Noel Young

Early Experience with Spiral CT in the Diagnosis of Intracranial Aneurysms

ABSTRACT: WE REPORT EXPERIENCE with 16 patients undergoing spiral CT Scans for the evaluation of cerebral aneurysms. There were 10 females and six males, aged between 36 and 73 years. The three‐dimensional scanning was useful in five situations: (i) Suspicion of aneurysm on conventional scan. An aneurysm was found in one of four patients and later confirmed by angiography, and two showed arterial ectasia with no saccular aneurysm; the fourth again appeared to have an aneurysm, but this was not shown on angiography. (ii) Follow‐up of previously detected aneurysms not planned for surgery. This has been done in three patients, the spiral CT findings correlating well with previous angiography. (iii) Follow‐up of aneurysm remnants after surgery (three cases); findings correlate well with previous angiography, and clips cause no artefact problems. (iv) Detection of ruptured aneurysms. In two cases, small aneurysms were found that had been missed on angiography, and in a third, with doubtful angiographic findings, spiral CT was useful. (v) Investigation of patients with past treated aneurysms, or of relatives. Three subjects have been screened so far for that purpose; in one a small aneurysm has been found, and confirmed angiographically.

Intracranial aneurysms: evaluation in 200 patients with spiral CT angiography.

Abstract The goal of this study was to assess the usefulness of spiral CT angiography (CTA) with three- dimensional reconstructions in defining intracranial aneurysms, particularly around the Circle of Willis. Two hundred consecutive patients with angiographic and/or surgical correlation were studied between 1993 and 1998, with CTA performed on a GE HiSpeed unit and Windows workstation. The following clinical situations were evaluated: conventional CT suspicion of an aneurysm; follow-up of treated aneurysm remnants or of untreated aneurysms; subarachnoid haemorrhage (SAH) and negative angiography; family or past aneurysm history; and for improved definition of aneurysm anatomy. Spiral CTA detected 140 of 144 aneurysms, and an overall sensitivity of 97 %, including 30 of 32 aneurysms 3 mm or less in size. In 38 patients with SAH and negative angiography, CTA found six of the seven aneurysms finally diagnosed. There was no significant artefact in 17 of 23 patients (74 %) with clips. The specificity of CTA was 86 % with 8 false-positive cases. Spiral CTA is very useful in demonstrating intracranial aneurysms.

Spiral CT Scanning in the Detection and Evaluation of Aneurysms of the Circle of Willis

PURPOSE To assess the utility of spiral computed tomography (CT) with three-dimensional reconstruction in defining aneurysms of the Circle of Willis. METHODS Eighty-one patients with angiographic or surgical correlation were studied between 1993 and 1995, with surface rendered reconstructions of the arteries of the Circle of Willis. RESULTS Spiral CT was useful in six clinical situations: further assessment in cases with CT suspicion of an aneurysm, follow-up of known untreated aneurysms or aneurysm remnants, subarachnoid hemorrhage (SAH) with negative angiography, a past or family history of aneurysms, and improved definition of aneurysm anatomy. Ten of fifteen patients with previous surgery had no significant artifacts on the spiral study. In 66 other patients studied in search of aneurysms, the sensitivity of detection was 95% and specificity 74%. Seventeen of nineteen aneurysms 3 mm or less in size and 38 of 39 larger were detected by spiral CT. Four of thirteen patients with SAH and previous negative angiography had aneurysms identified, which were confirmed at surgery. CONCLUSIONS There is great promise in the use of spiral CT in demonstrating aneurysms of the Circle of Willis, including very small ones. Careful detailing of scan protocols and meticulous examination of multiplanar images are needed for maximum accuracy.

Integration of medical imaging including ultrasound into a new clinical anatomy curriculum

In 2008 a new clinical anatomy curriculum with integrated medical imaging component was introduced into the University of Sydney Medical Program. Medical imaging used for teaching the new curriculum included normal radiography, MRI, CT scans, and ultrasound imaging. These techniques were incorporated into teaching over the first two years of the program as a part of anatomy practical sessions, in addition to dedicated lectures and tutorials given by imaging specialists. Surveys were conducted between 2009 and 2012 to evaluate the student acceptance of the integration. Students were asked to rate individual activities as well as provide open‐ended comments. The number of students who responded to the surveys varied from 40% to 98%. Over 90% of the respondents were satisfied with the overall quality of teaching in the anatomy units. In summary, 48% to 63% of the responding students thought that the specialist imaging lectures helped them learn effectively; 72% to 77% of students thought that the cross‐sectional practical sessions helped them to better understand the imaging modalities of CT, MRI, and ultrasound; 76% to 80% of students considered hands‐on ultrasound session to be useful in understanding the application of ultrasound in abdominal imaging. The results also revealed key similarities and differences in student perceptions of the new integrated curriculum for students with both a high and low prior exposure to anatomy. Further evaluation will aid in refining the integrated medical imaging program and providing its future direction. Anat Sci Educ 8: 205–220.

Pitfalls in the use of spiral CT for identification of intracranial aneurysms.

Abstract We describe problems encountered in our first 136 patients, with 95 aneurysms, who underwent spiral CT for investigation of possible aneurysms involving the circle of Willis and adjacent major vessels, and who had surgical and/or angiographic confirmation. There were seven false-positive cases, of which the first three could be explained by operator inexperience. There were four false negatives, all small aneurysms; two were not seen because of operator error and two were hidden by an adjacent larger aneurysm. Clip artefacts prevented diagnostic studies in six of 21 postoperative studies. One aneurysm was outside the CT field of view, being on a pericallosal artery. One basilar artery tip aneurysm was excluded from the field of the CT study because of a planning error. Inspection of the axial source images is critical if the diagnosis of small or thrombosed aneurysms is to be made. Close attention to image acquisition and computer modelling is required to reduce errors in spiral CT angiography of intracranial aneurysms.

