Non-EPI-DWI for Detection, Disease Monitoring, and Clinical Decision-Making in Thyroid Eye Disease.

BACKGROUND AND PURPOSE: The Clinical Activity Score is widely used to grade activity of thyroid eye disease and guide treatment decisions, but as a subjective measurement and being confined to the anterior orbit, it has limitations. Non-EPI-DWI of the extraocular muscles may offer advantages as a functional imaging technique with reduced skull base artifacts, but the correlation with the Clinical Activity Score and patient outcome is unknown. Our aim was to establish the correlation between the Clinical Activity Score and non-EPI-DWI and to describe the additional value provided by adjunctive non-EPI-DWI in making clinical decisions. MATERIALS AND METHODS: This was a retrospective longitudinal study of 31 patients seen in a multidisciplinary thyroid eye disease clinic during 5 years who had at least 1 ophthalmic and endocrine assessment including the Clinical Activity Score and a non-EPI-DWI ADC calculation. The Spearman rank correlation coefficient was used to determine the relationship between the Clinical Activity Score and non-EPI-DWI. A patient flow chart was constructed to evaluate clinical decision-making, and receiver operating characteristics were generated. RESULTS: From 60 non-EPI-DWI scans, 368 extraocular muscles were selected for analysis. There was a significant positive correlation between the Clinical Activity Score and ADC (r s = 0.403; 95% CI, 0.312-0.489; P < .001). ADC values were significantly higher in the Clinical Activity Score ≥ 3 group compared with the Clinical Activity Score < 3 group (P < .001). Our patient flow chart identified a third intermediate-severity cohort in which the non-EPI-DWI was particularly useful in guiding clinical decisions. CONCLUSIONS: The non-EPI-DWI correlated well with the Clinical Activity Score in our patients and was a useful adjunct to the Clinical Activity Score in making clinical decisions, especially in patients with intermediate activity and severity of thyroid eye disease.

The utility of computed tomography and diffusion-weighted magnetic resonance imaging fusion in cholesteatoma: illustration with a UK case series.

OBJECTIVE: Post-processing imaging techniques allow high-resolution computed tomography and diffusion-weighted magnetic resonance imaging of the temporal bone to be superimposed and viewed simultaneously (fusion imaging). This study aimed to highlight the practical utility of fusion imaging for disease localisation and evaluation in a UK case series of primary and post-operative cholesteatoma. METHOD: Fusion of computed tomography and diffusion-weighted magnetic resonance b1000 images was performed using specific software. Axial computed tomography images and coronal b1000 images were selected for fusion. RESULTS: A case series of primary and post-operative cholesteatoma in which computed tomography and magnetic resonance imaging fusion assisted the management of both the patient pathway and surgical approach is reviewed. CONCLUSION: Computed tomography and magnetic resonance imaging fusion can assist in pre-operative surgical planning and patient counselling through assessment of disease in both primary and revision scenarios. Computed tomography and magnetic resonance imaging fusion can assist the operative surgeon through accurate localisation that can influence both the operative technique and optimise operation theatre utilisation.

Does non-echo-planar diffusion-weighted magnetic resonance imaging have a role in assisting the clinical diagnosis of cholesteatoma in selected cases?

OBJECTIVE: To determine the diagnostic performance of diffusion-weighted magnetic resonance imaging in the assessment of patients with suspected, but not clinically evident, cholesteatoma. METHODS: A retrospective analysis of a prospectively collected database of non-echo-planar diffusion-weighted magnetic resonance imaging studies (using a half-Fourier single-shot turbo-spin echo sequence) was conducted. Clinical records were retrospectively reviewed to determine indications for imaging and operative findings. Seventy-eight investigations in 74 patients with suspected cholesteatoma aged 5.7-79.2 years (mean, 41.7 years) were identified. Operative confirmation was available in 44 ears. Diagnostic accuracy of the imaging technique was calculated using operative findings as a 'gold standard'. Sensitivity of the investigation was examined via comparison with clinically evident cholesteatoma. RESULTS: The accuracy of diffusion-weighted magnetic resonance imaging in assessment of suspected cholesteatoma was 63.6 per cent. The imaging technique was significantly less accurate in assessment of suspected cholesteatoma than clinically evident disease (p < 0.001). CONCLUSION: Computed tomography and diffusion-weighted magnetic resonance imaging may be complementary in assessment of suspected cholesteatoma, but should be used with caution, and clinical judgement is paramount.

MRI in otology: applications in cholesteatoma and Ménière's disease.

