Biomedical subjects

F Zonneveld

Publications and source records attributed to F Zonneveld.

11 recordsLinked to original sources

PubMed2001

Bony orbital development after early enucleation in humans.

AIM: To analyse the extent of bony orbital volume reduction after enucleation in humans. METHODS: Volumetric studies on bony orbital volumes based on three dimensional reconstructions acquired from high resolution computed tomograph (CT) scans were performed in 29 patients with acquired anophthalmia and four patients before enucleation (controls). Eight patients (follow up 25-52 years) were enucleated in childhood aged between 0.4 and 8 years (group I), 21 in adulthood aged between 15 and 53 years. Fifteen of these patients (group IIa) had long standing anophthalmia (follow up 7-53 years), six patients (group IIb) were enucleated 9 months to 4 years before CT. RESULTS: Bony orbital volumes were reduced in all patients with long standing anophthalmia. The median percentage reduction in enucleated orbits was 7.0% in group I, 3.8% in group IIa, and 1.9% in group IIb. In patients with long standing anophthalmia (I and IIa) the reductions were statistically significantly different (p <0.01) from zero. There was some evidence of a correlation between orbital volume reduction and age at enucleation (rho = 0.36, p = 0.09, Spearman rank correlation coefficient) and a statistically significant correlation between volume reduction and time interval since enucleation (rho = -0.5, p = 0.003). Clinically none of the patients showed significant facial asymmetry. CONCLUSIONS: These data provide strong evidence that enucleation both in children and adults is associated with a reduction of bony orbital volume and that this decrease in volume is associated with increasing time. However, the reduction is smaller than generally assumed and does not cause obvious facial asymmetry. It is more related to the time interval since enucleation than the age at enucleation, which makes a mechanism of volume adaptation more likely than just retardation of growth.

Adolescent↗

PubMed2000

Using diagnostic radiology in human evolutionary studies.

This paper reviews the application of medical imaging and associated computer graphics techniques to the study of human evolutionary history, with an emphasis on basic concepts and on the advantages and limitations of each method. Following a short discussion of plain film radiography and pluridirectional tomography, the principles of computed tomography (CT) and magnetic resonance imaging (MRI) and their role in the investigation of extant and fossil morphology are considered in more detail. The second half of the paper deals with techniques of 3-dimensional visualisation based on CT and MRI and with quantitative analysis of digital images.

Animals↗

PubMed2000

Quantification of osseous facial dysmorphology in untreated unilateral coronal synostosis.

Unilateral coronal synostosis results in dysmorphology of the midface in addition to well-characterized cranial and orbital deformities. Because most American infants with this problem have undergone cranio-orbital surgery within their first year of life for the past 25 years, a paucity of data exist regarding the natural history of untreated unilateral coronal synostosis. In an attempt to remedy this void, an international search was conducted to identify computed tomography data sets of living individuals with untreated unilateral coronal synostosis; data were obtained from two European centers and one center in the United States. Results limited to the study of the midface are presented here. Digital data from high-resolution head computed tomography scans of 11 living, white individuals with untreated unilateral coronal synostosis were obtained from three craniofacial centers (in Denmark, The Netherlands, and the United States). Image volumes were constructed from each scan using ANALYZE biomedical imaging software. Fourteen pairs of three-dimensional distances were calculated on the ipsilateral (the side of the synostosis) and the contralateral (the side opposite to the synostosis) hemifaces using 11 osseous landmarks. The resulting measurements were expressed as a ratio of the ipsilateral: contralateral sides. Descriptive statistics were derived for the untreated unilateral coronal synostosis population and compared with analogous measurements performed on dried skulls. Age at computed tomography ranged from 1.1 to 21.1 years (mean, 6.6 years; median, 4.1 years). Twelve of the 14 measured distances differed by greater than 5 percent on the ipsilateral side, and all but one of these measurements were decreased on the ipsilateral side when compared with contralateral values. The results of this study support the following conclusions: (1) There are discrete and measurable differences in the facial morphology between patients with untreated unilateral coronal synostosis and normal skulls. (2) Intercenter and international collaboration can provide a sufficient number of individuals with rare craniofacial anomalies to quantitatively determine group characteristics. (3) Quantitative documentation of rare anomaly natural history is necessary for quantitative outcome assessment of treated patients.

Adolescent↗

PubMed1998

Comparative review of the human bony labyrinth.

