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At least 721 records · Page 40Linked to original sources
PubMed2005

Multi-detector row CT angiography in the assessment of carotid artery disease in symptomatic patients: comparison with rotational angiography and digital subtraction angiography.

BACKGROUND AND PURPOSE: Compared with the single-detector technique, multi-detector row CT angiography permits larger anatomic coverage that includes both the epiaortic and entire carotid circulations. We evaluated the accuracy of multi-detector row CT angiography by using multiplanar reformation (MPR) for measuring carotid artery diameters compared with that of rotational angiography. We also evaluated the diagnostic performance of CT angiography compared with digital subtraction angiography (DSA). METHODS: In 35 patients, CT angiograms of 70 carotid arteries were compared with DSA images, and CT angiograms of 33 carotid arteries were compared with rotational angiograms. CT angiographic interpretation was performed first interactively at a workstation. Diameter measurements of normal and stenosed carotid arteries were performed on cross-sectional and oblique sagittal MPRs. Degree of stenosis was calculated per North American Symptomatic Carotid Endarterectomy Trial criteria independently by two observers for each technique. RESULTS: Degree of stenosis was slightly underestimated with CT angiography, with mean differences (+/- SD) per observer of 6.9 +/- 17.6% and 10.7 +/- 16.1% for cross-sectional and 2.8 +/- 19.2% and 9.1 +/- 16.8% for oblique sagittal MPRs compared with rotational angiography. CT angiography was somewhat inaccurate for measuring the absolute minimal diameter of high-grade stenoses. On symptomatic sides (n = 35), interactive CT angiographic interpretation combined with MPR measurements for lesions with a visual estimate of 50% or greater stenosis achieved a sensitivity of 95% (20/21) and specificity of 93% (13/14) in the detection of carotid stenosis (>/= 50%) verified with DSA. CONCLUSION: Regardless of slight underestimation of carotid stenosis with CT angiography compared with rotational angiography, diagnostic performance of CT angiography with interactive interpretation proved to be good. Also, the method is highly sensitive for detection of carotid artery stenosis, indicating the suitability of CT angiography as a screening method for symptomatic patients. For hemodynamically significant stenoses revealed by CT angiographic screening, conventional angiography still seems to be necessary.

Aged↗
PubMed2000

Quantitative vascularity of breast masses by Doppler imaging: regional variations and diagnostic implications.

Seventy-four biopsy proven breast masses were imaged by color and power Doppler imaging to evaluate vascular pattern of malignant and benign breast masses. The images were analyzed for vascularity. The measurements were made over the entire mass as well as regionally at its core, at its periphery, and in the tissue surrounding it. The surgical specimens were analyzed for microvessel density. The diagnostic performance of Doppler sonographic vascularity indices was evaluated by receiver operating characteristic analysis. The malignant masses were 14 to 54% more vascular than the benign masses. Both types of masses were more vascular by ultrasonography than the tissue surrounding them. Whereas benign masses were 2.2 times more vascular than the surrounding tissue, the malignant masses were 5.0 times more vascular. In a subset of patients the regional vascularity at the core, periphery, and surrounding tissue by Doppler imaging exhibited a strong correlation (R2 > 0.9) with the corresponding histologic microvessel density measurements. Although the malignant masses exhibited a strong gradient in vascularity, core > periphery > surrounding tissue, the benign masses had relatively uniform distribution of vascularity. The area under the receiver operating characteristic curve (A(Z)) for the Doppler indices ranged from 0.56 +/- 0.07 to 0.65 +/- 0.07. A nonlinear analysis including age-specific values of Doppler indices improved the diagnostic performance to A(Z) = 0.85 +/- 0.06. In conclusion, quantitative Doppler imaging when used in combination with a nonlinear rule-based approach has the potential for differentiating between malignant and benign masses.

Adult↗
PubMedDate not supplied

Digital subtraction versus film-screen angiography for detecting acute pulmonary emboli: evaluation in a porcine model.

