Real-World Performance of Large Vessel Occlusion Artificial Intelligence-Based Computer-Aided Triage and Notification Algorithms-What the Stroke Team Needs to Know.

PURPOSE: To evaluate the real-world performance of two FDA-approved artificial intelligence (AI)-based computer-aided triage and notification (CADt) detection devices and compare them with the manufacturer-reported performance testing in the instructions for use. MATERIALS AND METHODS: Clinical performance of two FDA-cleared CADt large-vessel occlusion (LVO) devices was retrospectively evaluated at two separate stroke centers. Consecutive "code stroke" CT angiography examinations were included and assessed for patient demographics, scanner manufacturer, presence or absence of CADt result, CADt result, and LVO in the internal carotid artery (ICA), horizontal middle cerebral artery (MCA) segment (M1), Sylvian MCA segments after the bifurcation (M2), precommunicating part of cerebral artery, postcommunicating part of the cerebral artery, vertebral artery, basilar artery vessel segments. The original radiology report served as the reference standard, and a study radiologist extracted the above data elements from the imaging examination and radiology report. RESULTS: At hospital A, the CADt algorithm manufacturer reports assessment of intracranial ICA and MCA with sensitivity of 97% and specificity of 95.6%. Real-world performance of 704 cases included 79 in which no CADt result was available. Sensitivity and specificity in ICA and M1 segments were 85.3% and 91.9%. Sensitivity decreased to 68.5% when M2 segments were included and to 59.9% when all proximal vessel segments were included. At hospital B the CADt algorithm manufacturer reports sensitivity of 87.8% and specificity of 89.6%, without specifying the vessel segments. Real-world performance of 642 cases included 20 cases in which no CADt result was available. Sensitivity and specificity in ICA and M1 segments were 90.7% and 97.9%. Sensitivity decreased to 76.4% when M2 segments were included and to 59.4% when all proximal vessel segments are included. DISCUSSION: Real-world testing of two CADt LVO detection algorithms identified gaps in the detection and communication of potentially treatable LVOs when considering vessels beyond the intracranial ICA and M1 segments and in cases with absent and uninterpretable data.

A novel multi-digital camera system based on tilt-shift photography technology.

Multi-digital camera systems (MDCS) are constantly being improved to meet the increasing requirement of high-resolution spatial data. This study identifies the insufficiencies of traditional MDCSs and proposes a new category MDCS based on tilt-shift photography to improve ability of the MDCS to acquire high-accuracy spatial data. A prototype system, including two or four tilt-shift cameras (TSC, camera model: Nikon D90), is developed to validate the feasibility and correctness of proposed MDCS. Similar to the cameras of traditional MDCSs, calibration is also essential for TSC of new MDCS. The study constructs indoor control fields and proposes appropriate calibration methods for TSC, including digital distortion model (DDM) approach and two-step calibrated strategy. The characteristics of TSC are analyzed in detail via a calibration experiment; for example, the edge distortion of TSC. Finally, the ability of the new MDCS to acquire high-accuracy spatial data is verified through flight experiments. The results of flight experiments illustrate that geo-position accuracy of prototype system achieves 0.3 m at a flight height of 800 m, and spatial resolution of 0.15 m. In addition, results of the comparison between the traditional (MADC II) and proposed MDCS demonstrate that the latter (0.3 m) provides spatial data with higher accuracy than the former (only 0.6 m) under the same conditions. We also take the attitude that using higher accuracy TSC in the new MDCS should further improve the accuracy of the photogrammetry senior product.

[Fludarabine-based increased-intensity conditioning regimen for allogeneic hematopoietic stem cell transplantation in acquired severe aplastic anemia].

