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Ernst J Rummeny

Publications and source records attributed to Ernst J Rummeny.

At least 19 recordsLinked to original sources
PubMed2007

MRI of the lung: value of different turbo spin-echo, single-shot turbo spin-echo, and 3D gradient-echo pulse sequences for the detection of pulmonary metastases.

PURPOSE: To compare the value of different MRI sequences of the lung for the detection of pulmonary metastases. MATERIALS AND METHODS: A total of 28 patients with 225 pulmonary metastases confirmed at multidetector-row computed tomography (MDCT) underwent MRI of the lung, including breathhold T2-weighted single-shot turbo spin-echo (half-Fourier single-shot turbo spin-echo [HASTE] and inversion recovery [IR]-HASTE) and conventional turbo spin-echo (TSE and short-tau inversion recovery [STIR]) sequences, a respiratory- and pulse-triggered black-blood STIR sequence (triggered STIR), and breathhold pre- and postcontrast volumetric interpolated 3D gradient-echo (VIBE) sequences. MR images were reviewed by three independent observers and results were correlated with MDCT, which served as standard of reference. Lesion-to-lung contrast-to-noise ratios (CNRs) and image artifacts were also assessed. RESULTS: CNRs were highest on TSE images (P < 0.001). Mean sensitivities for lesion detection with triggered STIR, TSE, and STIR were 72.0%, 69.0%, and 63.4%, respectively. With HASTE, IR-HASTE, and pre- and postcontrast VIBE, significantly lower sensitivities were obtained (P < 0.05), although artifacts due to physiological motion were less distinct with these sequences compared to TSE and STIR (P < 0.05). CONCLUSION: Conventional TSE sequences are more sensitive in depicting pulmonary metastases than single-shot TSE or 3D gradient-echo sequences. Respiratory and pulse triggering can improve lesion detection, but increases acquisition time substantially.

Adult↗
PubMed2006

Rectal carcinoma: high-spatial-resolution MR imaging and T2 quantification in rectal cancer specimens.

PURPOSE: To prospectively compare high-spatial-resolution T1-weighted, T2-weighted, and intermediate-weighted spectral fat-saturated magnetic resonance (MR) imaging for the differentiation of tumor from fibrosis and for delineation of rectal wall layers in rectal cancer specimens. MATERIALS AND METHODS: The local ethics committee approved the protocol, and written informed consent was obtained from each patient. Thin-section high-spatial-resolution MR imaging was performed in specimens obtained from 23 patients (16 men, seven women; median age, 64 years; age range, 39-84 years) immediately after resection. Seven patients underwent neoadjuvant treatment. T1-weighted spin-echo, T2-weighted fast spin-echo, and intermediate-weighted spectral fat-saturated MR images were obtained in the transverse plane. Differences in signal intensity between tumor and fibrosis and between tumor and rectal wall layers were evaluated by using visual scoring and measurements of T2 relaxation time. Statistical differences were evaluated by using the Wilcoxon signed rank test and a mixed-model regression analysis. All images were compared with whole-mount histopathologic slices (n = 86). RESULTS: T2-weighted MR images provided the best differentiation between tumor and fibrosis (P < .001). Mean visual signal intensity scores were -1.8 for T2-weighted MR images, -1.4 for intermediate-weighted spectral fat-saturated MR images, and -0.2 for T1-weighted MR images. T2 relaxation times were 97 msec +/- 4.6 for tumor and 70 msec +/- 3.8 for fibrosis (P < .001). Substantial overlap was noted between the tumor and the circular layer of the muscularis propria (97 msec +/- 2.1), and less overlap was noted between the tumor and the longitudinal layer of the muscularis propria (88 msec +/- 1.6). CONCLUSION: T2-weighted MR imaging provides superior delineation of rectal wall layers and better differentiation of tumor from fibrosis in rectal cancer specimens compared with T1-weighted MR imaging and intermediate-weighted spectral fat-saturated MR imaging by using thin-section high-spatial-resolution sequences.

Adult↗
PubMed2006

Pulmonary embolism at multi-detector row CT of chest: one-year survival of treated and untreated patients.

