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Biomedical subjects

V Nicolas

Publications and source records attributed to V Nicolas.

At least 91 records · Page 5Linked to original sources

[The relevance of sonography in the diagnosis of acute abdomen in the intensive care unit].

This study included 414 unselected sonographic examinations of the abdomen of patients in intensive care complaining of acute abdominal symptoms. Examinations of adequate quality showed a sensitivity of 88.8%, a specificity of 76.3% and an accuracy of 83.7%. Even when allowing for examination which could not be evaluated because of the presence of scars, bandages or air, there was a sensitivity of 72.9% and an accuracy of 74.2%. Sonography is therefore the examination of first choice. In a quarter of all cases, however, computer tomography examination was also necessary.

Abdomen, Acute↗

[MRT of acute soft tissue hematomas at 1.5 T: animal experimental results].

In 16 Göttingen minipigs 31 soft-tissue haematomas of different location were produced by reinjection of freshly drawn arterial and venous blood. Immediately after the injection, MRI of the haematomas was performed and continued for 2-3 h. The MRI appearance of the haematomas depended on the site of the injection. Intramuscular haematomas demonstrated on T2-weighted gradient-echo images a decrease in signal intensity within a few minutes after injection. With the same scan parameters, subcutaneous haematomas had a high signal intensity still at 3 h after injection. When section of the cadaver was performed, the subcutaneous haematomas consisted of compact clot, whereas with intramuscular injection diffuse infiltration of the muscle was present.

Acute Disease↗

[Clinical and technical experiences with digital luminescent radiography in phlebography of the leg].

Digital luminescence radiography is being increasingly integrated into clinical routine work and is fundamentally suited to replace x-ray film/screen takes. After the necessary optimization of the specific image processing procedure we examined the diagnostic efficacy of this method in respect of phlebography of the leg. If the radiation dose was reduced by 47% in relation to the reference system, the usefulness of the findings in arriving at the diagnosis was by no means reduced under the conditions of high contrast that apply in phlebography, but there was also no additional advantage in respect of diagnostic accuracy. The technical advantages concern mainly the absence of wrong exposures, the possibility of subsequent processing of the image to improve the image quality, and digital storage.

Evaluation Studies as Topic↗

[The lateral thoracic radiograph in the intensive care unit using digital luminescence radiography].

The digital luminescence radiography (DLR) technique is being used increasingly for clinical diagnosis, particularly in intensive care . Since the installation of a DLR unit, we have carried out more than 20,000 examinations of the chest on patients in intensive care. 12.1% of these were lateral radiographs. In this way, the diagnosis can be made of the extent of a pleural effusion, the presence of a ventral pneumothorax or of atelectasis. Using DLR, these examinations can be carried out at the bedside and have improved the radiological investigation of patients in intensive care.

Humans↗

Effects of acidic fibroblast growth factor and epidermal growth factor on fetal rat calvaria cell cultures.

An inhibitory effect of alkaline phosphatase (LP) activity on short and long term fetal rat calvaria cell cultures was recorded with both acidic fibroblast growth factor (aFGF) and epidermal growth factor (EGF) at a concentration of 30 ng ml-1. This inhibition was well correlated with the nodule number on long term culture, except for EGF treatment in subconfluent cell culture.

Alkaline Phosphatase↗

[Diagnostic evaluation of full x-ray pictures and computed tomography of bone tumors of the spine].

The conventional radiographs and CT examinations of 112 patients with primary and secondary bone tumours of the spine have been compared. Two hundred and sixty-eight vertebrae were shown to be involved, using CT; conventional radiographs showed correctly in 88% an involvement of the vertebral bone and in 66% of the different parts of the vertebrae. Of the intraspinal and paravertebral tumour extensions shown by CT, only 23% and 33% respectively were correctly diagnosed by plain radiography. Only 51% of the vertebrae showing a reduction in height on conventional radiographs could be diagnosed on horizontal CT cuts. The type of lesion could be diagnosed in only very few cases by either method.

Evaluation Studies as Topic↗

[Digital luminescence radiography. A new method of study in thoracic diagnosis at the intensive care unit].

The digital luminescence-radiography (DLR) technique relies on a complete digitalization of the X-ray image. Luminescence crystals on the imaging plate serve as an energy reservoir following their exposure to ionized radiation from any conventional X-ray source. A Helium-Neon laser stimulates the electrons in their high energy bands and therefore will be dropped back emitting luminescence. This luminescence is digitized by the DLR-System thus delivering a complete digital image to the image processor for subsequent processing and evaluation. The processed digital image is then recorded on a conventional film or a monitor screen. More than 3000 chest examinations using DLR have been performed on intensive care unit (ICU) patients at the University Hospital Eppendorf following the first eleven months since the clinical introduction of this new technique. The positive aspects of DLR such as high-contrast resolution and optimal reproducibility were clinically evaluated under ICU conditions. It was shown that DLR greatly improves the quality of the chest X-rays of all ICU patients and offers the following advantages: reproducibility, lateral chest projection, no insufficient exposure, reduction of exposure dose, electronical post-processing and storage, quality preserving digital storage and copying.

Humans↗

[Aspergillus infections of the lung].