PURPOSE: To compare the diagnostic performance of digital subtraction angiography (DSA) to that of film-screen angiography (FSA) for detecting acute pulmonary embolism (PE) in a porcine model. MATERIALS AND METHODS: DSA and FSA were performed in 13 pigs before and after central venous administration of autologous emboli. Results were compared to findings at necropsy with use of ex vivo pulmonary angiography to guide pathologic sectioning. The sensitivity and predictive value of a positive case for detecting each embolus were computed for each pulmonary artery branch order and compared with use of 95% confidence intervals. Interobserver variability among three readers for individual PE detection was calculated. RESULTS: Pathologic examination of the lungs revealed 100 total PEs (location by vessel order: 1st = 1, 2nd = 0, 3rd = 15, 4th = 32, > 5th = 52). On average, FSA review identified 72 (72%) emboli and DSA review, 65 (65%). There was no significant difference in sensitivity or predictive value of a positive case between DSA and FSA for detecting emboli (P > .05). There was similar agreement among readers for individual PE detection with DSA (mean, 84%) and FSA (mean, 80%). CONCLUSION: The diagnostic performance of DSA is equivalent to that of FSA for detecting emboli in porcine PA branches. Interobserver agreement for individual PE detection is similar for both imaging techniques.

Angiography↗
PubMed1997

Preliminary results from the Northern Ireland arms of the UK Multicentre Teledermatology Trial: effect of camera performance on diagnostic accuracy.

The diagnostic accuracy of realtime teledermatology was measured using two different video cameras. One camera was a relatively low-cost, single-chip device (camera 1), while the other was a more expensive three-chip camera (camera 2). The diagnosis obtained via the videolink was compared with the diagnosis made in person. Sixty-five new patients referred to a dermatology clinic were examined using camera 1 followed by a standard face-to-face consultation. A further 65 patients were examined using camera 2 and the same procedure applied. Seventy-six per cent of conditions were correctly diagnosed by telemedicine using camera 2 compared with 59% using camera 1. A working differential diagnosis was obtained in 12% of cases using camera 2 compared with 17% using camera 1. The percentage of 'no diagnosis', wrong and missed diagnoses was halved using camera 2 compared with camera 1. These results suggest that the performance of camera 2 was superior to that of camera 1 for realtime teledermatology.

Adolescent↗
PubMed2000

Simple anamnestic questions and recalled water-contact patterns for self-diagnosis of Schistosoma mansoni infection among schoolchildren in western Côte d'Ivoire.

A study to determine the diagnostic performance of simple anamnestic questions and recalled water-contact patterns for self-diagnosis of Schistosoma mansoni infection was carried out in western C te d'Ivoire. A total of 322 schoolchildren were screened over four consecutive days with the Kato-Katz technique to assess S. mansoni and concurrent geohelminth infections. Children were individually interviewed by teachers using a standardized questionnaire asking about symptoms, reported diseases, and water-contact patterns. The cumulative infection prevalence of S. mansoni was 76.4%. Univariate statistics revealed a significant association between the level of S. mansoni infection and three recalled water contact patterns: (1) fishing with nets, (2) swimming/bathing and (3) crossing rivers, but no significant association with reported symptoms and/or reported diseases. Multivariate analysis revealed significant adjusted odds ratios (OR) for crossing the river Tchéorbour (OR = 3.90, P = 0.007), crossing the river Sonbour (OR = 3.90, P = 0.008) and swimming/bathing in the latter (OR = 3.28, P = 0.017). The diagnostic performance of these water-contact patterns was characterized by high specificities but low sensitivities, hence negative predictive values. In the village studied here, recalled water-contact patterns were more useful variables than anamnestic questions for schoolchildren's self-diagnosis of S. mansoni infection, but no generalization of these findings beyond this population is possible at this time.

Adolescent↗
PubMed2006

Detection of acute ischemia from the EASI-derived 12-lead electrocardiogram and from the 12-lead electrocardiogram acquired in clinical practice.