PURPOSE: To retrospectively assess outcome in patients with clinically unsuspected pulmonary embolism (PE) at chest multi-detector row computed tomography (CT). MATERIALS AND METHODS: Institutional review board approval and informed consent were not required. PE was assessed in consecutive CT scans in 1966 patients (mean age, 60 years; range, 15-96 years; male-female ratio, 1.79) and graded with severity score. Studies with true-positive and false-negative radiologic diagnoses were determined. Coexisting morbidity, anticoagulant therapy (ACT), complications, and 1-year outcome were reviewed. Statistical evaluation included Mann-Whitney U test, chi(2) test, Poisson regression, and Kaplan-Meier statistics. RESULTS: Scans were PE positive in 117 patients. Clinical data review was complete in 96 patients; 63 of 96 patients had malignancy; in 58, PE was not suspected. In 38 of these 58 patients, radiology report findings were false-negative (mean severity score, 20.21 +/- 17.88 [standard deviation] and 9.55 +/- 7.12 for those with true-positive and false-negative findings, respectively; P = .012). Forty-nine patients received therapeutic ACT; 21, prophylactic ACT; and 26, no treatment. PE severity was higher in patients with therapeutic ACT versus those without (P < .001). Bleeding complications were more frequent with therapeutic ACT (two early deaths, five major nonfatal hemorrhages) than without (one minor hemorrhage; P = .037). There were eight early deaths (therapeutic ACT, seven; without ACT, one; P = .037). Positive predictors of early death included severity score >28, use of systemic thrombolytic therapy, occurrence of major hemorrhage, and new-onset cardiac or renal failure (P = .001-.043). Negative predictors were report with false-negative findings and no therapeutic ACT (P = .007-.037). Predictors of late death (n = 25) were older age, malignancy, and renal failure (P = .001-.043). CONCLUSION: Clinically unsuspected PE may remain undetected at routine chest CT; these patients have favorable short-term outcome without therapeutic ACT.

Adolescent↗
PubMed2006

Adenocarcinomas of esophagogastric junction: multi-detector row CT to evaluate early response to neoadjuvant chemotherapy.

PURPOSE: To prospectively evaluate multi-detector row computed tomography (CT) in the assessment of early response during neoadjuvant chemotherapy for adenocarcinoma of the esophagogastric junction (AEG). MATERIALS AND METHODS: The study protocol was approved by the local ethics committee. Written informed consent was obtained from all patients. Thirty-one patients with an AEG (stage T3 N0/1 M0 or T4 N0/1 M0) were examined with multi-detector row CT before and 2 weeks after the initiation of chemotherapy. There were seven women and 24 men with a mean age of 62 years +/- 8.1 (standard deviation). The maximal transverse tumor diameter was measured and tumor volumetry was performed by three independent readers. The resulting changes were correlated with the histopathologic grade of regression in 21 patients. The differentiation of responders from nonresponders was assessed with receiver operating characteristic analysis in these 21 patients. Interobserver variability was determined in all 31 patients with the Spearman rank correlation. Survival without disease progression was estimated in all patients according to the Kaplan-Meier method. Statistical comparisons between different groups of patients were performed with the log-rank test. RESULTS: The interobserver variability for the diameter measurements (R = 0.13-0.20) was higher than that for the volumetric measurements (R = 0.70-0.82). The correlation of histopathologic grades of regression with changes in diameter was not statistically significant for the three readers, whereas the correlation of volume changes with histopathologic grades of regression was statistically significant for two of the three readers (P = .01, .05, and .08). Results of receiver operating characteristic analysis revealed an optimal cutoff level for tumor volumetry at a reduction of volume of 14.8%, which resulted in a sensitivity of 100% (six of six patients) and a specificity of 53% (eight of 15 patients). Although the probability of progression was higher in the nonresponder group than in the responder group (61% vs 40%, respectively), the differences were not statistically significant. CONCLUSION: Tumor volumetry based on multi-detector row CT can help predict early response to treatment 2 weeks after the initiation of neoadjuvant chemotherapy in patients with AEG; however, the classic approach of tumor diameter measurement failed to show significant correlation with histopathologic tumor regression.

Adenocarcinoma↗
PubMed2006

Comparison of different radiography systems in an experimental study for detection of forearm fractures and evaluation of the Müller-AO and Frykman classification for distal radius fractures.

