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At least 19 recordsLinked to original sources
PubMed1987

Rhinoplasty: a CT-scan analysis.

In order to assess the postoperative consequences of various rhinoplasty techniques, CT scans were done in 35 patients having a rhinoplasty operation. This series can be subdivided into those having preoperative and postoperative scans at both 2 days and 6 months (15 patients), a postoperative scan only at 48 hours (10), or a long-term postoperative scan at a mean of 12 months (10). Preoperative analysis indicates that a wide variation exists in lateral nasal wall anatomy and angulation. Surgically, the lateral nasal walls undergo limited medial movement, with tilt a significant component. Postoperatively, extensive remodeling can occur, and virtually all osteotomies are healed by osseous union at 6 months. Future application of CT scans in severely deviated noses may be justified.

Adult↗
PubMed1990

Temporal dimensions of consonant and vowel production: an acoustic and CT scan analysis of aphasic speech.

This study explored a number of temporal (durational) parameters of consonant and vowel production in order to determine whether the speech production impairments of aphasics are the result of the same or different underlying mechanisms and in particular whether they implicate deficits that are primarily phonetic or phonological in nature. Detailed analyses of CT scan lesion data were also conducted to explore whether more specific neuroanatomical correlations could be made with speech production deficits. A series of acoustic analyses were conducted including voice-onset time, intrinsic and contrastive fricative duration, and intrinsic and contrastive vowel duration as produced by Broca's aphasics with anterior lesions (A patients), nonfluent aphasics with anterior and posterior lesions (AP patients), and fluent aphasics with posterior lesions (P patients). The constellation of impairments for the anterior aphasics including both the A and AP patients suggests that their disorder primarily reflects an inability to implement particular types of articulatory gestures or articulatory parameters rather than an inability to implement particular phonetic features. They display impairments in the implementation of laryngeal gestures for both consonant and vowel production. These patterns seem to relate to particular anatomical sites involving Broca's area, the anterior limb of the internal capsule, and the lowest motor cortex areas for larynx and tongue. The posterior patients also show evidence of subtle phonetic impairments suggesting that the neural instantiation of speech may require more extensive involvement, including the perisylvian area, than previously suggested.

Aged↗
PubMed1986

A fully-automated computer-assisted method of CT brain scan analysis for the measurement of cerebrospinal fluid spaces and brain absorption density.

Computer-assisted methods of CT brain scan analysis offer considerable advantages over visual inspection, particularly in research; and several semi-automated methods are currently available. A new computer-assisted program is presented which provides fully automated processing of CT brain scans, depending on "anatomical knowledge" of where cerebrospinal fluid (CSF)-containing spaces are likely to lie. After identifying these regions of interest quantitative estimates are then provided of CSF content in each slice in cisterns, ventricles, Sylvian fissure and interhemispheric fissure. Separate measures are also provided of mean brain density in each slice. These estimates can be summated to provide total ventricular and total brain volumes. The program shows a high correlation with measures derived from mechanical planimetry and visual grading procedures, also when tested against a phantom brain of known ventricular volume. The advantages and limitations of the present program are discussed.

Absorption↗
PubMed1992

[Usefulness of renal CT scan for analysis of nutcracker phenomenon].

Among 24 patients with confirmed left renal bleeding, 11 were diagnosed of having nutcracker phenomenon (NP) on the basis of the results of renal venography and pull-back pressure from the left renal vein to the inferior vena cava. Renal CT scan was performed for these 11 patients, and its usefulness as a means of diagnostic analysis was studied. The following results were obtained. 1. The left kidney was scanned at 5-mm intervals. The mean distance between the anterior surface of the abdominal aorta (Ao) and the posterior surface of the superior mesenteric artery (SMA) was 4.5 +/- 0.6 mm in the NP group, while it was 13.9 +/- 6.4 mm in the control group (p < 0.01). 2. Regarding the morphology of the left renal vein (LRV), tapering dilatation, i.e., funnel-like dilatation, from the left side of Ao was seen in the NP group. In the control group, the left renal vein showed a club-like shape continuing to the inferior vena cava and showed no dilatation. 3. Vascular structures indicative of collateral vessels were observed around the LRV in the NP group. If renal CT scan is performed at 5-mm intervals, the following CT finding are thought to be indicative of the nutcracker phenomenon; (1) a distance of 5 mm or less between Ao and SMA and (2) tapered dilatation of the LRV. This study suggests that renal CT scan is useful for diagnostic analysis of the nutcracker phenomenon.