ST-segment measurements in the standard 12-lead electrocardiogram (ECG) of patients with acute coronary syndromes are crucial for these patients' management. Our objective was to determine whether the 12-lead ECG derived from the 3-lead EASI system can attain a level of diagnostic performance similar to that of the Mason-Likar (ML) 12-lead ECG acquired in clinical practice (CP) by paramedics and emergency department technicians. Using 120-lead body surface potential maps recorded before and during balloon inflation angioplasty from 88 patients (divided into "responders" and "nonresponders"), and electrode placement data from 60 applications of precordial leads in CP, we generated for the "nonischemic" and "ischemic" states of each patient the following lead sets: the ML 12-lead ECG, the EASI-derived 12-lead ECG, and 60 sets of 12-lead CP ECGs. We extracted ST deviations at J + 60 milliseconds, summed them for all 12 leads of each lead set to obtain SigmaST, and, by using the bootstrap method, determined the mean sensitivity and specificity for recognizing the "ischemic" state at various thresholds of SigmaST. Results were displayed as receiver operating characteristics, and the area under these curves (AUC) +/- SE was used as the measure of diagnostic performance. AUC +/- SE for all patients were ML ECG, 0.66 +/- 0.03; EASI ECG, 0.64 +/- 0.03; and CP ECG, 0.67 +/- 0.03. Corresponding results for responders only were 0.81 +/- 0.04 for ML ECG, 0.78 +/- 0.04 for EASI ECG, and 0.81 +/- 0.04 for CP ECG. The differences between the AUCs for the different lead sets were not significant (P > .05). Thus, the EASI-derived 12-lead ECG is as good for detecting acute ischemia as is the 12-lead ECG acquired in CP.

Electrocardiography↗
PubMed2003

Functional magnetic resonance cholangiography (fMRC) of the gallbladder and biliary tree with contrast-enhanced magnetic resonance cholangiography.

PURPOSE: To determine the diagnostic performance of functional magnetic resonance cholangiography (fMRC) for the evaluation of anatomic and functional biliary disorders. MATERIALS AND METHODS: At 1.5 T, 39 MR examinations with conventional MRC and mangafodipir trisodium-enhanced fMRC were retrospectively reviewed by three observers who recorded anatomic (duct dilation, stricture, filling defects) and functional (cholecystitis, obstruction) abnormalities in three modes: MRC alone, fMRC alone, and MRC and fMRC images together (combined-MRC). Performance was determined by comparing findings with each mode to findings of invasive cholangiography (IC) and surgery. RESULTS: Among 75 biliary segments (correlated with IC), the sensitivity/specificity for diagnosing dilation (N = 41) with MRC was 95%/97%; with fMRC, 90%/100%; with combined-MRC, 100%/97%. For stricture (N = 7), the sensitivity/specificity of MRC was 86%/98%; of fMRC, 43%/100%; of combined-MRC, 86%/100%. For filling defects (N = 9), the sensitivity/specificity of MRC was 91%/98%; of fMRC, 82%/100%; of combined-MRC, 91%/100%. For diagnosing obstruction (N = 9), the sensitivity/specificity of MRC, fMRC, and combined-MRC were 89%/100%, 100%/100%, and 100%/100%, respectively. For surgically proven cholecystitis (N = 13), positive predictive values for diagnosing acute/chronic cholecystitis for MRC were 33%/40%; for fMRC, 100%/50%; for combined-MRC, 100%/50%. CONCLUSION: Although single-shot fast spin echo (SSFSE)-MRC is valuable, the addition of fMRC increased diagnostic performance for functional biliary disorders.

Biliary Tract↗
PubMed1997

Effect of camera performance on diagnostic accuracy: preliminary results from the Northern Ireland arms of the UK Multicentre Teledermatology Trial.

