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Tania Schink

Publications and source records attributed to Tania Schink.

14 recordsLinked to original sources

Diagnostic quality and scoring of synovitis, tenosynovitis and erosions in low-field MRI of patients with rheumatoid arthritis: a comparison with conventional MRI.

OBJECTIVE: To compare dedicated low-field MRI (lfMRI) with conventional MRI (cMRI) in the detection and scoring of synovitis, tenosynovitis and erosions in patients with rheumatoid arthritis. PATIENTS AND METHODS: The wrist and finger joints of 17 patients with rheumatoid arthritis (median (range) disease duration 8 years (7-12); Disease Activity Score 3.3 (2.6-4.5)) were examined by 0.2 T lfMRI and 1.5 TcMRI. The protocols comprised coronal spin-echo and three-dimensional gradient-echo sequences before and after contrast medium administration. Synovitis of the metacarpophalangeal and proximal interphalangeal joints 2-5 and the wrist joints was scored according to Outcome Measures in Rheumatology recommendations. Tenosynovitis and erosions were scored using 4-point and 6-point scales, respectively. The results were analysed by calculating kappa values and performing McNemar's test intra-individually on a joint-by-joint basis. RESULTS: Agreement between the two MRI techniques was good to excellent for synovitis and erosions, and moderate for tenosynovitis. Of the 306 joints evaluated, 245 and 200 joints showed synovitis in lfMRI and cMRI, respectively. Scoring of synovitis of the finger joints yielded kappa values from 0.69 to 0.94. Of the 68 flexor tendons evaluated, tenosynovitis was diagnosed by lfMRI in 24 and by cMRI in 33 instances. Of the 391 bones evaluated, 154 and 139 showed erosions in lfMRI and cMRI, respectively. kappa values for erosion scores were between 0.65 and 1. CONCLUSION: Dedicated, lfMRI shows high agreement with cMRI in diagnosing and scoring synovitis, tenosynovitis and erosions in rheumatoid arthritis when using standardised scoring systems.

Adult↗

Noninvasive detection of coronary artery stenoses with multislice computed tomography or magnetic resonance imaging.

BACKGROUND: Multislice computed tomography (CT) and magnetic resonance imaging (MRI) are the main candidates for noninvasive coronary angiography; however, multislice CT, unlike MRI, exposes patients to radiation and an iodinated intravenous contrast agent. OBJECTIVE: To compare the diagnostic accuracy of multislice CT and MRI for noninvasive detection of clinically significant coronary stenoses (> or =50%). DESIGN: Prospective intention-to-diagnose study. SETTING: Single tertiary referral center, Berlin, Germany. PATIENTS: 129 consecutive patients with suspected coronary artery disease. INTERVENTIONS: Multislice CT and MRI were both performed within a median of 1 day before conventional coronary angiography, which served as the reference standard. MEASUREMENTS: Diagnostic performance of multislice CT and MRI. RESULTS: 129 patients completed the study. Altogether, 108 patients with 430 vessels could be examined with both multislice CT and MRI and were used for analysis. In the per-patient analysis, the sensitivity of multislice CT (92% [95% CI, 82% to 96%]) was significantly higher than that of MRI (74% [CI, 61% to 83%]; P = 0.013). The sensitivity for detecting clinically significant stenoses was 82% for multislice CT and 54% for MRI (P < 0.001). Specificity and negative predictive value of multislice CT and MRI in the per-vessel analysis were 90% versus 87% (P = 0.73) and 95% versus 90% (P = 0.032), respectively. The effective radiation dose used with multislice CT (mean, 12.3 mSv [SD, 1.4]) in a consecutive subgroup of 73 patients was not significantly different from that used with diagnostic cardiac catheterization (11.4 mSv [SD, 4.8]) (P = 0.169). Most patients (74%) indicated that they would prefer multislice CT for future diagnostic imaging (P < 0.001). LIMITATIONS: This was a single-center study with 129 patients. CONCLUSIONS: In patients referred for conventional coronary angiography, multislice CT compares favorably with MRI for noninvasive detection of coronary stenoses.