Adolescent↗
PubMedDate not supplied

3-D femoral stress analysis using CT scans and p-version FEM.

The potential of the finite element method as a computational aid for making objective clinical decisions has not yet been exploited due to the unreliability of the results obtained. The main reasons for this may be attributed to the poor quality of the finite elements available in the conventional softwares, improper modeling of the three dimensional problem, and errors introduced by incorrect representation of geometry and material properties. Herein, we report an attempt to derive a three-dimensional finite element model for the adult human femur which permits reliable representation of the local stress patterns. The geometry was obtained by serial computed tomography scans. The mechanical properties were based on laboratory tests and information available in the literature. The analysis is performed with a new generation software. Preliminary results suggest that the scheme could be automated and used for in vivo analysis.

Biomechanical Phenomena↗
PubMed1979

Automated scene analysis of CT scans.

Since the advent of computed tomography, there has been an increasing realization that CT scans contain quantitative as well as qualitative information useful in the diagnostic process. Often however, the use of this information is impeded by the tedious manual outlining of the areas of interest in the scan. To alleviate this problem, we have developed a scene segmentation algorithm which will automatically delineate areas of interest in a CT scan. This procedure uses known information about the expected objects in the scan in conjuction with an algorithm to label those objects. The resultant scene segmentation divides the scan into four anatomical areas: skull, normal brain, high density lesions and CSF. After an area of interest is interactively selected by the clinician, volume, density or other quantitative measures may be computed. Limitations of the algorithm and its clinical applications are discussed.

Absorptiometry, Photon↗
PubMed1986

Multivolumetric analysis of CT scans on patients with glioma.

Brain tumor volumes in patients having multimodal therapy for cerebral gliomas were calculated using graphic methods and Simpsonian integration. Volume assessment calculations differed from the clinical assessment of the patient significantly in some cases. These calculations may be useful in on-going tumor therapy and should be used as a true scientific end point in brain tumor treatment protocols.

Brain Neoplasms↗
PubMed1985

Pineal region tumors.

The management of pineal region tumors has changed considerably since the introduction of microsurgery and CT scanning. Analysis of our own series of 36 patients, comparing those treated in the pre-CT scan and microsurgery era with those treated afterwards, shows the important role these two techniques play. Current controversies in treatment and our own approach to management of pineal region tumors are discussed.

Adolescent↗
PubMedDate not supplied

Schwannomas of the larynx: review and computed tomographic scan analysis.

Neurogenic tumors consist of schwannomas, neurofibromas, and neurosarcomas that arise from the Schwann cell of a peripheral nerve. Their occurrence in the larynx is rare, with only 115 cases having been reported. Three new cases are presented, the literature is reviewed, and the first computed tomographic (CT) scan of a benign schwannoma of the larynx is demonstrated. The diagnosis and treatment of these tumors and the CT scan analysis are discussed.

Adult↗
PubMed1989

Severe nonfluency in aphasia. Role of the medial subcallosal fasciculus and other white matter pathways in recovery of spontaneous speech.