The diagnostic accuracy of realtime teledermatology was measured using two different video cameras. One camera was a relatively low-cost, single-chip device (camera 1), while the other was a more expensive, three-chip camera (camera 2). The diagnosis obtained via the videolink was compared with the diagnosis made in person. Sixty-five new patients referred to a dermatology clinic were examined using camera 1 followed by a standard face-to-face consultation on the same day. A further 65 patients were examined using camera 2 and the same procedure implemented. Seventy-six per cent of conditions were correctly diagnosed by telemedicine using camera 2 compared with 62% using camera 1. A working differential diagnosis was obtained in 12% of cases using camera 2 compared with 14% using camera 1. The percentage of 'no diagnosis', wrong and missed diagnoses was halved using camera 2 compared with camera 1. These results suggest that the performance of the more expensive camera was superior for realtime teledermatology.

Dermatology↗
PubMed2003

Evaluation of urine sulfated and nonsulfated bile acids as a diagnostic test for liver disease in dogs.

OBJECTIVE: To evaluate 3 methods for measuring urine bile acids (UBA) and compare their diagnostic performance with that of the serum bile acids (SBA) test and other routine screening tests in dogs with hepatic disorders. DESIGN: Prospective study. ANIMALS: 15 healthy dogs, 102 dogs with hepatic disorders, and 9 dogs with clinical signs of hepatic disorders that were found to have nonhepatic disorders. PROCEDURES: Blood and urine samples were collected from sick dogs and healthy dogs for serum biochemical analyses, and determination of concentrations of SBA and UBA. Urine samples were obtained from 15 healthy dogs to establish an upper cutoff value for UBA concentrations. The UBA were measured by use of a quantitative-linked enzymatic colorimetric method. Three analytical modifications were evaluated; 1 quantified only urine sulfated bile acids (USBA), 1 only urine nonsulfated bile acids (UNSBA), and 1 quantified both (USBA plus UNSBA). The UBA values were standardized with the urine creatinine concentration. RESULTS: The UNSBA-to-creatinine ratio and USBA plus UNSBA-to-creatinine ratio tests had the best diagnostic performance of the UBA tests; each had a substantially higher specificity, slightly higher positive predictive value, slightly lower negative predictive value, and lower sensitivity than the SBA test. These UBA-to-creatinine values were positively correlated with SBA values. The USBA-to-creatinine ratio had poor sensitivity, indicating a low rate of bile acid sulfation in dogs. CONCLUSIONS AND CLINICAL RELEVANCE: The UBA can be measured in dogs with sufficient repeatability and accuracy for clinical application. The UNSBA-to-creatinine ratio and USBA plus UNSBA-to-creatinine ratio identified dogs with hepatic disorders nearly as well as the SBA test.

Animals↗
PubMed2005

Differentiation of benign from malignant solid breast masses: conventional US versus spatial compound imaging.

PURPOSE: To compare prospectively the diagnostic performance of radiologists who used conventional ultrasonography (US) with that of radiologists who used spatial compound imaging for the differentiation of benign from malignant solid breast masses. MATERIALS AND METHODS: The study was approved by the institutional review board, and informed consent was obtained. Before excisional or needle biopsy was performed, conventional US and spatial compound images were obtained in 67 patients (age range, 25-67 years; mean age, 45 years) with 75 solid breast masses (21 cancers and 54 benign lesions). Three experienced radiologists who did not perform the examinations independently analyzed US findings and indicated the probability of malignancy. Results were evaluated with kappa statistics and receiver operating characteristic (ROC) analysis. RESULTS: For US findings, the presence of calcifications was the most discordant feature (kappa = 0.372) between conventional US and spatial compound imaging, followed by echotexture (kappa = 0.439), boundary echo (kappa = 0.496), orientation (kappa = 0.518), echogenicity (kappa = 0.523), shape (kappa = 0.526), margin (kappa = 0.569), and posterior acoustic transmission (kappa = 0.669). The area under the ROC curve for conventional US was 0.79 for reader 1, 0.88 for reader 2, and 0.82 for reader 3, and the area under the ROC curve for spatial compound imaging was 0.85 for reader 1, 0.88 for reader 2, and 0.89 for reader 3. The partial area index for conventional US was 0.29 for reader 1, 0.69 for reader 2, and 0.39 for reader 3, and the partial area index for spatial compound imaging was 0.29 for reader 1, 0.65 for reader 2, and 0.39 for reader 3. The difference between the diagnostic performances of the two techniques was not significant (P > .05). CONCLUSION: The performance of the radiologists with respect to the characterization of solid breast masses was not significantly improved with spatial compound imaging.

