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Limited magnetic resonance (MR) pulse sequences facilitate lumbosacral nerve imaging with acceptable image quality. This study aimed to evaluate the impact of parameter modification for Diffusion Weighted Image (DWI) using Readout Segmentation of Long Variable Echo-trains (RESOLVE) sequence with opportunities for improving the visibility of lumbosacral nerves and image quality.Following ethical approval and acquisition of informed consent, imaging of an MR phantom and twenty healthy volunteers (n=20) was prospectively performed with 3T MRI scanner. Acquired sequences included standard two-dimensional (2D) turbo spin echo sequences and readout-segmented echo-planar imaging (EPI) DWI-RESOLVE using three different b-values b-50, b-500 and b-800 s/mmPhantom images revealed higher SNR for images with low b-values with 206.1 (±10.9), 125.1 (±45.2) and 59.2 (±17.8) for DWI-RESOLVE images acquired at b50, b500 and b800, respectively. Comparable results were found for SNR, ADC and nerve size across normal right and left sided for healthy volunteer images. The SNR findings for b-50 images were higher than b-500 and b-800 images for healthy volunteer images. The qualitative findings ranked images acquired using b-50 and b-500 images significantly higher than corresponding b-800 images (P0.05). Inter and intra-observer agreements for evaluation across all b-values ranged from 0.59 to 0.81 and 0.83 to 0.92, respectively.The modified DWI-RESOLVE images facilitated visualization of the normal lumbosacral nerves with acceptable image quality, which support the clinical applicability of this sequence.

Objective: The purpose of this study was to evaluate the technical success and complication rates of image-guided lumbar puncture (IGLP) and to evaluate for differences in approach employed to help establish the optimum technique. Methods: A retrospective search of the hospital picture archiving and communications system was performed to identify all IGLPs that had taken place over a 5-year period. Radiology reports and the electronic medical record were examined to identify technical parameters and complications associated with each procedure. Results: The technical success rate was 96% (219/228). 69.4% (n = 161) had a previously failed bedside attempt. The rate of complications was 0.01% (n = 2). No major complications were observed. There was no difference in the rates of failure (2.4% vs 3.6%, p = 0.68) or complications (0.008% vs 0.012%, p = 1) between interlaminar and interspinous approaches. Conclusion: IGLP is a safe procedure with a high rate of technical success. Where a difficult bedside attempt is anticipated, it is reasonable to forego this and proceed directly to IGLP. Advances in knowledge: : This paper helps to confirm what is already assumed about a common radiological procedure. This is important as there has been a shift from bedside technique to most lumbar punctures being performed via image guidance.

Objective A radiology sign that references a resemblance to something which is not actually present within an image has been termed a 'metaphoric' sign. Metaphoric signs are widely described in the literature and commonly used in teaching as a form of pattern recognition, or ‘pareidolia’. However, the educational benefit of metaphoric signs has not been previously assessed. We aimed to assess the utility of metaphoric signs in medical student teaching. Materials and Methods Fifteen radiology cases were prepared into two lecture formats for medical student education. A 'test' lecture utilizing metaphoric radiology signs to describe the appearance of the cases and a 'control' lecture where pathology was compared to normal anatomical appearances without reference to metaphoric signs. Forty-nine volunteer medical students were randomized with cluster sampling to receive either the test or control lecture. Four days later, students were quizzed to determine retention of knowledge and to assess interest in the lecture on a visual analogue scale from 0 to 100. Results The median interest level of the test group (69.5) was higher than the control group (50) (p = 0.001). The mean quiz score was higher in the test group (34.5) than in the control group (29) (Difference 5.5, 95% confidence interval 0.08-10.92, p = 0.047). Conclusion The use of metaphoric signs in radiology education of medical students increased interest, descriptive ability and short-term knowledge retention, compared to the same material taught with normal anatomy correlation. Metaphoric signs should be considered as a useful radiology teaching tool.

To determine the impact of breast shields on breast dose and image quality when combined with a low-dose computed tomography pulmonary angiography (CTPA) protocol for pregnancy.A low-dose CTPA protocol, with and without breast shields, was evaluated by anthropomorphic phantom and 20 prospectively recruited pregnant participants from January to October 2019. Thermoluminescent dosimeters measured surface and absorbed breast dose in the phantom and surface breast dose in participants. The Monte-Carlo method estimated the absorbed breast dose in participants. Image quality was assessed quantitatively by regions of interest analysis and subjectively by the Likert scale. Doses and image quality for CTPA alone were compared with CTPA with breast shields.Mean surface and absorbed breast dose for CTPA alone were 1.3±0.4 and 2.8±1.5 mGy in participants, and 1.5±0.7 and 1.6±0.6 mGy in the phantom. Shielding reduced surface breast dose to 0.5±0.3 and 0.7±0.2 mGy in the phantom (66%) and study participants (48%), respectively. Absorbed breast dose reduced to 0.9±0.5 mGy (46%) in the phantom.Noise increased with breast shields at lower kV settings (80 to 100 kV) in the phantom; however, in study participants there was no significant difference between shield and no-shield groups for main pulmonary artery noise (no-shield: 34±9.8, shield: 36.3±7.2, P=0.56), SNR (no-shield: 11.2±3.7, shield: 10.8±2.6, P=0.74) or contrast-to-noise ratio (no-shield: 10.0±3.3, shield: 9.3±2.4, P=0.6). Median subjective image quality scores were comparable (no-shield: 4.0, interquartile range: 3.5 to 4.4, shield: 4.3, interquartile range: 4.0 to 4.5).Combining low-dose CTPA with breast shields confers additional breast-dose savings without impacting image quality and yields breast doses approaching those of low-dose scintigraphy, suggesting breast shields play a role in protocol optimization for select groups.