The relationship between location and extent of lesion on CT scan and limitation in spontaneous speech was examined. The severity of spontaneous speech ranged from cases with no speech or only verbal stereotypies (first major group) to those with reduced, hesitant, poorly articulated, agrammatic speech (nonfluent Broca's aphasia, second major group). CT scan analysis revealed no single neuroanatomical area that contained an extensive lesion which could be used to discriminate the most severe cases from the least severe. The two groups were separable, however, on the basis of the CT scan when the extent of the lesion in two subcortical white matter areas were combined: (1) the most medial and rostral portion of the subcallosal fasciculus plus (2) the periventricular white matter near the body of the lateral ventricle, deep to the lower motor/sensory cortex area for the mouth. The most rostral portion of the medial subcallosal fasciculus, located in the lateral angle of the frontal horn (extremely deep to Broca's area), contains projections from the cingulate gyrus (area 24) and the supplementary motor area, to the caudate nucleus. We suggest that one explanation for the more severe limitation in spontaneous speech in the first group is the extensive white matter lesion in these two subcortical pathways had interrupted a large number of connections for (1) initiation and preparation of speech movements, and limbic aspects of speech (lesions in the medial subcallosal fasciculus), and (2) motor execution and sensory feedback for spontaneous speech (lesions in periventricular white matter deep to the motor/sensory cortex area for the mouth). Extensive lesion in only one of these two white matter pathway areas, alone was not sufficient to produce long-lasting severe limitation in spontaneous speech and could not be used to discriminate the two groups on the basis of the CT scans. The patients with less severe limitation in spontaneous speech (nonfluent Broca's aphasia) had less extensive lesion within these two white matter areas combined, and had interrupted a smaller number of these subcortical connections. The sites of the lesions in subcortical white matter in CT scans in Broca's original case who could only produce a verbal stereotypy are similar to those in our first group with the most severe limitation in spontaneous speech. The presence or absence of hemiplegia was not related to severity or recovery of spontaneous speech. Careful examination of lesion extent in these two areas of subcortical white matter on CT scanning appears to be relevant in predicting potential for recovery of spontaneous speech in some stroke patients.

Adult↗
PubMedDate not supplied

High resolution CT scan of temporal bone fractures: association of facial nerve paralysis with temporal bone fractures.

This radiologic study analyzed high resolution computed tomographic (CT) scans of 22 patients with temporal bone fractures. There were 19 males and three females. Fifteen of 22 had clinical evidence of facial nerve injury ranging from mild paresis to complete paralysis. The high resolution CT scan analysis identified a characteristic fracture of the temporal bone in every patient with facial nerve injury. A high percentage of these fractures (68%) could be classified as mixed and did not fall into a longitudinal or transverse fracture category. The characteristic fracture extends from the petrotympanic fissure at the glenoid fossa to the anterior inferior aspect of the medial bony external auditory canal. It resumes at the superior aspect of the external auditory canal (scutum) extending laterally along the external canal wall. If the vector force of the fracture is projected medially, it will cross the facial nerve in its horizontal portion. Often, the evaluation of trauma patients with routine CT scans for central nervous system (CNS) (brain) evaluation is inadequate for evaluation of temporal bone fractures. A high resolution CT scan should be performed when clinical criteria warrant its use. It is recognized that the incidence of facial nerve injury may be higher in this select population.

Adolescent↗
PubMed1991

Effect of the new dopaminergic agonist CV 205-502 on plasma prolactin levels and tumour size in bromocriptine-resistant prolactinomas.

Bromocriptine is currently and successfully used for the treatment of pituitary prolactinomas. However, bromocriptine appears unable to normalize plasma prolactin levels in about 10% and to reduce tumour size in one-third of cases. The lack of normalization of plasma prolactin levels in spite of a daily dose of bromocriptine equal to or higher than 15 mg suggests a bromocriptine resistance. We compared the long-term effects of bromocriptine and CV 205-502 (a non-ergot derivative D2 dopamine agonist) on plasma prolactin levels and tumour size in seven bromocriptine-resistant prolactinomas. Bromocriptine reduced significantly (P less than 0.001) plasma prolactin levels (from 2307 +/- 518 to 568 +/- 279 micrograms/l) (conversion to Sl units: 1 microgram/l = 20 mU/l). Visual field defects observed in five patients improved in four. However, CT scan analysis showed a decrease in tumour size in only three patients. Except for transient and minor side-effects at the beginning of the treatment, CV 205-502 was well tolerated in five of seven patients. In the remaining two patients nausea and vertigo occurred with high dosages of CV 205-502 and it was necessary to reduce the daily dose. CV 205-502 lowered plasma prolactin to levels similar to those obtained after bromocriptine therapy in four cases. In the three remaining patients, CV 205-502 was more potent than bromocriptine as demonstrated by the further 90% reduction in plasma levels obtained in one case and by the normalization of plasma prolactin levels in the two other cases. One woman became pregnant during CV 205-502 treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Mifepristone (RU 486) treatment of meningiomas.

