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Biomedical subjects

R Fischbach

Publications and source records attributed to R Fischbach.

At least 55 records · Page 3Linked to original sources

Influence of the hepatobiliary contrast agent mangafodipir trisodium (MN-DPDP) on the imaging properties of abdominal organs.

To assess the influence of Mangafodipir Trisodium on the imaging properties of abdominal organs when using T1-weighted gradient-echo (GE) and T2-weighted turbo spin-echo (TSE) sequences, thirty patients with focal lesions in the liver were examined at a field strength of 1.5 T before and after intravenous administration of Mangafodipir Trisodium (dose: 5 micromol/kg of body weight). Administration of Mangafodipir Trisodium led to a significant increase in the signal intensity of the liver tissue (p < 0.001), the spleen (p < 0.01), the pancreas (p < 0.001), and the kidneys (p < 0.001) in the T1-weighted GE sequence, while there was no relevant enhancement in fatty tissue and the musculature. In the T2-weighted turbo spin-echo sequence, there was no relevant change in the signal following administration of a contrast agent. The contrast-to-noise ratio (C/N) between the lesions and the liver tissue increased significantly in the post-contrast T1-weighted GE sequence (p < 0.001), while there was no change in the contrast-to-noise ratio in the post-contrast T2-weighted turbo spin-echo sequence. The contrast-to-noise ratio of the plain T2-weighted TSE sequence was significantly higher than that in the post-contrast T1-weighted GE sequence (p < 0.001). Although Mangafodipir Trisodium was primarily developed as a hepatobiliary contrast agent for demonstration and differentiation of liver lesions, it also affects the signal levels in the pancreas, spleen, and kidneys in the T1-weighted image. Awareness of this effect on the extrahepatic tissue makes it easier to interpret pathological findings in magnetic resonance imaging (MRI) of the abdomen.

Abdomen↗

Effect of early orthopedic intervention on hemifacial microsomia patients: an approach to a cooperative evaluation of treatment results.

The purpose of the present study was to analyze the effects of early orthopedic intervention in patients with hemifacial microsomia, clinically as well as radiologically, by computed tomographic examination to assess soft and hard tissue temporomandibular joint changes. Five patients, one with mandibular dysostosis, one with otomandibular dysostosis, two with Goldenhar syndrome, and one with a surgically revised fibroma of the right mandible that was reconstructed by a costochondral graft, were treated by means of an activator functional appliance. During functional appliance treatment, all patients showed improvement of function and occlusion, and facial asymmetry was reduced. Spiral computed tomographic examination before and during treatment provided data on the bony and muscular deficiencies. The volume and density of the lateral pterygoid muscle was measured with the standard computed tomography software. Evaluation of soft and hard tissue conditions before treatment has shown that the most important factor "lack of soft tissues" can be compensated by excellent cooperation during functional therapy. Pretreatment volume of the affected lateral pterygoid muscle in all patients was significantly smaller than on the unaffected side. In three patients, volume measurements between 4 and 8 years demonstrated that the lateral pterygoid muscle on the affected side had a third, less than a third, and a fifth of the volume of the unaffected side. Although increase, stability, and decrease of the ratio of left and right condylar dimension, muscular volume, and density were found, long-term prognosis cannot be given in the cases with extreme muscular deficiencies after cessation of growth. Prepubertal orthopedic treatment success is a desirable and feasible presurgical or nonsurgical treatment goal for the interdisciplinary team approach. From a study of the pathologic, we learn much about the normal.

Child↗

MRI examination of the TMJ and functional results after conservative and surgical treatment of mandibular condyle fractures.

Thirty patients with healed condylar fractures were included in this study. Ten patients were conservatively treated while in 20 patients the fractures were treated surgically. All patients were assessed using: magnetic resonance imaging of both temporomandibular joints (TMJs) to evaluate the disc position and morphology; radiographs to evaluate the alignment of the bony fragments after consolidation; and clinical examination including the stomatognathic functional status and mechanical axiography. The study shows that anatomical reduction of a low, displaced or dislocated condylar fracture by surgical approach may be of benefit for the functional recovery of the TMJ.

Adolescent↗

[Complications of CT guided lumbar sympathectomy: our own experiences and literature review].

AIM: To review the complications of CT guided lumbar sympathicolysis (CTLS) on the basis of our own experience and the available literature. METHODS: 241 CTLS were performed by a standard technique according to Haaga's method. Clinical follow-up revealed 4 serious complications; these were analysed and compared with published cases. RESULTS: Amongst our patients there were three fibrotic ureter stenoses and one retroperitoneal abscess. Analysis of the serious complications described in the literature indicates that introduction of CT guided lumbar sympathicolysis has reduced the severity and frequency of complications as compared with surgical and "blind" procedures. With CTLS, no deaths due to the procedure have been reported in the literature. The results indicate that damage to the ureters can be caused by substances used for the neurolysis. CONCLUSION: Provided certain safeguards are obeyed, CTLS is a very save treatment. However damage to the ureter may follow even when the procedure was technically satisfactory. Therefore, sonographic control of the kidneys after three months is recommended.