Adult↗
PubMed2002

Plasma natriuretic peptides for community screening for left ventricular hypertrophy and systolic dysfunction: the Framingham heart study.

CONTEXT: Several reports have suggested the usefulness of plasma brain natriuretic peptide (BNP) as a screening test for left ventricular hypertrophy (LVH) and systolic dysfunction (LVSD). Prior studies were limited by small sample sizes and selection bias and none compared the diagnostic performance of these peptides in men and women. OBJECTIVES: To examine the usefulness of natriuretic peptides for screening for elevated LV mass and LVSD in the community. DESIGN, SETTING, AND PARTICIPANTS: Community-based prospective cohort study of 3177 participants (1707 women) from the Framingham Study who attended a routine examination in 1995-1998. MAIN OUTCOME MEASURES: Receiver operating characteristic (ROC) curves, test sensitivity, specificity, positive and negative predictive values, and likelihood ratios for identifying elevated LV mass (sex-specific 90th percentile or higher of LV mass/[height](2)), LVSD (ejection fraction < or = 50% and/or fractional shortening <29%), and moderate to severe LVSD (ejection fraction < or = 40% and/or fractional shortening <22%) at different discrimination limits of plasma BNP and N-terminal proatrial natriuretic peptide (NT-ANP), with echocardiography as the criterion standard. RESULTS: The areas under the ROC curves for elevated LV mass or LVSD were at or below 0.75 for both peptides, were higher for men compared with women, and were similar for BNP and NT-ANP. The diagnostic performance of natriuretic peptides for LVSD improved in women but not in men when select high-risk subgroups were targeted. Discrimination limits based on high specificity (0.95) yielded better positive predictive values and likelihood ratios compared with age- and sex-specific reference limits yet only identified less than one third of participants who had elevated LV mass or LVSD. CONCLUSION: In our large community-based sample, the performance of BNP and NT-ANP for detection of elevated LV mass and LVSD was suboptimal, suggesting limited usefulness of natriuretic peptides as mass screening tools.

Atrial Natriuretic Factor↗
PubMed2003

Evaluation of neck and body metastases to nodes with ferumoxtran 10-enhanced MR imaging: phase III safety and efficacy study.

PURPOSE: To determine the safety and efficacy of ferumoxtran 10-enhanced magnetic resonance (MR) imaging for diagnosis of metastases to lymph nodes and the clinical usefulness of ferumoxtran 10 in nodal staging. MATERIALS AND METHODS: One hundred fifty-two patients were injected with ferumoxtran 10. Readers independently evaluated precontrast MR images by using node size criteria and subjective assessment of other imaging features. Ferumoxtran 10-enhanced MR images were evaluated alone and paired with precontrast images for comparison. The diagnostic performances of precontrast MR size criteria and postcontrast MR imaging were evaluated with receiver operating characteristic (ROC) analysis. Lymph node signal intensity was correlated with histopathologic findings. MR imaging and histopathologic nodal stages were compared. RESULTS: Node-level sensitivity, specificity, and accuracy of precontrast MR imaging were 54%, 82%, and 68%, respectively, with node size criterion alone; 91%, 51%, and 71%, respectively, with subjective reader assessment; 85%, 85%, and 85%, respectively, with postcontrast MR imaging alone; and 83%, 77%, and 80%, respectively, with paired pre- and postcontrast MR imaging. Compared with size criteria, subjective reader assessment had higher sensitivity but substantially lower specificity. Areas under the ROC curve for pre- and postcontrast MR imaging were 0.76 and 0.83, respectively. Nonmetastatic nodes had significantly lower signal intensity than metastatic nodes on postcontrast T2-weighted MR images (P <.001). Postcontrast nodal staging was significantly more accurate than precontrast nodal staging (P <.01). Headache, back pain, vasodilatation, and urticaria each occurred in 6% of patients. CONCLUSION: Ferumoxtran 10-enhanced MR imaging was safe and effective and facilitated improved diagnostic performance. Use of iron oxide-enhanced MR imaging increased the positive predictive value by 20% and the accuracy by 14% compared with reader assessment. Differentiating patients with no nodal metastatic involvement was more reliable with ferumoxtran 10-enhanced MR imaging than with precontrast MR imaging.

