PubMed Health⌕ Search

Biomedical subjects

O Jansen

Publications and source records attributed to O Jansen.

90 records · Page 5Linked to original sources
PubMed1993

Diagnosis of renal transplant failure by real-time and duplex Doppler sonography.

A total of 419 real-time and duplex Doppler ultrasound examinations of renal allografts were carried out in 61 patients. Results were related to the clinical diagnoses based on histomorphological, clinical, and laboratory findings. The results of all sonographic examinations in terms of the diagnostic parameters of normal function, acute tubular necrosis, and interstitial and vascular rejection did not yield reliable criteria for distinguishing between the different forms of transplant dysfunction. The maximum difference was calculated for each ultrasound parameter between a time of normal transplant function and at a time of dysfunction. By means of this 'maximum parenchyma-pyelon index difference' it was possible to discriminate between acute tubular necrosis and vascular rejection (P < 0.05). Acute tubular necrosis could be distinguished from interstitial rejection using the maximum longitudinal renal diameter difference and the maximum parenchyma-pyelon index difference (P < 0.05). To discriminate between interstitial and vascular rejection the maximum pulsatility index difference was very useful (P < 0.05). Combined real-time and duplex Doppler sonography is most valuable in the diagnosis of transplant failure when it is performed not only in the case of dysfunction but also when transplant function appears to be normal.

Female↗
PubMed1993

[Diagnosis of thrombophlebitis of the leg using duplex sonography].

In a prospective study 113 extremities of 98 patients with suspected lower extremity deep venous thrombosis were examined by duplex sonography and phlebography. In 66 examinations phlebography demonstrated fresh thromboses which were limited to the calf in 14 cases. In all other cases thrombosis was partially or totally localized above the knee. Duplex sonography had a sensitivity in detection of thromboses of 91% (calf veins) up to 94% (proximal veins) and a specificity of 95% and 97%, respectively. Duplex sonography is a reliable method in diagnosis of thrombosis in the popliteal, superficial and common femoral und distal iliac vein. If phlebography is contraindicated, duplex sonography is the method of choice. It should also be performed additionally to phlebography to visualise surrounding tissue and detect the possible cause of thrombosis and clinical symptoms. Duplex sonography can also visualise veins that are not shown phlebographically.

Adolescent↗
PubMed1989

[Percutaneous embolization with spirals in bleeding uterine cancer].

Percutaneous transcatheter embolization (PTE) in patients with life threatening bleeding carcinomas of the uterine cervix using stainless steel coils, proves to be an effective treating method. There is a low incidence of complications concerning the local cutis, nerves or arteries. PTE does not allow a causal therapy of the malignant disease, but in half of our patients (n = 13) embolization was the precondition for initial or further adequate therapeutic management.

Angiography↗
PubMed1989

[Plasma histamine liberation after the application of nonionic contrast media].

In 94 patients the levels of plasma histamine have been measured after application of three nonionic contrast media (iopromide, iopamidol, iohexol) and after application of blood-isotonic saline solution. A significant liberation of histamine could be observed after administration of contrast media and also after administration of saline solution. Neither between the three nonionic contrast media nor between the contrast media and the saline solution significant differences could be measured. Administering contrast media after subsequently saline solution the levels of histamine were lower than in case of pure contrast media application. Psychogenically induced histamine liberation is discussed.

Contrast Media↗
PubMed1989

[Analysis of dynamic CT curves in kidney transplants with rejection reaction and cyclosporin A poisoning].

The early differential diagnosis between transplant rejection and cyclosporin intoxication is often difficult, although it is important for treatment. We carried out dynamic CT on 48 occasions in patients with normal function, with acute tubular necrosis, rejection and cyclosporin A intoxication. Analysis of the time-density curve of the cortex showed significantly slower enhancement with cyclosporin A intoxication than during rejection. The peak and the arterial curve were also delayed in cyclosporin A intoxication. This evidence of reduced cortical perfusion during cyclosporin A intoxication can be explained by the results of modern pathophysiological studies. In principle, it is possible to distinguish between cyclosporin A intoxication and rejection by means of dynamic CT, but for its routine use the nephrotoxicity of the contrast medium must be taken into account.

Cyclosporins↗
PubMed1989

[Intramural pseudodiverticulosis of the esophagus].

A rare case of oesophageal intramural pseudodiverticulosis is described. The typical radiological appearance in the oesophagogram is demonstrated and correlated with the histopathology. Review of the literature leads to the hypothesis that oesophageal pseudodiverticulosis may be the identical result of different diseases.