Abscess↗

[Pilot study of effectiveness of electrotherapy in the experimental liver metastasis model].

The aim of the present was to assess the effectiveness of low level direct current therapy in liver metastases and the influence of polarity (anode or cathode in the center of the tumor) or current dose (60 or 80 C/cm3). Colorectal metastases were established in 25 BD IX rats by injection of DHD/K12 colon cancer cells under the liver capsule. After 3 weeks the tumors were treated by low level direct current therapy (applied with five platinum electrodes). Histological examination of the removed livers on postoperative day 7 revealed significant destruction of the metastases with localized necroses. The best treatment results were obtained in the group with an anode in the center and a current dose of 80 C/cm3. We conclude that low level direct current therapy may offer an alternative minimal invasive method in the treatment of liver metastases.

Animals↗

[Interventional palliative therapy].

From diagnostic procedures interventional radiology has developed a large number of therapeutic methods that have found a place in the treatment of palliative care patients. Minimal invasiveness and high efficiency characterise the implantation of metallic stents in the treatment of malignant biliary or esophageal obstruction and vena cava compression syndrome. Transcatheter arterial embolisation, chemoembolisation and chemoinfusion for palliative treatment of inoperable liver malignomas are performed at many centers. A specific concept and an accepted spectrum of indications have to be better defined by prospective trials. Therapeutic decisions in this patient group have to based on the individual case. The interventional radiologists is increasingly involved in the interdisciplinary decision making process.

Bile Duct Neoplasms↗

Iodixanol vs iopamidol in intravenous DSA of the abdominal aorta and lower extremity arteries: a comparative phase-III trial.

Iodixanol (Visipaque, 320 mgI/ml) was compared with iopamidol (Solutrast, 370 mgI/ml) in a double-blind, randomized, parallel group, intravenous DSA phase-III trial for evaluation of safety and efficacy. A total of 117 patients received iodixanol (n = 60) or iopamidol (n = 57). Diagnostic efficacy was evaluated using categoric and visual analogue scales. Discomfort and adverse events were recorded. A total of 39 patients collected urine up to 72 h after the examination for analysis. Diagnostic efficacy and radiographic density were similar in both groups. Discomfort was milder with iodixanol. The difference between the frequency of adverse events between both groups (iodixanol = 7, iopamidol = 2) was without statistical significance. Creatinine clearance was slightly more affected by iodixanol, whereas the increase in renal excretion of N-acetyl-beta-glucosaminidase (NAG) in the first 24-h collection period after the examination was significantly higher (p < 0.01) with iopamidol. Iodixanol was of equal diagnostic efficacy compared with iopamidol despite its reduced iodine content. Both contrast media are well suited for IV DSA.

Acetylglucosaminidase↗

Pharmacokinetics of intraarterial mitomycin C in the chemoembolisation treatment of liver metastases.

1. The pharmacokinetics of mitomycin C (MMC) were investigated in 12 colorectal cancer patients with liver metastases undergoing chemoembolisation. Hepatic artery branches were embolized using polyvinylalcohol microspheres (150-250 microns) before applying 20 mg MMC in 4-8 min. 2. Serum MMC concentrations were determined from peripheral venous blood samples by reverse-phase HPLC using ultraviolet detection. Pharmacokinetic parameters were computed assuming an open two-compartment model. 3. Pharmacokinetic parameters were similar to values given in the literature for intravenous (IV) or intraarterial (IA) bolus MMC injections (Tmax = 7.0 min following the beginning of MMC infusion, Vss = 0.57 1/kg, C1 = 8.9 ml/min.kg, T1/2 alpha = 8.3 min, T1/2 beta = 58.6 min). 4. The area under the serum concentration-time-curve (AUC), standardized by the MMC amount injected, was similar to values reported in the literature for IV or IA bolus injections. There is no evidence for reduced systemic MMC exposure following the embolization procedure used.

Antibiotics, Antineoplastic↗

[Comparison of fast turbo-spin-echo and gradient- and spin-echo sequences as well as echo planar imaging with conventional spin-echo sequences in MRI of focal liver lesions at 1.0 tesla].

