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PubMed1997

The role of color Doppler and staging biopsies in prostate cancer detection.

OBJECTIVES: To review the current published data on the role of color Doppler sonography and sonographically-guided staging biopsies in the detection and staging of prostate cancer. This article also discusses the role of color Doppler sonography in defining the ideal patients for neoadjuvant chemotherapy. METHODS: Peer-reviewed reports in the radiologic, urologic, and medical literature were reviewed. Data from our own institution served as illustrative material. RESULTS: Color Doppler sonography using state of the art ultrasound equipment produced from the mid 1990s onward can define areas of hypervascularity in the prostate. When located in the peripheral zone and associated with definable lesions, these areas likely represent carcinoma. More importantly, when isoechoic areas contain hypervascular foci with chaotic flow, cancer is also likely. In 93% of sites that contain normal vascularity, prostate cancer was not detected by biopsy. Staging biopsies are not frequently performed in current clinical practice. A positive seminal vesicle biopsy is associated with capsular penetration in 100% and positive lymph nodes in 50% of patients with prostate cancer. CONCLUSIONS: Color Doppler sonography and staging biopsies may have a more significant role as newer alternative therapies for prostate cancer become popular. These two techniques show promise for increasing the accuracy of pretreatment staging over current algorithms, which are less than adequate.

Biopsy↗
PubMed2006

[Application research on the flow-through hybridization and gene chip in human papillomavirus detection].

OBJECTIVE: To evaluate the clinical efficacy of flow-through hybridization and gene chip (HybriMax) on female low genital human papillomavirus (HPV) detection and to identify the most common HPV genotypes. METHODS: Five hundred and ninety-one of 7520 women who received cervical cancer screening in China-Japan Friendship Hospital during Jun 2004 to May 2005 were selected for 21 genotypes HPV detecting by HybriMax, including 138 women with normal cytological diagnosis and 453 women with abnormal cytological diagnosis. The abnormal patients were classified into groups according to their histological diagnosis as chronic cervicitis, cervical intraepithelial neoplasia (CIN) I, II, III, cervical cancer and condyloma acuminata. Among them 413 women were tested with HC-II for 13 types of high-risk HPV, and 101 paraffin-embedded specimens from these 453 patients were detected for HPV16, 18 with in situ hybridization (ISH). The accordance of the results was compared. The infection rates of each HPV type for each group were calculated. RESULTS: The total accordant rate of HybriMax and HC-II on 13 types of high-risk HPV detecting was 92.5% (382/413) and was 100.0% in group of cancer. The accordance was good, and the Kappa index (KI) was as below: overall 0.814, in normal group 0.750, in chronic cervicitis 0.781, in CIN I 0.755, in CIN II 0.619, in CIN III 0.548, in condyloma acuminata 0.800. The accordant rate of HybriMax and ISH was 89.1% (90/101), and KI was 0.766. The 10 most common genotypes were (in descending sequences): in normal group 16, 68, 18, 52, 58, 11, 53, 31, 39, 33; in abnormal group 16, 52, 58, 18, 33, 31, 81, 53, 68, 66, in cervical cancer 16, 18, 52, 58, 33, 66, 68, 31, 51, 53. CONCLUSIONS: HybriMax has good accordance to HC-II and ISH for HPV detection. It provides useful information on viral genotype and is more suitable for clinical use. The 6 most common genotypes in abnormal cytological group are 16, 18, 52, 58, 33, 31.

Adult↗
PubMed2000

Monitoring of isoflurane and desflurane breakdown: interfering gases and infrared detection.

