[A multicenter study to test the reliability and validity of the frailty assessment scale for elderly patients with inguinal hernia and to evaluate the value of clinical application].

Objectives: To verify the reliability and validity of the frailty assessment scale for elderly patients with inguinal hernia and to evaluate the value of its clinical application. Methods: A convenience sampling method was used to collect 129 geriatric patients who underwent inguinal hernia surgery from January 2018 to January 2023 in nine hospitals in Liaoning Province. There were 120 males and 9 females, of whom 89 patients were 60 to <75 years old, 33 patients were 75 to <85 years old and 7 patients were ≥85 years old. The 129 patients included 11 elderly patients with inguinal hernia who had recovered from preoperative infection with COVID-19. Statistical methods such as Cronbach's coefficient, Kaiser-Meyer-Olkin test, Bartlett's test, Pearson's correlation analysis, etc. were calculated to verify the reliability indexes such as feasibility, content validity, structural validity, criterion-related validity, internal consistency reliability, and re-test reliability. Taking the 5-item modified frailty index (5-mFI) as the gold standard, the area under the curve was used to analyze the ability of the two scales to predict the occurrence of postoperative acute urinary retention, postoperative delirium, poor incision healing, operative hematoma seroma, and postoperative complications. Results: The frailty assessment scale for elderly patients with inguinal hernia showed good reliability and validity (valid completion rate of 99.2%; item content validity index of 1.000, and the scale content validity index of 1.000; exploratory factor analysis extracted a total of 1 principal component, and factor loadings of each item of 0.565 to 0.873; the AUC for frailty diagnosis using 5-mFI as the gold standard of 0.795 (P<0.01) Cronbach's coefficient of 0.916, retest reliability coefficient of 0.926), it could effectively predict postoperative acute urinary retention, delirium, hematoma seroma in the operative area and total complications (AUC of 0.746, 0.870, 0.806, and 0.738, respectively; all P<0.05), and prediction efficiency was higher than that of 5-mFI (AUC of 0.694, 0.838, 0.626 and 0.641, P<0.05 for delirium only), but both scales were inaccurate in predicting poor incision healing (AUC of 0.519, P=0.913 for the frailty assessment scale and 0.455, P=0.791 for the 5-mFI). Conclusions: The frailty assessment scale for elderly patients with inguinal hernia is reliable and significantly predicts the occurrence of postoperative adverse events in elderly inguinal hernia patients. The scale can also be used for preoperative frailty assessment in elderly patients with inguinal hernia after rehabilitation from COVID-19 infection.

[Significance of histological assessment in drug-induced liver injury].

Liver histological assessment is of great clinical significance for the diagnosis, classification, and prognosis prediction of drug-induced liver injury (DILI). Liver histological evaluation can effectively supplement RUCAM. The clinical phenotypes of DILI are complex and diverse, including acute, chronic and severe hepatic injury. DILI has multiple insult-targets, including hepatocytes, cholangiocytes, and vascular endothelial cells and others. The pathological damage patterns are similar to many types of non-DILI liver diseases, therefore making differential diagnosis difficult. New anti-tumor drugs such as immune checkpoints inhibitors and targeted therapy are widely used in clinical antineoplastic practice, thus the growing incidence of related liver injury occurs. Liver histological examination can effectively assess the pathological phenotypes and severity of DILI, so as to guide treatment. In uncommon conditions such as special types of DILI (such as hepatic vascular disease), DILI with other competitive etiology overlapping, chronic DILI, and DILI induced liver failure, liver histological assessment can provide strong support for identifying the cause, rational treatment, and prognosis. Currently, the histological evaluation system for drug-induced liver injury seems to be a lack of consensus, and the diagnosis of DILI is short of highly specific and sensitive serological markers. All in all, liver histological assessment plays a crucial role in the diagnosis and differential diagnosis of DILI.

CT metal artifact reduction algorithms: Toward a framework for objective performance assessment.

