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E Rummeny

Publications and source records attributed to E Rummeny.

At least 19 recordsLinked to original sources
PubMed2006

[MRI of arthritis with the USPIO SH U 555 C: optimization of T1 enhancement].

PURPOSE: To optimize contrast agent dose and pulse sequence parameters in order to achieve a maximal T1 enhancement in arthritic knee joints with ultra small superparamagnetic iron oxides (USPIO)-enhanced MRI. MATERIALS AND METHODS: Antigen-mediated arthritis was induced in the right knee of nine Sprague Dawley rats. The arthritic knee joint as well as the contralateral normal knee were investigated in a 2 Tesla MR scanner before as well as in short intervals up to 2 h after USPIO injection, using T1-weighted gradient echo (GE) sequences. Three rats each received intravenous injections of the new USPIO SHU 555 C (SH U 555 C, Schering AG, Berlin) at doses of 40, 100 and 200 micromol Fe/kg. Pulse sequence parameters of the GE-sequence were optimized by varying flip angles (alpha) and echo times (TE). Changes in signal intensities (SI) of the arthritic knee and contralateral normal knee were quantified as DeltaSI (%) = /([SIpost - SIpre] / SIpre) x 100 %/ and compared with histopathology. RESULTS: Histology of the arthritic knees demonstrated a marked inflammatory proliferation of the synovium. The USPIO SH U 555 C caused a significant increase in signal intensity of the arthritic joints on T1-weighted MR images (p < 0.05). This effect was optimized using a flip angle of 60-70 degrees, a minimal TE and a dose of 200 micromol Fe/kg. Visually the contralateral normal knee did not show any USPIO enhancement. CONCLUSION: Inflammation can be depicted with marked T1 enhancement by the USPIO SH U 555 C using high contrast agent doses and optimized MR pulse sequence parameters.

Animals↗
PubMed2006

[Acute pulmonary embolism: prediction of cor pulmonale and short-term patient survival from assessment of cardiac dimensions in routine multidetector-row CT].

PURPOSE: Evaluation of the prognostic value of morphological cardiac parameters in patients with suspected and incidental acute pulmonary embolism (PE) using multidetector-row chest CT (MSCT). MATERIALS AND METHODS: 2335 consecutive MSCT scans were evaluated for the presence of PE. The arterial enhancement and analysability of pulmonary arteries and the heart were assessed as parameters of the scan quality. The diastolic right and left ventricular short axes (RV (D), LV (D)) and the interventricular septal deviation (ISD) were measured in all PE-positive patients and the echocardiography reports were reviewed. The clinical data assessment included cardio-respiratory and other co-morbidities, systemic anticoagulant therapy (ACT), and the 30-day outcome. Predictors of acute cor pulmonale and the short-term outcome were calculated by univariate and multivariate logistic regressions including odds ratios (OR) and ROC analyses using positive (PPV) and negative predictive values (NPV). RESULTS: 90 patients with acute PE were included (36 with clinically suspected PE, 54 with incidental PE). 26 patients had cardio-respiratory co-morbidities. Four patients underwent systemic thrombolysis, 43 underwent anticoagulation in therapeutic doses, 19 underwent anticoagulation in prophylactic doses, and 24 patients did not undergo ACT. 15 of 41 patients had echocardiographic evidence of acute cor pulmonale. 8 patients died within 30 days. The RV (D) was the best independent predictor of acute cor pulmonale (p = 0,002, OR = 9.16, PPV = 0.68, NPV = 1 at 4.49 cm cut off) and short-term outcome (p = 0,0005, OR = 2.82, PPV = 0.23, NPV = 0.98 at 4.75 cm cut off). The RV (D)/LV (D) ratio had a PPV of 0.85 for cor pulmonale. CONCLUSION: The RV (D) and RV (D)/LV (D) ratio were suitable for identifying patients with acute cor pulmonale and for benign short-term prognosis. Further studies should prospectively address the combined use of CT-morphological and clinical parameters for the prediction of patient outcome.

Adult↗
PubMed2005

Evaluation of reconstructed orbital wall fractures: high-resolution MRI using a microscopy surface coil versus 16-slice MSCT.

