Wade K. Smith

A general system for computer based acquisition, analysis and display of medical image data

A general computer-based system has been developed and implemented for acquiring and viewing medical image data. Originally developed for neuroanatomic studies (1), including investigations of cell topography and connectivity in brainstem nuclei, the system has become a versatile and powerful tool for three-dimensional analysis and display of a variety of types of image data, including studies of cardiac morphometry and 2-d gel electrophoresis. The system includes components for data input via video frame digitizer or digitizing tablet; graphical output through a high-resolution color graphics display or hardcopy plotter. Keys to the systems flexibility and power are a tree-structured data file system, in which line segments and shaded strips may be combined to form complex three-dimensional structures, and a disk-based virtual memory system which permits greater numerical accuracy and use of larger structures than would be otherwise possible with a 16-bit minicomputer.

Incertohypothalamic A13 Dopamine Neurons: Effect of Gonadal Steroids on Tyrosine Hydroxylase

In this study the effect of gonadectomy and steroid treatment on the dorsal component of the incertohypothalamic dopamine system or nucleus A13 was assessed by immunocytochemistry using an antibody raised to tyrosine hydroxylase (TH). A computer graphic system interfaced to a microscope was used to count and measure the diameters of TH-positive neurons and display the data in the three-dimensional space of the nucleus. In males, castration resulted in a dramatic decrease in the reaction product representative of TH. The number of TH-positive cells in the A13 DA nucleus decreased to 25% of intact levels. In females, ovariectomy also caused an impressive loss in the TH-immunostainable material, but this was not indicated by a change in the total number of TH-positive neurons. In both sexes the loss in TH immunostain was confined mainly to the mid-portion of the nucleus. Hormone treatment restored the TH immunostain (cell number and size) to and/or above intact levels in both sexes. These data suggest that A13 TH immunostain is stimulated by gonadal steroids in male and female rats.

Use of computed tomography for a three-dimensional treatment planning system

Computed tomography (CT) can generate a set of serial contiguous slices which form a volume of medical image data. We have developed new techniques for creating computer synthesized 3-D images directly from a volume encoded as a three-dimensional array. The operator can place the eye anywhere in object space to selectively view a portion of the volume from any angle. A set of volume processing tools have been recently developed to allow interactive manipulation of image data within the volume. These tools allow the system to be used for surgical planning, and craniofacial implant design.

Tasks in Computer-Assisted Neuroanatomy: Data Acquisition, Imaging and Database

There is a growing use of computer technology for neuroanatomical studies. First uses began nearly as soon as small laboratory computers became available in the late 1960’s and early ‘70’s. The benefits of being able to quantitate what could only be photographed and verbally described were obvious to many workers. It was also a hope that machine storage of two and three dimensional information would lead to new methods of imaging of what could only be represented numerically. However, it was not clear at the outset, perhaps due to the novelty of the concept, hew long these procedures would take to develop, and exactly what power and capacity the computing machines would be needed in order to bring the concepts into regular use in the neuroanatomical laboratory.

Topographic Distribution of Catecholaminergic Neurons in the Rat Medulla Oblongata Using Quantitative Three-Dimensional Reconstruction

In 1964 Dahlstrom and Fuxe (3), using the formaldehyde histof luorescence technique, first described a variety of monoamine containing neurons in the brain. A number of studies on the catecholamine (CA) neurons followed, (2, 4–8, 12–19, 24) resulting in the demonstration of the existence of the following populations of CA neurons: adrenaline containing neurons — C cell groups (Hokfelt, Fuxe et al, 1974), noradrenaline containing neurons — A cell groups (Dahlstrom and Fuxe, 1964) and dopamine containing neurons. Historically, the question of monoaminergic neurons located in the brain stem has been addressed using fluorescence histochemistry and immunof luorescence techniques (1,2,3,18,19,30).

Three-Dimensional Computer Reconstructions of Catecholaminergic Neuronal Populations in Man

Catecholamine-containing neurons have been found to subserve numerous functions (see reviews by Moore and Bloom, 1978, 1979; Mason, 1981). For example, dopamine (DA) and norepinephrine (NF) containing cells in the hypothalamus regulate pituitary hormone output. The midbrain DA neurons of the substantia nigra (nucleus A9) which innervate the neostriatum, play a role in motor control and cell loss in this nucleus is pathognomonic for Parkinson’s disease. The ventral teamental area DA neurons (nucleus A10), which innervate limbic and specific cortical regions (frontal, cingulate and entorhinal cortex) have been implicated in emotional regulation. Alteration of the receptors of these neurons is thought to be the mode of antipsychotic action for neuroleptic drugs. The locus coeruleus (LC) NF neurons, which diffusely innervate the entire cerebral cortex and spinal cord regions, have been hypothesized to play a role in arousal, attention and anxiety.

A data exchange format for neuroanatomy workstations

The development of the microprocessor has enabled biomedical researchers to use powerful computers as single user workstations. Many such systems are now in use--some developed for use within individual laboratories, and others purchased commercially. These systems typically mix computer graphics and image processing capabilities. No standard exists that allows users of these workstations to exchange anatomical data in graphical or image form. This paper considers issues involved in designing a flexible format for exchanging digital anatomical data between laboratories.