Imaging of middle-ear cholesteatoma with diffusion-weighted imaging (DWI) magnetic resonance imaging (MRI), and inner-ear endolymphatic hydrops (in Ménière's disease) with post-gadolinium high-resolution MRI, are reviewed. DWI MRI provides for a more specific diagnosis of tympano-mastoid cholesteatoma. There is an established and increasing role of DWI MRI in detecting both primary and postoperative cholesteatoma, localising disease, and planning surgery. The contemporary diagnostic accuracy of DWI is reviewed, pitfalls in interpretation are described, and potential future developments are highlighted. High-resolution post-gadolinium MRI of the inner ear is being explored for diagnosing endolymphatic hydrops. There is now increasing data to validate the application of three-dimensional (3D)-fluid attenuated inversion recovery (FLAIR) sequences, performed at 4 hours post-intravenous gadolinium, in the setting of potential Ménière's disease. The clinical context and the evolution of these MRI techniques are discussed. Current MRI-based grading schemes for endolymphatic hydrops are described, together with the available data on their clinical implications.

Endoscopic electrocautery and fibrin obliteration of an acutely complicated pyriform fossa sinus tract in a septuagenarian.

BACKGROUND: Pyriform fossa sinus tracts classically present with neck abscess, recurrent infections and suppurative thyroiditis in children; acute presentation in a geriatric patient is rare. METHODS: Case report and Medline literature review. CASE REPORT: A 79-year-old female presented with a left-sided neck mass and severe odynophagia of 3 days' duration. Magnetic resonance imaging revealed a large-volume, loculated fluid collection extending throughout the deep spaces of the neck on the left, within and around the thyroid gland capsule. There was radiological evidence of internal jugular vein thrombophlebitis. Abscess incision and drainage, and endoscopic evaluation, were performed. A deeply penetrating sinus was seen in the left pyriform apex, the entrance of which was circumferentially cauterised and the lumen obliterated with fibrin glue. Following post-operative intravenous antibiotics, the patient made a complete recovery. CONCLUSION: This paper describes the first use of fibrin glue to obliterate a pyriform fossa sinus tract in an adult.

Uncommon and rare causes of vocal fold paralysis detected via imaging.

BACKGROUND: Cross-sectional imaging can be used to trace the course of the vagus nerve and its laryngeal branches to detect many of the causes of vocal fold paralysis. The most frequent aetiologies are surgical injury and tumoural involvement of the recurrent laryngeal nerve anywhere along its course. METHOD: This review article focuses on the uncommon and rare causes of vocal fold paralysis that have been detected or diagnosed on cross-sectional imaging. RESULTS AND CONCLUSION: Uncommon causes included a tortuous oesophagus, tracheal diverticulum, cervical osteophytes and cardiovocal syndrome. These examples are presented with clinical case histories and radiological appearances, and are discussed in the context of the current literature.

Advances in imaging of obstructed salivary glands can improve diagnostic outcomes.

INTRODUCTION: Obstruction of the major salivary glands is a relatively common condition defined as the blockage of the salivary outflow in the glandular ductal system. It can however mimic more aggressive pathology. METHODS: The most common cause of salivary obstruction is sialolithiasis, followed by ductal strictures. Salivary obstruction is clinically characterized by a food-related painful swelling of the affected gland, known as 'mealtime syndrome'. RESULTS: When obstruction is clinically suspected, the role of imaging consists of confirming the obstruction, identifying its cause, evaluating the position and extent of the obstruction and evaluating for associated complications. However, if imaging shows up signs of a tumour or other pathology which can mimic an obstructed gland clinically instead, the radiologist can alert the clinician accordingly to change the course and plan of treatment. Several imaging techniques are available for investigating the obstructed salivary glands. CONCLUSIONS: This review looks at the causes of obstruction and the use, diagnostic performance and practicality of the various imaging modalities. Importantly, an imaging approach algorithm for the evaluation of the obstructed salivary gland is also proposed.

Cervical osteophytes causing vocal fold paralysis: case report and literature review.

OBJECTIVES: To increase awareness of cervical osteophytes as an extremely rare cause of recurrent laryngeal nerve palsy; to outline the clinical approach to patients with unilateral vocal fold paralysis and to provide an update on the current management of osteoarthritis and osteophytes. CASE REPORT: An elderly man presented with right unilateral vocal fold immobility and a small phonatory gap. By a diagnosis of exclusion, a cervical osteophyte at the level of the sixth and seventh cervical vertebrae was shown to be the cause. The patient responded to speech therapy and no further intervention was required. METHOD: A literature review, using Medline, identified only one previously published case of vocal fold paralysis due to osteophytes secondary to osteoarthritis. CONCLUSION: The aetiology of unilateral paralysis of the hemilarynx must be fully investigated, as the innervating system has a protracted course, particularly on the left side. Degenerative cervical spine disease, although rare, should be considered as part of the differential diagnosis.

The value of non-echo planar HASTE diffusion-weighted MR imaging in the detection, localisation and prediction of extent of postoperative cholesteatoma.