We evaluated high-resolution magnetic resonance imaging (MR) using a 47-mm microscopy surface coil in comparison to 16-slice multislice CT (MSCT) for postsurgical imaging of reconstructed orbital walls. Twenty-five patients with 27 internal orbital wall fractures were imaged prospectively after reconstruction with resorbable polydioxanone sulfate (PDS) sheets. Coronal high-quality T1- and T2-weighted MR images were obtained with an in-plane resolution of 350 microm within a measure time of 6-7 min for each sequence. Nineteen symptomatic patients underwent MSCT as the current gold standard. In MRI the PDS foil appears in T1- and T2-weighted images as a thin, low-signal-intensity linear structure. In CT it appears hyperdense in comparison to soft tissue and slightly hypodense in comparison to cortical bone. PDS foils could be clearly depicted in 20 out of 25 patients (80%) with MRI and in 13 out of 19 patients (68%) with MSCT. An inadequate foil position or size could be diagnosed in eight patients with MRI and in only three patients with MSCT. In ten symptomatic patients secondary surgery could be avoided because of regular MRI findings except mild hematoma and muscle edema. High-resolution MRI of the orbit using a 47-mm microscopy coil is a promising method to accurately demonstrate normal and pathologic conditions in symptomatic patients after orbital wall reconstruction with PDS foils.

Adolescent↗
PubMed2004

[PET/CT for colorectal and hepatic tumors].

This contribution presents clinical and technical aspects of combining positron emission tomography (PET) and computed tomography (CT) for patients with colorectal tumors and characterization of unclear liver foci. In which manner and for which patients combined PET/CT is superior to PET or CT alone is also discussed. PET/CT can fulfil most prerequisites for imaging in pre- and postoperative management of patients with colorectal tumors and best meets the desire for optimal imaging procedures. Some of the disadvantages encountered in frequently employed CT can be overcome by the combination of PET and CT while increasing both sensitivity in detecting lesions and specificity in their characterization. Questions regarding treatment response offer an opportunity for devising novel study concepts and initiating research on new PET tracers. Although few publications are available, we are of the opinion that the combination of functional and anatomical imaging provided by PET/CT can improve both preoperative management and aftercare. To this end, however, optimum cooperation between practitioners of nuclear medicine and radiology is imperative.

Adult↗
PubMed2003

Local 3D scaling properties for the analysis of trabecular bone extracted from high-resolution magnetic resonance imaging of human trabecular bone: comparison with bone mineral density in the prediction of biomechanical strength in vitro.

RATIONALE AND OBJECTIVES: A novel, nonlinear morphologic measure [DeltaP(alpha)] based on local 3D scaling properties was applied to high-resolution magnetic resonance images (HR-MRI) of human trabecular bone to predict biomechanical strength in vitro. METHODS: We extracted DeltaP(alpha) and traditional morphologic parameters (apparent trabecular volume fraction, apparent trabecular separation) from HR-MR images of 32 femoral and 13 spinal bone specimens. Furthermore, bone mineral density (BMD) and maximum compressive strength (MCS) were determined. The morphologic measures were compared with BMD in predicting the biomechanical strength. RESULTS: In the vertebral (femoral) specimens, R2 for MCS versus DeltaP(alpha) was 0.87 (0.61) (P < 0.001). Correlation between BMD and MCS was 0.53 (P = 0.05) (0.79 [P < 0.001]) for the vertebral (femoral) specimens. For the femoral specimens, prediction of MCS could be improved further by combining BMD and morphologic parameters by multiple regression (R2 = 0.88). CONCLUSIONS: Morphologic measures extracted from HR-MRI considering local 3D-scaling properties can be used to predict biomechanical properties of bone in vitro. They are superior to 2-dimensional standard linear morphometric measures and, depending on the anatomic location, more reliably predict bone strength as measured by MCS than does BMD.

Adult↗
PubMed2001

Differentiation between benign and malignant findings on MR-mammography: usefulness of morphological criteria.

The purpose of this study was to evaluate the usefulness of morphological criteria in differentiating between benign and malignant lesions on MR-mammography. Fifty-three women (18-82 years) with 62 lesions scheduled for excisional biopsy underwent dynamic contrast-enhanced MR-mammography using fast 3D Gradient-Echo sequences in coronal orientation (axial orientation in seven patients). Histology revealed 44 malignant and 18 benign lesions. For each lesion, five radiologists evaluated four morphological features: lesion shape, irregularity of contour, homogeneity of contrast enhancement and presence of ring enhancement. For each feature a receiver operating characteristic (ROC) curve was generated with calculation of the area under the curve (AUC). Interobserver variability was evaluated by the kappa-coefficient. The most reliable morphological feature indicating malignancy was an irregular lesion contour with a sensitivity/specificity/AUC of 83%/76%/0.9 followed by inhomogeneous contrast enhancement (85%/42%/0.7) and the presence of ring enhancement (71%/53%/0.64). The average interobserver agreement for the different features ranged between 0.35 and 0.4. Morphological criteria are useful features in MR-mammography for differentiating between benign and malignant lesions. However, due to the relatively high interobserver variability, standardization of terminology is important.