The bony labyrinth inside the petrous part of the temporal bone houses the organs of hearing and balance. Being functionally linked with sensory control of body movements and located in a part of the basicranium that is closely associated with the brain, this structure is of great interest in the study of human evolutionary history. However, few aspects of its morphology have been studied in nonhuman primates. This review compares the bony labyrinth of humans with that of the great apes and 37 other primate species based on data newly acquired with computed tomography combined with previous descriptions. With body mass taken into account, consistent differences are found between the size of the semicircular canals in humans, the great apes, and other primates. In particular, the arcs of the anterior and posterior canals are larger in humans than in the African apes. The functional implications of semicircular canal dimensions for registering angular head motion are evaluated in relation to locomotor behavior. Biophysical models, comparative studies, and some neurophysiological experiments all support a link between semicircular canal size and agility, or more specifically the frequency contents of natural head movements, but the evidence on the exact nature of this link is ambiguous. It is concluded that any link between the characteristic dimensions of the human canals and locomotion will be more complex than a simple association with the broad categories of quadrupedal vs. bipedal behavior. The functionally important planar orientations of the semicircular canals are similar in humans and the African apes as well as in many other species. In contrast, other aspects of the human labyrinth differ markedly in shape, following a pattern that seems to reflect the characteristic architecture of the human basicranium. Indeed, it is found that labyrinthine and basicranial shape are interspecifically correlated in the sample, and in most respects the human morphology is consistent with the general trend among primate species. Differences in brain growth and development are proposed as the predominant factor underlying both the unique shape of the human labyrinth as well as the interspecific labyrintho-basicranial correlations.

Anatomy, Comparative↗

PubMed1998

Rare temporal bone pathology of the Singa calvaria from Sudan.

Evidence has recently accumulated that the Singa calvaria from Sudan probably dates from Oxygen Isotope Stage 6 (>130 ka). Morphological studies have indicated a mixture of archaic and more modern human traits, but such analyses are complicated by the possibility that the vault is pathologically deformed, although the exact etiology has not been established. Now computed tomography (CT) has revealed that the right temporal bone lacks the structures of the bony labyrinth. The most likely cause of this rare pathological condition appears to be labyrinthine ossification, in which newly deposited bone obliterates the inner ear spaces following an infectious disease or occlusion of the labyrinthine blood supply. A possible cause of vascular compromise could have been the presence of an expanding acoustic neuroma in the internal acoustic meatus, which is suggested by a significantly wider right meatus compared with the left side. Interestingly, labyrinthine ossification is also consistent with the controversial diagnosis that an anemia caused the characteristic diploic widening at the parietal bosses, because prime etiological factors of ossification are among the common complications of some of these blood diseases. CT examination of the vault and a review of the literature suggest that a blood disorder may well have caused the unusual parietal morphology. Given the nature of these pathological conditions, the Singa individual must have experienced a period of considerable disability. The morphological evidence from the normal bony labyrinth on the left side and from the CT evaluation of the vault is consistent with the interpretation of Singa as a late archaic hominid or an early representative of Homo sapiens drawn from a population which might be directly ancestral to modern humans.

Animals↗

PubMed1998

Advances in three-dimensional diagnostic radiology.

The maturity of current 3D rendering software in combination with recent developments in computer vision techniques enable an exciting range of applications for the visualisation, measurement and interactive manipulation of volumetric data, relevant both for diagnostic imaging and for anatomy. This paper reviews recent work in this area from the Image Sciences Institute at Utrecht University. The processes that yield a useful visual presentation are sequential. After acquisition and before any visualisation, an essential step is to prepare the data properly: this field is known as 'image processing' or 'computer vision' in analogy with the processing in human vision. Examples will be discussed of modern image enhancement and denoising techniques, and the complex process of automatically finding the objects or regions of interest, i.e. segmentation. One of the newer and promising methodologies for image analysis is based on a mathematical analysis of the human (cortical) visual processing: multiscale image analysis. After preprocessing the 3D rendering can be acquired by simulating the 'ray casting' in the computer. New possibilities are presented, such as the integrated visualisation in one image of (accurately registered) datasets of the same patient acquired in different modality scanners. Other examples include colour coding of functional data such as SPECT brain perfusion or functional magnetic resonance (MR) data and even metric data such as skull thickness on the rendered 3D anatomy from MR or computed tomography (CT). Optimal use and perception of 3D visualisation in radiology requires fast display and truly interactive manipulation facilities. Modern and increasingly cheaper workstations ( < $10000) allow this to be a reality. It is now possible to manipulate 3D images of 256 at 15 frames per second interactively, placing virtual reality within reach. The possibilities of modern workstations become increasingly more sophisticated and versatile. Examples presented include the automatic detection of the optimal viewing angle of the neck of aneurysms and the simulation of the design and placement procedure of intra-abdominal aortic stents. Such developments, together with the availability of high-resolution datasets of modern scanners and data such as from the NIH Visible Human project, have a dramatic impact on interactive 3D anatomical atlases.