Aged↗
PubMedDate not supplied

Utilization of magnetic resonance imaging in autopsy planning with specimen preservation for thoraco-omphalopagus symmetricus conjoined twins.

Conjoined twinning is a rare obstetric event that has fascinated physicians and laypersons alike for centuries. When this event occurs, early diagnosis, close prenatal management, and the proper route of delivery will assure the best possible outcome for mother and affected infants. Magnetic resonance imaging (MRI) is used both as an ancillary technique to the sonography for the antepartum diagnosis and in the preoperative planning for the surgical separation of conjoined twins. This report describes the MRI findings in conjoined twins of the thoraco-omphalopagus symmetricus type, a condition incompatible with extrauterine life. The twins were delivered at 21 weeks gestation. The MRI was used to evaluate the anatomic nature of the internal anomalies. These findings were then used to develop an autopsy approach plan that preserved the external phenotype. After dissection, the specimen was preserved by using polyethylene glycol and ultimately prepared for use as a teaching specimen.

Autopsy↗
PubMedDate not supplied

Follow-up study of renal transplants by duplex Doppler and gray-scale ultrasound.

In the early postoperative period after renal transplantation 388 follow-up ultrasound examinations were performed in 77 patients. Over a period of 18 months standardized duplex indices (resistive index, pulsatility index) and gray-scale parameters (parenchyma/sinus index; medulla/cortex index) were sampled. These data were correlated retrospectively with clinical and pathological diagnoses. To delineate the individual course of duplex and gray-scale indices during different transplant diseases we created a new parameter: the MID (maximal index difference) which is a result of the difference between the highest index during the phase of renal dysfunction and the lowest index during the phase of normal renal function. This MID, calculated for duplex indices and for the parenchyma/sinus index, indicated significant differences in the behavior of renal transplants during the four main diseases: interstitial rejection, vascular rejection, acute tubular necrosis and Cyclosporine A nephrotoxicity. Using the MIDs, a table of cut-off values was established, which enables to differentiate retrospectively these four transplant complications with a sensitivity of 84% and specificity of 81%. In our opinion consequent follow-up examinations with duplex and gray-scale sonography should be performed, enabling sonography to become a helpful diagnostic instrument in the monitoring of renal transplants.

Cyclosporine↗
PubMedDate not supplied

[Classification of social medical products provided by the German Medical Services of the Statutory Health Insurance in Hessen].

Based on agreements presented by a task force the German Medical Services of the Statutory Health Insurance in Hessen developed its own classification of social medical assignments. According to economic systematics they were arranged in groups of external and internal products reflecting providing services in form of medical expertises and fulfilment of legal obligations. Further typologisation of the products can be achieved by relational marks. Documentation based on this classification as a part of social medical controlling supports modern planning and management concepts. This way practical sociomedicine as an applied health science makes its contribution to economic efficiency of the statutory health care system.

Cost-Benefit Analysis↗
PubMedDate not supplied

Magnetization transfer measurements in normal-appearing cerebral white matter in patients with chronic obstructive hydrocephalus.

PURPOSE: The purpose of this work was to assess the presence of subtle changes in normal-appearing white matter on T2-weighted MR images in patients with chronic obstructive hydrocephalus using magnetization transfer (MT) measurements. METHOD: In 12 patients with chronic obstructive hydrocephalus, MT ratios (MTRs) of normal-appearing rostral (PR) and caudal (PC) periventricular white matter, of the genu (CG) and the splenium (CS) of the corpus callosum, and of the thalamus (TH) were measured and compared with those of 16 healthy control subjects. RESULTS: We found a significantly lower MTR in chronic obstructive hydrocephalus than in the normal group for PR, PC, CG, and CS but not for TH. CONCLUSION: Our study shows that MT measurements give additional information that cannot be gained by conventional SE MRI, suggesting that chronic obstructive hydrocephalus is associated with diffuse white matter damage that also affects normal-appearing cerebral white matter.

Adult↗
PubMedDate not supplied

Gadolinium-enhanced magnetic resonance dacryocystography in patients with epiphora.

