Myocardial perfusion defects in contrast echocardiography: spatial and temporal localisation.

The position and size of experimental myocardial perfusion defects can be detected by using the echocardiographic contrast-medium Echoson together with digital image processing techniques. Video tapes showing the important sequences before, during and after cardial inflow of echo-enhancing agents are fed in total length into a digital image processing unit. The myocardial circumferences are then chosen interactively. All the frames are analysed and a synthetic picture is compiled, and shows the myocardial echo densities in a single, highly condensed form. Digital subtraction of blank values (condensed sequences before injection of contrast medium) greatly improves readability. Further concentration of the remaining information yields the following diagrams: flow/circumferential position (time summation); flow/time (position summation), which contain the desired information on homogeneity or defects of echo density against time and myocardial position.

Quantification of myocardial perfusion by contrast echocardiography.

Two-dimensional echocardiography allows identification of myocardial perfusion defects due to coronary artery occlusion by detection of regional wall motion abnormalities and absence of myocardial echocontrast enhancement after injection of echocontrast agents into the aortic root. In the current study twelve anesthetized closed chest dogs were examined before and after balloon occlusion of a coronary vessel. Size of perfusion defects was determined morphologically by Evans blue staining, while the circumferential extent of regional wall motion abnormality was calculated using radial wall motion analysis of the two-dimensional echocardiogram. Four mL of SH U 454 were injected into the aortic root for echocontrast studies. Perfusion defects in the echocardiogram were determined planimetrically in the analog two-dimensional echocardiographic image. In addition, perfusion defects in the contrast echocardiogram were estimated by a digital image processing technique along a circumferential mid-wall line. Along this line the time-intensity curves of the myocardial echocontrast were also calculated. There was a linear correlation between morphological determination of perfusion defects and their planimetric estimate in the contrast echocardiogram. The linear regression equation was y = 0.98x + 4.63, r = 0.92, and the standard error of estimate for the echocardiographic examination was SEE = 4.4%. Digital image processing did not increase accuracy in determining the size of perfusion defects (r = 0.88; y = 1.01x + 3.33; SEE = 5.7%). By comparing the extent of regional wall motion abnormalities with the size of anatomic perfusion defects there was a correlation of r = 0.85; SEE = 6.2%; y = 0.71x + 10.50.(ABSTRACT TRUNCATED AT 250 WORDS)

[Video-angiography: methods and nomenclature]. / Video-Angiographie: Methode und Nomenklatur.

This paper is a report from the First Symposium on Video Fluorescein Angiography, held on November 29, 1985, at the Charlottenburg Eye Clinic of the Free University of Berlin. Following a discussion among the working groups from Aachen, Tübingen, and Berlin, N. Körber (Cologne), V. Miszalok (Berlin), F. Jung (Homburg), and S. Wolf (Aachen) propose a new, uniform set of definitions relating to time and velocity measurable with video techniques.

[Relief pictures of the posterior pole of the eye (author's transl)]. / Reliefbilder des hinteren Augenpols.

A method for transformation of photographic transparencies into three-dimensional relief pictures is presented. Black-and-white or color slides of fundi were scanned by a TV camera, the video signals digitized point by point into 256 gray levels and fed into an image processing computer. After passing low pass filter programs, the pictures were retransformed in an analog form to display them on the monitor of an analog processor in relief form. Free choice of the analog relief parameters allow to produce topographic reliefs, which give three-dimensional impression of the optic disk, the macula and of other contrast-containing structures. The method is peculiarly suitable for the control of optic disk atrophies in case of glaucoma and neuritis.

[NMR-tomography of the human eye]. / NMR-Tomographie des menschlichen Auges.

The NMR relaxation data of tissue are the basis of an appropriate adjustment of NMR imaging parameters. The relaxation data of ocular tissues are presented, and the relaxation behaviour of the eye is discussed. NMR imaging of eyes with intraocular silicone and pseudophakia are shown. Up to the present time, neuritis of the optic nerve is not detectable by NMR tomography whereas intraocular melanoma are clearly distinguishable.

[Chorioiditis geographica]. / Chorioiditis geographica.

Two cases of geographic choroiditis are reported. This disease is characterized by multiple confluent lesions of the pigment epithelium and the choriocapillaris leading to scars. During the initial episodes geographic choroiditis may look like APMPP but the prognosis is worse. A remarkable depression of the EOG was observed in an apparently unaffected corresponding eye. The etiology of this disease is so far unknown.

[Linearity of applanation tonometry]. / Uber die Linearität der Applanationstonometrie.

A method has been developed for measuring intraocular pressure continuously. By comparing the results with theoretical models it has been established that only viscoelasticity of the sclera and cornea is able to compensate for rapid pressure fluctuations, whereas facility does this only to a minor degree.

[Further clinical studies on chorioiditis geographica]. / Weitere klinische Beobachtungen über Chorioiditis geographica.

We present two further cases of choroiditis geographica. One of them we were able to follow up for two years. This allowed us to observe from the beginning the eye which was not at first involved. Weeks before the first lesions were visible, alterations of the EOG appeared. In the other case both eyes were already involved at the time of first presentation to our hospital. The more involved eye had shown typical degeneration as long as 19 years ago, and we found a proliferation of glia at the macula. We propose a systemic therapy with corticosteroids.

Quantitative monitoring of fundus changes.

The proposed method allows to discover and quantify small changes in series of fundus photographs which are normally not directly comparable. The principle of geometric conformality of small parts between the fundus and its photographs is developed into a practical method of stereoscopic measurement, numerical adjustment and quantitative evaluation. Very high accuracy is possible without special conditions on repeated fundus photography. The aim is to create a theoretical and methodical basis for ophthalmoscopic change detection with image-processing computers.

Contrast echography of the eye and orbit.

SH U 454 is a new echocontrast agent which was developed primarily for echocardiography. It seems that there is a further potential in ophthalmic ultrasound diagnostics. SH U 454 produces contrast enhancement in the orbit, choroid and ciliary body, and permits determination of intraocular blood flow parameters in dogs' eyes. The effects are measured with digital picture processing techniques.