, marked 15[Formula: see text] larger volume compared to the volume delineated by physicians. CONCLUSION: An automated infarction core segmentation method based on local neighborhood features was developed and tested, demonstrating its utility in distinguishing between infarcted and non-infarcted areas, as well as reduction in the number of false positives and volume error.
- MeSH
- krevní objem * MeSH
- lidé MeSH
- mozek diagnostické zobrazování patofyziologie MeSH
- mozkový infarkt diagnóza patofyziologie MeSH
- mozkový krevní oběh fyziologie MeSH
- počítačová rentgenová tomografie metody MeSH
- regionální krevní průtok fyziologie MeSH
- software * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