PURPOSE: Although several metal artifact reduction (MAR) algorithms for computed tomography (CT) scanning are commercially available, no quantitative, rigorous, and reproducible method exists for assessing their performance. The lack of assessment methods poses a challenge to regulators, consumers, and industry. We explored a phantom-based framework for assessing an important aspect of MAR performance: how applying MAR in the presence of metal affects model observer performance at a low-contrast detectability (LCD) task This work is, to our knowledge, the first model observer-based framework for the evaluation of MAR algorithms in the published literature. METHODS: We designed a numerical head phantom with metal implants. In order to incorporate an element of randomness, the phantom included a rotatable inset with an inhomogeneous background. We generated simulated projection data for the phantom. We applied two variants of a simple MAR algorithm, sinogram inpainting, to the projection data, that we reconstructed using filtered backprojection. To assess how MAR affected observer performance, we examined the detectability of a signal at the center of a region of interest (ROI) by a channelized Hotelling observer (CHO). As a figure of merit, we used the area under the ROC curve (AUC). RESULTS: We used simulation to test our framework on two variants of the MAR technique of sinogram inpainting. We found that our method was able to resolve the difference in two different MAR algorithms' effect on LCD task performance, as well as the difference in task performances when MAR was applied, vs not. CONCLUSION: We laid out a phantom-based framework for objective assessment of how MAR impacts low-contrast detectability, that we tested on two MAR algorithms. Our results demonstrate the importance of testing MAR performance over a range of object and imaging parameters, since applying MAR does not always improve the quality of an image for a given diagnostic task. Our framework is an initial step toward developing a more comprehensive objective assessment method for MAR, which would require developing additional phantoms and methods specific to various clinical applications of MAR, and increasing study efficiency.

[Effect of integrated schistosomiasis control measures in Hunan Province from 2004 to 2019].

OBJECTIVE: To examine the effect of the integrated schistosomiasis control measures in Hunan Province from 2004 to 2019, so as to provide insights into the development of the schistosomiasis elimination strategy. METHODS: The integrated schistosomiasis control measures implemented by the health, agriculture, water resources, forestry, land and resources sectors were retrospectively collected in Hunan Province from 2004 to 2019, and the completion of each measure, cost of control measures, Schistosoma japonicum infections in humans and bovines, and snail status were analyzed each year. An index system for assessing the integrated schistosomiasis control effect was constructed using the Delphi method to calculate the integrated schistosomiasis control effect index. In addition, a cost-effect analysis was performed in terms of the decline in the prevalence of S. japonicum infections in humans and bovines, areas with snails in inner embankments, and areas with infected snails. RESULTS: A total of 7 110 926 500 Yuan were invested into the integrated schistosomiasis control program of Hunan Province from 2004 to 2019. During the 16-year period, a total of 277 437.12 hm2 snail habitats received molluscicidal treatments, 6 927 230 person-times given expanded chemotherapy, 2 116 247 bovine-times given expanded chemotherapy, 954 850 harmless toilets built, 290 359 bovines fenced, 136 666 bovines eliminated, 141 905 machines used to replace bovines, 39 048.63 hm2 water lands improved as dry lands, 724.12 km irrigation regions improved, 3 994 300 populations covered with safe water, 191 102.89 hm2 forests planted and 38 535.27 hm2 lands leveled. The prevalence of S. japonicum infections was 4.29% in humans and 4.48% in bovines in Hunan Province in 2004, with 2 449.37 hm2 snail habitats in inner embankments and 3 423.74 hm2 infected snail areas. In 2019, the prevalence of S. japonicum infections reduced to 0 in both humans and bovines, and areas of snail habitats reduced to 540.92 hm2 (77.92% reductions), while the areas with infected snails reduced to 0. The overall integrated schistosomiasis control effect index appeared a tendency towards a rise over years since 2004, and the integrated schistosomiasis control effect index was 97.35 in 2019; the annual mean costs for a 1% reduction in the prevalence of S. japonicum infections in 100 populations and 100 bovines were 70.11 Yuan and 4 204.78 Yuan, and the annual mean costs for a 1% reduction in the snail areas in inner embankments and infected snail areas were 2 010.20 Yuan and 1 298.09 Yuan, respectively. CONCLUSIONS: The integrated control measures achieve remarkable effectiveness for schistosomiasis control in Hunan Province, with a remarkable decline in the prevalence of S. japonicum infections in humans and bovines and great shrinking of snail areas in inner embankments and infected snail areas. Adequate fund investment is required to improve the integrated schistosomiasis control measures and consolidate the control achievements.