Adolescent↗
PubMed2001

Event-related functional magnetic resonance imaging in Parkinson's disease before and after levodopa.

Event-related functional MRI (fMRI) was used to study blood oxygen level dependent cortical signal changes associated with volitional limb movements off and on levodopa in Parkinson's disease. Eight patients with early stage akinetic Parkinson's disease and eight healthy volunteers underwent three functional imaging runs (high speed echo planar imaging with 600 scans/run) while performing paced single joystick movements in a freely chosen direction every 7-15 s. The non-magnetic joystick was linked to a monitoring system for on-line registration of performance parameters along with timing of the pacing tones and fMRI-scan acquisition parameters. This allowed correlation of movement onset, i.e. event-onset, to scanning time. We repeated the scanning procedure in the Parkinson's disease patients when akinesia improved 30 min after oral levodopa. Compared with the control group, patients both off and on levodopa showed movement-related impaired activation in the rostral supplementary motor area and increased activation in primary motor cortex (M1) and the lateral premotor cortex bilaterally. Levodopa led to a relative normalization of the impaired activation in the mesial premotor cortex and decreased signal levels in M1, lateral premotor and superior parietal cortex. We conclude that levodopa improves impaired motor initiation in the supplementary motor area and decreases hyperfunction of lateral premotor and M1 associated with Parkinson's disease during simple volitional movements.

Aged↗
PubMed2000

Cross-sectional area of lumbar vertebrae in peri- and postmenopausal patients with and without osteoporosis.

The purpose of this study was to analyze the midvertebral area of lumbar vertebrae in osteoporotic and nonosteoporotic female patients and to find out whether the midvertebral area may be used as an additional parameter in the diagnosis of osteoporosis. In 195 peri- and postmenopausal patients (average age 51.7 +/- 5.2 years) trabecular and cortical bone mineral density (BMD) were determined using quantitative CT (QCT) in L2-4. In addition, midvertebral cross-sectional area was measured in a standardized fashion on the CT sections and the height of the second lumbar vertebra was determined on the lateral digital radiographs. Body height and weight were obtained and vertebral fracture status was determined. According to WHO criteria 29 patients (average age 57.2 years) were considered osteoporotic, 93 osteopenic (average age 52.2 years) and 73 normal (average age 48.6 years). Body weight and size did not show significant differences between the individual groups. Average midvertebral area was 1278 +/- 173 mm2 in the osteoporotic patients, 1186 +/- 125 mm2 in the osteopenic patients and 1126 +/- 127 mm2 in the normals. A correlation of r = -0.39 (p < 0.05) was obtained between BMD and area. Thirty-six of 195 patients showed osteoporotic vertebral fractures. Midvertebral area in these patients was 1266 +/- 171 mm2 versus 1159 +/- 133 mm2 in the nonfractured females (p < 0.05). We therefore conclude that the lumbar midvertebral area is larger in osteoporotic and osteopenic patients compared with women with normal BMD. In contrast to biomechanical considerations midvertebral area seems not to be suited as an additional measure of bone strength in vivo.

Anatomy, Cross-Sectional↗
PubMed2000

Focal liver lesions: evaluation of the efficacy of gadobenate dimeglumine in MR imaging--a multicenter phase III clinical study.

PURPOSE: To evaluate gadobenate dimeglumine (Gd-BOPTA) for dynamic and delayed magnetic resonance (MR) imaging of focal liver lesions. MATERIALS AND METHODS: In 126 of 214 patients, MR imaging was performed before Gd-BOPTA administration, immediately after bolus administration of a 0.05- mmol/kg dose of Gd-BOPTA, and 60-120 minutes after an additional intravenously infused 0.05-mmol/kg dose. In 88 patients, imaging was performed before and 60-120 minutes after a single, intravenously infused 0.1-mmol/kg dose. T1- and T2-weighted spin-echo and T1-weighted gradient-echo images were acquired. On-site and blinded off-site reviewers prospectively evaluated all images. Intraoperative ultrasonography, computed tomography (CT) during arterial portography, and/or CT with iodized oil served as the reference methods in 110 patients. RESULTS: Significantly more lesions were detected on combined pre- and postcontrast images compared with on precontrast images alone (P <. 01). All reviewers reported a decreased mean size of the smallest detected lesion and improved lesion conspicuity on postcontrast images. All on-site reviewers and two off-site reviewers reported increased overall diagnostic confidence (P <.01). Additional lesion characterization information was provided on up to 109 (59%) of 184 delayed images and for up to 50 (42%) of 118 patients in whom dynamic images were assessed. Gd-BOPTA would have helped change the diagnosis in 99 (47%) of 209 cases and affected patient treatment in 408 (23%) of 209 cases. CONCLUSION: Gd-BOPTA increases liver lesion conspicuity and detectability and aids in the characterization of lesions.