Meningiomas are common brain tumours which are generally benign, well circumscribed and slow growing. In a minority of patients complete surgical removal is not possible and re-growth of tumour tissue is a major clinical problem. Most meningiomas contain progesterone receptors. The anti-progestational drug mifepristone (RU 486) binds to these receptors. Ten patients were treated with 12 recurrent or primary "inoperable" meningiomas, all of whom had shown recent neuroradiological and/or ophthalmological evidence of tumour growth. They received 200 mg mifepristone daily for 12 months. Most patients initially had complaints of nausea, vomiting and/or tiredness. In four patients prednisone (7.5 mg/day) was given after which these side-effects subsided. CT scan analysis of tumour size, showed progression of growth of five meningiomas in four patients, stable disease in three patients with three tumours and regression of four tumours in three patients. A decrease in the complaints of headache and an improved general well being was observed in five patients. Two patients died during the treatment period from unrelated causes. Mifepristone treatment resulted in control of tumour growth (= stable disease) in six of 10 patients who had shown recent evidence of tumour growth. In three of these six patients consistent tumour shrinkage was observed.

Adult↗
PubMed1986

Depression influences intellectual impairment in stroke patients.

Patients with ischaemic lesions of the left cerebral hemisphere were examined for depression and intellectual impairment: in non-depressed patients, the severity of impairment was related to both lesion volume and location, as assessed by CT scan analysis. Cognitive impairment in patients with major depression was greater than predicted by lesion volume alone, and when patients were matched for severity of impairment, depressed patients had smaller lesion volumes than the non-depressed. After six months, non-depressed patients had significantly less cognitive impairment than depressed patients who showed no improvement. Both depression and lesion volume were significantly and independently related to cognitive impairment. These findings suggest that post-stroke depression can produce a true dementia in its own right, and that treatment of post-stroke depression might benefit cognitive function.

Adult↗
PubMed1991

[Qualitative assessment of centrilobular emphysema using computed tomography].

The ability of computed tomography (CT) in the qualitative assessment of centrilobular emphysema (CLE) was studied, with special reference to the morphological relationship between emphysematous change and relatively large bronchovascular bundle forming the margin of secondary pulmonary lobule. Three autopsied lobes with mild, moderate and severe CLE were fixed by the method of Heitzman. Then high resolution CT (HRCT) was applied to those inflation-fixed lobes, which allowed for direct one-to-one pathologic correlation. Furthermore, HRCT findings of these clinical cases with emphysema were analysed. Emphysematous change in CLE was observed as low-attenuation area (LAA) within the homogeneous background on Ct images. In mild and moderate cases, LAA's were round or oval in shape, however in severe case they were observed to be irregular in shape. The border between LAA and parenchyma was not clearly defined, however in severe case LAA was found to be bordered partially or rather subtotally by the bronchovascular bundle. In mild and moderate cases, LAA's were observed to be distant from relatively large bronchovascular bundle. On the other hand, in severe case, only a small amount of lung parenchyma was left between LAA and bronchovascular bundle. These findings correspond to morphologic characteristics of CLE, that is, the process of emphysematous change tends to take place in the center of the secondary lobule, and even if the lobe is severely destroyed, some portion of the peripheral acinus is still preserved at lobular margin. Thus, CT can help to identify the presence of CLE. Furthermore, CT scan analysis of severe grade emphysema may lead to the differentiation between CLE and panlobular emphysema.

Aged↗
PubMedDate not supplied

[A case of Wilson's disease studied using magnetic resonance: a new approach?].

Wilson's disease is a genetically determined disorder of copper metabolism with increased deposition in brain and liver. With current imaging techniques--CT scan and conventional Nuclear Magnetic Resonance (NMR)--it has been possible to demonstrate oedema, neuronal loss and reactive gliosis, but not copper deposition. In the present study we report the observations, done in one patient, using a new high magnetic field (1.5 Tesla) NMR device. In these circumstances, we are able to expand the CT scan analysis by showing not only the oedema and the brain cell death but also the probable existence of copper deposits. Will this be true, it is first instance in which it has been possible to demonstrate, by a non invasive method, increased copper deposition in Wilson's disease. This possibility may be important to monitor the therapeutic efficacy of chelating agents and also to distinguish asymptomatic homozygous patients from heterozygous healthy carriers.

Adolescent↗