Adolescent↗
PubMed2004

Validation of dental panoramic radiography measures for identifying postmenopausal women with spinal osteoporosis.

OBJECTIVE: Measurements of mandibular inferior cortical shape and width detected on dental panoramic radiographs may be a useful screening tool for spinal osteoporosis in postmenopausal women. The purposes of this study were to clarify whether these measures are validated compared with simple screening tools based on questionnaires, such as the osteoporosis self-assessment tool (OST) and whether these measures can be used in postmenopausal women with histories of hysterectomy, oophorectomy, or estrogen use. SUBJECTS AND METHODS: We calculated the diagnostic performances of panoramic measurements and the OST for identifying women with spinal osteoporosis in both 159 healthy postmenopausal and 157 postmenopausal women with histories of hysterectomy, oophorectomy, or estrogen use. Spinal osteoporosis was defined as a bone mineral density T score of -2.5 or less at the lumbar spine. Cortical shape and width were evaluated on dental panoramic radiographs. Receiver operating characteristic curve analyses were used to determine the optimal cutoff thresholds for cortical width and the OST in healthy postmenopausal women. RESULTS: The sensitivity and specificity, respectively, for identifying women with spinal osteoporosis were 89.5% and 33.9% for cortical width, 86.8% and 57.8% for the OST, and 86.8% and 63.6% for cortical shape in healthy postmenopausal women. Sensitivity and specificity, respectively, were 92.5% and 35.0% for cortical width, 72.5% and 58.1% for the OST, and 80.0% and 64.1% for cortical shape in postmenopausal women with histories of hysterectomy, oophorectomy, or estrogen use. CONCLUSION: Dentists may be able to refer postmenopausal women with suspected spinal osteoporosis for bone densitometry on the basis of dental panoramic radiographs with diagnostic performance similar to that of osteoporosis screening tools based on questionnaires.

Adult↗
PubMed2005

Reproducibility of nighttime salivary cortisol and its use in the diagnosis of hypercortisolism compared with urinary free cortisol and overnight dexamethasone suppression test.

BACKGROUND/METHODS: Nighttime salivary cortisol (NSC) has been suggested to be a useful diagnostic test for Cushing's syndrome (CS). In the absence of published data on its day-to-day variability, we assessed the reproducibility of NSC by repeated measurements in healthy volunteers. Its diagnostic performance was compared with 24-h urinary free cortisol (UFC) and 1 mg overnight dexamethasone suppression test in 12 patients with CS, 20 healthy volunteers, 14 referred patients in which CS was excluded or not firmly established, 16 obese patients, and 20 women in late pregnancy. RESULTS: NSC showed a superior reproducibility in healthy volunteers with a low day-to-day variability as reflected by an intraclass correlation coefficient of 0.78. The receiver operating characteristic curve-estimated cutoff of 6.1 nmol/liter (0.22 microg/dl) demonstrated a sensitivity and specificity of 100% (area under the receiver operating characteristic curve, 1.0; 95% confidence interval, 0.94-1.0) in the diagnosis of CS. NSC, 24-h UFC [after adjusting the local laboratory cutoff to 504 nmol/d (183 microg/d)], and the urinary cortisol/creatinine ratio showed a tendency to be superior to 1 mg dexamethasone suppression test in correctly identifying CS. In late pregnancy, the preserved diurnal variation at a higher level of salivary cortisol reduced the specificity of NSC to 75%. CONCLUSION: Based on its remarkable reproducibility, easy noninvasive nature, and at least similar diagnostic performance, NSC appears to be a preferable alternative to 24-h UFC as a first-line screening test for CS. The cutoff values of NSC, 24-h UFC, and urinary cortisol/creatinine ratio have to be carefully adjusted using assay and center-specific reference ranges of sufficiently large populations.