[Assessment on Application of 24 Y-STR Loci in Forensic Science].

OBJECTIVES: To select a Y-STR marker system with strong haplotype identification ability, appropriate mutation rate and high compatibility and to assess its forensic application. METHODS: The 24 Y-STR loci were tested by self-built fluorescent multiplex system, and the forensic assessment was conducted by 139 pairs of father-son samples collected in Jinan, Shandong province. RESULTS: Totally 176 alleles were identified among the 24 Y-STR loci in the sample of 139 unrelated individuals labeled with father, and the gene diversity （GD） distributed between 0.083 7 （DYS645）-0.966 9 （DYS385a/b）. According to the 24 Y-STR loci, 139 different haplotypes were detected from 139 unrelated male individuals labeled with father in Han population of Shandong province and with no shared haplotype observed. The overall haplotype diversity （HD） was 1 and the discrimination capacity （DC） was 1. A total of 5 one-step mutations events were observed among the 24 Y-STR loci in 139 pairs of father-son. The average mutation rate was 0.001 5 [95% CI （0.000 5, 0.003 5）]. CONCLUSIONS: The system of 24 Y-STR loci shows a strong individual recognition ability and low mutation rate in the population in Jinan, Shandong province, and it has good application value in forensic science.

[Assessment of Height Prediction Model Based on SNPs Loci].

OBJECTIVES: To establish a height prediction model of Chinese Han male based on the reported 547 height-associated single nucleotide polymorphisms （SNPs） loci in Europeans, and assess its accuracy for height estimation. METHODS: The DNA typing was analyzed in 59 Han male samples of Shandong province by Affymetrix SNP Array 6.0 chip and HiSeq 4000 sequencing platform. Prediction model was established using 547 height-associated SNPs loci as predictors and weight allele sums （WAS） as computing method. The accuracy of height prediction model was analysed using receiver operating characteristic （ROC） curve and area under curve （AUC）. RESULTS: There was no height-associated SNPs locus was found by genome-wide association studies. In present study, height prediction model was established by WAS and obtained an AUC of 0.67 （95% CI: 0.53-0.90）. CONCLUSIONS: It has reference value for predicting the height of Han male in Shandong province by WAS model based on 547 SNPs loci, while it is still necessary to further promote the accuracy of the prediction model by screening more height-associated SNPs loci with population heterogeneity.

[Radiographic assessment of vertebral artery injury in anterior cervical surgery in healthy adults].

Objectives: To study the relationship between the anatomical parameters of transverse foramen and intervertebral discs in the cross-section of the cervical spine in healthy adults, and to evaluate the risk of vertebral artery injury in the anterior cervical spine surgery. Methods: There were 24 healthy adults(12 male, 12 female) underwent neck CT angiography with clear vertebral artery and the adjacent structure imaging from June to December 2014 in Huashan Hospital, Fudan University. The anatomical parameters of vertebral artery V2 segment with lower cervical vertebrae and intervertebral discs were measured by cross-sectional images of C(3-6). The corresponding parameters of different sex and both sides of the same segment were analyzed by independent samples t-test and paired t test, respectively. The least significant difference(LSD) t test was used to compare the corresponding data between different segments. Results: The vertebral artery was not walking in the middle of the transverse foramen in healthy individual, but partial medial, partial front walking. Transverse diameter of transverse foramen in male and female were 6.62-6.89 mm and 6.21-6.45 mm, and sagittal diameter was 5.41-6.48 mm and 5.40-6.10 mm, respectively.The transverse foramen were slightly oval. The distance between vertebral artery and midline in male and female were 14.23-16.12 mm and 13.60-15.04 mm, respectively, which was much larger than the width of cervical vertebral corpectomy. Compared with C(3-4), intervertebral disc, the transverse distance between the vertebral artery and the uncovertebral joint of C(4-5), C(5-6) was smaller, and the distance from the vertebral artery to the posterior margin of the uncovertebral joint was relatively small, the difference was statistically significant (t=2.449, P=0.022). The distance from vertebral artery to the posterior margin of uncinate process was 1/5-2/5 of the distance between the anterior and posterior edge of the corresponding segmental vertebra. Conclusion: Based on this anatomical study, the risk of vertebral artery injury in conventional anterior cervical decompression is small, and the risk of vertebral artery injury in different segments is slightly different.

