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Biomedical subjects

R Hermans

Publications and source records attributed to R Hermans.

At least 55 records · Page 3Linked to original sources
PubMed1998

CT findings in chondroradionecrosis of the larynx.

PURPOSE: Our goal was to describe the CT findings before and after radiation therapy in a series of patients with laryngeal chondroradionecrosis. METHODS: The CT studies obtained before and after radiation therapy in nine patients with the diagnosis of laryngeal chondroradionecrosis were reviewed retrospectively. RESULTS: CT scans revealed abnormalities in all patients. A variable degree of laryngeal soft-tissue swelling was seen in eight of the patients. In four patients, cartilaginous abnormalities were visible initially, and appeared in three of four other patients who had further follow-up CT studies. Six patients had involvement of the thyroid cartilage; collapse of the thyroid cartilage was seen in two cases and gas bubbles were visible adjacent to the thyroid cartilage in three cases. Four patients with involvement of the thyroid cartilage eventually underwent total laryngectomy, and one died suddenly in severe respiratory distress. In all three patients with arytenoidal involvement, anterior dislocation of this cartilage was seen; in two of these patients, the adjacent part of the cricoid cartilage showed some sclerosis. Two patients with arytenoidal necrosis (both with cricoidal sclerosis) kept a functional larynx. In one case, cricoidal sclerosis was seen in association with lysis of the thyroid cartilage. CONCLUSION: The CT appearance of laryngeal chondroradionecrosis is nonspecific, but the diagnosis can be strongly suggested in cases of sloughing of the arytenoid cartilage, fragmentation and collapse of the thyroid cartilage, and/or in the presence of gas bubbles around the cartilage.

Adult↗
PubMed1998

Computed tomography of laryngeal carcinoma: technique, imaging findings and implications for radiation therapy.

Optimal radiological visualisation of laryngeal carcinoma demands for a tailored imaging technique. The technique for computed tomography of the larynx is reviewed, and imaging findings in laryngeal carcinoma are described. The application of CT-findings for selection of patients into the favourable group for radiation therapy is discussed. The use of CT in the follow-up of irradiated laryngeal carcinoma is reviewed.

Carcinoma, Squamous Cell↗
PubMed1997

Volume estimation of the preepiglottic and paraglottic space using spiral computed tomography.

The purpose of this study was to estimate the volume variability of the preepiglottic and paraglottic space in the normal larynx. In 23 adult patients (12 women, 11 men), a spiral CT acquisition through the larynx was obtained. No laryngeal pathology was observed. The area of the this submucosal fat space was estimated on each slice by semi-automatic segmentation; the volume was calculated by the summation-of-areas technique. The obtained volumes were correlated with body area, body mass index and gender. The mean estimated volume of the preepiglottic and paraglottic space was 2.8 ml (SD 1.7 ml, range 0.7-5.9). No correlation with body mass index (p = 0.6), but a significant correlation with body area (p < 0.001) was found. A significant volume difference was present between men (mean 4.5 ml, SD 1.0 ml, range 2.8-5.9) and women (mean 1.4 ml, SD 0.5 ml, range 0.7-2.4)(p < 0.0001). Multiple regression analysis showed gender (p < 0.0001) to be a more important variable than body area (p = 0.17) in predicting the volume of the preepiglottic and paraglottic space. In conclusion, the volume of the preepiglottic and paraglottic space appears to be very variable, and should only be analysed with consideration of the gender of the examined subjects.

Adult↗
PubMed1997

MRI screening for acoustic neuroma without gadolinium: value of 3DFT-CISS sequence.

To evaluate the efficacy of a gradient-echo sequence (3DFT-CISS) in the diagnosis of acoustic neuromas, two independent observers twice reviewed the images of the temporal bones of 83 patients. Contrast-enhanced T1-weighted spin echo images were used as the reference, showing 18 acoustic neuromas, including 5 purely intracanalicular and one intralabyrinthine tumours. High sensitivity (89-94%), specificity (94-97%) and accuracy (94-95%) were found. Intraobserver (kappa 0.93-1) and interobserver (kappa 0.83-0.84) reproducibility were very good. The smallest intracanalicular tumour was overlooked twice by both observers; the intralabyrinthine tumour once by one observer. All tumours were detected with a less stringent decision criterion, at the expense of lower specificity.

Artifacts↗
PubMed1997

Estimation of thyroid gland volume by spiral computed tomography.