OBJECTIVE: The reaction of isoflurane, enflurane or desflurane with dried CO2 absorbents produces carbon monixide (CO), a highly toxic gas which cannot be detected by gas monitors typically available in the operating room. Trifluoromethane (CHF3) is produced along with CO when this reaction occurs with isoflurane and desflurane, and can be detected by gas monitors. This study will determine the ability of a modified SAM module (Smart Anesthesia Multigas Module, GE/Marquette Medical Systems, Milwaukee, WI) to identify the presence of CHF3, and provide a clinically useful indirect warning of CO production. METHODS: Isoflurane (1.5%) and desflurane (7.5%) were reacted under clinical conditions with desiccated absorbents resulting in CO production. CO and CHF3 concentrations were measured using gas chromatography. The CHF3 concentrations measured by a modified SAM monitor were compared with the measurements obtained by gas chromatography. Alarm limits set on the SAM monitor were used to warn of the presence of CHF3. RESULTS: A concentration of 0.25% CHF3, as measured by the SAM monitor, corresponds to an average CO concentration of 780 ppm for isoflurane and 1700 ppm for desflurane. Lowering the threshold to 0.05% CHF3 would result in an average CO concentration of 155 ppm CO for isoflurane and 345 ppm CO for desflurane. CONCLUSIONS: We have shown that the SAM module is capable of measuring CHF3 due to anesthetic breakdown. With appropriate changes in the display programming and reference cell spectra the monitor would be able to provide an early warning of CO exposure, although the amount of CO would not be reported.

Anesthesia, General↗
PubMed1994

Assessment of left ventricular performance by on-line pressure-area relations using echocardiographic automated border detection.

OBJECTIVES: The purpose of this study was to evaluate left ventricular performance by on-line pressure-area relations using echocardiographic automated border detection in the in situ canine heart in a manner similar to pressure-volume analyses. BACKGROUND: Echocardiographic automated border detection can measure ventricular cavity area as an index of volume and may be interfaced with pressure to construct pressure-area loops on-line. METHODS: Eight anesthetized open chest dogs had simultaneous measurement of ventricular pressure, aortic flow and midventricular short-axis area. Pressure-area loops were constructed by a computer workstation interfaced with the ultrasound system. Stroke area (Maximal area--Minimal area) and stroke force (integral of P dA [P = pressure; A = area]) values during inferior vena cava (n = 8) and aortic (n = 4) occlusions were compared with stroke volume and estimates of stroke work, respectively. Inotropic modulation was induced with dobutamine infusion (2 to 5 micrograms/kg body weight per min), followed by propranolol infusion (2 to 5 mg). End-systolic and maximal elastance and preload recruitable stroke force (stroke force versus end-diastolic area) were derived for each period. RESULTS: Changes in stroke area and stroke force were significantly correlated with changes in stroke volume and estimates of stroke work during caval occlusion (n = 8) (r = 0.87 +/- 0.02, SEE = 8 +/- 1% and r = 0.90 +/- 0.03, SEE = 8 +/- 2%, respectively). In dogs with aortic occlusion (n = 4), changes in stroke area significantly correlated with changes in stroke volume for pooled data (r = 0.84, SEE = 8%, y = 1.0x + 3). Ventricular performance increased with dobutamine infusion (n = 7): end-systolic elastance 30 +/- 11 to 67 +/- 24 mm Hg/cm2 (p < 0.02 vs. control values); maximal elastance 37 +/- 11 to 82 +/- 26 mm Hg/cm2 (p < 0.02 vs. control values); preload recruitable stroke force 81 +/- 24 to 197 +/- 92 mm Hg (p < 0.02 vs. control values). Decreases occurred with propranolol infusion (n = 5) end-systolic elastance 20 +/- 4 to 13 +/- 4 mm Hg/cm2 (p < 0.002 vs. control values); maximal elastance 29 +/- 8 to 15 +/- 5 mm Hg/cm2 (p < 0.002 vs. control values); preload recruitable stroke force 66 +/- 14 to 40 +/- 9 mm Hg (p < 0.002 vs. control values). CONCLUSIONS: On-line pressure-area relations are a potentially useful means to assess left ventricular performance in a manner that is quantitatively similar to the predicted responses of pressure-volume relations.

Animals↗
PubMed2002

Comparative evaluation of total PSA, free/total PSA, and complexed PSA in prostate cancer detection.