OBJECTIVE: To observe the effects of increased-intensity conditioning regimen with FBCA (Fludarabine, Busulfan, Cyclophosphamide, and Antithymocyte globulin) for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in acquired severe aplastic anemia (SAA). METHODS: From January 2000 to June 2011, twenty-two patients (male 12, female 10) with SAA underwent allo-HSCT with FBCA conditioning regimen which consisted of fludarabine (30 mg·m⁻²·d⁻¹×5 d), busulfan (3 mg/kg×2 d), cyclophosphamide (60 mg·kg⁻¹·d⁻¹×2 d) and ATG (2.5 mg·kg⁻¹·d⁻¹×5 d). GVHD prophylaxis was performed by cyclosporine and short-term course methotrexate. Nine patients received mobilized peripheral blood stem cells transplantation and 13 patients underwent mobilized peripheral blood combined with bone marrow stem cells. Fourteen cases were human leukocyte antigen (HLA)-matched related donors, while the other 8 cases were HLA-haploidentical transplantation. Engraftment was documented by short tandem repeats with polymerase chain reaction (STR-PCR) on approximately day + 30, + 90, + 180, + 1 year and + 2 year, respectively. Long-term survival and transplantation-related complications were analyzed. RESULTS: All patients obtained prompt and sustained hematopoietic reconstitution. Median time for neutrophil and PLT engraftment was 15 (range: 11-22) days and 16 (range: 12-27) days, respectively. All patients were full donor chimerism identified by STR-PCR. 2 of the total 22 cases (9.1%) had grade I-III acute GVHD and 3 (15.8%) was chronic GVHD. Three patients (13.6%) died of transplantation related mortality and the other 19 cases were disease-free survival with a median time of 24 (range: 0.5-140.5) months. The causes of death were cytomegalovirus pneumonia (n=1), acute GVHD (n=1) and severe pulmonary infection (n=1). CONCLUSION: Increased-intensity of FBCA conditioning regimen could favor donor stem cell sustained engraftment for allo-HSCT in SAA.

[Research on crop-weed discrimination using a field imaging spectrometer].

Discrimination of weeds from crop is the first and important step for variable herbicides application and precise physical weed control. Using a new field imaging spectrometer developed by our group, hyperspectral images in the wavelength range 380-870 nm were taken in the wild for the investigation of crop-weed discrimination. After normalizing the data to reduce or eliminate the influence of varying illuminance, stepwise forward variable selection was employed to select the proper band sets and fisher linear discriminant analysis (LDA) was performed to discriminate crop and weeds. For the case of considering each species as a different class, classification accuracy reached 85% with eight selected bands while for the case of considering overall weed species as a class, classification accuracy was higher than 91% with seven selected bands. In order to develop a low-cost device and system in future, all combinations of two and three bands were evaluated to find the best combinations. The result showed that the best three bands can achieve a performance of 89% comparable to the performance achieved by five bands selected using stepwise selection. The authors also found that "red edge" could afford abundant information in the discrimination of weed and crop.

Hepatitis C virus prevalence and clearance among US blood donors, 2006-2007: associations with birth cohort, multiple pregnancies, and body mass index.

BACKGROUND: During the period 1992-1993, the prevalence of hepatitis C virus (HCV) antibodies (anti-HCV) among US blood donors was 0.36%, but contemporary data on the prevalence of antibody to HCV and the prevalence of HCV RNA are lacking. METHODS: We performed a large, cross-sectional study of blood donors at 6 US blood centers during 2006-2007. Anti-HCV was measured with enzyme-linked immunosorbent assay followed by immunoblot, and HCV RNA was measured with nucleic acid testing. Adjusted odds ratios (aORs) were derived using multivariable logistic regression. RESULTS: Of 959,281 donors, 695 had anti-HCV detected (prevalence, 0.072%). Of those with anti-HCV, 516 (74%) had test results positive for HCV RNA, and 179 (26%) had test results that were negative for HCV RNA. Compared with the prevalence during the period 1992-1993, prevalence during 2006-2007 was lower and peaked in older age groups. Anti-HCV was associated with a body mass index (BMI) >30 (aOR, 0.6; 95% confidence interval [CI], 0.5-0.8), and among women, it was associated with higher gravidity (aOR for 5 vs 0 pregnancies, 3.2; 95% CI, 1.9-5.4). HCV RNA negative status was associated with black race (aOR, 0.4; 95% CI, 0.2-0.7), having more than a high school education (aOR, 1.6; 95% CI, 1.1-2.4), and BMI >30 (aOR, 2.4; 95% CI, 1.4-3.9). CONCLUSIONS: Decreasing HCV prevalence is most likely attributable to culling of seropositive donors and a birth cohort effect. We found new associations between anti-HCV prevalence and gravidity and obesity. Recently discovered genetic factors may underlie differences in HCV RNA clearance in black donors.