Adult↗
PubMed2000

Evaluation of the accuracy of gadobenate dimeglumine-enhanced MR imaging in the detection and characterization of focal liver lesions.

OBJECTIVE: We evaluated the extent to which hepatic lesion characterization and detection is improved by using gadobenate dimeglumine for enhancement of MR images. MATERIALS AND METHODS: Eighty-six patients were imaged before gadobenate dimeglumine administration, immediately after the 2 mL/sec bolus administration of a 0.05 mmol/kg dose (dynamic imaging), and at 60-120 min after the IV infusion at 10 mL/min of a further 0.05 nmol/kg dose (delayed imaging). The accuracy for lesion characterization was assessed for a total of 107 lesions. Sensitivity for lesion detection was assessed for a total of 149 lesions detected on either intra-operative sonography, iodized oil CT, CT during arterial portography, or follow-up contrast-enhanced CT as the gold standard. RESULTS: The accuracy in differentiating benign from malignant liver lesions increased from 75% and 82% (the findings of two observers) on unenhanced images alone, to 89% and 80% on dynamic images alone (p<0.001, p = 0.8), and to 90.7% when combining the unenhanced and dynamic image sets (p<0.001, p = 0.023). Delayed images did not further improve accuracy (90% and 91%; p = 0.002, p< 0.05). A similar trend was apparent in terms of accuracy for specific diagnosis: values ranged from 49% and 62% on unenhanced images alone, to 76% and 70% on combined unenhanced and dynamic images (p<0.001, p = 0.06), and to 75% and 70% on inclusion of delayed images (p<0.001, p = 0.12). The sensitivity for lesion detection increased from 77% and 81% on unenhanced images alone, to 87% and 85% on combined unenhanced and dynamic images (p = 0.001, p = 0.267), and to 92% and 89% when all images were considered (p<0.001, p = 0.01). CONCLUSION: Contrast-enhanced dynamic MR imaging with gadobenate dimeglumine significantly increases sensitivity and accuracy over unenhanced imaging for the characterization of focal hepatic lesions, and delayed MR imaging contributes to the improved detection of lesions.

Adult↗
PubMed1998

[Can noninvasive gadolinium 3D MR subtraction angiography of visceral arteries replace conventional intra-arterial catheter angiography?].

Classic catheter angiography is compared with 3D gadolinium MR angiography for evaluation of the vascular anatomy of the celiac trunk, liver supplying arteries, and the portal venous system. Based on 10 patients, this study shows the value of this new non-invasive method of angiography for the diagnosis of visceral vascular anatomy. For this diagnosis MR angiography is expected to replace conventional angiography in the near future.

Angiography↗
PubMed1996

In vivo 31P NMR spectroscopy of human musculoskeletal tumors as a measure of response to chemotherapy.

The value of in vivo 31P NMR spectroscopy to provide indicators of response to cytostatic chemotherapy was studied in patients with malignant musculoskeletal tumors. Characteristics of untreated cancers were strong signals of PME and PDE, moderately increased Pi and low PCr. The intracellular pH was slightly alkaline. The intracellular concentration of free magnesium was 70% of that in muscle. Spectroscopic findings at different times of therapy were compared with the percentage of tumor necrosis after surgical resection in 28 patients. In follow-up studies, energy-rich phosphates declined in nonresponders, while PME, Pi and frequently PDE increased. Treatment response appeared to involve the reversal of these trends. In five responders, a biphasic pattern was observed, i.e. initially the spectrum changed into that of severely ischemic cell injury followed by a successive phase of apparent 'tumor activation'. Pretreatment levels of (PCr+Pi)/total phosphate > or = 0.35 and PCr/ alpha-NTP > or = 1.5, an accelerated increase in total low-energy phosphates/total high-energy phosphates (> or = 3.0%/day) after the initial drug application, and a long-term decrease (< or = -0.4%/day) during later therapy were highly indicative of tumor response to chemotherapy. Such spectroscopic predictors for treatment response proved to be superior to currently used indices such as tumor size.

Adolescent↗
PubMed1996

[The value of 3-phase spiral CT and magnetic resonance tomography in preoperative diagnosis of pancreatic carcinoma].