Comparison of Upper Midline Incision With and Without Laparoscopic Assistance for Living-Donor Right Hepatectomy.

BACKGROUND: Since minimally invasive procedures for living-donor right hepatectomy (LDRH) became popular in recent years, several studies comparing the outcomes of donors undergoing an upper midline incision (UMI) under laparoscopic assistance for LDRH with those undergoing the traditional open LDRH have been published. However, there are very few comparative studies of outcomes for a UMI for LDRH with and without laparoscopic-assistance. We designed the present study to compare the benefits and shortcomings of a UMI for LDRH with and without laparoscopic assistance. METHODS: Forty-eight patients in our center were included in the study: group hybrid (n = 28) versus group UMI (n = 20). Their surgical outcomes, postoperative course, and cosmetic outcomes were studied from medical records. RESULTS: No differences existed between the 2 groups regarding their baseline characteristics except that group Hybrid had more donors with positive hepatitis B core antibody. No difference was observed in operative time, graft weight, warm ischemia time, blood loss, incision length, liver and coagulation function test results, postoperative complications, or cosmetic parameters. No deaths occurred in both groups. The length of postoperative hospital stay was similar for both groups, but the hospital cost was significantly lower for group UMI than for group hybrid (6,906.7 ± 777.4 USD vs 7,643.3 ± 918.6 USD; P = .005). CONCLUSIONS: An UMI without laparoscopic assistance can be considered as the first-line incision of choice for LDRH.

"Of and beyond medical consequences": Exploring health information scanning and seeking behaviors of Filipino domestic service workers in Hong Kong.

The increasing trend for women in developing countries to engage in international and temporary labor migration has exposed female migrant workers to health inequities. In this article, we problematize the impact of international and temporary labor migration on the health of Filipino domestic workers in Hong Kong by exploring their general patterns of health information acquisition. Through a series of focus group discussions with Filipino domestic workers in Hong Kong, we found that employers serve as stakeholders in migration health, social networking sites can be a platform for participatory health promotion, and religious beliefs and behaviors can promote favorable health behaviors.

Effect of specialized diagnostic assessment units on the time to diagnosis in screen-detected breast cancer patients.

BACKGROUND: The duration of the cancer diagnostic process has considerable influence on patients' psychosocial well-being. Breast diagnostic assessment units (DAUs) in Ontario, Canada are designed to improve the quality and timeliness of care during a breast cancer diagnosis. We compared the diagnostic duration of patients diagnosed through a DAU vs usual care (UC). METHODS: Retrospective population-based cohort study of 2499 screen-detected breast cancers (2011) using administrative health-care databases linked to the Ontario Cancer Registry. The diagnostic interval was measured from the initial screen to cancer diagnosis. Diagnostic assessment unit use was based on the biopsy and/or surgery hospital. We compared the length of the diagnostic interval between the DAU groups using multivariable quantile regression. RESULTS: Diagnostic assessment units had a higher proportion of patients diagnosed within the 7-week target compared with UC (79.1% vs 70.2%, P<0.001). The median time to diagnosis at DAUs was 26 days, which was 9 days shorter compared with UC (95% CI: 6.4-11.6). This effect was reduced to 8.3 days after adjusting for all study covariates. Adjusted DAU differences were similar at the 75th and 90th percentiles of the diagnostic interval distribution. CONCLUSIONS: Diagnosis through an Ontario DAU was associated with a reduced time to diagnosis for screen-detected breast cancer patients, which likely reduces the anxiety and distress associated with waiting for a diagnosis.

Cisplatin plus etoposide versus other platin-based regimens for patients with extensive small-cell lung cancer: a systematic review and meta-analysis of randomised, controlled trials.

