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Biomedical subjects

R Hermans

Publications and source records attributed to R Hermans.

At least 91 records · Page 5Linked to original sources
PubMed1994

CT and MR imaging in tumors of the tongue, tongue base, and floor of the mouth: a comparative study.

A retrospective comparative study was done between CT and MR in 23 patients with a tumor of the tongue, tongue base, or floor of the mouth. Tumor detection, delineation of tumor extent and the visualisation of enlarged lymph nodes was examined. Sixty per cent of the tumors were better visualised with MR, and in 21% supplementary information was acquired using MR. There were no significant differences between CT and MR regarding the visualisation of adenopathies. Despite the differences in tumor visualisation, the radiological staging according to the TNM-classification was not altered by MR.

Carcinoma, Squamous Cell↗
PubMed1993

Atypical aesthesioneuroblastoma: CT and MRI findings.

Aesthesioneuroblastoma is an uncommon tumour of the superior nasal cavity, originating from the olfactory mucosa. Usually no specific radiological features indicate the diagnosis; normally these tumours are seen on CT as homogeneous, enhancing, soft tissue masses causing bone remodelling. Typical but quite nonspecific MRI findings include high signal on T2-weighted images and strong enhancement after gadolinium. The extent of tumour in the paranasal sinuses and anterior cranial fossa is best assessed with MRI after intravenous gadolinium, and this is considered as the most accurate method for assessing preoperative resectability. We report an aesthesioneuroblastoma in an atypical location, with extensive calcification.

Adolescent↗
PubMed1993

Pleomorphic adenoma of the parotid gland.

A retrospective analysis of the CT (n = 18) and MR (n = 4) examinations was performed in 21 patients with a histologically proven pleomorphic adenoma of the parotid gland. This group included 15 primary pleomorphic adenomas, 5 tumor recurrences and one carcinoma ex pleomorphic adenoma. There was a clear female predominance (15/21). On CT, pleomorphic adenoma usually presented as a well defined, round or oval-shaped tumor in the superficial part of the parotid gland, round or oval-shaped tumor in the superficial part of the parotid gland, showing an inhomogeneous captation pattern on contrast enhanced CT. CT sialography offered no complementary information. Although not specific for pleomorphic adenoma, the hyperintense appearance on spin-echo (SE) T2-weighted MRI was helpful in the detection of tumor masses, more specifically small recurrent tumor nodules.

Adenocarcinoma↗
PubMed1993

Arthrography of the temporomandibular joint: pictorial essay.

Although arthrography of the TMJ is nowadays considered as old-fashioned, the technique remains a valuable alternative in cases where MRI is contraindicated. The authors discuss the technique of inferior joint space arthrography and present a review of typical arthrographic cases of the most common types of TMJ pathology.

Arthrography↗
PubMed1993

Retropharyngeal liposarcoma.

We report a case of a large inhomogeneous tumor confined to the retropharyngeal space, visualised by CT and MRI, which proved to be a liposarcoma. Liposarcoma in the head and neck region is a very rare condition and a retropharyngeal location has only been described once previously.

Adult↗
PubMed1992

Postoperative imaging of labyrinthine fistulae in cholesteatomas.

We evaluated the morphology of three operatively closed labyrinthine fistulae which were due to acquired middle ear cholesteatoma in three patients. In all three cases the fistula location was in the horizontal semicircular canal. The fistulae were closed by a mixture of bone powder and Tissucol. The layer closing the fistula was in all cases indistinguishable from the bony otic capsule on the postoperative CT.

Adult↗
PubMed1992

[Technique and interpretation of arthrography of the temporomandibular joint. Study of 120 cases].

The goal of the study was to assess the predictive value of inferior joint space arthrography for detection of abnormalities found during surgery. Therefore, a retrospective analysis of arthrographic and surgical findings in 120 joints was performed. Arthrography showed high accuracy for detection of anterior disk displacement (90%) and disk perforation (90.8%). The shape of the anterior recess proved to be the most valuable arthrographic criterium for detection of anterior disk displacement. Cinematographic registration of joint dynamics after injection of contrast material and arthrotomographic analysis of the shape of the superior margin of the anterior recess of the inferior joint space were necessary for an optimal evaluation of the disk position.

Arthrography↗
PubMed1992

Congenital arterial anomaly in the middle ear presenting as a glomus tumor.

A case of congenital agenesis of the cervical internal carotid artery with rerouting via the inferior tympanic artery and the embryonic hyoid artery to the horizontal internal carotid artery is presented. At otoscopy the anomaly simulated a glomus tumor. CT scan, by demonstration of the absence of the vertical portion of the carotid canal, the enlargement of the inferior tympanic canaliculus, and the soft tissue mass within the middle ear in continuity with the horizontal internal carotid artery, diagnosed the anomaly very accurately.

Angiography↗
PubMed1992

Temporomandibular joint imaging.