PURPOSE: To evaluate the value of rapid T2-weighted turbo-spin sequences (TSE), turbo-spin-echo sequences with shortened echo spacing (UTSE), gradient-and-spin-echo sequences (GraSE) and T1-weighted echo-planar imaging (EPI) in comparison with conventional spin-echo sequences (SE) in the diagnosis of focal liver lesions. METHODS: 20 patients with malignant focal liver lesions underwent magnetic resonance imaging at 1.0 tesla. RESULTS: The use of fast T2-sequences (TSE, UTSE, GraSE) reduced the examination time to about 35-50%. Artifacts were reduced compared with the conventional T2-SE sequence. Quantitative analysis demonstrated that UTSE imaging had the highest tumor/liver contrast-to-noise ratio (CNR) followed by TSE, T2-SE and GraSE sequences. CNR with EPI was lower than with the T1-SE sequence (p < 0.05). CONCLUSION: Turbo-spin-echo sequences with shortened echo spacing yield a shorter imaging time and improved image quality without loss of signal intensity in tumor/liver-CNR, compared with conventional T2-pulse sequences in liver imaging at 1.OT.

Adult↗

[Infections of the cervical spine].

Diagnosis of infectious disease of the spine in an early stage ist difficult. Conventional X-ray examinations, often used as a basic screening study, will show the characteristic narrowing of the intervertebral disc space and the osteolytic and sclerotic changes in the adjointing vertebra only after two to eight weeks. Magnetic resonance imaging (MRI) has a sensitivity equivalent to bone scintigraphy and, due to its superior delineation of anatomic details, MRI has become the method of choice not only for the assessment of location, extent, and associated lesions in infectious bone disease, but also in the diagnosis of intradural infections including myelitis. MRI examination in the assessment of a successful therapy or osteomyelitis of the spine aims for the detection of regression of bone marrow edema, reappearance of fatty marrow, and less pronounced contrast enhancement. Computed tomography (CT) is mainly used for image-guided biopsy to obtain specimen for microbiologic culture or for the placement of a percutaneous drainage.

Abscess↗

[A critical evaluation of the functional treatment of mandibular neck fractures in children. The results of a spiral computed tomographic follow-up].

In this retrospective follow-up study after 6 months of treatment with functional appliance therapy of 12 children who had suffered condylar fractures, spiral CT was employed for the radiological examination with 2D and 3D reconstructions. Although all patients exhibited restoration of normal function, only 4 showed favorable remodeling. The other patients had developed 5 hypoplastic, 5 moderate and 5 severe deformed condyles. Seven condylar fragments were resorbed; 2 were uprighted; 4 had developed bony spurs and 3 neoarthrosis. The results revealed a fracture dependent remodeling. The authors discuss the etiology of the functional stimulated new bone formation of the condylar process. Excessive bone apposition as a reaction to the anterior shift of the mandible seems to play an important role during the overgrowth of the head of the condyle.

Adolescent↗

Diagnostic performance of digital subtraction angiography (DSA) and magnetic resonance angiography (MRA): preliminary results in vascular occlusive disease of the abdominal and lower-extremity arteries.

Fifty-nine patients with occlusive disease of the aorto-iliac and femoro-popliteal arteries were investigated prospectively by intravenous (IV) or intraarterial (IA) digital subtraction angiography (DSA) and magnetic resonance angiography (MRA). This was accomplished using a two-dimensional (2D) Inflow- (59 patients) and a 2D Phase Contrast- (RSE--rapid sequential excitation) sequence (29 patients). The spectrum of pathology included stenoses < 50%, stenoses 50-89%, stenoses 90-99%, occlusions, aneurysms and status following reconstructive surgery. MRA- and DSA-examinations were evaluated by four radiologists. The diagnoses were made by consent decisions of a radiologist and a vascular surgeon based on clinical and radiological findings. Diagnostic performance of IA-DSA was superior to all other imaging modalities. Vascular delineation of 2D Inflow-MRA was comparable to that of IV-DSA. The image quality of RSE-MRA was not adequate for diagnosis. In conclusion, 2D Inflow-MRA is a promising method for evaluating abdominal and peripheral arteriosclerotic disease. Interpretation of MR-angiograms, however, requires profound knowledge of MRA-techniques, X-ray angiography and hemodynamics.

Adult↗

[Peripheral occlusive arterial diseases: comparison of diagnostic value of MRA and DSA].

MATERIAL AND METHODS: In 59 patients with arterial flow disturbances 2-D inflow sequence of the abdominal and lower leg arteries were prospectively obtained on a 1.5 T MR-imager and were compared with additional DSA examinations. Supplementary Phase Contraste RSE ("Rapid Sequential Excitation") sequences were carried out in 29 patients. MRA and DSA angiograms were evaluated in random order by 4 readers using a questionnaire. The assessment of image quality were evaluated by variance analysis. Diagnostic performance of MRA and DSA was assessed by comparison of the readers' diagnostic assessments with reference diagnoses established by a radiologist and a vascular surgeon with full knowledge of all data concerning a patient. Image quality of inflow MRA was considered inferior to i.a. DSA (p < 0.001) and comparable with i.v. DSA (p = 0.1361). Image quality of RSE-MRA was inadequate (p < 0.001). Correspondingly, i.a. DSA was the superior and RSE-MRA the inferior imaging technique. The accuracy of inflow MRA in determining stenosis grade was 66% and that of RSE-MRA 59%.