Coronary Angiography↗

Head-to-head comparison of multislice computed tomography and exercise electrocardiography for diagnosis of coronary artery disease.

AIMS: To prospectively compare multislice computed tomography (MSCT) and exercise electrocardiography (ex-ECG) for diagnosis of coronary artery disease (CAD) with conventional coronary angiography as the reference standard. METHODS AND RESULTS: A consecutive cohort of 80 patients with suspected CAD was examined with MSCT using 16 x 0.5 mm detector collimation, ex-ECG, and conventional coronary angiography according to standard protocols. Results were compared using the paired McNemar's test, the chi(2) test, and 95%CIs. Both the sensitivity and specificity of MSCT [91% (40 of 44 patients, 95%CI 78-97%) and 83% (30 of 36 patients, 95%CI 67-94%)] were significantly higher (P = 0.039 and P < 0.001) than those for ex-ECG [73% (32 of 44 patients, 95%CI 57-85%) and 31% (11 of 36 patients, 95%CI 16-48%)]. The pairwise McNemar's test showed significant differences between MSCT and ex-ECG in the overall diagnosis in patients with suspected CAD (P = 0.036). The rate of non-diagnostic examinations was not significantly (P = 0.078) different between MSCT and ex-ECG [8% (6 of 80 patients, 95%CI 3-16%) vs. 19% (15 of 80 patients, 95%CI 11-29%)]. CONCLUSION: In this consecutive cohort of patients scheduled to undergo conventional coronary angiography, the performance of MSCT for diagnosis of CAD was superior to that of ex-ECG.

Aged↗

Focal liver lesions: SPIO-, gadolinium-, and ferucarbotran-enhanced dynamic T1-weighted and delayed T2-weighted MR imaging in rabbits.

PURPOSE: To compare a superparamagnetic iron oxide (SPIO), VSOP-C184, with a gadopentetate dimeglumine with regard to signal-enhancing effects on T1-weighted dynamic magnetic resonance (MR) images and with another SPIO contrast medium with regard to signal-reducing effects on delayed T2-weighted MR images. MATERIALS AND METHODS: All experiments were approved by the responsible Animal Care Committee. Twenty rabbits (five for each contrast agent and dose) implanted with VX-2 carcinoma were imaged at 1.5 T. VSOP-C184 at 0.015 and 0.025 mmol Fe/kg was compared with gadopentetate dimeglumine at 0.15 mmol Gd/kg and ferucarbotran at 0.015 mmol Fe/kg. The imaging protocol comprised a T1-weighted dynamic gradient-echo (GRE) MR before injection and at 6-second intervals for up to 42 seconds after injection and a T2-weighted turbo spin-echo MR before and 5 minutes after injection. Images were evaluated quantitatively, and contrast media were compared by using nonparametric analysis of variance. RESULTS: At dynamic T1-weighted GRE MR imaging with 0.015-mmol Fe/kg VSOP-C184, 0.025-mmol Fe/kg VSOP-C184, gadopentetate dimeglumine, and ferucarbotran, the median peak contrast-to-noise ratio (CNR) was 20.7 (25th percentile, 16.3; 75th percentile, 22.6), 24.2 (25th percentile, 19.3; 75th percentile, 28.5), 16.4 (25th percentile, 13.7; 75th percentile, 20.3), and 14.0 (25th percentile, 11.4; 75th percentile, 16.8), respectively. Both doses of VSOP-C184 yielded significantly higher CNR (P < .05) than the other two agents. At T2-weighted turbo spin-echo imaging with 0.015-mmol Fe/kg VSOP-C184, 0.025-mmol Fe/kg VSOP-C184, gadopentetate dimeglumine, and ferucarbotran, the median CNR was 15.0 (25th percentile, 13.4; 75th percentile, 21.3), 15.7 (25th percentile, 14.5; 75th percentile, 19.8), 11.3 (25th percentile, 8.2; 75th percentile, 12.2), and 15.7 (25th percentile, 12.5; 75th percentile, 22.4), respectively. There was no significant difference between VSOP-C184 and ferucarbotran; both had a significantly higher CNR than did gadopentetate dimeglumine. CONCLUSION: VSOP-C184 produces higher liver-to-tumor contrast at dynamic T1-weighted imaging than does gadopentetate dimeglumine; at delayed T2-weighted imaging, the contrast is comparable to that achieved with ferucarbotran.