OBJECTIVES: We sought to compare the diagnostic performance of screen-film radiography, storage-phosphor radiography, and a flat-panel detector system in detecting forearm fractures and to classify distal radius fractures according to the Müller-AO and Frykman classifications compared with the true extent, depicted by anatomic preparation. MATERIALS AND METHODS: A total of 71 cadaver arms were fractured in a material testing machine creating different fractures of the radius and ulna as well as of the carpal bones. Radiographs of the complete forearm were evaluated by 3 radiologists, and anatomic preparation was used as standard of reference in a receiver operating curve analysis. RESULTS: The highest diagnostic performance was obtained for the detection of distal radius fractures with area under the receiver operating curve (AUC) values of 0.959 for screen-film radiography, 0.966 for storage-phosphor radiography, and 0.971 for the flat-panel detector system (P > 0.05). Exact classification was slightly better for the Frykman (kappa values of 0.457-0.478) compared with the Müller-AO classification (kappa values of 0.404-0.447), but agreement can be considered as moderate for both classifications. CONCLUSIONS: The 3 imaging systems showed a comparable diagnostic performance in detecting forearm fractures. A high diagnostic performance was demonstrated for distal radius fractures and conventional radiography can be routinely performed for fracture detection. However, compared with anatomic preparation, depiction of the true extent of distal radius fractures was limited and the severity of distal radius fractures tends to be underestimated.

Area Under Curve↗
PubMed2006

Comparison of 16-MDCT and MRI for characterization of kidney lesions.

OBJECTIVE: The objective of our study was to compare the diagnostic performance of 16-MDCT with that of MRI in the characterization of kidney lesions. SUBJECTS AND METHODS: Twenty-eight patients with kidney lesions detected with sonography and requiring further evaluation were examined. MDCT was performed in the unenhanced, arterial, and portal venous phases. MRI was performed at 1.5 T with T2- and T1-weighted and dynamic gadolinium-enhanced sequences. Consensus reading was done by two radiologists. Image quality was rated on a four-point scale. Classification of lesions as surgical or nonsurgical was done with five levels of confidence, and it was required that a definite diagnosis be assigned to each lesion. The 1997 TNM classification was used for staging. Statistical analysis was done by receiver operating characteristic analysis or paired Student's t test. Histologic or follow-up findings at least 12 months after the primary diagnosis served as the standard of reference. RESULTS: The image quality of MDCT (mean grade, 2.79 on a 0-3 scale) was superior to that of MRI (1.93; p < 0.01). The area under the curve for differentiating surgical from nonsurgical lesions was 0.979 for MDCT and 0.957 for MRI with resulting sensitivity and specificity values of 92.3% and 96.3% for MDCT and 92.3% and 91.3% for MRI. Sensitivity and specificity for definite classification of the lesions were 93.8% and 68.4% for MDCT and 93.8% and 71.4% for MRI. CONCLUSION: Both MDCT and MRI are excellent for differentiating surgical from nonsurgical kidney lesions. Both methods have low specificity for the differentiation of benign from malignant lesions.

Adult↗
PubMed2006

Acute pulmonary embolism on MDCT of the chest: prediction of cor pulmonale and short-term patient survival from morphologic embolus burden.

OBJECTIVE: To predict cor pulmonale and short-term outcome in patients with pulmonary embolism (PE), we retrospectively investigated three morphology-based MDCT systems for scoring pulmonary artery obstruction. MATERIALS AND METHODS: Eighty-nine consecutive patients (51 men and 38 women; age range, 23-83 years; median, 63.3 years) with an MDCT diagnosis of acute PE were included in the study. Sixty-four patients had a coexisting malignancy. PE severity was assessed by two masked observers using three percentage arterial obstruction indexes: two severity scores adapted from conventional angiography (excluding and including arterial branch obstruction grading: scores A and B, respectively) and a CT-derived severity score (index C). Echocardiographic reports were reviewed for elevation of right ventricular pressure. Obstruction index results were analyzed for correlation with pulmonary artery pressures and for prediction of cor pulmonale and 30-day survival. Statistical analysis included kappa, analysis of variance, linear correlation, chi-square, and logistic regression tests. RESULTS: Kappa values of 0.89, 0.82, and 0.78 were obtained for interobserver agreement on PE severity for indexes A, B, and C, respectively. PE severity was moderate but varied significantly between the scores (for index A: median, 25.0%; range, 6.3-100; for index B: median, 12.5%; range, 3.1-65.6; for index C: median, 7.1%; range, 0.65-65.8; p < 0.0001 [analysis of variance]). Index C correlated best with pulmonary artery pressures (r = 0.69; p < 0.0016) and the presence of cor pulmonale (p = 0.0051; odds ratio [OR], 1.20/percentage increase [95% confidence interval, 1.05-1.35]; for an index C cutoff of 21.3%: p = 0.0001; positive predictive value, 1; negative predictive value, 0.87). Eight patients died within 30 days after CT. The PE severity of indexes A and B was not associated with patient outcome (p > 0.05). With score C, PE severity was a significant predictor of early death (p = 0.018; OR, 1.03/percentage increase [95% confidence interval, 1.00-1.06]; for an index C cutoff of 21.3%: p = 0.018; overall OR, 6.77; positive predictive value, 0.24; negative predictive value, 0.96). CONCLUSION: Mastora score was a significant predictor of cor pulmonale and short-term outcome and may therefore allow therapy and risk stratification in patients with acute PE.