The potential impact of selective donor deferrals based on estimated blood volume on vasovagal reactions and donor deferral rates.

BACKGROUND: Whole blood donation in the United States is restricted in volume to 10.5 mL/kg or less in an effort to prevent hypovolemic reactions, but still may exceed more than 15% of a donor's estimated blood volume (EBV). We analyzed the association of EBV with prefaint and systemic vasovagal reactions (SVRs) among whole blood donors and the potential impact of an EBV-based deferral policy. STUDY DESIGN AND METHODS: Independent predictors for prefaint reactions and SVRs were assessed by multivariate logistic regression analysis on 591,177 unique donors participating in the Retrovirus Epidemiology Donor Study-II study. RESULTS: Young age (16 years old odds ratio [OR], 3.70; 95% confidence interval [CI], 2.78-4.94), low EBV (<3.5 L OR, 3.30; 95% CI, 2.57-4.23), and first-time donation status (OR, 2.33; 95% CI, 2.03-2.67) were the strongest predictors for SVRs, with similar trends seen for prefaint reactions. Sex, height, race, blood center, and donation site were weakly associated predictors. A total of 5.6% of all donors had an EBV of less than 3.5 L and experienced 12.5% of all prefaint reactions and 14.5% of SVRs. The highest reaction rates were seen in donors less than 23 years old with an EBV of less than 3.5 L who comprised 2.7% of all donors, who were mostly female (99.9%), and who experienced 8.8% of prefaint reactions and 11.0% of SVRs. CONCLUSION: Young age, low EBV, and first-time donation status are the major correlates of prefaint reactions and SVRs, suggesting that high school and college donors are at particular risk. Deferral of donors with low EBV who are less than 23 years old may offer a rational approach to protecting donors at greater risk of reactions without jeopardizing the adequacy of the blood supply.

Minority and foreign-born representation among US blood donors: demographics and donation frequency for 2006.

BACKGROUND: Historically, minority populations have represented only a small proportion of US blood donors, but recent trends in immigration and potential blood shortages emphasize the need for recruitment strategies to increase minority donations. STUDY DESIGN AND METHODS: Donation data from a network of six US blood centers for 2006 were analyzed. Race/ethnicity, country of birth, and educational attainment data were collected specifically for the study and assessed for their influence on donation behavior. Logistic regression was used to determine independent associations with repeat donors status and annual donation frequency. RESULTS: A total of 1,288,998 donations from 729,068 donors were studied; most donors had data on race/ethnicity (97.1%) and country of birth (93.1%). The proportion of minority donors differed by blood center, with African American donors (16%) most common at the Southeastern blood center and Asian (12%), Hispanic (13%), and foreign-born donors (13%) most common at the Northern California blood center. Minority donors and those born in Mexico or Latin America were younger than white donors. Minority and non-US-born donors were less likely than white and US-born donors to be repeat donors (odds ratio [OR], 0.60-0.78), and most were less likely to give two or more annual donations (OR, 0.82-1.11). CONCLUSION: Minority and Mexico/Latin America-born donors represent a younger and often first-time donor population compared to white and US-born donors, but their annual donation frequency was only slightly lower than white and US-born donors. Increasing the retention and donation frequency of minorities will be important for supplementing the blood supply.