OBJECTIVES: To compare the performance of prostate-specific antigen (PSA), the free/total PSA (F/T PSA) ratio, and complexed PSA (cPSA) in prostate cancer detection. METHODS: Five hundred thirty-five patients evaluated at the UROMED prostate cancer detection clinic had total PSA, free PSA, and cPSA measured before undergoing transrectal ultrasonography and sextant prostate biopsies. A direct comparison was performed between the different PSA assays to evaluate their ability to detect prostate cancer. RESULTS: Of the 535 patients evaluated, 38.1% had prostate cancer detected. The mean age of the entire population was 63.6 years (range 35 to 86). Abnormal digital rectal examination findings were present in 33.4% of the patients. The mean and median values of PSA and cPSA were significantly higher and the F/T PSA ratio was lower in patients with prostate cancer. The F/T PSA ratio performed better than either cPSA or total PSA. A higher specificity was observed with the F/T PSA ratio than with cPSA using either the entire patient population or subsets of patients with PSA levels between 4.0 and 10 ng/mL or 4.0 to 6.0 ng/mL. CONCLUSIONS: The use of the F/T PSA ratio offers improved prostate cancer detection compared with either cPSA or total PSA.

Adult↗
PubMed2006

[Determination of propofol in cerebral spinal fluid by HPLC with fluorescence detection].

OBJECTIVE: To establish a method for determining propofol in human cerebrospinal fluid (CSF). METHODS: Reverse phase high-performance liquid chromatography (HPLC) with fluorescence detection was applied to quantitative analysis. CSF samples were centrifuged (12,500 r/min for 3 min) and filtered (the diameter of the filter is 0.45 microm). Twenty mul of supernatant was directly injected and separated by Supelco Discovery C(18)column. The mobile phase was composed of methanol-water (80:20); the flow rate was 1 ml/min, and the column temperature was 30 degree. The fluorescence detective waves were: lambda ex=276 nm and lambda em=310 nm. RESULTS: The linear range of propofol in CSF was 5-200 ng/ml (r=0.9994). The recovery rates for high, intermediate and low concentrations were 101.2%, 99.8%, 98.8%, respectively. The RSD of inter-day assay was 1.55%, 1.73%, 6.01% and it of intra-day assay was 1.69%, 2.37%, 8.60%. The limit of detection proved to be 2 ng/ml. CONCLUSION: The method is rapid, simple, accurate and sensitive for measurement of propofol concentration in CSF.

Anesthetics, Intravenous↗
PubMed2003

Manually respiratory-triggered single-shot fast spin-echo: a non-breath-hold T2-weighted method for liver lesion detection.

OBJECTIVES: To determine whether manual respiratory triggering of a T2-weighted single-shot fast spin-echo sequence (M-SSFSE) improves detection and characterization of liver lesions compared with conventional breath-held single-shot fast spin-echo (C-SSFSE) technique. METHODS: M-SSFSE is performed by manually triggering a series of single-slice acquisitions through the liver at end of expiration. There were 171 hepatic lesions in 49 patients. Images were randomized and reviewed by 3 radiologists. Lesions were characterized as hemangiomas, cystic or solid. Dynamic gadolinium-enhanced sequences were used as the reference standard. Contrast-to-noise ratios (CNR) were calculated for all lesions that measured 1 cm or more. RESULTS: M-SSFSE was more sensitive than C-SSFSE in the detection of liver lesions (48%-58% v. 37%-46%, p < 0.001). There were no significant differences in the specificity of lesion detection between the 2 sequences. Artifacts were significantly less severe for M-SSFSE compared with C-SSFSE (p = 0.001). The CNR was significantly higher for all liver lesions on M-SSFSE compared with C-SSFSE (p < 0.001). CONCLUSION: M-SSFSE significantly improved hepatic lesion detection and, in particular, improved characterization of solid liver lesions and hemangiomas compared with C-SSFSE imaging.

Adult↗
PubMed1999

Prospective evaluation of free beta-subunit of human chorionic gonadotropin and dimeric inhibin A for aneuploidy detection.