Acute Disease↗
PubMed2006

Quadruple-phase MDCT of the liver in patients with suspected hepatocellular carcinoma: effect of contrast material flow rate.

OBJECTIVE: The purposes of this study were to evaluate the effect of contrast material flow rate (3 mL/sec vs 5 mL/sec) on the detection and visualization of hepatocellular carcinoma (HCC) with MDCT and the safety profile of iodixanol at different injection rates. SUBJECTS AND METHODS: In a prospective, randomized multicenter trial, 97 patients (83 men and 14 women, with a mean age of 64 years) suspected of having HCC underwent quadruple-phase (double arterial, portal venous, delayed phase) 4-16-MDCT. Patients were randomized to receive iodixanol, 320 mg I/mL (1.5 mL/kg body weight), at a flow rate of 3 mL/sec (48 patients) or 5 mL/sec (49 patients). Qualitative (lesion detection, image quality) and quantitative (liver and aortic enhancement, tumor-liver contrast) analyses and safety assessment were performed. RESULTS: Overall, 145 HCCs were detected in the 5 mL/sec group and 100 HCCs in the 3 mL/sec group (p < 0.05). More lesions equal to or less than 1 cm were detected at 5 mL/sec (33 vs 16 lesions). The late arterial phase showed significantly more lesions than the early, arterial phase (133 vs 100 and 96 vs 67 lesions, respectively, p < 0.0001). Hyperattenuating HCCs were better visualized in the late arterial phase at 5 mL/sec (excellent visualization: 54% vs 27%). Using a flow of 5 mL/sec did not increase the rate of patient discomfort or contrast media-related adverse events. Most discomfort in both groups was of mild intensity and there was no severe discomfort. CONCLUSION: For detection of HCC with MDCT, a higher flow rate of 5 mL/sec is recommended. Visualization of hyperattenuating HCC is improved with no greater discomfort or adverse events.

Carcinoma, Hepatocellular↗
PubMed2005

Inadequacy of manual measurements compared to automated CT volumetry in assessment of treatment response of pulmonary metastases using RECIST criteria.

The purpose of this study was to compare relative values of manual unidimensional measurements (MD) and automated volumetry (AV) for longitudinal treatment response assessment in patients with pulmonary metastases. Fifty consecutive patients with pulmonary metastases and repeat chest multidetector-row CT (median interval=2 months) were independently assessed by two radiologists for treatment response using Response Evaluation Criteria In Solid Tumours (RECIST). Statistics included relative measurement errors (RME), intra-/interobserver correlations, limits of agreement (95% LoA), and kappa. A total of 202 metastases (median volume=182.22 mm(3); range=3.16-5,195.13 mm(3)) were evaluated. RMEs were significantly higher for MD than for AV (intraobserver RME=2.34-3.73% and 0.15-0.22% for MD and AV respectively; P<0.05. Interobserver RME=3.53-3.76% and 0.22-0.29% for MD and AV respectively; P<0.05). Overall correlation was significantly better for AV than for MD (P<0.05). Intraobserver 95% LoAs were -1.85 to 1.75 mm for MD and -11.28 to 9.84 mm(3) for AV. The interobserver 95% LoA were -1.46 to 1.92 mm for MD and -11.17 to 9.33 mm(3) for AV. There was total intra-/interobserver agreement on response using AV (kappa=1). MD intra- and interobserver agreements were 0.73-0.84 and 0.77-0.80 respectively. Of the 200 MD response ratings, 28 (14/50 patients) were discordant. Agreement using MD dropped significantly from total remission to progressive disease (P<0.05). We therefore conclude that AV allows for better reproducibility of response evaluation in pulmonary metastases and should be preferred to MD in these patients.