AIM: To determine whether the cisplatin plus etoposide (EP) combination was more efficacious and less toxic than other platinum-based regimens for patients with extensive-stage small-cell lung cancer. METHODS: We performed an extensive literature search (from their inception to July 2010). Two reviewers independently assessed search results and methodological quality of included studies. Pooled hazard ratios (HRs) and relative risks (RRs) were calculated according to a random-effects model. RESULTS: Twelve randomised, controlled trials involving seven different platinum-based chemotherapy regimens were included into this meta-analysis. The meta-analysis showed that compared with EP regimen, irinotecan plus cisplatin (IP) might decrease the risk of death (HR = 0.87, 95% confidence interval (CI) 0.78-0.97, P = 0.01) (five trials), unlike the sensitivity analysis (HR = 0.91, 95% CI 0.81-1.02, P = 0.12), progression-free survival (HR = 0.95, 95% CI 0.86-1.05, P = 0.28) and overall response rate (RR 1.08, 95% CI 0.93-1.24) that were not superior for IP. IP regimen produced more non-haematological toxicities and less haematological toxicities. One trial found that etoposide + cisplatin + epirubicin + cyclophosphamide and cisplatin + etoposide + ifosfamide regimen might prolong the overall survival respectively. Etoposide + cisplatin + epirubicin + cyclophosphamide regimen also might improve progression-free survival but with high rate of haematological toxicities. None of the other trials included in the study demonstrated a significant improvement in survival. CONCLUSIONS: There is no strong evidence that any clinical advantage for extensive small-cell lung carcinoma patients requiring chemotherapy when comparing EP with other platin-based regimens, with exception of IP that might prolong overall survival. The decision to prescribe which chemotherapy should take into consideration both cost and treatment preference.

Assessment of the ex vivo biomechanical properties of porcine cornea with inflation test for corneal xenotransplantation.

OBJECTIVE: This study aims to obtain the biomechanical properties of porcine cornea so as to provide necessary biomechanical experimental basis for pig-to-human corneal xenotransplantation. METHODS: Seventeen fresh porcine corneal specimens obtained from pigs aged 4-6 months were examined under inflation conditions to determine the constitutive relationships of the material through dynamic loading conditions (pressure range: 1.47-42.66 mmHg). The forward deflection of porcine anterior corneal apex was measured by the laser displacement sensor. The pressure deformation results were analysed on the basis of shell theory to estimate Young's modulus of the cornea and derive its relationship with intraocular pressure (IOP). RESULTS: The porcine corneas showed a nonlinear corneal forward displacement/IOP and stress/strain relationship with an initial low stiffness stage and a later high stiffness stage. In spite of the nonlinearity between the internal pressure and apex forward deflection, the relationship between the Young's modulus and the IOP was almost linear. CONCLUSIONS: Compared with human corneas, porcine corneas exhibited a similar nonlinear behaviour but lower stiffness values. The biomechanical parameters of porcine cornea obtained from this test could be applied to numerical simulations of refractive surgery procedures and lay a foundation for pig-to-human corneal xenotransplantation.

Application of multifocal visual evoked potentials in the assessment of visual dysfunction in macular diseases.

PURPOSE: To evaluate the use of AccuMap multifocal visual evoked potentials (mfVEP) in visual dysfunction caused by macular diseases. METHODS: Forty-eight eyes with known macular diseases underwent AccuMap mfVEP and microperimetry 1 (MP1) assessments. Evaluation of mfVEP abnormality was based on an amplitude deviation probability plot and the AccuMap Severity Index (ASI). Correlation analyses of the mean mfVEP amplitude corresponding to a radius of 2°, 5°, and 10° of the central visual field, minimum angle of resolution best-corrected visual acuity (BCVA), and MP1 mean sensitivity of the corresponding areas were performed. RESULTS: Among the 48 affected eyes, AccuMap mfVEP detected an abnormality of the central visual field in 45 eyes, with a sensitivity of 93.8%. The mean mfVEP amplitudes within a radius of 2°, 5°, and 10° of the central visual field were found to be positively correlated with BCVA (P<0.01 for all groups). The mean amplitudes also positively correlated with the MP1 mean sensitivity value of the corresponding visual field (P<0.01 for all groups). In the group with stable fixation or predominantly central fixation, the mean mfVEP amplitudes did not correlate with the BCVA or the MP1 mean sensitivity value. Regardless of the fixation status, the ASI was found to correlate with both the BCVA and the total MP1 mean defect value. CONCLUSION: Objective perimetry using AccuMap mfVEP might be applied in the assessment of macular function, with the ASI offering a potentially useful indicator for evaluating macular dysfunction.