UNLABELLED: The purpose of this study was to assess the role of spiral computed tomography (SCT) and magnetic resonance imaging (MRI) in the preoperative work-up of patients with pancreatic carcinoma, regarding local resectability and vascular involvement. METHODS AND MATERIALS: A total of 28 patients (19 men and 9 women; mean age 58 years) with known or highly suspected carcinoma of the pancreas were included in this study. All patients prospectively underwent MRI ( +/- gadolinium-DTPA ) and SCT (3-phase examination) as preoperative diagnostic imaging studies, and laparotomy was carried out within 7 days, irrespective of the MRI or SCT findings. SCT and MR studies were reviewed independently by two radiologists, without knowing the results of the surgical exploration. Standardized image analysis was correlated with findings at laparatomy. RESULTS: Laparotomy identified 10 patients to be suitable for surgical resection and 18 pancreatic carcinomas to be unresectable. In 17 of 18 non-resectable carcinomas MRI and SCT were able to obtain correct information about unresectability (sensitivity 94%), in 7 (MRI), resp. 8 (SCT) carcinomas were correctly considered to be resectable (sensitivity 70% of MRI and 80% for SCT). The presence of vascular involvement was depicted by SCT with a sensitivity of 82-100% and 62-100% by MRI. The specificity varied between 85-100% for SCT and 77-100% for MRI. CONCLUSION: Both MRI and SCT are good techniques for the preoperative work-up of pancreatic carcinomas in order to obtain a correct assessment of local resectability.

Adult↗
PubMed1996

Oral magnetic particles (ferristene) as a contrast medium in abdominal magnetic resonance imaging.

RATIONALE AND OBJECTIVES: In this phase III study, we evaluated the efficacy and safety of a negative contrast medium, ferristene (oral magnetic particles), among 277 patients undergoing magnetic resonance (MR) imaging of the abdomen. METHODS: Enhanced (800 ml ferristene) MR images were compared with unenhanced MR images in an intraindividual-patient control design. Adverse events were recorded. The examinations were performed on 1.5-T MR systems (T1- and T2-weighted sequences). RESULTS: Ferristene increased the diagnostic information in 50.9% of the patients, particularly in those with abdominal masses, lymphoma, or pancreatic disease. Distribution of ferristene in the stomach, duodenum, jejunum, and ileum was complete or sufficient in 70.5-85% of the studies. In 64% of the patients, we were confident in the MR findings after the use of ferristene, and ferristene disclosed additional findings in 22% of the patients. The incidence of adverse events was 9.0%, but only 3.6% of all patients experienced ferristene-related adverse events (e.g., nausea, vomiting). Most events were mild or moderate in intensity. CONCLUSION: Ferristene was well tolerated, and for 50% of the patients it added useful diagnostic information.

Administration, Oral↗
PubMed1996

[Diagnosis of recurrence of a glomus carotid artery tumor by somatostatin receptor scintigraphy].

Glomus caroticum tumours belong to the non chromaffine paragangliomas. As the incidence is very poor with 1% in the collective of a vascular-surgery department, the correct diagnosis is preoperatively only found in 10-20% of the cases. The early detection of primary- or recurrence-tumour is important for the surgical proceedings. With advanced tumour-stage, i.e. with involvement of the carotid artery in the tumour-process, the perioperative mortality increases. Furthermore nerve lesions following surgical tumour-resection as a complication are more frequent. This case-report point out the importance of the somatostatin-receptor-scintigraphy in the differentiation of glomus caroticum tumour-recurrence and postoperative scar. In our patient the suspicion of tumour-recurrence came up already 2 years ago, but could not be verified by MRT and angiography.

3-Iodobenzylguanidine↗
PubMed1993

The uptake of manganese dipyridoxal-diphosphate by chemically induced hepatocellular carcinoma in rats. A correlation between contrast-media-enhanced magnetic resonance imaging, tumor differentiation, and vascularization.

OBJECTIVES AND RATIONALE: Negative enhancement of implanted liver tumors has been achieved in preclinical studies on manganese dipyridoxal-diphosphate (Mn-DPDP), a new hepatobiliary specific contrast agent for magnetic resonance imaging (MRI). The authors investigated the effects of Mn-DPDP on primary liver cancer and its possible mechanisms. METHODS: Magnetic resonance imaging was performed in 15 rats with chemically induced hepatocellular carcinoma (HCC) before and after Mn-DPDP injection. Both tumor-liver contrast-to-noise ratio and absolute tumor enhancement were evaluated and compared with the MRI results of a nonspecific contrast agent, gadolinium-DOTA, and correlated with corresponding microangiographic and histologic findings. RESULTS: Mn-DPDP injection led to a persistent positive enhancement in differentiated solid HCCs (22/23) with maximal conspicuity at 24 hours. Undifferentiated HCCs were all delineated by a prompt negative enhancement (20/20) with maximal conspicuity within 30 minutes.

Angiography↗