In this article the three different manifestations of pulmonary aspergillosis are compared with each other: bronchopulmonary aspergillosis, aspergilloma and invasive pulmonary aspergillosis, and their different clinical and radiological manifestations. In particular, invasive pulmonary aspergillosis--being a severe complication in immunosuppressed patients whose defenses are weak--often presents diagnostic problems due to its initially mostly unspecific clinical and radiological signs. The late signs of a pulmonary aspergillus infection, such as formation of a cavern or the manifestation of the "air crescent" sign, however, are seen only when the patient is just beginning to convalesce.

Aspergillosis↗

[Color Doppler sonography: non-invasive potential for morphologic and functional vascular diagnosis].

A linear array colour Doppler sonographic method was used experimentally on a vessel phantom in order to determine flow velocity, and the results were compared with DSA. Both the Doppler and the DSA method showed very good agreement with true velocities (r greater than 0.97). The Doppler method underestimated flow velocity. Early clinical results indicate that colour Doppler sonography is able, at the same time, to demonstrate morphology and function (direction flow and flow velocity) of significant vascular abnormalities by a non-invasive method.

Blood Flow Velocity↗

[Value of imaging procedures in the diagnosis and staging of bladder tumors].

A retrospective study of 161 patients with carcinomas of the bladder was carried out to assess the value of CT (247 examinations), transurethral sonography (32 examinations), and the early results of MRT. For TA-T3a staging, according to the TNM classification of the IUCC, transurethral sonography was particularly valuable. CT is useful for demonstrating transmural tumour growth (T3b) and organ invasion (T4), involvement of regional lymph nodes and distant metastases. Tumours in the roof of the bladder and at its base are well shown by MR tomography, using multiplanar sections.

Adult↗

[Arterial DSA using a trans-brachial 4-French catheter].

Arterial DSA by the trans-brachial route, using a 4-French-catheter has been performed in 33 patients. In these patients, trans-femoral DSA is contra-indicated because of previous surgery or markedly reduced femoral pulsation. Intravenous DSA was not expected to provide diagnostically adequate information in these patients, in view of the well known method limitations of this method. In 20 patients, the abdominal aorta, pelvis and lower limb arteries were examined, in 14 only the leg arteries, in ten patients the arteries in the neck and in three patients the thoracic and abdominal aorta. Trans-brachial DSA provided good demonstration of the vessels in all cases.

Angiography↗

[Radiological diagnosis and therapy of postoperative abdominal lymphoceles].

Eighty-one patients with postoperative abdominal lymphoceles were examined by CT and ultrasound. Both methods provide accurate information regarding localisation and extent of the lymphocele. In 51 patients conservative treatment under sonographic or CT observation was carried out. In seven patients, irradiation lead to complete regression. In 21 patients, interventional radiological therapy was carried out with simultaneous irradiation in seven cases. In five patients surgery was necessary. Asymptomatic lymphoceles should be treated conservatively and only after the appearance of clinical symptoms should interventional radiological or surgical measures be carried out.

Abdomen↗

Radiological diagnosis of the thoracic aortic aneurysm.

Indications and the diagnostic value of radiological investigation methods in thoracic aortoaneurysm are reported. The suspected diagnosis can already be made on the basis of conventional x-ray examination of the thorax. Computer tomography (CT) with i.v. administration of contrast medium allows unequivocal identification of a mediastinal space occupation as an aneurysm. However, preoperative angiography is indispensable in many cases for appraisal of the vessel origins. Depending on the condition to be investigated, digital subtraction angiography (DSA) which is carried out with i.v. or i.a. injection of contrast medium has replaced conventional angiography here. Nuclear magnetic resonance tomography has only minor importance so far despite the good imaging of the aorta.

Angiography↗

[Results and complications of percutaneous nephropyelostomy in 215 patients].

The results of 242 percutaneous nephropyelostomies in 215 patients were analysed retrospectively. No consideration was given to the experience of the individual operators. There was a total complication rate of 36.4% (mild complications 32.2%, serious complications 34.1%, fatality 0.4%). Rapid reduction in serum creatinine could be demonstrated following drainage in patients in whom renal function had been damaged by obstruction.

Creatinine↗

[Diagnosis of muscle hematomas and pseudotumors in hemophilia].

Two hundred and twenty-six patients with haemophilia A and B were examined by CT. In 135 cases, some form of bleeding was demonstrated. CT permits exact anatomical localisation of the haematoma and its delineation from neighbouring structures. Measurements of the densities of the haematomas make it possible to determine their age from the change in absorption values. Computed tomography makes it easier for the clinician to choose between conservative or surgical treatment and to determine the duration of treatment during the regression of the haematoma.

Adolescent↗

[Magnetic resonance tomography (MRT) of the adrenals].

Thirty-eight MRT examinations were carried out in 35 patients who, between them, had 19 abnormalities in the adrenal glands. These included ten adenomas, three metastases, two carcinomas, two phaeochromocytomas, and two primary retroperitoneal tumours. MRT provides images of normal and abnormal adrenal glands which are equivalent to those of CT, with the exception that it cannot demonstrate calcification. Using a ratio of signal intensity from the adrenal tumours and the liver on T2-weighted images, it is usually possible to differentiate adenomas from metastases, carcinomas or phaeochromocytomas. The increased specificity of MRT is valuable in the investigation of patients with asymptomatic enlargement of the adrenal glands.

Adrenal Gland Neoplasms↗