Search PubMed⌕ Search

Biomedical subjects

K D Dolan

Publications and source records attributed to K D Dolan.

85 records · Page 5Linked to original sources
PubMedDate not supplied

Paranasal sinus radiology, Part 3A: sphenoidal sinus.

This article describes the complex anatomy of the sphenoid bone. The development and size of the sphenoidal sinuses are quite variable and complete analysis of the sinus walls requires several views. The essential plain film projections and use of tomography and CT scans are described. Sphenoidal sinus inflammatory disease produces changes similar to those already discussed in the articles in this series on the frontal sinus and the ethmoidal sinus. Illustrations of sphenoidal sinus inflammatory disease are provided.

Humans↗
PubMedDate not supplied

Paranasal sinus radiology, Part 3B: Sphenoidal sinus.

Mucoceles involving the sphenoidal sinus are not as common as those affecting the frontal and ethmoidal sinuses. The subtle expansile change produced by a sphenoidal sinus mucocele often requires conventional tomography or computed tomography examination to be detected. Similarly, involvement of surrounding structures by a sphenoidal mucocele may require special study, which this section illustrates. The sphenoidal enlargement and density change produced by fibrous dysplasia may mimic sinus disease. Focal or widespread bone destruction resulting from neoplastic involvement of the sphenoidal sinus requires special examination similar to that used with mucoceles.

Carcinoma↗
PubMedDate not supplied

Paranasal sinus radiology, Part 4A: Maxillary sinuses.

The maxillary sinus is frequently involved by inflammatory change. It is also the sinus that is most affected by intrinsic or nearby neoplasms. Since neoplasia and inflammatory disease may mimic each other, radiologic examination often becomes the principal means of differentiating them. Principles of radiologic diagnosis, with attention to changes in the various bony margins in maxillary disease processes, form the basis of this article.

Adolescent↗
PubMedDate not supplied

Paranasal sinus radiology, Part 4B: Maxillary sinuses.

The maxillary sinus is frequently involved by inflammatory change. It is also the sinus that is most often affected by intrinsic or neighboring neoplasms. Since neoplasia and inflammatory disease may mimic each other, radiologic examination often becomes the principal means of differentiating them. Principles of radiologic diagnosis, with attention to changes in the various bony margins in maxillary disease processes, form the basis of this article.

Humans↗
PubMedDate not supplied

High resolution CT air cisternography in the diagnosis of small acoustic neuromas.

High resolution CT air cisternography was used to examine 38 patients with clinical findings and audiovestibular function studies consistent with a retrocochlear lesion. Four strictly intracanalicular lesions and 10 acoustic neuromas extending medially into the cerebellopontine angle (CPA) cistern by no more than 1 cm were detected and verified at surgery. There was one false-positive diagnosis produced by a tortuous inferior cerebellar artery branch. The contrast-enhanced axial scan was positive in only two patients. Both had extension of the tumor into the CPA by 1 cm. In these two cases the axial intravenous (IV) contrast-enhanced scan provided more information than the air CT. A patient with suspected acoustic neuroma is best examined initially with an IV contrast-enhanced axial scan followed by CT air cisternography where the contrast study is negative.

Adult↗
PubMedDate not supplied

Infratemporal fossa meningioma: CT and MR findings.

We report an unusual case of an extracranial meningioma presenting as a large facial mass. The CT and magnetic resonance findings and a brief review of extracranial meningiomas are presented.

Facial Neoplasms↗
PubMedDate not supplied

Preservation of cochlear function after extensive labyrinthine destruction.

Four ears are presented with extensive destruction of the bony and membranous labyrinth with the loss of caloric function but with retention of hearing. Fourteen similar cases described previously in the literature are reviewed. Our cases are unique in that hearing was preserved after surgical removal of the disease in the inner ear itself. We are unaware of any previous well-documented reports showing such extensive destruction of the pars superior portion of the labyrinth with the preservation of hearing. Possible explanations and theoretical implications are discussed.

Adult↗
PubMedDate not supplied

Asymmetry of the internal auditory canals without acoustic neuroma.

During the past five years, nine patients with "significant" unilateral enlargement of one internal auditory canal by polytomography were subsequently found to have freely filling canals on contrast posterior fossa myelography. The radiographic appearance of the enlarged canals varied greatly and included all the various configurations usually suggestive of acoustic neuroma. Likewise, the clinical presentation varied greatly from asymptomatic to highly suggesting of cerebellopontine angle tumor. This series underscores the essential nature of posterior fossa studies in the evaluation of potential acoustic neuromas and the variability of the normal architecture of the internal auditory meatus.

Adolescent↗
PubMedDate not supplied

Gadolinium-enhanced MR of the postoperative internal auditory canal following acoustic neuroma resection via the middle fossa approach.

PURPOSE: To evaluate the ability of gadolinium-enhanced MR in detecting recurrent tumor in patients whose acoustic neuromas were surgically removed via the middle cranial fossa approach. PATIENTS AND METHODS: Postoperative gadolinium-enhanced exams of 13 of 44 patients who underwent excision of acoustic neuromas via the middle cranial fossa approach were reviewed. RESULTS: Postoperative enhancement was seen in 12 of the 13 patients; two patients underwent serial exams without significant change. On the basis of a single exam, we were unable to conclusively differentiate postoperative enhancement from residual or recurrent tumor. CONCLUSIONS: A single exam is of limited value. Serial studies are recommended to identify changes that would indicate tumor growth. A proposed MR follow-up schedule is an initial baseline exam within 2 months of surgery and a repeat exam during the second postoperative year.

Contrast Media↗
PubMedDate not supplied

Air CT cisternography in the diagnosis of vascular loop causing vestibular nerve dysfunction.

Considerable interest has developed in otology concerning the relationship between the vascular loop and compression of the eighth nerve, producing vertigo. Several authors have described the radiographic findings relative to the anatomy of these vascular loops. Few previous articles have dealt with cases that have had surgical confirmation or repair of the defect. Our presentation concerns 27 patients who were studied by air CT cisternography of the cerebellopontine angle cistern and internal auditory canal followed by surgical repair. We postulate dampened pulsation as the reason for being able to visualize the vessels on the air study. The diversity of vessel-eighth nerve defects is illustrated. Compression of the vestibular nerve by a vascular loop should be considered one of the causes of intractable vertigo and motion intolerance and is a differential diagnosis in Meniere disease. Air CT cisternography is useful in diagnosing this condition in patients who do not respond to medical treatment.

Adult↗
PubMedDate not supplied

Nuclear lacrimal scan vs dacryocystography.

The lacrimal drainage systems of 78 eyes were studied by technetium scanning at the University of Iowa and, of these, 25 were also subjected to conventional contrast dacryocystography. Twenty-six eyes were asymptomatic for epiphora and normal scans were recorded on all of them. All of the remaining 52 symptomatic eyes had an abnormal lacrimal scan with either a presac or a postsac blockage. In general, there was good correlation with dacryocystography, with the exception of three cases of functional block which had a normal dacryocystogram. Technetium scanning should serve as a valuable tool for diagnosing and localizing lacrimal obstruction.

Adolescent↗