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Mastoiditis is an otological emergency, and cross-sectional imaging has a role in the diagnosis of complications and surgical planning. Advances in imaging technology are becoming increasingly sophisticated and, by the same token, the ability to accurately interpret findings is essential.
Methods
This paper reviews common and rare complications of mastoiditis using case-led examples. A radiologist-derived systematic checklist is proposed, to assist the ENT surgeon with interpreting cross-sectional imaging in emergency mastoiditis cases when the opinion of a head and neck radiologist may be difficult to obtain.
Results
A 16-point checklist (the ‘mastoid 16’) was used on a case-led basis to review the radiological features of both common and rare complications of mastoiditis; this is complemented with imaging examples.
Conclusion
Acute mastoiditis has a range of serious complications that may be amenable to treatment, once diagnosed using appropriate imaging. The proposed checklist provides a systematic approach to identifying complications of mastoiditis.
The study primarily aimed to calculate the orientation of the cochlea pre-operatively, using high-resolution computed tomography of the temporal bone, and predict the ease of electrode insertion.
Methods
Pre-operatively, high-resolution computed tomography scans were conducted on children scheduled for cochlear implantation, and two angles, α and β, were calculated. The values of α and β were then correlated with intra-operative difficulty in insertion of the electrode array.
Results
Ninety-six children were included in the study. Of the seven patients who had an α angle of less than 50 degrees, the surgeon experienced difficulties in electrode insertion. However, there were four patients with an α angle of more than 50 degrees for whom the surgeon also experienced difficulties in electrode insertion. In all these patients, the β angle was more than 20 degrees.
Conclusion
Calculation of cochlear orientation and its angle with the surgical axis (α and β) can aid the planning of surgery, particularly with regard to the cochleostomy site and preservation of residual hearing.
There is variation regarding the use of surgery and interventional radiological techniques in the management of epistaxis. This review evaluates the effectiveness of surgical artery ligation compared to direct treatments (nasal packing, cautery), and that of embolisation compared to direct treatments and surgery.
Method:
A systematic review of the literature was performed using a standardised published methodology and custom database search strategy.
Results:
Thirty-seven studies were identified relating to surgery, and 34 articles relating to interventional radiology. For patients with refractory epistaxis, endoscopic sphenopalatine artery ligation had the most favourable adverse effect profile and success rate compared to other forms of surgical artery ligation. Endoscopic sphenopalatine artery ligation and embolisation had similar success rates (73–100 per cent and 75–92 per cent, respectively), although embolisation was associated with more serious adverse effects (risk of stroke, 1.1–1.5 per cent). No articles directly compared the two techniques.
Conclusion:
Trials comparing endoscopic sphenopalatine artery ligation to embolisation are required to better evaluate the clinical and economic effects of intervention in epistaxis.
This study aimed to compare the reporting of high-resolution computed tomography of temporal bones for otosclerosis by general radiologists and a neuroradiologist within a local National Health Service Trust.
Methods:
A retrospective case review of 36 high-resolution temporal bone computed tomography images obtained between 2008 and 2015 from 40 otosclerosis patients (surgically confirmed) was performed in a district general hospital setting. The main outcome measures were correct identification of otosclerosis by high-resolution computed tomography and adherence to the petrous temporal bone imaging protocol.
Results:
Correct diagnosis rates were significantly different when made by general radiologists vs a neuroradiologist (p < 0.0001; two-tailed Fisher's exact test). None of the high-resolution computed tomography scans adhered to the temporal bone imaging protocol.
Conclusion:
The use of high-resolution computed tomography for suspected otosclerosis is helpful for diagnosis, disease staging, obtaining informed consent, surgical planning and prognosis. This study suggests that radiological detection of otosclerotic changes by high-resolution computed tomography of the temporal bone is significantly better when performed by a dedicated neuroradiologist than by a general radiologist. Use of a standardised temporal bone computed tomography protocol is recommended to provide consistently high-quality images for maximising disease detection.
Pre-operative radiological identification of facial nerve anomalies can help prevent intra-operative facial nerve injury during cochlear implantation. This study aimed to evaluate the incidence and configuration of facial nerve anomalies and their concurrence with inner-ear anomalies in cochlear implant candidates.
Methods:
Inner-ear and concomitant facial nerve anomalies were evaluated by magnetic resonance imaging and temporal high-resolution computed tomography in 48 children with congenital sensorineural hearing loss who were cochlear implant candidates.
Results:
Inner-ear anomalies were present in 11 out of 48 patients (23 per cent) and concomitant facial nerve anomalies were present on 7 sides in 4 patients (7 per cent of the total). Facial nerve anomalies were accompanied by cochlear or vestibular malformation.