Adult↗
PubMed2005

Ferumoxtran-10-enhanced MR imaging of the bone marrow before and after conditioning therapy in patients with non-Hodgkin lymphomas.

To quantify permeability changes of the "blood-bone marrow barrier" (BMB) and to detect malignant bone marrow infiltrations before and after conditioning therapy for subsequent leukapheresis using ferumoxtran-10-enhanced magnetic resonance (MR) imaging. Twenty-two patients with malignant non-Hodgkin lymphomas (NHL), including 9 patients (group A) before and 13 patients (group B) after conditioning therapy, underwent MR of the spine before and after infusion of ferumoxtran-10 (0.045 mmol Fe/kg BW). Pulse sequences comprised dynamic T1-GE and pre- and post-contrast T1-SE and STIR sequences. Dynamic deltaSI-data were correlated with the quantity of mobilized CD34+ cells. In addition, the number of focal bone marrow lesions was compared before and after ferumoxtran-10 administration. Dynamic deltaSI-data were higher in group B than in group A, indicating an increased BMB permeability after conditioning therapy. However, deltaSI-data did not correlate with the quantity of mobilized CD34+ cells. Ferumoxtran-10-enhanced STIR images demonstrated a significant signal decline of the normal, non-neoplastic bone marrow and a significantly increased detection of focal neoplastic lesions compared to pre-contrast images (P<0.05). Ferumoxtran-10 depicted the bone marrow response to conditioning therapy by an increase in BMB-permeability, which, however, did not correlate with the number of mobilized CD34+ cells. Ferumoxtran-10 improved the detection of focal bone marrow lesions significantly (P<0.05).

Adult↗
PubMed2005

Multifocal epithelioid hemangioendothelioma of the phalanges of the hand.

Epithelioid hemangioendothelioma (EH) of bone is a rare vascular neoplasm characterized by epithelioid endothelial cells and a variable biologic behaviour. The principal sites of occurrence of this osteolytic tumor are the lower extremity and the axial skeleton. Approximately half of the cases present with multifocal disease. The latter feature can be helpful in suggesting the diagnosis of a vascular tumor; on the other hand, it strengthens the need for a skeletal survey or whole-body MRI/CT. We report on the clinical, histologic and radiologic features-including CT and MRI findings-of EH in a case of multifocal disease of the phalanges of the hand, a very uncommon anatomic site of affliction.

Adult↗
PubMed2005

Variants of the superior labrum and labro-bicipital complex: a comparative study of shoulder specimens using MR arthrography, multi-slice CT arthrography and anatomical dissection.

The purpose of the present study was to evaluate the anatomical variability of the superior labrum and to compare the value of MR arthrography and multi-slice CT arthrography in the diagnosis of variants of the labro-bicipital complex. Forty-three human shoulder specimens (age range and mean age at death, 61-89 years and 78.3 years) were examined with the use of MR arthrography and multi-slice CT arthrography prior to joint exploration and macroscopic inspection of the superior labrum and labro-bicipital complex. Two radiologists evaluated MR and CT arthrograms, and the results were compared with macroscopic assessments. Anatomical dissection of all shoulder specimens revealed a sublabral recess in 32/43 (74%) cases. The attachment of the superior labrum was categorised as type 1 in ten (23%) cases, as type 2 in eight (19%), as type 3 in ten (23%), and as type 4 in 14 (33%) cases. One superior labrum showed detachment consistent with a superior labral anteroposterior (SLAP) type 3 lesion. On MR arthrography and CT arthrography the attachment of the superior labrum was categorised in concordance with macroscopic assessments in 79% and 84% of cases, respectively. The anteroposterior extension of sublabral recesses was accurately determined with MR and CT arthrography in 59% and 81% of cases, respectively. The attachment of the superior labrum shows considerable variability. Thus, exact depiction of variants is essential in order to avoid the false positive diagnosis of a superior labral tear (SLAP or Andrews lesion). Both, MR arthrography and multi-slice CT arthrography were effective in the detection and classification of sublabral recesses.

Aged↗
PubMed2005

Normal and pathological MR findings in osteochondral autografts with longitudinal follow-up.