Animals↗

Multisegment and halfscan reconstruction of 16-slice computed tomography for assessment of regional and global left ventricular myocardial function.

RATIONALE AND OBJECTIVES: We sought to prospectively compare multisegment and halfscan reconstruction of 16-slice computed tomography (CT) for the assessment of regional and global left ventricular myocardial function with magnetic resonance imaging (MRI) as the reference standard. MATERIALS AND METHODS: Forty-two patients underwent CT with 16 x 0.5-mm detector collimation. Electrocardiogram-gated reconstructions were generated with multisegment reconstruction (using up to 4 segments correlated with the raw data of up to 4 heartbeats) and standard halfscan reconstruction. Steady-state free-precession cine MRI was acquired within 24 hours. RESULTS: More normal myocardial segments were identified correctly with multisegment (95%, 620/656) compared with halfscan reconstruction (88%, 582/656) of CT (P < 0.001). Also, the accuracy (92% [657/714] vs. 87% [620/714]) and rate of nondiagnostic segments (0% vs. 5% [33/714]) were significantly better when using multisegment reconstruction (P < 0.001). The image quality with multisegment reconstruction was significantly superior to that achieved with halfscan reconstruction (P < 0.001). In the assessment of global left ventricular function, multisegment and halfscan reconstruction of CT showed high correlations for all parameters with MRI, whereas Bland-Altman analysis revealed smaller limits of agreement for assessment of myocardial mass with multisegment reconstruction (P = 0.025), but no significant differences between both reconstruction techniques in the measurement of left ventricular volumes as compared with MRI. CONCLUSIONS: Multisegment reconstruction of 16-detector row CT improves image quality and assessment of regional wall motion compared with standard halfscan reconstruction.

Adult↗

Postoperative analgesia after major spine surgery: patient-controlled epidural analgesia versus patient-controlled intravenous analgesia.

BACKGROUND: Spinal fusion surgery causes severe postoperative pain, hampering reconvalescense. We investigated the efficacy of patient-controlled epidural analgesia (PCEA) in a prospective, double-blind, randomized, controlled comparison with patient-controlled IV analgesia (PCIA). METHODS: After lumbar anterior-posterior fusion receiving an epidural catheter intraoperatively, 72 patients were given either PCEA (ropivacaine 0.125% and sufentanil 1.0 microg/mL at 14 mL/h; bolus: 5 mL; lockout time: 15 min) and IV placebo or PCIA (morphine 2.0 mg/mL; bolus: 3 mg; lockout time: 15 min) and epidural placebo. Pain levels (visual analog scale 0-10), functional capabilities (turning in bed, standing, and walking), analgesic consumption, and side effects were evaluated until 72 h after surgery. RESULTS: Fourteen patients were excluded by predetermined criteria, leaving 58 patients for data analysis. Pain levels at rest and during mobilization were significantly lower in the PCEA when compared with that in the PCIA group throughout the study period (P < 0.0001 in all cases). Time until able to turn in bed was achieved earlier in the PCEA group (P < 0.05). Patients in the PCEA group were significantly more satisfied with pain therapy (P < 0.01). CONCLUSION: We conclude that PCEA with ropivacaine and sufentanil, using intraoperatively placed epidural catheters, provides superior analgesia and higher patient satisfaction when compared with PCIA after spinal fusion surgery.

Adult↗

Hypovolemia after traditional preoperative care in patients undergoing colonic surgery is underrepresented in conventional hemodynamic monitoring.

