PubMed · 9155761
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S Singh, J Rees. 1997. A 'destructive' headache.. https://doi.org/10.1177/014107689709000413
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Microsurgical approaches to the skull base require a thorough knowledge of the microvasculature of this region. Interestingly, most standard texts of anatomy do not mention the branches of the internal carotid artery as it travels through the temporal bone and cavernous sinus. Although small and with often conflicting descriptions, these arterial branches may be of significance when contributing to the vascular supply of such pathological entities as meningiomas and vascular malformations. Furthermore, multiple anastomoses exist between these branches and branches of the external carotid artery, thus providing a potentially important collateral circulation between these two systems and thus retrograde flow needed to maintain the patency of the distal internal carotid artery (ICA) when this vessel is obstructed proximally. We review the literature regarding these branches of the internal carotid artery and their clinical significance.
We compared three techniques for enhancement of microcatheter tips in fluoroscopic images: conventional subtraction technique (CST); averaged image subtraction technique (AIST), which we have developed; and double average filtering (DAF) technique, which uses nonlinear background estimates. A pulsed fluoroscopic image sequence was obtained as a microcatheter was passed through a carotid phantom that was on top of a head phantom. The carotid phantom was a silicone cylinder containing a simulated vessel with the shape and curvatures of the internal carotid artery. The three techniques were applied to the images of the sequence, then the catheter tip was manually identified in each image, and 100 x 100 pixel images, centered at the indicated microcatheter tip positions, were extracted for the evaluations. The signal-to-noise ratio (SNR) was calculated in each of the extracted images from which the mean value of the SNR and its standard deviation (SD) were calculated for each technique. The mean values and the standard deviations were 4.36 (SD 3.40) for CST, 6.34 (SD 3.62) for AIST, and 3.55 (SD 1.27) for DAF. AIST had a higher SNR compared to CST in almost all frames. Although DAF yielded the smallest mean SNR value, it yielded the best SNR in those frames in which the microcatheter tip did not move between frames. We conclude that AIST provides the best SNR for a moving microcatheter tip and that DAF is optimal for a temporarily stationary microcatheter tip.
We report a case with dysgenesis of the carotid artery associated with congenital Homer syndrome. A 6-year-old boy, who had undergone surgical repair for pulmonary atresia, ventricular septal defect, and patent ductus arteriosus at 20 months of age, presented with miosis of the left eye, and anhidrosis of the left face, neck, and shoulder girdle. Since the anhidrosis was obvious in early childhood, he was suspected as having congenital Horner syndrome. Cranial and cervical CT showed unpredicted abnormalities of the left carotid arteries, including the absence of an internal carotid artery (ICA), and hypoplasia of the common carotid and external carotid arteries. The anterior and middle cerebral arterial flow was supplied through the communicating arteries. Congenital agenesis of the ICA was highly suspected, because the left carotid canal could not be discerned at all. The concurrence of agenesis of ICA with ipsilateral Horner syndrome is accounted for by simultaneous organogenesis of the carotid artery and cervical sympathetic nerve, both of which are derived from neural crest cells. Developmental anomalies of the cervical neural crest, though rare, should be included in the differential diagnosis of congenital Homer syndrome.