OBJECTIVE: Our goal was to prospectively evaluate the use of the free beta-subunit of human chorionic gonadotropin and dimeric inhibin A for the detection of fetal Down syndrome and other aneuploidies. STUDY DESIGN: Women who had a second-trimester multiple-marker screening test (alpha-fetoprotein, unconjugated estriol, human chorionic gonadotropin) and genetic amniocentesis from August 1996 to August 1998 were included. Serum was also analyzed for inhibin and the free beta-subunit of human chorionic gonadotropin. Detection and false-positive rates for 4 analyte combinations at 5 different screening risk cutoff points for Down syndrome were determined and compared. RESULTS: We evaluated 1256 patients, including 23 with aneuploidy (13 with Down syndrome, 10 others). The maternal age was 35.9 +/- 4.6 years (mean +/- SD). At the optimal risk cutoff point for Down syndrome detection (1:190; false-positive rate, 19%), the multiple-marker screening test plus inhibin was superior, detecting 85% of Down syndrome cases, in comparison with 69% when the multiple-marker screening test alone was used and 62% when the other 2 combinations were used. The multiple-marker screening test plus inhibin also detected 60% of the other aneuploidies. CONCLUSIONS: When evaluated prospectively in a high-risk population, the multiple-marker screening test plus inhibin was superior to the traditional multiple-marker screening test and 2 other analyte combinations, with a lower false-positive rate and increased detection of all aneuploidies in a high-risk population.

Amniocentesis↗
PubMed1986

Object-motion detection affected by concurrent self-motion perception: psychophysics of a new phenomenon.

Thresholds for object-motion detection are significantly raised when concurrent self-motion perception is induced by either vestibular, or visual, or cervico-somatosensory stimulation. Active sinusoidal horizontal head oscillations with compensatory vestibulo-ocular reflex (VOR) and foveal or eccentrical target presentation; 'passive' head movements with fixation suppression of the VOR; pure body oscillations with the head fixed in space (cervical stimulation); optokinetically induced apparent self-motion (circularvection). This new visual phenomenon of a physiological 'inhibitory interaction' between object- and self-motion perception seems to have a somatosensory motor analogue. It may reflect the disadventageous side effect due to unspecificness of an otherwise beneficial space constancy mechanism, which provides us with the image of a stable world during locomotion.

Adolescent↗
PubMed2000

Selective intraarterial contrast-enhanced CT of pancreaticoduodenal tumors: early clinical experience in evaluating blood supply and detectability.

OBJECTIVE: The purpose of this study was to compare CT with selective intraarterial contrast enhancement with IV contrast-enhanced CT for diagnostic usefulness in the detection of tumors in the pancreaticoduodenal region. SUBJECTS AND METHODS: intraarterial contrast enhanced CT was performed in 36 patients with tumors of the pancreaticoduodenal region. Feeding arteries of the tumors and distribution of hyperattenuating areas on intraarterial contrast-enhanced CT were analyzed with various routes of contrast material injections. The intraarterial contrast-enhanced CT scans were compared with the IV contrast-enhanced CT scans. RESULTS: In all 29 patients with standard vascular anatomy, the right cephalic portion of the pancreatic head was enhanced on CT during common hepatic or gastroduodenal arteriography and the left caudal portion was enhanced on CT during superior mesenteric arteriography. The enhanced areas were complementary to each other in the whole pancreatic head, including the tumor. Tumor conspicuity from the surrounding pancreatic tissue on intraarterial contrast-enhanced CT was not superior to that on IV contrast-enhanced CT in all but four patients with cystic tumors. After intraarterial contrast-enhanced CT, three patients with tumors less invasive than pancreatic ductal carcinoma underwent local resection of their lesions. CONCLUSION: Intraarterial contrast-enhanced CT for pancreaticoduodenal tumors has potential technical problems and is not valuable in improving the detectability of tumors other than cystic lesions because the enhancement of the wall and septa of the tumor is emphasized. However, the feeding artery of the tumor and its surrounding tissue were clearly depicted.

Adult↗
PubMed1987

Object-motion detection affected by concurrent self-motion perception: applied aspects for vehicle guidance.

Thresholds and response times for object-motion detection are significantly raised during concurrent real or visually induced self-motion perception. This was demonstrated by standardized laboratory experiments in which subjects had to react to a suprathreshold visual stimulus (1 degree-light spot moving with 5 degrees/s speed) under different stimulus conditions of simultaneously perceived self-motion. Elevated response times (mean elevation factor: 3.27) were also obtained for the detection of changes in inter-vehicle distance (headway) under real road conditions with the simultaneous involvement of self- and object-motion perception compared to a corresponding (object-motion perception) simulation in the laboratory without any self-motion. With regard to vehicle guidance, existing concepts of safe stopping distances, which depend upon adequate detection of a collision course and the corresponding reaction times, have to be recalculated.

Adult↗
PubMed2003

Testing a conceptual locus for the inconsistent object change detection advantage in real-world scenes.