OBJECTIVE: To evaluate the diagnostic performance of half-Fourier-acquisition single-shot turbo-spin-echo (HASTE) diffusion-weighted magnetic resonance imaging in the detection, localisation and prediction of extent of cholesteatoma following canal wall up mastoid surgery. STUDY DESIGN: Prospective blinded observational study. SETTING: University affiliated teaching hospital. PATIENTS: Forty-eight patients undergoing second-look surgery after previous canal wall up mastoid surgery for primary acquired cholesteatoma. INTERVENTIONS: All patients underwent non-echo planar HASTE diffusion-weighted imaging prior to being offered 'second-look' surgery. MAIN OUTCOME MEASURES: Radiological findings were correlated with second-look intra-operative findings in 38 cases with regard to presence, location and maximum dimensions of cholesteatoma. RESULTS: Half-Fourier-acquisition single-shot turbo-spin-echo diffusion-weighted imaging accurately predicted the presence of cholesteatoma in 23 of 28 cases, and it correctly excluded in nine of 10 cases. Five false negatives were caused by keratin pearls of <2 mm and in one case 5 mm. Overall sensitivity and specificity for detection of cholesteatoma were 82% (95% confidence interval [CI] 62-94%) and 90% (CI 55-100%), respectively. Positive predictive value and negative predictive value were 96% (CI 79-100%) and 64% (CI 35-87%), respectively. Overall accuracy for detection of cholesteatoma was 84% (CI 69-94%). Half-Fourier-acquisition single-shot turbo-spin-echo diffusion-weighted imaging has good performance in localising cholesteatoma to a number of anatomical sub-sites within the middle ear and mastoid (sensitivity ranging from 75% to 88% and specificity ranging from 94% to 100%). There was no statistically significant difference in the size of cholesteatoma detected radiologically and that found during surgery (paired t-test, P = 0.16). However, analysis of size agreement suggests possible radiological underestimation of size when using HASTE diffusion-weighted imaging (mean difference -0.6 mm, CI -5.3 to 4.6 mm). CONCLUSION: Half-Fourier-acquisition single-shot turbo-spin-echo diffusion-weighted imaging performs reasonably well in predicting the presence and location of postoperative cholesteatoma but may miss small foci of disease and may underestimate the true size of cholesteatoma.

Imaging of postoperative middle ear cholesteatoma.

Cholesteatoma is often treated surgically using canal wall-preserving techniques. Clinical and otoscopic diagnosis of residual or recurrent disease after this form of surgery is unreliable and thus radiological imaging is often used prior to mandatory "second-look" surgery. Imaging needs to be able to differentiate residual or recurrent disease from granulation tissue, inflammatory tissue or fluid within the middle ear cavity and mastoid cavity. High-resolution computed tomography (HRCT), conventional magnetic resonance imaging (MRI), and delayed contrast MRI have all been used in detecting postoperative cholesteatoma. Although delayed contrast MRI performs better than HRCT and conventional MRI, the sensitivities and specificities of these different imaging methods are relatively poor. Diffusion-weighted MRI (DWI and, in particular, non-echo planar DWI) has been shown to have a high sensitivity and specificity for detecting recurrent cholesteatoma. In this review we provide examples of postoperative imaging appearances following cholesteatoma surgery and we review the relevant literature with an emphasis on studies evaluating the diagnostic accuracy of DWI.

Submandibular gland ectopia associated with atrophy of floor of mouth muscles.

OBJECTIVE: We describe a rare case of an ectopic submandibular gland associated with atrophy of the ipsilateral floor of the mouth muscles. METHOD: Case report and review of the world literature regarding ectopic submandibular glands. RESULTS: The reported patient had an ectopic submandibular gland associated with atrophy of the ipsilateral anterior digastric and mylohyoid muscles. This implies maldevelopment of these muscles in the floor of the mouth and arrest of the normal migration of the submandibular gland. The condition was diagnosed using magnetic resonance imaging and conventional submandibular gland sialography. CONCLUSION: Submandibular gland ectopia in the floor of the mouth is a rare phenomenon. The described case represents the first report of an ectopic submandibular gland associated with atrophy of the ipsilateral floor of the mouth muscles. Radiologists and clinicians should familiarise themselves with this entity and its imaging findings, in order to prevent unnecessary biopsy of this benign condition.

Diagnostic performance of CT versus MR in detecting aldosterone-producing adenoma in primary hyperaldosteronism (Conn's syndrome).