Adult↗
PubMed2005

3.0 vs 1.5 T MRI in the detection of focal cartilage pathology--ROC analysis in an experimental model.

OBJECTIVE: To use receiver operator characteristics (ROC) analysis for assessing the diagnostic performance of three cartilage-specific MR sequences at 1.5 and 3 T in detecting cartilage lesions created in porcine knees. DESIGN: Eighty-four cartilage lesions were created in 27 porcine knee specimens at the patella, the medial and lateral femoral and the medial and lateral tibial cartilage. MR imaging was performed using a fat saturated spoiled gradient echo (SPGR) sequence (in plane spatial resolution/slice thickness: 0.20 x 0.39 mm2/1.5 mm) and two fat saturated proton density weighted (PDw) sequences (low spatial resolution: 0.31 x 0.47 mm2/3 mm and high spatial resolution: 0.20 x 0.26 mm2/2 mm). The images were independently analyzed by three radiologists concerning the absence or presence of lesions using a five-level confidence scale. Significances of the differences for the individual sequences were calculated based on comparisons of areas under ROC curves (A(Z)). RESULTS: The highest A(Z)-values for all three radiologists were consistently obtained for the SPGR (A(Z) = 0.84) and the high-resolution (hr) PDw (A(Z) = 0.79) sequences at 3T. The corresponding A(Z)-values at 1.5 T were 0.77 and 0.69; the differences between 1.5 and 3 T were statistically significant (P < 0.05). A(Z)-values for the low-resolution PDw sequence were lower: 0.59 at 3 T and 0.55 at 1.5 T and the differences between 1.5 and 3T were not significant. CONCLUSION: With optimized hr MR sequences diagnostic performance in detecting cartilage lesions was improved at 3 T. For a standard, lower spatial resolution PDw sequence no significant differences, however, were found.

Animals↗
PubMed2006

Hepatic macrosteatosis: predicting appropriateness of liver donation by using MR imaging--correlation with histopathologic findings.

PURPOSE: To retrospectively evaluate the diagnostic performance of magnetic resonance (MR) imaging in predicting the appropriateness of liver donation in potential living liver donors by using histopathologic results as the reference standard. MATERIALS AND METHODS: This study was approved by institutional review board; all patients gave informed consent for the use of MR data for future research. Fifty-seven potential liver donors (40 male, 17 female; age range, 17-57 years; mean age, 32 years) underwent dual-echo 1.5-T MR imaging. Two radiologists qualitatively graded each MR image, with consensus for disagreements. Livers were assigned one of three degrees of hepatic steatosis on the basis of changes in hepatic signal intensity (SI) between in-phase and opposed-phase images. For quantitative analysis, a third radiologist calculated mean hepatic and mean splenic SI by averaging 25 hepatic regions of interest and three splenic regions of interest. Relative SI decrease (RSID) in the liver on opposed-phase images compared with in-phase images was calculated. Linear regression analysis was used to correlate RSID with the degree of total steatosis, macrosteatosis, and microsteatosis. Diagnostic performance for predicting the appropriateness of liver donation was analyzed. RESULTS: Histologic findings of macrosteatosis resulted in 52 patients being categorized as appropriate donors, with the remaining five being categorized as inappropriate donors. RSID was correlated with total steatosis (r = 0.850). When the RSID criterion for inappropriateness of liver donation was set at 20%, the sensitivity, specificity, and accuracy were 100%, 92.3%, and 93%, respectively. When RSID was used, four livers that had been misclassified as inappropriate for transplantation were found to have microsteatosis of various degrees and a less than moderate degree of macrosteatosis at histologic analysis. Qualitative and quantitative analyses were comparably accurate. CONCLUSION: When an RSID criterion of less than 20% was used, dual-echo MR imaging facilitated the correct prediction of appropriateness of liver donation in 53 of 57 patients.