Study of patients with intravenous contrast extravasation on CT studies, with radiology staff and ward staff cannulations

Introduction: Intravenous (IV) contrast extravasation is an adverse outcome of computed tomography (CT) studies. This study evaluates for any differences in rates of extravasation between radiology (radiographer) staff and ward medical staff cannulations, and secondarily by cannula size and study type.

Adaptive Tutorials Versus Web-Based Resources in Radiology: A Mixed Methods Comparison of Efficacy and Student Engagement

RATIONALE AND OBJECTIVES Diagnostic imaging is under-represented in medical curricula globally. Adaptive tutorials, online intelligent tutoring systems that provide a personalized learning experience, have the potential to bridge this gap. However, there is limited evidence of their effectiveness for learning about diagnostic imaging. MATERIALS AND METHODS We performed a randomized mixed methods crossover trial to determine the impact of adaptive tutorials on perceived engagement and understanding of the appropriate use and interpretation of common diagnostic imaging investigations. Although concurrently engaged in disparate blocks of study, 99 volunteer medical students (from years 1-4 of the 6-year program) were randomly allocated to one of two groups. In the first arm of the trial on chest X-rays, one group received access to an adaptive tutorial, whereas the other received links to an existing peer-reviewed Web resource. These two groups crossed over in the second arm of the trial, which focused on computed tomography scans of the head, chest, and abdomen. At the conclusion of each arm of the trial, both groups completed an examination-style assessment, comprising questions both related and unrelated to the topics covered by the relevant adaptive tutorial. Online questionnaires were used to evaluate student perceptions of both learning resources. RESULTS In both arms of the trial, the group using adaptive tutorials obtained significantly higher assessment scores than controls. This was because of higher assessment scores by senior students in the adaptive tutorial group when answering questions related to topics covered in those tutorials. Furthermore, students indicated significantly better engagement with adaptive tutorials than the Web resource and rated the tutorials as a significantly more valuable tool for learning. CONCLUSIONS Medical students overwhelmingly accept adaptive tutorials for diagnostic imaging. The tutorials significantly improve the understanding of diagnostic imaging by senior students.

Use of inferior vena cava filters in a tertiary referral centre in Australia.

Introduction:  To investigate the use of inferior vena cava (IVC) filters in a tertiary referral centre, looking at indication, types of filters and, with temporary/optional filters, removal rates.

Do delays in radiology lead to breaches in the 4-hour rule?

AIM To assess trends in medical imaging requests before and after the 4-hour rule commenced and to assess the imaging time component of emergency department (ED) length of stay (LOS). MATERIALS AND METHODS Retrospective analysis of ED patients and imaging requests 1 year prior to and 3 years after implementation of the 4-hour rule (April to December for 2011-2014) was performed at a single adult tertiary referral Level 1 trauma hospital with Level 6 ED. Logistic regression was used to evaluate trends in the number of ED patient presentations, patient triage categories, and imaging requests for these patients. The imaging component of the total ED LOS was compared for patients who met the 4-hour target and patients who did not. RESULTS Compared to 2011 (before the 4-hour rule), ED presentations increased 4.74% in 2012, 12.7% in 2013, 21.28% in 2014 (p<0.01). Total imaging requests increased 23.05% in 2012, 48.04% in 2013, 60.77% in 2014 (p<0.01). For patients breaching the 4-hour rule, the mean time before radiology request was 2.4-2.8 hours; mean time from imaging request to completion was 1.2-1.3 hours; mean time from imaging completion to discharge from ED was the longest component of ED LOS (4.9-5.9 hours). CONCLUSIONS There has been a significant increase in imaging requests, with a trend towards more CT and less radiography requests. Imaging requests for patients who breached the 4-hour target were made on average 2.4-2.8 hours after triage and average time after imaging in itself, exceeded 4 hours. Imaging is not likely a causative factor for patients breaching the 4-hour target.

Correlation of CT findings remote from prime area of interest: a multitrauma study

Background Multitrauma patients represent a difficult cohort of patients from a diagnostic standpoint. Current trauma recommendations do not advise whole-body computed tomography (CT) in hemodynamically stable patients. Objective To measure the prevalence of abnormal CT findings in areas other than the prime area of clinical interest in multitrauma patients. Method The records of 462 consecutive adult patients who underwent whole-body CT scans between 2004 and 2005 at Westmead Hospital, a Level 1 trauma center, were assessed. Clinical parameters, including suspected clinical injury, regional tenderness, bruising, loss of consciousness, scalp laceration, and unequal chest air entry, were examined. Correlation was made with CTs performed from the brain to symphysis pubis, on a Toshiba 16 slice machine, with evaluation of clinically significant findings. Results The prevalence of abnormal CT findings distant to the prime area of concern varied between anatomical areas: brain (10.3%–88.7%), skull (6.7%–39.7%), facial bones (4.4%–54.3%), cervical spine (5.6%–13.7%), thoracolumbar spine (5.6%–26.7%), chest (30.8%–54.4%), and abdomen/pelvis (20%–27.2%). Conclusion There is a high prevalence of injuries remote from the prime area of clinical concern in multitrauma patients. Whole-body CT is a rapid, accurate, and systematic imaging modality that provides an early, complete, clinical picture for the treating physician.