Changes to objects that are inconsistent with the scene in which they appear are detected more accurately than changes to consistent objects. In three experiments, we tested whether this inconsistent object advantage derives from the differential retention of conceptual codes generated from a brief view of a real-world scene in accordance with a conceptual short-term memory (CSTM) hypothesis. A scene was presented for 250 msec, followed by a brief mask and a test scene in which a target object was either changed or not changed. In Experiment 1, changes that altered conceptual content (object deletion) were contrasted with visual changes (left-right orientation changes). In Experiment 2, the duration of the mask was manipulated to vary the amount of time available for conceptual consolidation of the initial scene. In Experiment 3, the type of mask was manipulated: Either a meaningless pattern mask or a meaningful, and thus conceptually disruptive, scene was shown. The inconsistent object advantage was obtained in each experiment, yet in none was it modulated in the direction predicted by the CSTM hypothesis. Instead, the inconsistent object advantage is likely to be caused by contextual influence on memory for visual object representations.

Discrimination, Psychological↗
PubMed2004

Population-based newborn screening for genetic disorders when multiple mutation DNA testing is incorporated: a cystic fibrosis newborn screening model demonstrating increased sensitivity but more carrier detections.

OBJECTIVES: Newborn screening for cystic fibrosis (CF) provides a model to investigate the implications of applying multiple-mutation DNA testing in screening for any disorder in a pediatric population-based setting, where detection of affected infants is desired and identification of unaffected carriers is not. Widely applied 2-tiered CF newborn screening strategies first test for elevated immunoreactive trypsinogen (IRT) with subsequent analysis for a single CFTR mutation (DeltaF508), systematically missing CF-affected infants with any of the >1000 less common or population-specific mutations. Comparison of CF newborn screening algorithms that incorporate single- and multiple-mutation testing may offer insights into strategies that maximize the public health value of screening for CF and other genetic disorders. The objective of this study was to evaluate technical feasibility and practical implications of 2-tiered CF newborn screening that uses testing for multiple mutations (multiple-CFTR-mutation testing). METHODS: We implemented statewide CF newborn screening using a 2-tiered algorithm: all specimens were assayed for IRT; those with elevated IRT then had multiple-CFTR-mutation testing. Infants who screened positive by detection of 1 or 2 mutations or extremely elevated IRT (>99.8%; failsafe protocol) were then referred for definitive diagnosis by sweat testing. We compared the number of sweat-test referrals using single- with multiple-CFTR-mutation testing. Initial physician assessments and diagnostic outcomes of these screened-positive infants and any affected infants missed by the screen were analyzed. We evaluated compliance with our screening and follow-up protocols. All Massachusetts delivery units, the Newborn Screening Program, pediatric health care providers who evaluate and refer screened-positive infants, and the 5 Massachusetts CF Centers and their affiliated genetic services participated. A 4-year cohort of 323 506 infants who were born in Massachusetts between February 1, 1999, and February 1, 2003, and screened for CF at approximately 2 days of age was studied. RESULTS: A total of 110 of 112 CF-affected infants screened (negative predictive value: 99.99%) were detected with IRT/multiple-CFTR-mutation screening; 2 false-negative screens did not show elevated IRT. A total of 107 (97%) of the 110 had 1 or 2 mutations detected by the multiple- CFTR-mutation screen, and 3 had positive screens on the basis of the failsafe protocol. In contrast, had we used single-mutation testing, only 96 (87%) of the 110 would have had 1 or 2 mutations detectable by single-mutation screen, 8 would have had positive screens on the basis of the failsafe protocol, and an additional 6 infants would have had false-negative screens. Among 110 CF-affected screened-positive infants, a likely "genetic diagnosis" was made by the multiple-CFTR-mutation screen in 82 (75%) versus 55 (50%) with DeltaF508 alone. Increased sensitivity from multiple-CFTR-mutation testing yielded 274 (26%) more referrals for sweat testing and carrier identifications than testing with DeltaF508 alone. CONCLUSIONS: Use of multiple-CFTR-mutation testing improved sensitivity and postscreening prediction of CF at the cost of increased referrals and carrier identification.

