Recall rates

The effects of competition among the IR rules were explored by using the complete system, with the STIRS module disabled, to interpret the spectra of 1807 compounds from the library. For the test, we selected 500 of the 900 chemical substructures which both are chemically interesting and display at least one distinctive infrared band. Some of the selected substructures were subsets of others for example, alcohol, phenol, and primary alcohol were all in the test set. As expected, some functional groups displaying very distinctive infrared bands were detected much more reliably than others. Figure 6 shows the reliability, false positive and recall rates for a few selected functional groups. 

Examples on How to Ese Table 8-1. Wc now couple the energy balance equations in Table 8-1 with the appropriate reactor mole balance, rate law. stoichiometry algorithm to solve reaction engineering problems with heat effects. For example, recall rate law for a first-order reaction. Equation (E8-1.5) in Example 8-1. 

Clinical Studies for CADe 96 Methodology 96 Recall Rate 98... 

The results from the CADe observer studies are equivocal. The early studies showed a definite advantage in using CADe, but the more recent and clinically realistic studies have been less clear. The studies by Taylor et al. showed no net benefit from using CADe, while the Gilbert study showed a 25% increase in sensitivity, but a 32% increase in the recall rate. As we shall see in the next section, the clinical evaluations of CADe presented a clearer picture. 

Most of the clinical studies to date show a comparable increase in the cancer detection rate and recall rate. However, in some studies, the increase in recall rate is much greater than the increase in the cancer detection rate (Fenton et al. 2007). This may be attributed to the time it takes for the radiologists to learn how to use CADe most efficiently (Hall 2007). In one study (Dean and Ilvento 2006), the radiologists recall rate initially increased by over 100% and did not decrease to a reasonable value (which is approximately a 10% increase) until after 22 months of use. This indicates that it takes almost 2 years for some radiologists to be able to judge CADe-detected lesions in the same manner as they judge lesions that... 

Performance of current commercial CAD systems Based on a range of radiologists recall rates between 1 and 5%... 

One of die reasons why radiologists may have increased recall rate when first using CADe is that false detection rate of CADe is high, especially when compared with the number of correct marks. Given that the cancer prevalence in a screening population is 5 per 1,000 women screened, at most there will be ten correct CADe marks and 1,000 false marks. As illustrated in Table 6.3, the false detection of current CADe schemes would have to decrease by at least a factor of 10 to be comparable with the false detection rate by radiologists. 

Taylor and Potts performed a meta-analysis and found that independent double reading increases the number of cancers detected by 13%, whereas the recall rate increases by 31%. These numbers are comparable with what is found by the clinical CADe studies that used the sequential or cross-sectional method (9% increase in the number of cancers detected), with CADe having a lower increase in the recall rate (10%),... 

Fenton JJ, Taplin SH, Carney PA, et al (2007) Influence of computer-aided detection on performance of screening mammography. N Engl J Med 356 1399-1409 Fieg SA, Sickles EA, Evans WP, et al (2004) Re changes in breast cancer detection and mammography recall rates after the introduction of a Computer-Aided detection system. J Natl Cancer Inst 96 1260-1261... 

A total of 3,683 women were included in the study. The recall rate for diagnostic work-up after consensus meeting was 3.5% for SFM and 4.6% for FFDM (p < 0.05). The cancer detection rate in the study group (n = 3,683 women) was significantly higher when compared with women not included in the study (Fisher s exact test, p < 0.05). This was, however, of no importance for the study itself, as the aim was to compare SFM vs. FFDM in a paired study design. A total of 31 cancers were found in the study group (detection rate 0.84%), of which 28 were... 

Table 10.2. Studies comparing screen-film mammography (SFM) and full-field digital mammography (FFDM) in hreast cancer screening number of examinations, recall rate, cancer detection rate (including invasive cancers and DCIS), and positive predictive value (PPVj) (percentage of cancer among women recalled for diagnostic work-up)...

Study I xiiiiiiiKUioiis ( ) Recall rate (%) Cancer detection (%) PPV. (%) ... 

The recall rate was 1.4% (372 of 25,901 women) for SFM when compared with 1.0% (102 of 9,841) for FFDM, and this difference was significant (p = 0.003). The cancer detection rate for SFM was 0.31% (81 cancers among 25,901 women) and 0.49% (48 cancers among 9,841 women) for FFDM. The higher detection rate for FFDM was statistically significant (p = 0.01). As a consequence of the lower recall rate and higher cancer detection rate for FFDM, the PPV, was remarkable high for FFDM (47.1%) when compared with SFM (21.8%). Performance indicators from this study are listed in Table 10.2. 

The recall rate for FFDM for abnormal mammographic findings (4.09%) did not differ significantly from the SFM control group (4.16%) in this study (p = 0.645). However, for recalls owing to technically inadequate mammograms, the recall rate was... 

DSPP study were found to be associated with the very low recall rates. The PPV, for both the imaging techniques was considerably lower in the Barcelona study when compared with the other European studies, hut was still higher than those found in the US studies (Table 10.2). 

Sala M, Commas M, Macia F, et al (2009) Implementation of digital mammography in a population-based breast cancer screening program Effect of screening round on recall rate and cancer detection 252 31-39 Shapiro S,Strax P,Venet L (1971) Periodic breast cancer screening in reducing mortality from breast cancer. JAMA 215 1777-1785... 

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