Background: There is growing concern about emergency physicians overuse of computed tomography (CT). In an attempt to ensure appropriate ordering many hospitals implement strict protocols for ordering of CT scans in the emergency department (ED) that include approval of all scans by a board-certified radiologist, and a reduced access to CT overnight. Aim Statement: The aim of this study is to review the impact of RAD ED – direct access to CT ordering by ED physicians, 24hr CT technologist and third-party reporting on CT scans overnight. Our objectives were to assess the effect on; 1) ED length of stay, 2) number of CT scans ordered and 3) admission rates. Measures & Design: We conducted a prospective pilot before & after study at a single tertiary-care emergency department between February 1st, 2018 and July 31st, 2018. Inclusion criteria were adult patients presenting to the emergency department and undergoing CT for any of the following: face, neck, spine, upper and lower extremities, chest, abdomen and pelvis. Exclusion criteria were those undergoing CT head for stroke or trauma. Evaluation/Results: A total of 924 patients met our criteria, 352 before and 568 after implementation. Comparison of the patient populations demonstrate very similar characteristics in both groups; (49% male, average age 56 years, CTAS 2(40%) and 3(47%). Results demonstrate that an additional 216 scans were performed in post-implementation group. This equates to an increase of 61%. ED length of stay averaged 5.6 hours pre-implementation and 4.7 hours post-implementation. This corresponds to a significant reduction in length of stay of approximately 0.9 hours (p < 0.01). Collection is currently ongoing for factors that we will adjust for a multivariate analysis, including admission rates. Discussion/Impact: RAD ED led to a significant increase in CT ordering and decrease in ED length of stay. We believe that this project provides important information to clinicians and patients with regards to overall CT utilization, ED wait times, follow up visits for CT scanning and admission rates. It is also important for administrators to help decide if these new rules are leading to improved efficiency, and to help estimate their financial impact.

Proboscis lateralis is one of the rare craniofacial congenital anomalies which presents as an obvious deformity of the nose. It tends to occur in male offspring of consanguineous marriages. This is a report of computerized tomography of this rare anomaly. In proboscis lateralis, the nasal cavity on one side is completely normal, while on the affected side it is replaced by a trunk-like process attached to the medial portion of the orbital roof. This anomaly occurs sporadically as an isolated defect or in association with other anomalies. It is usually associated with developmental failure of the paranasal sinuses and the nasolacrimal duct.

Maxillary sinusitis due to dental causes is usually secondary to periodontal disease or periapical infection and is commonly associated with mucosal thickening of the floor of the maxillary antrum. Computed tomography (CT) is currently the modality of choice for evaluating the extent of disease and any predisposing factors in patients with symptoms of chronic maxillary sinusitis, but it is unable to diagnose dental disease reliably. The presence of restorative dentistry is, however, easily seen at CT and is associated with both periapical and periodontal disease. We aimed to determine whether its presence at CT may predispose to maxillary sinusitis, and in particular to focal mucosal thickening of the sinus floor characteristic of dental origin.

Three hundred and thirty maxillary sinus CT images in 165 patients were reviewed for the presence of restorative dentistry in the adjacent teeth, focal maxillary sinus floor mucosal thickening, any maxillary sinus disease (including complete opacification, air fluid levels, diffuse mucosal thickening, focal mucosal thickening) and evidence of a rhinogenic aetiology (osteomeatal complex pathology, mucosal thickening in other sinuses).

One hundred and ninety two sinuses adjacent to restorative dentistry and 178 sinuses not adjacent to restorative dentistry were analysed. Focal floor thickening both with, and without, evidence of a rhinogenic aetiology, was significantly more common adjacent to restorative dentistry. Maxillary sinus disease overall was no more common adjacent to restorative dentistry.

This work demonstrated that the presence of restorative dentistry predisposes to focal mucosal thickening in the floor of the maxillary sinus and its presence should prompt clinical and radiographical assessment to exclude dental disease as a source of chronic maxillary sinusitis.

A combination of computed tomography (CT) and magnetic resonance imaging (MRI) is now established as the optimum assessment of sinonasal malignancy. CT and MRI are of particular value in assessing the skull base, orbit and pteryo-palatine and infratemporal fossae. Although MRI offers better differentiation of tumour from surrounding tissue and fluid, coronal CT is still required for the demonstration of bone erosion particularly in the region of the cribriform plate. Thus the extent of local tumour spread may be determined with a degree of accuracy in excess of 98 per cent. However, the final determinant of penetration of the dura and orbital periosteum requires per-operative frozen section assessment. A knowledge of the tissue characteristics and site of origin can be of value in distinguishing some of the commoner sinonasal malignancies such as squamous cell carcinoma, adenocarcinoma, adenoid cystic carcinoma, olfactory neuroblastoma and chondrosarcoma. Imaging, particularly MRI also plays an important role in the post-therapeutic follow-up of patients, indicating areas of residual or recurrent disease, defining suspicious areas for biopsy. Post-operative surveillance is best achieved with three planar T1-weighted MRI, with, and without, gadolinium and axial T2-weighted sequences. The subtraction of the T1 pre- and post gadolinium T1 sequences can be of particular value in delineating recurrence.

The total surface areas of human mastoid air cells were measured using digital CT scans. Using 24 normal ears, the lining of the mastoid air cells was digitally scanned, traced and analysed. The mean surface area of the mastoid air cell system was 167.0.cm2 and ranged from 74.78 to 330.01 cm2. The volume was also measured, the mean being 10.43.cm3 ranging from 6.25 to 20.52.cm3. The correlation coefficient between surface area and volume was 0.95. These results indicate that well pneumatized mastoid air cells serve to provide an extremely large surface area in the temporal bone which in normal mastoid air cells is proportional to the volume.

There have been few accounts of multi-channel cochlear implants in patients with congenital structural deformities of the inner ear which are associated with severe and sometimes progressive deafness. These malformations can now be recognized easily on 2 plane thin section high resolution CT studies which are mandatory for the pre-implantation assessment. However, no attempt seems to have been made to describe which of these malformations would be suitable for an implant or for which would this procedure be contra-indicated. True Mondini deformity of both the cochlea and dilated vestibular aqueduct type would appear suitable for a multi channel implant, but this type of implant should not be used for a primitive otocyst, severe labyrinthine dysplasia or the characteristic X-linked deformity.