BACKGROUND AND AIMS: Hypovolemia after bowel preparation as well as capnoperitoneum (CP) may compromise hemodynamic function during laparoscopic colonic surgery. A fall in arterial pressure after induction of anesthesia is often answered by generous fluid administration, which might impair "fast-track" rehabilitation. Intraoperative assessment of the needed infusion volume is difficult because of a lack of data regarding the volume status in these patients. PATIENTS AND METHODS: Nineteen patients scheduled for laparoscopic colonic surgery after bowel preparation were prospectively monitored using the PULSION COLD Z-021 system and central venous catheter. Intrathoracic blood volume index (ITBVI), mean arterial pressure (MAP), cardiac index (CI), central venous pressure (CVP), and heart rate (HR) were measured after induction of anesthesia (M1), during CP in head-down position with an intraabdominal pressure (IAP) of 20 mmHg (M2) and 12 mmHg (M3). RESULTS: Although MAP (87 mmHg), HR (64 min(-1)), and CVP (8 mmHg) were within normal ranges at the induction of surgery, ITBVI (834 ml m(-2)), and CI (2.66 l m(-2)) were decreased, indicating a relative hypovolemia. CP with 12 mmHg increased ITBVI (p<0.05) and CI (p<0.01), while an IAP of 20 mmHg reduced CI (p<0.05) compared to 12 mmHg (M3). Mean infusion during the measurements was 1,355 ml. CONCLUSION: Combination of CP with 12 mmHg, head-down position, and infusion of 1,500 ml fluids compensated relative hypovolemia during colonic surgery. With conventional monitoring, intravascular volume status might be underestimated after traditional preoperative care.

Blood Pressure↗

The impact of anaemia and kidney function in congestive heart failure and preserved systolic function.

BACKGROUND: The importance of anaemia in chronic heart failure was highlighted recently by different cohort studies. The aim of this study was to assess the prevalence of anaemia and its relationship to renal function, left ventricular function and symptoms of heart failure. METHODS: We surveyed cases of patients admitted to the Department of Cardiology during 22 consecutive months. Laboratory measurements, blood pressure and echocardiographic parameters were obtained with standardized methods. RESULTS: Out of a total number of 2941 patients, 238 patients (8.1%) had haemoglobin values <11 g/dl. There was a positive association of anaemia with the symptoms of heart failure with a lowering of the median haemoglobin from 14.2 g/dl [New York Heart Association (NYHA) I] to 12.9 g/dl (NYHA IV, P<0.001). Interestingly, anaemia was not associated with left ventricular function or any left ventricular parameters. Symptoms of heart failure, however, were associated with kidney function. The estimated glomerular filtration rate (GFR) was 82 ml/min at NYHA I and 59 ml/min at NYHA IV, P<0.05. There was an association between impaired renal function and haemoglobin values. Haemoglobin was 14.2 g/dl in the group with normal renal function and 11.1 g/dl in the group with a GFR <25 ml/min (P<0.001). Even in patients with normal renal function (878 patients, GFR >85 ml/min), we still found an association of anaemia with the symptoms of heart failure. Haemoglobin was 14.5 g/dl at NYHA I and 13.4 g/dl at NYHA IV, P<0.0001. CONCLUSION: Anaemia is found in 8.1% of patients admitted to cardiology service. Anaemia was clearly associated with symptoms of congestive heart failure even in patients with normal renal function. Anaemia was not associated with left ventricular function.

Aged↗

High dose rate (HDR) brachytherapy with conformal radiation therapy for localized prostate cancer.

