Objectives: The aim of this study was to analyze and describe process and outcomes of two pilot assessments based on the HTA Core Model, discuss the applicability of the model, and explore areas of development.

Methods: Data were gathered from HTA Core Model and pilot Core HTA documents, their validation feedback, questionnaires to investigators, meeting minutes, emails, and discussions in the coordinating team meetings in the Finnish Office for Health Technology Assessment (FINOHTA).

Results: The elementary structure of the HTA Core Model proved useful in preparing HTAs. Clear scoping and good coordination in timing and distribution of work would probably help improve applicability and avoid duplication of work.

Conclusions: The HTA Core Model can be developed into a platform that enables and encourages true HTA collaboration in terms of distribution of work and maximum utilization of a common pool of structured HTA information for national HTA reports.

A 54-year-old man complained of severe throat pain and showed subglottic oedema on fibre-optic endoscopy with a distinctly narrowed subglottic space on anteroposterior radiography of the neck and dense linear opacity at the level of the cricoid cartilage on lateral plain radiography. These findings suggested a foreign body just posterior to the cricopharyngeus, but a computed tomography (CT) scan demonstrated a dense calcified ridge on the posterior lamina of the cricoid cartilage but no foreign body.

The patient improved symptomatically with systemic antibiotics and topical steroids, and gastrointestinal endoscopy did not detect any foreign body. This is a rare case of vertical ossification of the cricoid lamina masquerading as a foreign body.

Bell’s palsy or idiopathic facial palsy is the commonest cause of unilateral lower motor neuron facial palsy. Misdiagnosis of facial nerve palsy as Bell’s palsy is still seen in clinical practice. The clinician should always consider the possibility of a potentially serious underlying pathology before making the diagnosis of Bell’s palsy.

We present a series of 13 patients referred to our ENT department with an initial diagnosis of Bell’s palsy. Further clinical examination and investigation revealed the underlying cause. Many had additional symptoms and signs related to the ear.

In all patients with unilateral facial palsy a detailed history should be taken and thorough clinical examination carried out. Where no recovery occurs within the expected time period further radiological investigations such as computerized axial tomography (CT) and magnetic resonance imaging (MRI) should be performed. Current scanning techniques provide good quality images, which can show occult lesions of the temporal bone, internal acoustic canal and/or cerebellopontine angle. Radiologists with a special interest and experience in otoneurological radiology should ideally report these images, and a close co-operation between ENT surgeon and radiologist is essential in arriving at a proper diagnosis.

Facial nerve neuromas occur throughout the course of the facial nerve and its branches, however lesions occurring on the chorda tympani branch are exceptionally rare.

We present a case where the diagnosis was made intra-operatively; the patient was pre-operatively thought to have had a cholesteatoma.

Total resection is the treatment of choice for these cases. Early diagnosis, aided by high resolution computed tomography (CT) scanning, will facilitate complete excision without damage to the facial nerve itself or the ossicular chain. The slow growing nature of the neuroma is likely to allow compensatory mechanisms to occur without the patient experiencing dysgeusia. As with any rarity the diagnosis can only be made with a high index of suspicion.

Congenital internal auditory canal stenosis is a rare cause of sensorineural hearing loss in children. A retrospective analysis including clinical manifestation and radiological findings was made for seven patients who were diagnosed with congenital internal auditory canal stenosis from 1996 to 2002. Chief presenting symptoms were hearing loss, facial nerve palsy, dizziness, and tinnitus. Hearing loss including deafness was found in five cases, vestibular function loss in four cases, and profound functional loss of facial nerve in two cases. In all cases, the diameter of the internal auditory canal was less than 2 mm on high-resolution temporal bone computed tomography (CT) scan. Two cases revealed bilateral internal auditory canal stenosis, and others were unilaterally involved cases. Congenital internal auditory canal stenosis can be an important cause of sensorineural hearing loss, facial nerve palsy, and vestibular dysfunction. High resolution temporal bone CT scan and magnetic resonance (MR) imaging were important tools for diagnosis.

Optimal imaging protocols for cochlear implantation have yet to be determined. Pre-operative computed tomography (CT) and magnetic resonance image (MRI) scans are used to assess cochlear anatomy and patency, to delineate surgical access, and to aid in choice of side for implantation. However, opinion still differs as to which modality provides more information in pre-operative assessment, or if, indeed, a combination of the two is superior.

The first 88 patients on the Irish National Cochlear Implant Programme (NCIP) were retrospectively studied to determine the accuracy of pre-operative CT and MRI in predicting abnormalities at the time of surgery. Correlation with surgical findings was determined in three separate groups of patients (those who had CT only, those who had MRI only, and those who had both CT and MRI performed).

Of the 24 patients that had both CT and MRI performed, both modalities had a 79 per cent correlation with surgical findings. CT and MRI reports concurred in 75 per cent of cases. Specificity and negative predictive value were high (86 per cent and 90 per cent, respectively). CT alone (47 cases) correlated with surgery in 39 cases (83 per cent); MRI alone (17 cases) correlated in 15 cases (88 per cent).