The purpose of this study was to analyze normal and pathological MR findings in osteochondral autograft transfer systems (OATS) of the knee and ankle in the longitudinal follow-up and in relation to the clinical findings. MR imaging was performed in 55 patients (21 females: 34 males; mean age 34.5+/-12.1 years) after OATS procedures in the knee (n=45) and ankle (n=10). MR sequences were obtained with and without intravenous Gd-DTPA administration within the first year post-operatively, in 30 patients within the second and in 13 patients in the third year. One hundred and five OATS cylinders were implanted. MR findings consistent with osteonecroses were detected in eight cylinders (n=6 in the knee and n=2 in the ankle) in six patients; four out of eight were demonstrated during the first year and four/eight in the second year. Edema around and/or in the cylinders was found in 28/55 of the patients within the first year, five/30 in the second year and in two/13 in the third year. No substantial changes in the cartilage signal intensity or the cartilage-cartilage interface were demonstrated in the longitudinal follow-up within the first three years. Clinical and MR findings were not consistently associated in particular in the patients with osteochondral autograft necroses.

Adult↗
PubMed2005

Comparison of iron oxide labeling properties of hematopoietic progenitor cells from umbilical cord blood and from peripheral blood for subsequent in vivo tracking in a xenotransplant mouse model XXX.

RATIONALE AND OBJECTIVES: To compare and optimize ferumoxides labeling of human hematopoietic progenitor cells from umbilical cord blood and from peripheral blood for subsequent in vivo tracking with a clinical 1.5 T MR scanner. MATERIALS AND METHODS: Human hematopoietic progenitor cells, derived from umbilical cord blood or peripheral blood, were labeled with Ferumoxides by simple incubation or lipofection. Cellular iron uptake was quantified with spectrometry. Then, 3 x 10(7)-labeled cells were injected into the tail vein of 12 female nude Balb/c mice. The mice underwent magnetic resonance imaging before and 24 hours after injection. Precontrast and postcontrast signal intensities of liver, spleen, and bone marrow were measured and tested for significant differences with the t-test. Immunostains served as a histopathologic standard of reference. RESULTS: After labeling by simple incubation, only umbilical cord blood cells, but not peripheral blood cells, showed a significant iron uptake and could be tracked in vivo with magnetic resonance imaging. Using lipofection, both cell types could be tracked in vivo. A significant decline in signal intensity was observed in liver, spleen, and bone marrow at 24 hours after injection of efficiently labeled ferumoxides cells (P < .05). Histopathology proved the distribution of iron oxide-labeled cells to these organs. CONCLUSION: Hematopoietic progenitor cells from umbilical cord blood can be labeled by simple incubation with an Food and Drug Administration-approved magnetic resonance contrast agent with sufficient efficiency to provide an in vivo cell tracking at 1.5 T. Progenitor cells from peripheral blood need to be labeled with adjunctive transfection techniques to be depicted in vivo at 1.5 T.

Animals↗
PubMed2005

Migration of iron oxide-labeled human hematopoietic progenitor cells in a mouse model: in vivo monitoring with 1.5-T MR imaging equipment.

PURPOSE: To evaluate the use of clinical 1.5-T magnetic resonance (MR) imaging equipment to depict the in vivo distribution of iron oxide-labeled human hematopoietic progenitor cells in athymic mice. MATERIALS AND METHODS: This study was approved by the ethical committee, and all women had given consent to donate umbilical cord blood for research. Twenty athymic female Balb/c mice underwent MR imaging before and 1, 4, 24, and 48 hours after intravenous injection of (1-3) x 10(7) human hematopoietic progenitor cells labeled with the superparamagnetic iron oxide particles ferumoxides through simple incubation (n = 10) or P7228 through lipofection (n = 10). Fifteen female Balb/c control mice were examined after intravenous injection of the pure contrast agents (n = 6 for both probes) or nonlabeled cells (n = 3). Signal intensities of liver, spleen, and bone marrow on MR images obtained before and after injection were measured and compared for significant differences by using the t test. MR imaging data were compared with the results of immunostaining against human CD31(+) cells and against the coating of the contrast agents; these results served as the standard of reference. RESULTS: Ferumoxides was internalized into more mature CD34(-) cells but not into CD34(+) stem cells, while P7228 liposomes were internalized into both CD34(-) and CD34(+) cells. After injection of iron oxide-labeled hematopoietic cells, a significant decrease in MR signal intensity was observed in liver and spleen at 1, 4, 24, and 48 hours after injection (P < .05) and in the bone marrow at 24 and 48 hours after injection (P < .05). The signal intensity decrease in bone marrow was significantly stronger after injection of iron oxide-labeled cells compared to controls that received injections of the pure contrast agent (P < .05). Results of histopathologic examination confirmed homing of iron oxide-labeled human progenitor cells in the murine recipient organs. CONCLUSION: The in vivo distribution of intravenously administered iron oxide-labeled hematopoietic progenitor cells can be monitored with 1.5-T MR imaging equipment.