Prophylaxis against hepatitis B recurrence posttransplantation using lamivudine and individualized low-dose hepatitis B immunoglobulin.

Although the combination of lamivudine (LAM) and high-dose intravenous (IV) hepatitis B immunoglobulin (HBIG) is very effective in preventing hepatitis B virus (HBV) recurrence after liver transplantation (LT), the major limitation of this regimen is its high cost. A more cost-effective, convenient and widely accepted regimen is urgently needed. We evaluated the safety and efficacy of another strategy using LAM and individualized low-dose intramuscular (IM) HBIG. Between May 2002 and December 2009, a total of 254 adult patients undergoing LT for HBV-related benign end-stage liver diseases received this regimen in our center. The mean follow-up of these patients was 41.2 +/- 22.7 months. Their 1-, 3- and 5-year survival rates were 85.3%, 77.4% and 76.4%, respectively, and 1-, 3- and 5-year HBV recurrence rates were 2.3%, 6.2% and 8.2%. Fourteen patients experienced posttransplant HBV recurrence. Pretransplant high viral load and posttransplant prednisone withdrawal time were observed to be associated with recurrence. In conclusion, combination therapy with LAM and individualized low-dose IM HBIG provides a safe and effective prophylaxis against HBV recurrence after LT at about 5% of the cost of conventional high-dose IV HBIG regimens.

Removal efficiency of high-concentration H2S in a pilot-scale biotrickling filter.

A pilot-scale biotrickling filter (BTF) packed with polyurethane (PU) foam was installed at one pharmaceutical factory in Zhejiang Province to study the removal of high-concentration H2S from water treatment plant. Experiments were performed at different empty bed residence times (EBRTs), H2S input load, ratio of liquid flow rate to gas inlet rate (L/G) and sulfate concentration in recirculating liquid to examine their effects on the performance of the BTF. The performance of this bioreactor was monitored continuously over a period of 56 days. After the start-up within 8 days, H2S removal efficiency remained between 90% and 100% with inlet concentration fluctuating from 238 to 590 mg m(-3). H2S removal efficiency was consistently greater than 90%, even at a short EBRT of 9 s and inlet H2S load higher than 187 g m(-3) h(-1). Profiles over the height of the reactor indicated that H2S removal took place mostly in the first section of the column. The performance of BTF could be maintained at high and stable levels when L/G was below 0.005 and sulfate concentration down to 28 g l(-1). The results led to the conclusion that BTF is the optimal choice for treating high-concentration H2S.

A perspective on medical infrared imaging.

Since the early days of thermography in the 1950s, image processing techniques, sensitivity of thermal sensors and spatial resolution have progressed greatly, holding out fresh promise for infrared (IR) imaging techniques. Applications in civil, industrial and healthcare fields are thus reaching a high level of technical performance. The relationship between body temperature and disease was documented since 400 bc. In many diseases there are variations in blood flow, and these in turn affect the skin temperature. IR imaging offers a useful and non-invasive approach to the diagnosis and treatment (as therapeutic aids) of many disorders, in particular in the areas of rheumatology, dermatology, orthopaedics and circulatory abnormalities. This paper reviews many usages (and hence the limitations) of thermography in biomedical fields.

Mouse BAC ends quality assessment and sequence analyses.

A large-scale BAC end-sequencing project at The Institute for Genomic Research (TIGR) has generated one of the most extensive sets of sequence markers for the mouse genome to date. With a sequencing success rate of >80%, an average read length of 485 bp, and ABI3700 capillary sequencers, we have generated 449,234 nonredundant mouse BAC end sequences (mBESs) with 218 Mb total from 257,318 clones from libraries RPCI-23 and RPCI-24, representing 15x clone coverage, 7% sequence coverage, and a marker every 7 kb across the genome. A total of 191,916 BACs have sequences from both ends providing 12x genome coverage. The average Q20 length is 406 bp and 84% of the bases have phred quality scores > or = 20. RPCI-24 mBESs have more Q20 bases and longer reads on average than RPCI-23 sequences. ABI3700 sequencers and the sample tracking system ensure that > 95% of mBESs are associated with the right clone identifiers. We have found that a significant fraction of mBESs contains L1 repeats and approximately 48% of the clones have both ends with > or = 100 bp contiguous unique Q20 bases. About 3% mBESs match ESTs and > 70% of matches were conserved between the mouse and the human or the rat. Approximately 0.1% mBESs contain STSs. About 0.2% mBESs match human finished sequences and > 70% of these sequences have EST hits. The analyses indicate that our high-quality mouse BAC end sequences will be a valuable resource to the community.