OBJECTIVES: To evaluate the outcome of high dose rate (HDR) brachytherapy with iridium 192 (Ir(192)) and 3D conformal external beam radiotherapy in patients with localized prostate cancer. METHODS: A total of 442 patients with localized prostate cancer underwent combined radiotherapy with interstitial brachytherapy with Ir(192) and 3D conformal external beam radiotherapy between December 1992 and March 2001. Patients underwent laparoscopic pelvic lymph node dissection to exclude patients with lymphatic involvement. Iridium 192 was delivered twice with a one-week interval in afterloading technique. 247 patients (56%) had clinical T3 disease and 128 patients (29%) had an initial PSA of more than 20 ng/ml. Progression was defined as biochemical failure according to ASTRO criteria. Patients were divided according to pretreatment variables that independently affected prostate-specific antigen (PSA) relapse-free survival in three risk groups. Low risk was defined as cT1c-cT2 and G1-G2 and PSA<10 ng/ml (n=94). Intermediate risk included patients with cT1c-cT2 and G1-G2 and PSA between 10 and 20 ng/ml (n=53). High risk group patients were cT3 or G3 or PSA>20 ng/ml (n=295). RESULTS: Median follow-up was 5 years. Late grade 3-4 complications according to RTOG/EORTC criteria occurred in 50 patients (11%). The initial PSA value decreased from median 11.8 ng/ml to 0.98 ng/ml 12 months after treatment, to 0.3 ng/ml after 60 months and to 0.1 ng/ml 10 years after therapy. 53% of the patients (n=235) reached a PSA nadir of 0.5 ng/ml. 66 patients (15%) had a local recurrence, 54 (12%) developed systemic disease and 12 (3%) had both local and systemic failure. The progression free survival rate was 65% at 5-year follow-up. Five-year progression free survival was 81% in the low risk group, 65% in the intermediate risk group and 59% in the high risk group. Five-year overall survival was 87% and 5-year disease specific survival 94%. Initial PSA value, risk group and age were significantly related to progression free survival. CONCLUSIONS: Combined HDR brachytherapy with Iridium 192 is an alternative treatment option for patients with localized prostate cancer. Initial PSA value, risk group, and age are important prognostic factors for progression free survival.

Aged↗

Optimal timing for postprandial glucose measurement in pregnant women with diabetes and a non-diabetic pregnant population evaluated by the Continuous Glucose Monitoring System (CGMS).

OBJECTIVE: Using the Continuous Glucose Monitoring System (CGMS; Medtronic Minimed) for a group of pregnant women with and without glucose intolerance, we attempted to answer the following questions: (1) when does the physiological peak of postprandial glucose occur?; (2) do non-diabetic pregnant women and pregnant women with diabetes have different postprandial glucose profiles?; and (3) what is the optimal time for postprandial glucose measurement rated according to clinical outcome? METHODS: We included 53 pregnant women in our study. Based on the criteria of the German Diabetes Association (fasting, 5.0 mmol/L; 1-h, 10.0 mmol/L; 2-h, 8.6 mmol/L) we included 13 women with gestational diabetes, four with type 1 diabetes and 36 non-diabetic pregnant (NDP) women. Gestational and type 1 diabetics were classed as one group: pregnancy complicated by diabetes (PCD). Patients with carbohydrate intolerance underwent dietary counseling in accordance with the recommendations of the American Diabetes Association. Patients received a CGMS for use over 72 h. This was calibrated seven times a day with an Accu-Check. The pre- and postprandial glucose levels were documented at 15-min intervals for 3 h from the beginning of each meal. The postprandial data from the three meals were added. The group was divided according to three clinical outcome parameters: mode of delivery, birth weight percentile, and diabetes-associated complications. RESULTS: Statistically significant differences between groups were found for body mass index, fetal birth weight and oral glucose tolerance test. No significant differences were found for age, parity and gestational age, mode of delivery, and diabetes-associated complications. The sensor provided similar numbers of measurements in both groups (278+/-43 vs. 298+/-73, P = 0.507). The postprandial glucose peak was reached after 82+/-18 min in the non-diabetics vs. 74+/-23 min in the PCD group (not significant). Postprandial glucose values were normally slightly higher in PCD (not significant). We added the postprandial glucose values at each time interval for the three meals for each day. For the sum, there was a significant difference between the measurements at 120 min and at 135 min postprandial (P < 0.05). Dividing the group by clinical outcome showed a significant difference between the postprandial time intervals of 75 min and 105 min (P < 0.05). In addition, the time interval was different from 60 min to 135 min for the mode of delivery and birth weight percentile (P < 0.05). CONCLUSION: The 120-min interval is too long and has a lower correlation to clinical outcome parameters than earlier measurements. Our findings show that the optimal time for testing is between 45 and 120 min postprandial. Based on our practical experience and dietary recommendations, we would prefer a 60-min interval, because patients can calculate this more easily and can have more freedom to eat the recommended number of snacks.

Adult↗

Comparison of the iron oxide-based blood-pool contrast medium VSOP-C184 with gadopentetate dimeglumine for first-pass magnetic resonance angiography of the aorta and renal arteries in pigs.