Humans↗

PubMed1998

Is Whitnall's ligament responsible for the curved course of the levator palpebrae superioris muscle?

BACKGROUND AND PURPOSE: The levator palpebrae superioris (LPS) muscle courses anteriosuperiorly to culminate cranial to the posteriosuperior surface of the globe from where it courses anterioinferiorly to the trasal plate. Whitnall's superior transverse ligament (STL) has been suggested to suspend the LPS at its culmination. If this was the case, one would expect the STL to be located near the culmination of the LPS. In order to elucidate this functional aspect of the STL, the spatial relation of the STL of the LPS muscle is investigated in this study. METHODS: Surface coil MRI in an oblique sagittal plane along the optic nerve was performed in 6 orbits from 3 human cadavers in which the STL was marked with synthetic material. RESULTS: The MR images showed that in human cadaver specimens the STL is situated in the anterior descending portion of the LPS. CONCLUSION: This result suggests that the STL does not suspend the LPS at its culmination and is therefore not responsible for the curved course of the muscle.

Aged↗

PubMed1996

A late Neanderthal associated with Upper Palaeolithic artefacts.

The French site of Arcy-sur-Cure is a key locality in documenting the Middle-Upper Palaeolithic transition in Europe. Reliable attribution of the fragmentary hominid fossils associated with its early Upper Palaeolithic Châtelperronian industry has not been possible. Here we report the first conclusive identification of one of these fossils as Neanderthal on the basis of newly discovered derived features of the bony labyrinth. Dated at about thirty-four thousand years (34 kyr) ago, the fossil is representative of the youngest known Neanderthal populations, and its archaeological context indicates that these hominids used a rich bone industry as well as personal ornaments. The evidence supports the hypothesis of a long term coexistence with technocultural interactions between the first modern humans and the last Neanderthals in Europe. However, the complete absence of the derived Neanderthal traits in labyrinths of modern Upper Palaeolithic specimens from western Europe argues against phylogenetic continuity between the two populations in this region.

Animals↗

PubMed1995

Morphometry of the primate bony labyrinth: a new method based on high-resolution computed tomography.

A method is described for taking accurate measurements of the bony labyrinth of humans and other primates using high-resolution computed tomography (CT). The measurements comprise 8 dimensions, 14 orientations and 2 indices of the labyrinth, as well as 7 orientations of related structures of the petrous pyramid. Comparison of the measurements taken from CT scans with those taken from subsequently made casts and cryosections demonstrates that the method is sufficiently accurate to permit the morphometric analysis of labyrinthine size and shape. Since the CT method is nondestructive, fast and easy to perform, it is applicable to large samples and to rare or precious anthropological specimens.

Animals↗

PubMed1994

Implications of early hominid labyrinthine morphology for evolution of human bipedal locomotion.

The upright posture and obligatory bipedalism of modern humans are unique among living primates. The evolutionary history of this behaviour has traditionally been pursued by functional analysis of the postcranial skeleton and the preserved footprint trails of fossil hominids. Here we report a systematic attempt to reconstruct the locomotor behaviour of early hominids by looking at a major component of the mechanism for the unconscious perception of movement, namely by examining the vestibular system of living primates and early hominids. High-resolution computed tomography was used to generate cross-sectional images of the bony labyrinth. Among the fossil hominids the earliest species to demonstrate the modern human morphology is Homo erectus. In contrast, the semicircular canal dimensions in crania from southern Africa attributed to Australopithecus and Paranthropus resemble those of the extant great apes. Among early Homo specimens, the canal dimensions of Stw 53 are unlike those seen in any of the hominids or great apes, whereas those of SK 847 are modern-human-like.

Animals↗

PubMed1987

Anatomical relations in the carpal tunnel: a computed tomographic study.

Computed tomography of the carpal tunnel was performed in the hands of both patients and controls in a neutral position, in flexion and in extension. The median nerve was not compressed between the long flexors and the flexor retinaculum in either flexion or extension of the wrist. In flexion, the nerve usually moved dorsally, away from the flexor retinaculum. No difference could be found between the cross-sectional area of the carpal tunnel between patients and controls.

Adult↗