The objective of this study was to test the accuracy of CT for the estimation of the volume of enlarged thyroid glands. An unenhanced spiral CT scan of neck and upper mediastinum was obtained in 36 patients with an enlarged thyroid gland. By manual segmentation the surface of the thyroid gland on 5-mm-thick slices was calculated; these surfaces were multiplied by the slice interval (10 mm) and summated to obtain the volume of the gland. All patients underwent a total or subtotal thyroidectomy. 1 cm3 of thyroid gland tissue was considered to weigh 1 g. A good correlation was found between the volume estimated by CT and the weight at pathological examination of the resected gland (r = 0.98, p < 0.001), with a mean difference of + 12 % (range: + 57.3 to -13.9 %). The volume calculation is reproducible among different observers (r = 0.99, p < 0.01). Computed tomography allows an easy, reliable and reproducible volume determination of enlarged thyroid glands.

Adult↗
PubMed1997

Image interpretation in CT of laryngeal carcinoma: a study on intra- and interobserver reproducibility.

The object of our study was to evaluate the intra- and interobserver reproducibility of the interpretation of CT examinations of laryngeal carcinoma. The CT examinations of 100 laryngeal cancers were retrospectively reviewed twice by two independent reviewers. Involvement of different structures was assessed, using a standard scoring form. Statistical analysis was done using the Wilcoxon signed rank test and Cohen's kappa. A borderline significant difference between the observers (p < 0.04) was present. Fair to substantial intraobserver reproducibility (kappa = 0.29-0.86), and fair to substantial interobserver reproducibility (average kappa = 0. 26-0.74) were found for most laryngeal structures when a dichotomous categorical scale was used. On the average somewhat lower, but still fair to substantial, intraobserver (kappa = 0.36-0.72), and fair to moderate interobserver (average kappa = 0.29-0.47) reproducibility, were found when a nominal or ordinal categorical scale was used. In conclusion, the interpretation of CT images of laryngeal tumors is reproducible.

Carcinoma, Squamous Cell↗
PubMed1997

Non-invasive tumour perfusion measurement by dynamic CT: preliminary results.

In 18 patients the perfusion of a malignant head and neck tumour was estimated using contrast enhanced dynamic computed tomography. The mean estimated perfusion was 75.5 ml/100 g/min, varying between 27.9 and 131.9. Eleven patients were treated with radiation therapy; the obtained perfusion rates were significantly different between tumours with a favourable and those with an unfavourable early outcome.

Adult↗
PubMed1997

Necrotizing fasciitis of the head and neck: role of CT in diagnosis and management.

PURPOSE: To determine the characteristic diagnostic features of necrotizing fasciitis and to evaluate the role of computed tomography (CT) in its management. MATERIALS AND METHODS: Fourteen patients with surgically proved necrotizing fasciitis of the extracranial head and neck were examined with contrast material-enhanced CT. Clinical, radiologic, surgical, pathologic, and anatomic findings at admission and after initial treatment were analyzed retrospectively. RESULTS: Constant CT features of necrotizing fasciitis were diffuse thickening and infiltration of the cutis and subcutis (cellulitis); diffuse enhancement and/or thickening of the superficial and deep cervical fasciae (fasciitis); enhancement and thickening of the platysma, sternocleidomastoid muscle, or strap muscles (myositis); and fluid collections in multiple neck compartments. Inconstant CT features included gas collections, mediastinitis, and pleural or pericardial effusions. All patients underwent extensive surgical debridement. Follow-up CT scans in 11 patients revealed clinically unsuspected progression of the inflammatory process in previously unaffected areas, a finding that warranted additional surgery in nine patients. Twelve patients survived, and two patients died of septic shock and aspiration pneumonia despite intensive surgical and medical treatment. CONCLUSION: Early recognition of necrotizing fasciitis with CT enables appropriate surgical treatment. CT may also be a useful guide in further patient treatment after initial surgical debridement.

Adolescent↗
PubMed1997

Use of a composite fascial carrier for laryngotracheal reconstruction.

A vascularized fascia flap may be used as a vascular carrier for free mucosal and cartilage grafts. This composite reconstruction technique has been performed in clinical situations with complex laryngeal or tracheal defects. This paper describes the technique and the rationale for applying this concept to some particular laryngotracheal defects. Morphologic and histologic aspects of this composite reconstruction technique using a transferable recipient bed are discussed.

Humans↗
PubMed1997

Imaging of maxillo-facial trauma.