Conclusion:
Potential facial nerve abnormalities should always be considered in patients with inner-ear anomalies. Pre-operative facial nerve imaging can increase the surgeon's confidence to plan and perform cochlear implantation. Magnetic resonance imaging should be used to detect inner-ear anomalies; if these are identified, temporal high-resolution computed tomography should be used to evaluate the facial nerve.
Background: Image review on computer-based workstations has made film-based review outdated. Despite advances in technology, the lack of portability of digital workstations creates an inherent disadvantage. As such, we sought to determine if the quality of image review on a handheld device is adequate for routine clinical use. Methods: Six CT/CTA cases and six MR/MRA cases were independently reviewed by three neuroradiologists in varying environments: high and low ambient light using a handheld device and on a traditional imaging workstation in ideal conditions. On first review (using a handheld device in high ambient light), a preliminary diagnosis for each case was made. Upon changes in review conditions, neuroradiologists were asked if any additional features were seen that changed their initial diagnoses. Reviewers were also asked to comment on overall clinical quality and if the handheld display was of acceptable quality for image review. Results: After the initial CT review in high ambient light, additional findings were reported in 2 of 18 instances on subsequent reviews. Similarly, additional findings were identified in 4 of 18 instances after the initial MR review in high ambient lighting. Only one of these six additional findings contributed to the diagnosis made on the initial preliminary review. Conclusions: Use of a handheld device for image review is of adequate diagnostic quality based on image contrast, sharpness of structures, visible artefacts and overall display quality. Although reviewers were comfortable with using this technology, a handheld device with a larger screen may be diagnostically superior.
Inflammatory pseudotumours of the head and neck are rare. A connection has been made between inflammatory pseudotumours and human immunodeficiency virus positivity.
Case report:
This paper reports a case of an inflammatory pseudotumour presenting with a lesion in the left tonsil and left cervical lymph node in a 49-year-old human immunodeficiency virus positive patient. A histological diagnosis was obtained after biopsy and serial radiological imaging.
Conclusion:
Diagnostic uncertainties can lead to unnecessary surgery. It is important to recognise the clinical, radiological and histological indicators of an inflammatory pseudotumour to enable a timely diagnosis and arrange appropriate treatment. In patients with co-morbidities causing immunocompromise, the potential diagnosis of an inflammatory pseudotumour should be considered. This is especially the case in human immunodeficiency virus patients, as inflammatory pseudotumours have been associated with immune reconstitution inflammatory syndrome, which can manifest up to several years after the initiation of, or change in, antiretroviral therapies.
Central skull base osteomyelitis is clinically difficult to distinguish from malignancy.
Method:
The computed tomography and magnetic resonance imaging scans of six patients with central skull base osteomyelitis were compared with scans from patients with a range of skull base conditions.
Results and conclusion:
Computed tomography scans of central skull base osteomyelitis show much less bony destruction relative to the magnetic resonance imaging changes, whereas malignancy cases were associated with similar bony destruction on computed tomography and magnetic resonance imaging. In magnetic resonance imaging scans, it was possible to confirm previous findings of clival hypointensity on T1-weighted images relative to normal fatty marrow. In addition, there were signs of pre- and para-clival soft tissue infiltration, with the obliteration of normal fat planes and frank soft tissue masses in all six central skull base osteomyelitis patients. Signal intensity on T2-weighted images of the clivus was high in five central skull base osteomyelitis patients. With intravenous contrast, fascial plane anatomy appeared restored in central skull base osteomyelitis cases, almost in keeping with that of non-involved areas. This was not a feature in any of the malignant conditions.
To determine the effect of triage nurse initiated radiographs using the Ottawa Ankle Rules (OAR) on emergency department (ED) throughput. We hypothesized OAR use would reduce median ED length of stay (LOS) by 25 minutes or more.
Methods
A randomized controlled trial was conducted at a tertiary centre ED with an annual census of over 90,000 patients. Adult patients presenting within 10 days of isolated blunt ankle trauma were eligible. Participants were randomly assigned to standard triage or OAR application by 15 explicitly trained triage nurses. Our primary outcome was ED LOS. Secondary outcomes included triage nurses' and patients’ satisfaction. A power calculation indicated 142 patients were required. The Mann-Whitney U test was used to compare the medians between the two groups.
Results
Of 176 patients with blunt ankle injury screened, 146 were enrolled (83.0%); baseline characteristics in the two groups were similar. The median/mean ED LOS in the control and OAR groups were 128/143 minutes and 108/115 minutes respectively (median difference 20 minutes; p=0.003). Agreement in OAR use between emergency physicians and nurses was moderate (kappa 0.46/0.77 for foot/ankle rule components), and satisfaction of both nurses and participants was high.