Algorithms↗
PubMedDate not supplied

Prevalence of bacterial vaginosis in a community setting and role of the pap smear in its detection.

OBJECTIVE: To study the revalence of bacterial vaginosis (BV) in symptomatic and asymptomatic women in a community setting, to assess the validiy of the Pap smear in the detection of BV and to determine the sensitivity and specificity of clinical criteria for the diagnosis of BV. STUDY DESIGN: Gram staining was performed on vaginal secretions collected from 301 women to determine the prevalence of BV. Each smear was assigned a score on the basis of the bacterial morphotypes identified. The bacterial pattern was also studied on 270 adequate, Pap-stained cervical smears and compared with the gold standard, the morphotypes on gram stain, to derive the validity of the Pap smear in diagnosing BV. Also each clinical criterion defined for diagnosis of BV was independently evaluated to determine their sensitivity and specificity. RESULTS: The overall prevalence of BV was 41.5% in the study subjects using Amsel's and Nugent's criteria. The Pap smear was 78.3% sensitive and 86.9% specific in detection of BV. Among the clinical criteria, the presence of clue cells on wet mounts was both highly sensitive (76.7%) and specific (92.4%) for diagnosing BV, while a positive whiff test had a specificity of 86.9% with sensitivity of 33.9%. Vaginal pH > 4.5 was sensitive (88.3%) but less specific (58.6%). The presence of a thin, homogeneous discharge clinging to vaginal mucosa had low sensitivity (56.3%) and specificity (48.9%). In this study, BV was prevalent in both symptomatic and asymptomatic women. The routine Pap smear was able to detect BV in the majority of women. Its utility can be greater in asymptomatic women, in whom this infection may go undetected otherwise, resulting in future complications related to reproductive health. Among Amsel's clinical criteria, the most sensitive and specific was the presence of clue cells in wet mounts. They can be detected easily by laboratory staff with little training in primary health care seting

Adolescent↗
PubMed2001

Volume-specific cutoffs are necessary for reproducible application of prostate-specific antigen density of the transition zone in prostate cancer detection.

OBJECTIVES: To determine the effect of prostate volume on the specificity of prostate-specific antigen density (PSAD) and PSAD of the transition zone (PSA-TZ) in the detection of prostate cancer. METHODS: Between February 1994 and April 1998, transrectal ultrasound-guided prostate needle biopsies were performed in 235 men with serum prostate-specific antigen (PSA) levels between 4.0 and 10.0 ng/mL. The PSAD and PSA-TZ specificities were calculated at 95% sensitivity cutoff levels generated from the whole group, as well as from cohorts stratified by transition zone index or prostate volume. RESULTS: Statistical significance was noted between the benign (n = 176) and prostate cancer (n = 59) groups for all tested PSA parameters. At 95% sensitivity, PSA-TZ carried a specificity of 37.5% compared with 29.6% for PSAD. When applying a single 95% sensitivity cutoff derived from the entire group to individual volume-stratified cohorts, the specificity decreased to 0% in glands less than 30 g in size. A 95% sensitivity PSA-TZ cutoff generated individually for volume-stratified cohorts of glands less than 30, 30 to 40, and 40 to 60 g resulted in more consistent specificity of 28.2%, 35.2%, and 45.7% for each cohort, respectively. CONCLUSIONS: Unlike whole group-derived cutoffs, the use of volume-specific PSA-TZ cutoffs allows consistently high specificity in all volume-stratified cohorts. The discrepancies in the PSA-TZ and PSAD specificities in published reports are likely due to the application of published cutoffs to populations of differing prostate volumes. The use of volume-specific cutoffs results in reproducible specificity in populations with differing prostate volume distribution, and thereby definitively resolves the differences in PSA-TZ specificity reported in published reports.

Biomarkers, Tumor↗
PubMed2001

Generation of TACT image slices using different reconstruction algorithms: effects on natural caries detection.