The maxillofacial skeleton is vulnerable to injury. Radiological evaluation of facial injury can be difficult due to the complex anatomy and the difficulties in obtaining high-quality imaging studies in the severely traumatised patient. Adequate imaging is nevertheless necessary to obtain satisfactory clinical results. This paper gives a review of common and some less common injuries that may be encountered in facial trauma.

Ethmoid Bone↗
PubMed1997

Osteoma of the internal auditory canal.

A case of an osteoma of the internal auditory canal in a patient with severe hearing loss is presented. Osteomata of the internal auditory canal have only rarely been diagnosed. Symptoms consist in sensorineural hearing loss, vertigo and/or tinnitus. CT scan is an appropriate imaging modality. In selected cases surgery can be beneficial. A review of the literature is presented.

Adolescent↗
PubMed1997

Anatomical variations and sinusitis.

Paranasal sinus anatomy and variations have gained interest with the introduction of functional endoscopic sinus surgery and the concept of the ostiomeatal complex. Anatomical variations can be divided in structural abnormalities, (increased) pneumatization and supplementary openings. Most anatomical variations are equally found in control and sinusitis patients. The anatomical variations which are most commonly associated with sinus pathology are septal deviations, true conchae bullosae and supplementary maxillary ostia but the latter one only when recycling is present. The knowledge of anatomical variations is most important in the surgical management and specifically in the prevention of complications.

Adolescent↗
PubMed1996

Imaging of the oropharynx and oral cavity. Part I: Normal anatomy.

This article reviews the anatomy of the oropharynx and oral cavity, as seen on CT and MR imaging studies. Emphasis is placed on the description and illustration of the structures which are of importance to detect tissue alterations and interprete them adequately. Common pitfalls in the image interpretation of this region are indicated.

Humans↗
PubMed1996

Impact of cartilage invasion on treatment and prognosis of laryngeal cancer.

Invasion of laryngeal cartilage has long been considered as a contraindication to radiation treatment and to all types of conservation surgery. With the advent of axial imaging techniques clarification of the submucosal extent of disease became possible. However, controversies regarding diagnosis (preferred modality, accuracy of detection of cartilage invasion) and treatment of cartilage invasion (Is cartilage invasion really a contraindication for irradiation treatment?) arose. Based on currently accepted criteria, CT appears to be more specific in detecting neoplastic cartilage invasion than MRI, but tends to underestimate invasion and may therefore result in undertreatment. Magnetic resonance has a higher sensitivity than CT for detection of cartilage invasion. The superiority of MRI lies in its ability to detect intracartilaginous tumor spread. Unfortunately, MR findings suggesting neoplastic cartilage invasion may be false positive in a considerable number of instances. Two MRI-dependent parameters appear to be significant as a prognostic factor for success of radiation therapy: tumor volume and abnormal MR signal pattern in cartilage. Minimal abnormal MR signal patterns in cartilage in patients with small tumors (under 5 cc) does not appear to be a very ominous finding for tumor recurrence after radiation therapy. On the other hand, abnormal MR signal pattern in cartilage combined with large tumor volume (above 5 cc) appears to worsen the prognosis significantly. If voice conservation surgery is being considered, MR imaging is useful for assessing those structures (such as cartilages) whose involvement would contraindicate partial laryngectomy. Magnetic resonance imaging appears to be the optimal method of examination in cooperative patients. If MRI fails or if it is contra-indicated, CT may still be recommended. The radiologist's experience with CT or MRI also determines the choice between the two modalities.

Contraindications↗
PubMed1996

Imaging features in 35 cases of submucosal laryngeal mass lesions.

We evaluated the clinical and radiological findings in 35 patients with submucosal laryngeal masses. The presenting symptoms were hoarseness, stridor, dysphagia and external neck mass. In 20 cases an important delay between the onset of symptoms and direct laryngoscopy was found. There was a considerable delay between laryngoscopy and definitive diagnosis in 13 cases due to repeated negative biopsies. Computed tomography pointed out the location and extension of the masses in all cases. In 27 mass lesions CT allowed correct prediction of the malignant or benign character of the lesion. In 6 cases no reliable differentiation could be made. The lesion was mischaracterised in 2 cases. Magnetic resonance imaging was also performed in 4 patients, and showed the extent of the lesion better; in 1 case MRI narrowed the differential diagnosis. In the case of a negative biopsy result, radiological findings should incite further investigation, reducing the possible delay between the onset of symptoms and definitive diagnosis.

Adult↗