Prognostic radiology: quantitative assessment of tumor oxygen dynamics by MRI.

It is generally recognized that tumor hypoxia has a strong influence over therapeutic outcome in the clinic. The authors have developed an oximetry approach using 19F echo planar magnetic resonance imaging-FREDOM (Fluorocarbon Relaxometry using Echoplanar imaging for Dynamic Oxygen Mapping), which reveals dynamic changes based on sequential maps of regional tumor PO2. Preclinical investigations focused on diverse sublines of the Dunning prostate R3327 tumor. As expected, intratumoral heterogeneity was considerable. However, large tumors (>3.5 cm3) were significantly less well oxygenated than smaller tumors (<2 cm3). Faster growing, less differentiated tumors were less well oxygenated than size-matched tumors of slower growing sublines. The greatest potential of this technique is the ability to follow the fate of individual tumor regions with respect to interventions. For each subline, there was a significant response to respiratory challenge with oxygen for initially well-oxygenated regions (baseline PO2 > 10 mm Hg). More interestingly, subline dependent behavior was found for initially hypoxic regions that correlated with rate of growth. The authors believe the FREDOM approach is essentially ripe for translation to the clinic. This approach could help to identify patients with hypoxic tumors and indicate the feasibility of manipulating tumor characteristics through adjuvant interventions to improve therapeutic response.

Quantitative assessment of stenotic aortic valve area by using intracardiac echocardiography: in vitro validation and initial in vivo illustration.

Quantitative assessment of aortic stenosis (AS) is subject to the limitations of all current noninvasive and invasive methods. The ability to obtain a direct measure of aortic valve area with high resolution by intracardiac echocardiography (ICE) could be of great benefit to catheterized patients. To provide a fixed AS area as an ideal standard for comparison, we performed ICE in 12 sheep hearts with experimentally created AS and five human AS hearts from autopsies. ICE catheters were passed retrograde across the aortic valve, and the minimal orifice area on pullback was planimetered and compared with calibrated video imaging. The entire orifice circumference could be successfully recorded in 16 (94%) hearts. Orifice area from ICE correlated well with actual values (r=0.98; standard error of the estimate [SEE] = 0.06 cm2). To illustrate the applicability in vivo, two canine models and 10 patients with AS were studied. The limiting orifice could be imaged in both animals and in 8 of 10 patients, in whom values agreed well with invasive data (r= 0.95; SEE = 0.04 cm2). ICE can therefore accurately measure AS orifice area in vitro; it can be applied in vivo as well. These validation studies laid the foundation for subsequent clinical studies and applications.

Intracardiac ultrasonographic assessment of atrial septal defect area: in vitro validation and technical considerations.

Assessment of atrial septal defect (ASD) size and shape is important for planning and guiding its transcatheter occlusion and can potentially be achieved by intracardiac ultrasonography (ICUS). ICUS accuracy, however, must first be established against stable standards and technical imaging requirements defined. We therefore used 10, 20, and 30 MHz ICUS catheters to examine 17 ASDs that were 0.16 to 6.7 cm2 in area and were surgically created in excised ovine hearts with 10, 20, and 30 MHz ICUS catheters. ASD shape and area by ICUS were compared with direct video images of the actual ASD. In all instances minimal area by ICUS pullback agreed well with actual values (y = 1.04x + 0.2, SEE = 0.23 cm2, r = 0.99) and corresponded well with defect shapes. The maximum angle between ultrasonography beam and septal plane allowing for complete ASD visualization was 20 degrees. The angle depended on transducer frequency and septal thickness. This new technique has potential value for the accurate assessment of ASD shape and size and may be especially useful in the setting of transcatheter occlusion.