OBJECTIVE: The purpose of this study was to determine whether the method of reconstruction of tuned-aperture computed tomography (TACT) slices has an influence on observer performance in caries detection. STUDY DESIGN: Eight images of each of 40 extracted posterior teeth were acquired by using a solid state intraoral detector. Stacks of tuned-aperture computed tomography slices were generated by using the minimum and average reconstruction methods. Slices of the 2 experimental conditions were presented to 8 observers in a balanced order. Images were viewed on a high-resolution 21-in color monitor. Observers scored the presence/absence of caries by using a 5-point confidence scale. Observers' assessments were compared with histologic examinations of tooth sections. Receiver operating characteristic curves measured observers' diagnostic performance. Analysis of variance was used to test for possible significant differences between observers and between experimental conditions. Sensitivity, specificity, accuracy, and interobserver reliability were also calculated. RESULTS: No statistically significant differences between the 2 methods of reconstruction were found for the detection of either occlusal (P =.07) or proximal (P =.52) caries. Interobserver reliability was similar for both experimental conditions. CONCLUSIONS: The minimum and average methods of TACT reconstruction provide comparable performances for caries detection tasks.

Algorithms↗
PubMed2000

[Clinical study of direct digital radiography in caries detection].

OBJECTIVE: Direct digital radiography is a computer-based image technique, the purpose of this paper is to investigate possible usage of direct digital radiography-radio visiography (RVG) in caries detection in clinic. METHODS: A human head model with teeth was used to establish the operative exposure time for RVG in vitro, then RVG images for normal and carious tooth were obtained in vivo and were compared with conventional E-speed film in image quality and diagnostic accuracy. RESULTS: The optimal exposure time for RVG image was obtained, and the exposure time was different in each tooth quarter. The acceptable rate of image quality and diagnostic accuracy of RVG was statistically equivalent to that of E-speed film (P > 0.05), however, the excellent rate of RVG was statistically superior to that of E-speed film (P < 0.05). CONCLUSION: The conventional X-ray will be substituted by RVG in caries detection in clinic.

Adolescent↗
PubMed1999

Total and transition zone prostate volume and age: how do they affect the utility of PSA-based diagnostic parameters for early prostate cancer detection?

OBJECTIVES: To define the role of total prostate (TP) volume, transition zone (TZ) volume, and age as determinants of the utility of prostate-specific antigen (PSA)-based diagnostic parameters for early detection of prostate cancer (PCa) in a prospective multicenter study. METHODS: The study participants were 974 consecutive men with serum total PSA (tPSA) levels of 4 to 10 ng/mL who were referred for early PCa detection or lower urinary tract symptoms. All patients underwent prostate ultrasound examination and sextant biopsy with two additional TZ biopsies. In patients with negative initial biopsies, repeated biopsies were performed at 6 weeks. tPSA, the free/total PSA ratio (f/t PSA), PSA density of the TZ (PSA-TZ), PSA density (PSAD), and PSA velocity (PSAV) were determined and compared across TP volume strata of 30 cm3 or less and greater than 30 cm3, TZ volume strata of 20 cm3 or less and greater than 20 cm3, and various age groups to evaluate the need for volume and/or age-specific reference ranges. RESULTS: PCa was found in 345 (35.4%) of 974 patients and benign prostatic tissue was found in 629 (64.6%) of 947 patients. Across TP volume strata, significantly higher values of tPSA (P <0.01), PSA-TZ, PSAD (P <0.001), and PSAV (P <0.05) and lower values of f/t PSA (P <0.001) were observed in patients with PCa than in those without PCa. Similar results were obtained with respect to TZ volume strata, except in the case of PSAV (P <0.05). tPSA, PSA-TZ, and PSAD were significantly higher (P <0.05) in patients with PCa than in those without PCa for all corresponding age ranges. In patients with PCa, f/t PSA was significantly lower (P <0.001) within the same age ranges. Within each group (PCa or benign), f/t PSA, PSAD, PSA-TZ, and PSAV values were unaffected by age strata. However, PSA parameters dependent on prostate volume (PSAD, PSA-TZ) were statistically lower (P <0.001) in prostates with a higher TP volume (greater than 30 cm3) and TZ volume (greater than 20 cm3); f/t PSA values were unaffected by TP and TZ volumes. CONCLUSIONS: f/t PSA and PSA-TZ were the most powerful parameters to differentiate between benign prostatic tissue and PCa. f/t PSA was the sole parameter unaffected by age and prostate volume. We believe new volume-specific cutpoints, as presented in the current study, should be employed when using PSAD and PSA-TZ for the early detection of PCa.

Adult↗