Pain and discomfort caused by internal derangement of the temporomandibular joint are frequent in our society. Patients can present with very divergent complaints, not always clearly related to the temporomandibular joint. Good imaging studies of the temporomandibular joint that can show the presence or absence of a problem and give an idea as to type of disease and its seriousness are, therefore, necessary. The choice of which imaging study to use largely depends on whether MR imaging is easily available. Ongoing investigations show that MR imaging of the temporomandibular joint not only depicts the soft tissue derangements very well, but also shows the associated bony changes. However, the exact significance of disk displacement is not always clear because anterior displacement is also seen in asymptomatic volunteers and after clinically successful treatment.

Diagnostic Imaging↗
PubMed1991

Denta Scan: CT software program used in the anatomic evaluation of the mandible and maxilla in the perspective of endosseous implant surgery.

A radiological technique, using a new CT software program for the evaluation of alveolar process height and width, is presented. Irradiation is kept within acceptable limits when this technique is used. Measurements obtained with this technique were compared with those obtained on panoramic radiographs in 40 "half-jaws" (21 maxillar and 19 mandibular). We found that new indications for implantation emerge in the mandibular region because 'Denta Scan' can sometimes show possibilities to place implants on the buccal side of the canal (2 of 19 mandibular cases) when no possibilities are present above the canal on both the panoramic radiographs and Denta Scan images. In the maxillar region Denta Scan avoids unnecessary interventions by demonstrating the insufficient width of the alveolar ridge, often missed on panoramic radiographs (4 of 21 maxillar cases). Moreover the use of Denta Scan allows the use of implants with optimal length and diameter (23 of the 40 cases), giving better long-term results.

Alveolar Process↗
PubMed1991

Phlebectasia of the external jugular vein: a case report.

A case of localized dilatation of the external jugular vein, with an irregularly thickened wall, enlarging during the Valsalva manoeuver, is presented. It is believed to represent a venous aneurysm, which is a rather rare condition.

Adult↗
PubMed1990

Mutagenicity of deep-frying fat, and evaluation of urine mutagenicity after consumption of fried potatoes.

Mutagen formation during deep-frying was evaluated using standard frying conditions. Portions of pre-fried, sliced potatoes were fried in a commercial brand of hydrogenated vegetable frying fat, which was used repeatedly and for a prolonged period of time. Concentrations of polar oxidation and degradation products, and of dimeric and polymeric triglycerides, were found to increase in the frying fat as well as in fried potatoes with prolonged use of the fat. Thiobarbituric acid-reactive substances were detectable neither in the frying fat nor in the fried potatoes. Polar fractions of repeatedly used frying fat significantly increased the number of revertants in Salmonella typhimurium strain TA97 without S-9 mix. In the presence of S-9 mix mutagenic activity was reduced. As a consequence of ongoing formation of polar degradation and oxidation products, the mutagenicity of the fat increased after repeated use. Polar fractions of lipids extracted from commercially obtained pre-fried potatoes, as well as from fried potatoes, marginally increased the number of revertants in strain TA97 without S-9 mix. The mutagenicity of the lipid fractions of fried potatoes was not related to the heating time of the fat. Methanol extracts of fat-free residues of fried potatoes significantly increased numbers of revertants in strain TA97 after metabolic activation, which indicated that a different class of mutagens had been isolated. The mutagenicity of methanol extracts was not increased after either prolonged or repeated use of the fat. Urine samples of six healthy, non-smoking volunteers, collected during the 24 hr following consumption of portions of potatoes fried in repeatedly used fat, showed no increase in mutagenicity compared with control samples. Since the exact identity of mutagens formed during deep-frying, as well as their metabolic fate in man, is unclear at present, evaluation of possible adverse biological effects associated with consumption of fried foods will require strictly controlled metabolic studies.

Adult↗
PubMed1990

[Nodular fasciitis: a case at the level of the zygomatic arch].

The case of a man who developed a nodular fasciitis at the zygomatic arch after a minor facial trauma is presented. Nodular fasciitis is a benign fibroblastic proliferation with unknown etiology; in a number of cases, a recent trauma is mentioned as the triggering cause. The CT characteristics are discussed and the recent literature is reviewed.

Adult↗
PubMed1988

Silent periods in single orbicularis oculi motoneurones.

The activity of single motor units (MUs) of the orbicularis oculi muscle was recorded in normal volunteers. While the subject maintained a constant firing rate, electrical stimuli were applied to the ipsilateral supraorbital nerve. Peristimulus histograms were constructed showing 2 periods of discharge accumulation at times corresponding to the R1 and R2 component of the blink reflex, each followed by a silent period, called SP1 and SP2, respectively. Whereas SP1 may merely result from the synchronisation of discharges in the preceding R1, SP2 can only be explained by an inhibition of the motoneurone activity. These findings confirm the existence of silent periods in the orbicularis oculi muscle in spite of the absence of mechanisms probably responsible for silent periods in load-bearing muscles.

Adult↗