Conclusion
Triage nurse initiated radiography using OAR leads to a statistically significant decrease of 20 minutes in the median ED LOS at a tertiary care centre. The overall impact of implementing such a process is likely site-specific, and the decision to do so should involve consideration of the local context.
This study aimed to evaluate the prevalence of normal variations of temporal bone anatomy on high-resolution computed tomography imaging and report their clinical importance.
Methods:
A retrospective review was conducted of high-resolution temporal bone computed tomography imaging performed at NHS Greater Glasgow and Clyde over an eight-year period. The presence of five variants was determined. These variants were: a high dehiscent jugular bulb, an anteriorly located sigmoid sinus, a deep sinus tympani, an enlarged cochlear aqueduct and a large internal auditory meatus.
Results:
A total of 339 temporal bones were examined. The incidences of a high dehiscent jugular bulb, anteriorly located sigmoid sinus, deep sinus tympani, enlarged cochlear aqueduct and an enlarged internal auditory meatus were 2.76 per cent, 2.94 per cent, 5.01 per cent, 0.58 per cent and 1.76 per cent respectively.
Conclusion:
Anatomical variations of the temporal bone are not uncommon and it is important for the investigating otologist to be aware of such variations prior to undertaking surgery.
One of the many challenges facing emergency departments (EDs) across North America is timely access to emergency radiology services. Academic institutions, which are typically also regional referral centres, frequently require cross-sectional studies to be performed 24 hours a day with expedited final reports to accelerate patient care and ED flow.
Objective
The purpose of this study was to determine if the presence of an in-house radiologist, in addition to a radiology resident dedicated to the ED, had a significant impact on report turnaround time.
Methods
Preliminary and final report turnaround times, provided by the radiology resident and staff, respectively, for patients undergoing computed tomography or ultrasonography of their abdomen/pelvis in 2008 (before the implementation of emergency radiology in-house staff service) were compared to those performed during the same time frame in 2009 and 2010 (after staffing protocols were changed).
Results
A total of 1,624 reports were reviewed. Overall, there was no statistically significant decrease in the preliminary report turnaround times between 2008 and 2009 (p = 0.1102), 2009 and 2010 (p = 0.6232), or 2008 and 2010 (p = 0.0890), although times consistently decreased from a median of 2.40 hours to 2.08 hours to 2.05 hours (2008 to 2009 to 2010). There was a statistically significant decrease in final report turnaround times between 2008 and 2009 (p < 0.0001), 2009 and 2010 (p < 0.0011), and 2008 and 2010 (p < 0.0001). Median final report times decreased from 5.00 hours to 3.08 hours to 2.75 hours in 2008, 2009, and 2010, respectively. There was also a significant decrease in the time interval between preliminary and final reports between 2008 and 2009 (p < 0.0001) and 2008 and 2010 (p < 0.0001) but no significant change between 2009 and 2010 (p = 0.4144).
Conclusion
Our results indicate that the presence of a dedicated ED radiologist significantly reduces final report turnaround time and thus may positively impact the time to ED patient disposition. Patient care is improved when attending radiologists are immediately available to read complex films, both in terms of health care outcomes and regarding the need for repeat testing. Providing emergency physicians with accurate imaging findings as rapidly as possible facilitates effective and timely management and thus optimizes patient care.
This study investigates the linguistic characteristics of Swedish clinical text in radiology reports and doctor's daily notes from electronic health records (EHRs) in comparison to general Swedish and biomedical journal text. We quantify linguistic features through a comparative register analysis to determine how the free text of EHRs differ from general and biomedical Swedish text in terms of lexical complexity, word and sentence composition, and common sentence structures. The linguistic features are extracted using state-of-the-art computational tools: a tokenizer, a part-of-speech tagger, and scripts for statistical analysis. Results show that technical terms and abbreviations are more frequent in clinical text, and lexical variance is low. Moreover, clinical text frequently omit subjects, verbs, and function words resulting in shorter sentences. Clinical text not only differs from general Swedish, but also internally, across its sub-domains, e.g. sentences lacking verbs are significantly more frequent in radiology reports. These results provide a foundation for future development of automatic methods for EHR simplification or clarification.
This work suggests a classification of interventional radiology and cardiology procedures
based on statistical analysis of operators’ finger doses measured in routine clinical
conditions. In total, 346 finger doses were measured and the observed mean finger dose per
class of procedure ranged from 0.03 mSv to 1.56 mSv for Cerebral, and Bone and Joint
procedures, respectively. The statistical analysis showed that the finger dose in Cerebral
procedures is significantly lower than in Cardiac procedures, which was significantly
lower than the rest. Furthermore, finger doses in therapeutic procedures and in close ones
were significantly greater than in diagnostic procedures and in distal ones. This work
also studied the statistical relation between the use of ceiling-suspended shields or
leaded gloves and the extremity dose. From the set of collected and analyzed data, a
finger dose classification was proposed for different criteria: procedure type
(diagnostics/therapeutic), proximity (close/distal), procedure class and access route.