The aim of the present study is to compare the diagnostic performance of CT and MR imaging in detecting aldosterone-producing adenoma and to compare the interobserver variability in the detection of an aldosterone-producing adenoma on CT and MR. A retrospective study of 34 patients with primary hyperaldosteronism was performed. A total of 17 cases of aldosterone-producing adenoma and 17 cases of bilateral adrenal hyperplasia were included. The final diagnosis of an adenoma was made by surgery with histological confirmation, whereas that of bilateral adrenal hyperplasia was made on adrenal venous sampling or a good biochemical and clinical response following medical treatment alone and in the absence of a unilateral radiological abnormality. The CT (n=30) and MR (n=24) scans were reviewed independently by two radiologists experienced in adrenal imaging, who were unaware of the cause of the primary hyperaldosteronism. The diagnostic performances of both observers in detecting an aldosterone-producing adenoma on CT and MR imaging were compared. The 16 adenomatous nodules that were detected on imaging ranged from 1 to 4.75 cm in diameter. The calculated sensitivity and specificity for detecting aldosterone-producing adenoma were 87 and 93% for one observer and 85 and 82% for the other observer on CT, and 83 and 83% for one observer and 92 and 92% for the other observer on MR, respectively. Receptor operating characteristics curve analysis showed similar performances of both observers in detecting an aldosterone-producing adenoma on CT and MR imaging. There was good interobserver agreement on CT (k=0.71) and on MR (k=0.67). We have demonstrated comparable diagnostic performance and good interobserver agreement on CT and MR imaging for the detection of aldosterone-producing adenoma.

CT of primary hyperaldosteronism (Conn's syndrome): the value of measuring the adrenal gland.

OBJECTIVE: The objectives of our study of patients with primary hyperaldosteronism (Conn's syndrome) were to determine whether the adrenal glands are larger in patients with bilateral adrenal hyperplasia than in those with aldosterone-producing adenomas or in healthy control subjects; and whether a CT criterion based on adrenal gland size can be developed to positively diagnose bilateral adrenal hyperplasia. MATERIALS AND METHODS: A retrospective study of CT scans of 28 patients with primary hyperaldosteronism was performed. The means of two observers' measurements of adrenal gland size were recorded and compared with published normal values. In addition, a radiologist experienced in adrenal imaging and unaware of the cause of the primary hyperaldosteronism diagnosed either bilateral adrenal hyperplasia or aldosterone-producing adenoma by visual inspection. RESULTS: The adrenal glands in patients with bilateral adrenal hyperplasia were significantly (p < 0.05) larger than those in patients with aldosterone-producing adenoma or in healthy control subjects. A sensitivity of 100% was achieved when a mean limb width of greater than 3 mm was used to diagnose bilateral adrenal hyperplasia, and a specificity of 100% was achieved when the mean limb width was 5 mm or greater. Receiver operating characteristic curve analysis showed that the overall performance of the radiologist and the mean adrenal limb width in detecting bilateral adrenal hyperplasia were equivalent. CONCLUSION: In patients with primary hyperaldosteronism, adrenal limb measurements on CT can aid in differentiating bilateral adrenal hyperplasia from aldosterone-producing adenoma because the adrenal glands in bilateral adrenal hyperplasia are larger.

Case report. Metastatic pulmonary calcification in renal failure: a new HRCT pattern.

A 56-year-old male with chronic renal failure presented with a 6 month history of progressive dyspnoea. High resolution CT of the chest showed multiple, peripheral, centrilobular nodules in the upper and mid zones, consistent with metastatic pulmonary calcification. Some of these pulmonary nodules showed ring calcification, a pattern that to our knowledge has not been described before. Calcification was also seen in the segmental pulmonary arteries, bronchi, trachea and subcutaneous vessels of the chest wall.

An investigation into the extrinsic blood supply and the microvasculature of the rat stellate ganglion.

The extrinsic supply of the rat stellate ganglion (STG) has been investigated by histological examination of the vasculature following india ink injections by a variety of routes. The main arterial supply to the STG is derived from an un-named branch of the pericardiophrenic branch of the costocervical trunk of the subclavian artery but a small contribution is made to the rostral part of the STG from microvessels running in the cervical sympathetic trunk. Similarly there are microvessels running in the nerve trunks connected to the STG and these, together with those in the cervical sympathetic trunk, can perfuse the STG when the subclavian artery is occluded. The second and third intercostal arteries do not supply the STG. Measurements of alkaline phosphate-stained microvascular endothelial cells reveal that microvessel diameters (6.5 +/- 0.54 microns) in the rat STG are comparable to those in other rat sympathetic ganglia as is the endothelial surface area available for exchange to a given volume of blood. However the density of the microvascular bed in the STG is greater (553.2 mm/mm3) than in other rat sympathetic ganglia and individual neurones in the STG are surrounded by a higher number of microvessels within a radius of 25 microns from the centre of the nucleus. These results suggest that the metabolic demands of STG neurones may be higher than in other sympathetic ganglia.