Evaluation of self-collected vaginal swab, first void urine, and endocervical swab specimens for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae in adolescent females.

OBJECTIVE: To assess the concordance of self-obtained vaginal swabs (SVS), first void urine samples (FVU) and provider-collected endocervical swabs (PES) for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhea (NG) in adolescents. METHODS: A total of 342 adolescent women and 1080 baseline and semi-annual visits were analyzed. FVU, SVS and PES were collected at each biannual visit. All specimens were tested by BDProbeTec ET(trade mark) Amplified DNA Assay. Sensitivity, specificity, positive predictive value (PPV) negative predictive value (NPV) and kappa coefficient were calculated to evaluate the ability to identify possible infected cases using samples from three anatomic sites and the test agreement between any two of these three specimen types. Positive results from at least two of the three specimens collected from same subject at the same study visit was considered true positive. RESULTS: The positivity rates for CT and NG were 26.6 and 11.7 per 100 women respectively. The sensitivities of SVS, FVU and PES for detecting CT were 97.3%, 89.2% and 90.1% respectively. For the detection of NG, the sensitivities of the three sampling methods were 100%, 88.6% and 95.5% respectively. The specificities were between 94.7% and 99.7% for both CT and NG. Kappa coefficients of CT test results were 0.89, 0.88 and 0.83 for specimen pairs SVSvsPES, SVSvsFVU and PESvsFVU respectively. For the detection of NG, kappa coefficients were 0.91, 0.87 and 0.91 for these three pairs (all P<0.0001). Kappa>0.75 is considered excellent agreement between specimens. CONCLUSION: There were strong agreements among SVS, PES and FVU specimens on the detection of CT and NG infections in adolescent females using nucleic acid amplification test. SVS represented as high as or more sensitive an approach for detecting both CT and NG compared to PES. Although FVU was the least sensitive sampling method, it is also the least invasive method. Thus SVS and FVU may provide a reliable alternative to endocervical specimens for CT and NG screening.

More than just vaginal intercourse: anal intercourse and condom use patterns in the context of "main" and "casual" sexual relationships among urban minority adolescent females.

PURPOSE: Receptive anal intercourse has long been recognized as a risk factor for the transmission of HIV and STIs. Most HIV/STI prevention messages continue to emphasize penile-vaginal transmission, so many teens do not recognize anal intercourse as risky sexual behavior. This purpose of this study was to determine the prevalence of anal intercourse, and to describe the relationship between types of sexual relationships (main vs. casual), types of sexual behaviors (vaginal vs. anal sex), and types of contraception used among inner-city sexually experienced adolescents. METHODS: Reproductive health histories were obtained from 350 sexually experienced adolescent females aged 12-18 years participating in a 5-year STI acquisition study at an urban health center. Baseline sexual behavior data was analyzed and described using frequencies, percentages and chi-square tests. RESULTS: 41% of teens and 86.5% of teens reported engaging in sexual activity with casual and main partners respectively. Sixteen percent of teens with main partners and 12% of those with casual partners engaged in receptive anal intercourse (P = 0.31). Condom use is more prevalent for both vaginal (61% vs. 32.4%, P < or = 0.0001) and anal (47.1% vs. 21.3%, P = 0.0428) intercourse in the context of casual as compared to main sexual relationships. Teens involved in a casual relationship were more likely to use anal intercourse as a form of contraception (41.2% vs. 8.5%, P = 0.0022). CONCLUSION: It is imperative that health care providers recognize that adolescents engage in anal sex, specifically inquire about their types of sexual behavior and types of sexual relationships so that anticipatory guidance regarding HIV/STI transmission risk reduction education can be tailored to meet their needs.

Prostate specific antigen predicts the long-term risk of prostate enlargement: results from the Baltimore Longitudinal Study of Aging.