RATIONALE AND OBJECTIVES: VSOP-C184 at a dose of 0.045 mmol Fe/kg has been shown to be an efficient blood pool contrast medium for equilibrium magnetic resonance angiography (MRA) that can be administered as a bolus. The present study was performed to determine whether VSOP-C184 is also suitable for first-pass MRA. MATERIALS AND METHODS: Fifteen MRA examinations at 1.5 T were performed in minipigs using a fast 3D fast low-angle shot (FLASH) sequence (repetition time = 4.5 ms, echo time = 1.7 ms, excitation angle = 25 degrees, matrix 256, body phased-array coil). The citrate-stabilized iron oxide preparation VSOP-C184 was investigated (total particle diameter: 7.0 +/- 0.15 nm; core size: 4 nm) and compared with gadopentetate dimeglumine (Gd-DTPA). The following doses were tested: VSOP-C184: 0.015, 0.025, and 0.035 mmol Fe/kg; Gd-DTPA: 0.1 and 0.2 mmol Gd/kg; n = 3 examinations/dose. Data were analyzed quantitatively (signal enhancement (ENH) and vessel edge definition (VED)) and qualitatively. RESULTS: First-pass MRA using the 3 doses of VSOP-C184 yielded the following ENH: aorta: 9.4 +/- 2.6; 12.31 +/- 1.2; 16.53 +/- 1.7; renal arteries: 7.6 +/- 2.2; 9.9 +/- 1.0; 13.2 +/- 0.5. The values for the 2 doses of Gd-DTPA were aorta: 12.9 +/- 1.0; 16.8 +/- 2.2; renal arteries: 11.2 +/- 1.23; 11.3 +/- 1.7. VED for the 3 doses of VSOP-C184 was aorta: 106.3 +/- 31.0; 135.3 +/- 58.8; 141.3 +/- 71.0; renal arteries: 102.2 +/- 24.3; 146.8 +/- 63.0; 126.9 +/- 37.6 and for the 2 doses of Gd-DTPA, aorta: 157.2 +/- 47.8; 164.2 +/- 36.8; renal arteries: 165.9 +/- 30.4; 170.3 +/- 38.2 respectively. The differences between VSOP-C184 and Gd-DTPA are clinically not relevant and statistically not significant (p > or = .05). Qualitative evaluation of image quality, contrast, and delineation of vessels showed the results obtained with VSOP-C184 at doses of 0.025 and 0.035 mmol Fe/kg to be similar to those of Gd-DTPA at 0.1 and 0.2 mmol Gd/kg. CONCLUSION: VSOP-C184 is suitable for first-pass MRA at doses of 0.025 and 0.035 mmol Fe/kg and thus, in addition to its blood pool characteristics, allows for selective visualization of the arteries without interfering venous signal.

Animals↗

Rheumatoid arthritis of the shoulder joint: comparison of conventional radiography, ultrasound, and dynamic contrast-enhanced magnetic resonance imaging.