The findings of this study suggest that CT and MRI are effective at predicting normal inner ear anatomy, and thus at predicting the patient and the cochlea most suitable for implantation. Both modalities are useful in determining the side of implantation, thus avoiding potential surgical difficulties in cases of unilateral abnormalities. There was no significant difference between the ability of MRI and CT to detect abnormalities at the time of surgery. In this series the combination of CT and MRI has not been shown to be superior to either modality used alone, although anecdotal evidence to the contrary was noted.

Proper selection of an osteotome for nasal osteotomy is important for minimizing soft tissue trauma. Radiographic analysis of the facial bony lateral wall thickness was performed to suggest a guideline for an appropriate osteotome size for Asians. Facial bone computed tomography (CT) of 100 patients (50 male, 50 female) were studied. The thickness of the facial bony lateral wall at three points along the track of a lateral osteotomy, and two points along the track of a medial osteotomy and intermediate osteotomy were measured. The average bony thickness along the track of a lateral osteotomy was 2.61 ± 0.66 mm at the low level, 2.75 ± 0.76 mm at the middle level, and 2.72 ± 0.53 mm at the high level in subjects. The average bony thickness along the track of an intermediate osteotomy were 1.26 ± 0.34 mm at the low level, and 1.31 ± 0.32 mm at the high level in the subjects. The average bony thickness along the track of the medial osteotomy were 2.54 ± 0.31 mm at the lowlevel, and 2.77 ± 0.30 mm at the high level in subjects. These results may provide a guideline for choosing an osteotome of appropriate size for the Asian population.

Spontaneous orbital haematoma is uncommon in ENT practice. The sudden presentation of proptosis and diplopia may guide the differential diagnosis towards more common pathologies such as an intraorbital complication of acute sinusitis or neoplasm of the orbit. The diagnosis by computed tomography (CT) scan, the management of this orbital disease and the literature in this field are discussed.

Twenty-eight patients with a clinical diagnosis of sinonasal Wegener’s granulomatosis were referred for imaging during the period 1990-2001. Of these, 10 had clinical symptoms and signs confined to the nose and sinuses and 18 had classical systemic Wegener’s. The computed tomography (CT) and magnetic resonance (MRI) scans of the series were reviewed by a panel of one otolaryngologist and two radiologists. From the total of 28 patients, 85.7 per cent showed non-specific mucosal thickening in the nasal cavity or paranasal sinuses, 75 per cent showed evidence of bone destruction, and 50 per cent new bone formation in the walls of the sinus cavities. In addition the orbit was affected in 30 per cent of patients.

The diagnosis of systemic Wegener’s granulomatosis is made clinically but the condition may present characteristic features on imaging by CT and MRI. In a patient without a history of previous sinonasal surgery, a combination of bone destruction and new bone formation on CT is virtually diagnostic of Wegener’s especially when accompanied on MRI by a fat signal from the sclerotic sinus wall. These changes are important diagnostically in localized sinonasal Wegener’s granulomatosis where the clinical diagnosis may be uncertain and the cANCA test can be negative.

The detection of cervical lymph nodal metastasis and carotid artery invasion by metastatic lymph nodes is an important issue in the management of head and neck malignancies. This study compared the evaluation of metastasis by palpation, ultrasonography (USG) and computed tomography (CT) in patients with known head and neck malignancies.

Twenty-five consecutive patients with head and neck malignancy were prospectively evaluated for the presence of cervical lymphadenopathy and carotid artery invasion. All patients underwent clinical examination (palpation), USG and CT examination. A modified CT criteria was employed which yielded acceptable results for the detection of metastatic nodes. Radical neck dissection was performed for 26 neck sides, and the results of pre-operative evaluation were confirmed by the surgical and histopathological findings.

Palpation, ultrasound and CT have comparable sensitivity in the determination of metastasis involving cervical lymph nodes. Thus palpation should be employed as the primary method of assessment of secondaries in the neck.

However, palpation is less sensitive than CT and USG in the detection of carotid artery involvement, hence the clinical suspicion of arterial invasion should be confirmed by either CT or USG which have similar accuracy in the detection of carotid artery invasion.

In Langerhans’ cell histiocytosis, radiological findings on temporal bone involvement show destructive bone lesions involving the mastoid, with the squamous part and middle ear less affected. Computed tomography (CT) is the preferred imaging modality for describing the extent of temporal bone involvement. CT also has an important role in monitoring disease activity and response to treatment. Bone scintigraphy seems to be less sensitive than radiography in detection of these lesions.

Images of fibrous dysplasia (FD) on computed tomography (CT) or magnetic resonance imaging (MRI) vary depending on the relative proportions of the fibrous and osseous components. Based on analysis of the literature, Camilleri suggested that structural changes revealed by conventional radiography may be indicative of the progression of FD. Here we describe the case of a boy who presented at 12 years of age with monostotic FD located in the right maxilla. The lesion first appeared as a lamellar, ‘onion peel’-like structure on CT; then over the course of the next five years, the structure became what has been termed an ‘egg-shell lesion’, before eventually assuming the form of a ‘ground-glass lesion’.