PURPOSE: Digital subtraction dacryocystography (DS-DCG) is considered the "gold standard" in the assessment of the nasolacrimal duct system but fails to delineate the soft tissue structures that surround the lacrimal drainage apparatus. The goal of this study was to compare high resolution MR surface coil imaging with DS-DCG to determine the value of gadolinium-enhanced MR dacryocystography (MR-DCG) in patients with epiphora. METHOD: We performed bilateral MR-DCG and unilateral DS-DCG in 11 patients (aged 3-70 years) with epiphora using Gd-DTPA-containing eyedrops (Magnevist; 78.63 mg of Gd/ml diluted in a sterile 0.9% NaCl solution 1:100) and a water-soluble contrast medium (Omnipaque; 677 mg of Iohexol/ml). Radiographic and MR findings were separated and reviewed by two radiologists who were blinded to patients' names and histories. Afterwards, the passage of the contrast material was compared in the two procedures. The gold standard was defined as the distal-most point of the contrast material identified on either study. RESULTS: Obstruction of the nasolacrimal duct system was diagnosed with a sensitivity of 100% with both MR-DCG and DS-DCG. With MR-DCG, the two readers correctly diagnosed the location of an obstruction in 67 and 89% and with DS-DCG in 56 and 67%. With MR-DCG, contrast material was traced further distally than with DS-DCG in three patients. DS-DCG was superior in only one case in which MR-DCG failed to delineate fistulas distal to the nasolacrimal sac. CONCLUSION: Our data suggest that MR-DCG is suitable for assessing drainage problems of the nasolacrimal duct system, giving additional information concerning the surrounding soft tissue structures. Further studies are required to show whether MR-DCG can replace DS-DCG as the gold standard in the assessment of the nasolacrimal duct system.

Adult↗
PubMedDate not supplied

Thrombolytic therapy in acute occlusion of the intracranial internal carotid artery bifurcation.

PURPOSE: To evaluate efficacy and clinical benefit of early thrombolytic therapy in intracranial internal carotid artery occlusion. METHODS: Thirty-two patients (mean age, 56 years) with acute intracranial internal carotid artery occlusion were studied clinically and with CT and angiography before and after thrombolytic therapy with intravenous alteplase (n = 16), superselective intraarterial alteplase (n = 8), and superselective intraarterial urokinase (n = 8). RESULTS: Initial CT showed a large parenchymal hypodensity in 11 (34%) patients, a small hypodensity in 15 (47%) patients, and no hypodensity in 6 (19%) patients. Recanalization after thrombolytic therapy was observed in 4 patients (12.5% in each treatment group). Follow-up CT showed six hemorrhagic infarcts and four parenchymal hematomas unrelated to recanalization, alteplase, or urokinase administration, but commonly associated with intraarterial treatment. Clinical outcome was fatal in 53%, poor in 31%, and moderate or good in 16% of the patients. Outcome was equal in different treatment groups and closely linked to both the quality of leptomeningeal collaterals and the extent of parenchymal hypodensity on the first CT. CONCLUSION: Because intravenous or intraarterial treatment with alteplase or urokinase fails to recanalize the vascular obstruction, it does not improve the prognosis of intracranial internal carotid artery occlusion over that of the natural course. Improved results may be possible with novel recanalization techniques.

Adult↗
PubMedDate not supplied

Potential of CT angiography in acute ischemic stroke.

PURPOSE: To study the ability of CT angiography to show intracranial arterial occlusion and collateral blood flow in patients with acute stroke. METHODS: Twenty-one patients with acute nonhemorrhagic stroke were studied prospectively with conventional CT, CT angiography, and digital subtraction angiography. On the basis of CT angiographic findings, two neuroradiologists independently assessed the site of arterial occlusion, the contrast enhancement in arterial branches beyond the occlusion as a measure of collateral blood supply, and the extent of diminished parenchymal enhancement; they then predicted the extent of ischemic infarction. RESULTS: Both raters correctly assessed all trunk occlusions of the basilar artery (n = 4), the internal carotid artery (n = 4), and the middle cerebral artery (n = 9). The chance adjusted interrater agreement was kappa = .78. The assessment of branch occlusions of the middle cerebral artery was less reliable. The agreement rate in judging the collateral state in 17 occlusions in the anterior cerebral circulation was 88%. The size of 21 (62%) of 34 hemispheric infarctions was predicted correctly. CONCLUSION: CT angiography quickly and reliably adds important information to conventional CT studies in cases of acute ischemic stroke. It shows the site of occlusion, the length of the occluded arterial segment, and the contrast-enhanced arteries beyond the occlusion as an estimate of collateral blood flow.

Adult↗