Radiologists require accurate clinical information to formulate reports. This is particularly relevant to computed tomography of the temporal bone, in which previous surgery can mimic disease.
Objectives:
The information provided with temporal bone computed tomography scan requests was evaluated. The study aimed to minimise inappropriate requests and improve the clinical value of reports.
Method:
A two-cycle prospective audit was undertaken using a proforma designed on the basis of national guidelines. Following the first cycle (in which the requests and reports of 100 scans were evaluated), new guidelines and training were implemented. A follow-up audit (of 50 scans) was then performed.
Results:
Following intervention, the percentage of clinically relevant reports increased from 52 to 94 (p < 0.01), whilst unnecessary or inappropriate scan requests decreased from 11 to 2 per cent (p < 0.05).
Conclusion:
Optimising the clinical value of temporal bone computed tomography scan requests will have positive implications for patient care, time management and cost. The quality of the clinical information provided can have a significant impact on the clinical value of radiology reports, and can mean that unnecessary irradiation is avoided.
To determine the rate of spontaneous tumour shrinkage in a group of patients with sporadic vestibular schwannoma managed with a ‘wait and scan’ approach.
Patients:
All patients with a unilateral cerebello-pontine angle tumour resembling a vestibular schwannoma were registered prospectively in a national database in Denmark. Patients registered with tumour shrinkage were identified and all computed tomography and magnetic resonance imaging scans retrieved, re-evaluated and related to the clinical data.
Results:
Of 1261 observed patients, 48 displayed spontaneous shrinkage (3.81 per cent). Mean absolute shrinkage was 6.25 mm, equivalent to 52.1 per cent. Absolute shrinkage correlated with tumour size and follow-up period, whereas relative shrinkage was significantly greater for tumours which were purely intrameatal at diagnosis. There was no correlation between age and the degree of shrinkage.
Conclusion:
Four per cent of sporadic vestibular schwannomas shrink spontaneously. These findings substantiate the ‘wait and scan’ strategy for tumours with a largest extrameatal diameter of up to 20 mm.
To evaluate the impact of an emergency department (ED) automatic preauthorization policy on after-hours utilization of neuroradiology computed tomography (CT).
Methods:
All CT studies of the head with contrast facial bones, orbits, spine, and neck requested through the ED and performed between January 1, 2004, and December 31, 2010, were reviewed. The preauthorization policy was instituted on February 25, 2008. A control group of noncontrast CT head studies was used for comparison. Pre- and postpolicy implementation utilization rates were compared between the control group of noncontrast CT head studies and the study group neuroradiology CT studies.
Results:
During the study period, 408,501 ED patient visits occurred and 20,703 neuroradiology CT studies were carried out. The pre- and postimplementation groups of noncontrast CT head scans totalled 7,474 and 6,094, respectively, whereas the pre- and postimplementation groups of all other neuroradiology CT studies totalled 3,833 and 3,302, respectively. The CT utilization between the two groups did not differ significantly: the noncontrast head group pre- and postpolicy implementation increased by 0.31 to 3.41%, whereas the utilization of all other neuroradiology CT studies increased by 0.22 to 1.84% (p value = 0.061 for a difference between groups).
Conclusion:
Implementation of an automatic preauthorization policy for after-hours neuroradiology CT studies did not result in a statistically significant increase in CT utilization. This suggests that concerns regarding the negative effects of such policiesmay be unfounded, and further research in this area is warranted.
We examined our experience of image guidance surgery in rhinology, and compared image guidance surgery cases with non-image guidance cases. We also audited our practice against the American Academy of Otolaryngology–Head and Neck Surgery image guidance surgery guidelines.
Method:
The study employed a single institution retrospective approach comprising 174 image guidance surgery patients (106 males and 68 females) and 134 non-image guidance surgery patients (75 males and 59 females).
Results:
In the image guidance surgery group, tumour operations represented 45 per cent of cases (55 per cent were non-neoplastic). Basic, intermediate and advanced (structured classification) procedures represented 19 per cent, 24 per cent and 61 per cent, respectively. Five minor complications were recorded. In non-image guidance surgery, tumour operations represented 8 per cent of cases (92 per cent were non-neoplastic). Basic, intermediate and advanced procedures represented 73 per cent, 12 per cent and 15 per cent, respectively. One minor complication was observed.
Conclusion:
We report the largest series of image-guided ENT surgical procedures in the UK. In the cases we examined, image guidance surgery was predominantly used in advanced procedures and tumour surgery.