Aged↗

[A comparison of NMR tomography and arthrography in functional disorders of the temporomandibular joint].

PATIENTS AND METHODS: 31 patients with clinically diagnosed dysfunction of the temporomandibular joint (TMJ) were examined by magnetic resonance imaging (MRI; 1.5 Tesla, TR/TE 600/30) in closed and open mouth position and functional arthrography with digital image recording. RESULTS: Both methods agreed in the evaluation of the disc position. In 23 joints with displaced disc reposition was found in 11 cases and in 14 cases using MRI or arthrography, respectively. MRI proved to be superior in the diagnosis of sideways disc rotations. Joint hypermobility, eccentric disc displacement (n = 4) and perforation (n = 3) were shown by functional arthrography. Due to the good demonstration of osseous, muscular and discoligamentous structures, MRI as a noninvasive imaging modality is the method of choice for TMJ evaluation. Arthrography can be advantageous in complex functional disturbances or if MRI and clinical findings are inconclusive. The clinical diagnosis of disc displacement was found to be accurate in only 68% of the cases.

Adolescent↗

Temporomandibular joint morphology in children after treatment of condylar fractures with functional appliance therapy: a follow-up study us computed tomography.

The consequences of treating fractures of the temporomandibular joint in children by means of functional appliance therapy remain controversial. In this retrospective study we evaluated the temporomandibular joint morphology of 19 children and adolescents who had sustained a total of 21 condylar fractures between three and nine years previously and who had been treated in this way. Restoration of function was assessed clinically by measurement of mandibular movements, and palpation and auscultation of the joint. Spiral CT was used for the radiological examination with 2D and 3D reconstructions. Eleven patients with 13 fractures of different types showed restoration of normal function with favourable remodelling. The remaining eight patients had only good function with a deformed condyle and significant asymmetry in condylar angle and length of the condylar neck. Four of these cases had also developed bony spurs, neo-arthrosis and a bifid condyle. On the basis of these results, spiral CT imaging appears to be a valuable diagnostic aid in cases of condyle fractures where severe morphological changes are not recognized in earlier conventional X-ray examinations. The authors recommend a quantitative and qualitative analysis of the temporomandibular joint in order to encourage patients' compliance and, in cases of poor cooperation, to extend the treatment time.

Adolescent↗

Intercellular adhesion molecule-1 levels in plasma and vitreous from patients with vitreoretinal disorders.

Intercellular adhesion molecule 1 (ICAM-1) is a member of the immunoglobulin superfamily with important functions in immune activation and inflammation. Its interaction with different cytokines [interleukin 1 (IL-1), tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma)] is important for lymphocyte migration into inflammatory sites. We used a sandwich enzyme immunoassay (EIA) for the quantitative determination of soluble ICAM-1 (cICAM-1) in vitreous and plasma from patients undergoing vitrectomy for a variety of proliferative vitreoretinal disorders. The values obtained were compared with the total vitreal protein. The respective concentrations of cICAM-1 in vitreous were as follows control samples, 3.47 +/- 1.84 ng/ml; proliferative diabetic retinopathy (PDR) of diabetes type I 27.43 +/- 14.72 ng/ml; PDR of diabetes type II, 32.46 +/- 10.31 ng/ml; idiopathic proliferative vitreoretinopathy 35.74 +/- 15.30 ng/ml; and traumatic PVR, 45.23 +/- 24.24 ng/ml. Plasma samples yielded the following concentrations: controls, 415 +/- 43.4 ng/ml; PDR of diabetes type I, 469 +/- 96.9 ng/ml; PDR of diabetes type II, 425 +/- 65.4 ng/ml; idiopathic PVR, 402 +/- 119.9 ng/ml; and traumatic PVR, 434 +/- 118.6 ng/ml. Our results demonstrate high levels of ICAM-1 in most proliferative vitreoretinal disorders. In PDR and in traumatic PVR, cICAM-1 levels were elevated significantly more than were total vitreal protein levels. In traumatic PVR, patients with a short interval between previous surgery or traumatic event demonstrated the highest levels of cICAM. Since plasma levels were not significantly altered, we suggest that local cICAM-1 production, possibly from macrophages, may be of importance in the early phase of PVR and PDR by enhancing immune activation and inflammation.

Diabetes Mellitus, Type 1↗