OBJECTIVE: To determine the role of ultrasound and magnetic resonance imaging (MRI) compared with conventional radiography in the detection of chronic and acute inflammatory manifestations of rheumatoid arthritis (RA) of the shoulder joint. METHODS: Forty-three consecutive patients with known RA prospectively underwent clinical examination, radiography, ultrasound, and MRI of the shoulder joints. Each patient was assigned a clinical/laboratory score consisting of 7 parameters, including measurements of shoulder mobility, the erythrocyte sedimentation rate, and C-reactive protein level. Conventional radiography was standardized and performed in 2 planes. Ultrasound was performed in 10 predefined planes using a 7.5-MHz linear transducer. MRI at 1.5T comprised transverse and oblique coronal T1- and T2*-weighted fast spin-echo, gradient-echo (GRE), and inversion-recovery sequences with a matrix size of up to 512 pixels. A dynamic T1-weighted GRE sequence was acquired with intravenous administration of contrast medium. Erosions were assessed using all 3 imaging techniques on a 4-point scale. Soft-tissue involvement was evaluated according to the presence of synovitis, tenosynovitis, and bursitis on ultrasound and MRI. The results in the study group were compared with those obtained in a control group of 10 patients with shoulder pain. RESULTS: In the study group, erosions of the humeroscapular joint were detected by conventional radiography in 26 patients, by ultrasound in 30 patients, and by MRI in 39 patients; the differences were statistically significant for the comparisons of conventional radiography with MRI and for ultrasound versus MRI (P < 0.0001). Conventional radiography detected 12 erosions of the scapula and MRI detected 15. Synovitis was demonstrated in 12 patients by ultrasound and in 27 patients by MRI (P = 0.0003). Tenosynovitis was observed in 15 patients by ultrasound and in 28 patients by MRI (P = 0.0064). Bursitis was detected in 13 patients by ultrasound and in 18 patients by MRI. The findings on dynamic contrast-enhanced MRI correlated significantly with the detection of synovitis by ultrasound and erosions by static MRI (P < 0.05). CONCLUSION: Ultrasound and MRI supplement conventional radiography in assessing the shoulder joint. Although conventional radiography can be used as the sole method of following up known joint destruction in RA, ultrasound and, preferably, MRI are recommended as additional techniques in the initial diagnostic evaluation when radiography yields negative results.

Adult↗

Comparison of eight computer programs for receiver-operating characteristic analysis.

BACKGROUND: ROC analysis is widely accepted to assess and compare diagnostic validity of laboratory tests. Within the last few years, many new ROC programs have become available but have not been systematically evaluated. The aim of this study was to assess different ROC programs regarding their ease of use, mathematical correctness, final output, and their compatibility with other graphics programs. METHODS: Eight available programs running under Windows (AccuROC, Analyse-It, CMDT, GraphROC, MedCalc, mROC, ROCKIT, and SPSS) were evaluated. ROC analyses of prostate-specific antigen and related values were performed from a dataset of 928 men with prostate cancer and benign prostatic hyperplasia and corresponding subsets. Criteria such as data input, data output, and correctness and completeness of results were used to evaluate the practicability of the programs. RESULTS: Although the programs produced equivalent results (areas under the curves and their characteristics), we observed deficiencies concerning input of data, processing of the output data, and completeness of the results. Analyse-It, AccuROC, and MedCalc exhibited good performance, but each program had different shortcomings. Only GraphROC could compare curves at a certain sensitivity or specificity cutoff. CONCLUSIONS: Adequate ROC analysis and ROC plotting cannot be performed with a single program. Analyse-It, AccuROC, and MedCalc can be recommended with certain limitations. Further improvements of the programs are necessary.

Area Under Curve↗

Coronary MR angiography: experimental results with a monomer-stabilized blood pool contrast medium.

PURPOSE: To evaluate the signal-enhancing characteristics of monomer-coated very small superparamagnetic iron oxide (SPIO) particles used as a blood pool contrast medium for magnetic resonance (MR) angiography in the coronary arteries. MATERIALS AND METHODS: The particles used in this study were coated with citrate as the monomer (VSOP-C91). The particles have a total diameter of 7 nm and show the following relaxivities at 0.47 T: T1, 19 L/mmol. sec(-1); T2, 29 L/mmol. sec(-1). Fifteen cardiac MR examinations were performed at 1.5 T in five pigs. Images were acquired from immediately to 35 minutes (equilibrium phase) after intravenous injection of gadopentetate dimeglumine, gadobenate dimeglumine, and the very small SPIO particles (n = 5 for each substance). RESULTS: Immediately after administration of gadopentetate dimeglumine, gadobenate dimeglumine, and the very small SPIO particles, respectively, increases in the signal-to-noise ratio in blood were 94%, 103%, and 102% and in myocardium were 83%, 83%, and 29% (P <.05, very small SPIO particles versus the low-molecular-weight gadolinium-based compounds). Differences in the blood-to-myocardium contrast-to-noise ratio and visualization of the coronary arteries and their branches were also significant. CONCLUSION: VSOP-C91 significantly improves visualization of the coronary arteries at MR angiography from immediately to 35 minutes after injection.

Analysis of Variance↗