PURPOSE: Prostate specific antigen (PSA) is a predictor of prostate growth in men with lower urinary tract symptoms. The long-term risk of prostate enlargement as a function of PSA among community dwelling volunteers is unknown. MATERIALS AND METHODS: A Cox proportional hazards regression model was used to study the relationship between baseline PSA level at ages 40 to 49.9 years in 194 men, 50 to 59.9 in 191 and 60 to 69.9 in 144, and prostate enlargement, defined as a prostate volume larger than the 75th percentile for age decade, as measured by magnetic resonance imaging in a longitudinal study of aging (Baltimore Longitudinal Study of Aging, National Institute on Aging). Kaplan-Meier survival analysis was performed to estimate the probability of freedom from prostate enlargement with time as a function of baseline PSA level. RESULTS: The relative risk of prostate enlargement was 3- to 6-fold higher for men 40 to 49.9 years old with a baseline PSA of 0.31 ng./ml. or more compared to men with PSA levels of 0.30 ng./ml. or less at baseline. The relative risk was increased 5- to 9-fold in men 50 to 59.9 years old and 11-fold in those 60 to 69.9 years old when comparing men with PSA greater than 0.80 ng./ml. and greater than 1.70 ng./ml. with those with PSA 0.50 or less. The cumulative probability of freedom from prostate enlargement at 20 years was 0.89 (95% confidence interval ([CI] 0.79-0.99) and 0.63 (0.52-0.74) for men 40 to 49.9 years old with PSA levels below and above 0.30 ng./ml., respectively. For men 50 to 59.9 years old the 10-year probability of freedom from prostate enlargement was 0.90 (95% CI 0.84-0.96) and 0.59 (0.43-0.74) when PSA levels were below and above 0.80 ng./ml., respectively. At age 60 to 69.9 years the 10-year probability of freedom from prostate enlargement was 0.83 (95% CI 0.72-0.93) and 0.27 (0.09 to 0.48) when PSA levels were below and above 1.70 ng./ml., respectively. CONCLUSIONS: These data demonstrate the long-term risk of prostate enlargement by PSA level. Risk stratification based on PSA level may be useful to identify men at greatest risk for adverse events due to prostate enlargement and selection of men for future benign prostatic hyperplasia studies.

PSA velocity for assessing prostate cancer risk in men with PSA levels between 2.0 and 4.0 ng/ml.

OBJECTIVES: To evaluate the use of prostate-specific antigen (PSA) velocity (PSAV) in assessing prostate cancer risk among men with PSA levels less than 4.0 ng/mL. METHODS: The relative risk of, and cumulative probability of freedom from, prostate cancer by PSAV was evaluated in 89 male participants (21 with cancer and 68 controls) of a longitudinal aging study-the Baltimore Longitudinal Study of Aging (National Institute on Aging)-who had serial PSA levels between 2.0 and 4.0 ng/mL for at least 18 months. The relative risk was estimated from a Cox proportional hazards regression model, and the disease-free probability was determined by Kaplan-Meier survival analysis. The sensitivity and specificity of PSAV were calculated as a measure of test validity. RESULTS: The sensitivity and specificity of a PSAV of 0.1 ng/mL per year was 81% and 50%, respectively. The relative risk of prostate cancer was 6.53 (range 1.90 to 22.51) when the PSAV was 0.1 ng/mL per year or more compared with a PSAV of less than 0.1 ng/mL per year (P = 0.0029). At 10 years, the cumulative probability of freedom from prostate cancer was 97.1% (range 91.4% to 100%) and 35.2% (range 14.0% to 56.4%) when the PSAV was less than and greater than 0.1 ng/mL per year, respectively. Survival curves began to differ at less than 5 years after the baseline PSAV determination. CONCLUSIONS: The association between PSAV and the subsequent risk of prostate cancer suggests that the PSAV may be useful in the risk assessment of men with lower PSA levels.