Adolescent↗
PubMedDate not supplied

Prostate cancer probability after total PSA and percent free PSA determination.

UNLABELLED: The percent free PSA value is a promising diagnostic tool for prostate cancer. However, its actual role has not yet been established because of the widely diverging sensitivity and specificity values. This could depend at least in part on analytical difficulties, since the free PSA concentration is much lower than that of total PSA. The present investigation was designed to evaluate the diagnostic performance of the percent free PSA in the most favorable analytical conditions. MATERIALS AND METHODS: 81 patients affected by newly diagnosed, untreated primary prostate cancer (CaP) and 239 patients with untreated benign prostatic hyperplasia (BPH) were prospectively enrolled. Hybritech total and free PSA were measured by the same technician using the same reagent batch. RESULTS: The percent free PSA was not significantly associated with age, tumor stage, gland volume, Gleason score, and total PSA, nor was it significantly affected by concomitant prostatic complications either in CaP or BPH. Percent free PSA was more effective than total PSA in the differential diagnosis between CaP and BPH in every evaluated dose range of total PSA. Percent free PSA determination could have reduced the rate of unnecessary biopsies in cases with total PSA > or = 4 ng/mL and > or = 10 ng/mL (avoided biopsies 61% and 63%, respectively). The post-test probability of the disease, which represents the proportion of patients with a positive percent free PSA value who have the disease, was, however, relatively low in younger patients with total PSA within the normal range. CONCLUSIONS: The diagnostic performance of the percent free PSA value is enhanced when the methodological variability is reduced, particularly in men with low total PSA. Percent free PSA is superior to total PSA in distinguishing primary CaP from BPH in patients with total PSA between 2 and 30 ng/mL. The percent free PSA value is effective in reducing the rate of unnecessary biopsies in men with total PSA higher than 4 or 10 ng/mL. However, due to its relatively low post-test probability, the percent free PSA value should be interpreted with caution in the decision-making related to individual patients and should be used in association with clinical and instrumental evaluation of the patient.

Aged↗
PubMed2004

MR cystography for bladder tumor detection.

The purpose of the study was to assess the diagnostic performance of MR cystography with virtual cystoscopic and multiplanar reconstructions for detection of malignant bladder tumors. Thirty-two patients with 43 bladder tumors previously confirmed by cystoscopy (mean size 2.5 cm; 0.4-9.1 cm;) were examined at 1.5 T with a three-dimensional T2-weighted turbo spin echo sequence (TR=2911 ms, TE=500 ms, echo train length 256). Virtual cystoscopic reconstructions (VC) and multiplanar reconstructions (MPR) were obtained and analyzed separately by three radiologists without knowledge of the tumor location. Intraoperative or cystoscopic findings served as standard of reference. Sensitivities and specificities were calculated using a receiver-operating characteristic analysis with five levels of confidence. Area-under-curve values were similar for MPRs (0.952), VC (0.932) and the combination of both methods (0.954). Optimal sensitivity was 92.3% for MPR and 90.7% for VC, respectively, with a specificity of 91.1% for MPR and 90.4% for VC. The combination of MPR and VC resulted in a sensitivity of 90.7% and specificity of 94.0%. MR cystography is a promising, completely non-invasive technique for the detection of bladder lesions with a high diagnostic performance.

Aged↗