J B Ball

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Grantham [Grantham, J. Acoust. Soc. Am. 79, 1939-1949 (1986)] has proposed that subjects are able to resolve the velocity of a moving sound source simply by determining the distance traveled and the time required to complete the movement. In the current experiment, subjects were able to discriminate between accelerated and decelerated movements which were(More)
In a review of more than 1,000 posteroanterior views of normal adult chests, a curving contour that relates to the major fissure laterally along the superior segment of the lower lobe was identified in 14%. The contour, which was more often seen as an edge rather than a line, was noted only on the right in 4%, only on the left in 6%, and on both the right(More)
One hundred computed tomograms of patients with normal lungs were reviewed to determine the normal characteristics of the major fissures and the minor fissure and how often each is seen. Each major fissure was imaged most often as a lucent band, less often as a line, and least often as a dense band. The percentage visualization of these three appearances is(More)
Direct oblique sagittal CT was used to evaluate trauma to 77 orbits. Sixty-seven orbital wall fractures with intact orbital rims (36 floor, 22 medial wall, nine roof) were identified in 47 orbits. Since persistent diplopia and/or enophthalmos may warrant surgical repair of orbital floor fractures, optimal imaging should include an evaluation of extraocular(More)
Computed tomographic (CT) examinations were performed in seven patients after cochlear implant surgery. Preimplantation CT demonstrated the petrous anatomy well and revealed an abnormality in one case. Postimplantation CT adequately assessed electrode position in all cases. Malposition of the active electrode was identified in one patient. Electrode(More)
Extracranial carotid occlusive disease can be evaluated with either intravenous (IV) digital subtraction angiography (DSA) or standard angiography. In a prospective study, complications related to 500 IV DSA examinations occurred in 16.6% of patients, including local complications in 2.0%, systemic complications in 15.0%, and neurologic complications in(More)
Direct sagittal computed tomography (CT) scanning of the cranium and face was facilitated using a fabricated to maintain the position of an adult patient's head on the scanner. A sponge was designed to fulfill the same purpose for children. Sagittal CT scanning of the head is easy to perform using these devices, and the additional equipment is inexpensive.
Direct sagittal computed tomography (CT) was performed on 47 children with pathology in the posterior fossa, orbit, parasellar region, face and ear. The direct sagittal projection provided additional information about the extent of disease and relationship of the pathologic process to the adjacent tissues in 43% of patients studied. Direct sagittal CT has(More)