Animals↗
PubMed2005

Chest radiography with a digital flat-panel detector: experimental receiver operating characteristic analysis.

PURPOSE: To evaluate the influence of different detector radiation doses and peak kilovoltage settings on diagnostic performance and radiation dose at posteroanterior (PA) chest radiography performed with an amorphous silicon flat-panel detector (FPD). MATERIALS AND METHODS: All examinations were performed by using a digital FPD. PA chest radiographs of an anthropomorphic chest phantom were obtained with detector radiation doses of 2.50 microGy (system speed, 400), 1.56 microGy (speed, 640), and 1.25 microGy (speed, 800) and with peak kilovoltage values of 100, 120, and 140 kVp. Four types of simulated lesions-nodules of different sizes, polylobulated lesions, interstitial-nodular lesions, and interstitial-reticular lesions-were superimposed on the phantom. After four radiologists assessed all of the images, receiver operating characteristics analysis was performed. In addition, the entrance surface dose was measured and the effective dose was calculated. RESULTS: Reduced detector dose led to significantly decreased diagnostic performance in overall lesion detection (P <.05). However, over pulmonary areas only, this effect could not be seen. With use of the same kilovoltage values, reducing the detector dose, even to 1.25 microGy (speed, 800), did not lead to significantly decreased lesion detectability. In terms of diagnostic performance and effective dose, 120 kVp was the most effective. CONCLUSION: Standard PA chest radiographs should still be acquired at a detector dose of 2.50 microGy (speed, 400) with 120 kVp to yield the highest diagnostic performance. However, when the present analysis was focused on the lung fields only, no significant loss in diagnostic performance could be demonstrated, even after a 50% reduction in radiation dose.

Observer Variation↗
PubMed2005

Anterior shoulder instability: accuracy of MR arthrography in the classification of anteroinferior labroligamentous injuries.

PURPOSE: To retrospectively evaluate the accuracy of magnetic resonance (MR) arthrography in the classification of anteroinferior labroligamentous injuries by using arthroscopy as the reference standard. MATERIALS AND METHODS: Ethical committee approval and informed consent were obtained. MR arthrograms obtained in 205 patients, including a study group of 104 patients (74 male and 30 female; mean age, 28.2 years) with arthroscopically proved labroligamentous injuries and a control group of 101 patients (65 male and 36 female; mean age, 31.4 years) with intact labroligamentous complex, were reviewed in random order. MR arthrograms were analyzed for the presence and type (Bankart, anterior labral periosteal sleeve avulsion [ALPSA], Perthes, glenolabral articular disruption [GLAD], or nonclassifiable lesion) of labroligamentous injuries by two radiologists in consensus. Results were compared with arthroscopic findings. Sensitivity, specificity, accuracy, and corresponding 95% confidence intervals for the detection and classification of anteroinferior labroligamentous lesions with MR arthrography were calculated. RESULTS: At arthroscopy, 104 anteroinferior labroligamentous lesions were diagnosed, including 44 Bankart lesions, 22 ALPSA lesions, 12 Perthes lesions, and three GLAD lesions. Twenty-three labral lesions were nonclassifiable at arthroscopy, all of which occurred after a history of chronic instability. Nineteen (83%) of these 23 lesions were also nonclassifiable at MR arthrography. With arthroscopy used as the reference standard, labroligamentous lesions were detected and correctly classified at MR arthrography with sensitivities of 88% and 77%, specificities of 91% and 91%, and accuracies of 89% and 84%, respectively. Bankart, ALPSA, and Perthes lesions were correctly classified in 80%, 77%, and 50% of cases, respectively. The three GLAD lesions were all correctly assessed. CONCLUSION: MR arthrography is accurate in enabling classification of acute and chronic anteroinferior labroligamentous injuries, although correct interpretation of Perthes lesions remains difficult.

Adolescent↗