Multi-detector computed tomography (MDCT) is superior in fracture detection than conventional radiography; however, dose is increased. Cone-beam computed tomography (CBCT) offers higher spatial resolution and lower dose than MDCT. Manufacturers offer an ultra-low-dose algorithm. This study compares the diagnostic accuracy of the ultra-low-dose CBCT (ULDCBCT) with that of the standard-dose CBCT (SDCBCT). In total, 64 patients were scanned with both the SDCBCT and the ULDCBCT protocols. Both studies were reported by two consultant radiologists with fellowship training in emergency radiology separated in time. The reporter recorded a diagnosis of fracture or normal and diagnostic confidence using a 5-point Likert scale. The gold standard was taken as the SDCBCT. Reporters were blinded to the indication and the SDCBCT report. Cases of discrepancy were resolved by consensus. There were 34 fractures and 30 cases had no fracture. Several fractures were missed using the UDCBCT, and there were also several cases of overdiagnosis. ULD was inferior to SD for fracture diagnosis (p

AIM: To report an audit of the evaluation of suspected, unconfirmed cases of COVID-19 including chest computed tomography (CT), as compared to World Health Organization recommendations. METHODS: A clinical audit was undertaken examining the evaluation of patients with suspected COVID-19 with negative SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) results, with comparison to WHO recommendations. A retrospective chart review was undertaken for 90 patients examining investigations, in particular CT, used to clarify the diagnosis. RESULTS: Ninety patients underwent additional investigation. Seventy-five per cent adherence to WHO recommendations was observed. Fifty-two men (57.78%) and 38 (42.22%) women were investigated, with a median age of 69 years (range 20-96 years). Seventy-nine chest CT examinations demonstrated positive, indeterminate, and negative rates for COVID-19 of 3.79%, 24.1%, and 72.15% respectively. Three patients had discordant swab results with initially negative and subsequently positive results for SARS-CoV-2, resulting in false-negative rates of 5.1% for those retested. Combining discordant RT-PCR swab results, positive radiology, and patients treated as COVID-19-positive due to indeterminate radiology and highly consistent symptoms, resulted in a false-negative rate for initial SARS-CoV-2 RT-PCR swabs of 16.67%. CONCLUSION: Seventy-five per cent compliance with relevant WHO guidance and a false-negative rate for initial swabs of 16.67% was demonstrated. Further evidence is needed to fully determine the utility of chest CT in the diagnosis of COVID-19 in the context of initial false-negative RT-PCR results.

Radiology trainees have an important role to play in advancing more sustainable and environmentally conscious radiology practices through research, education, and local advocacy.

To establish the incidence and define the nature of complications occurring following image-guided musculoskeletal injections at our institution. All patients undergoing image-guided musculoskeletal injection during the study period (16/3/2016 to 24/01/2020) were included. Departmental records were reviewed to identify all patients describing possible complications following injection, what therapy was required (if any) and what the outcome was. No patients were excluded. Complications were classified as minor or major. Injections were categorised as follows: cervical spine, lumbar facet joint, lumbar nerve root, caudal epidural and ‘other’. The complication rate for each individual category of procedure was compared with the combined complication rate for all other categories by constructing contingency tables and using Fisher’s exact test. A total of 8226 patients underwent image-guided musculoskeletal injections within the study period. Exactly 100 patients were identified as having reported a complication, producing an overall complication rate of 1.2%. One complication was categorised as ‘major’, with the patient requiring expedited surgery. The remainder (99 patients) were categorised as having experienced minor complications. The incidence of complications after ‘other’ injections was significantly greater than for other categories of injection (1.86%, p = 0.028). There was no significant difference in the complication rate for cervical spine (0.93%, p = 0.257), lumbar nerve root (0.85%, p = 0.401), lumbar facet joint (0.67%, p = 0.326) or caudal epidural (1.29%, p = 0.687) injections. ‘Other’ injections were subsequently further sub-categorised by anatomical site and imaging modality used. Glenohumeral (2.97%, p = 0.0361) and sacro-iliac (3.51%, p = 0.0498) joint injections were associated with a significantly increased risk of complications. There was no difference in the incidence of complications with fluoroscopic or ultrasound guidance. In conclusion, image-guided musculoskeletal injections are safe and well-tolerated procedures. Complications are rare, occurring in just 1.2% of patients. 99% of complications are minor, either not requiring intervention or resolving with simple supportive treatment.

Currently, there is much variation in the terminology used to describe groin pain in athletes. Several groups have attempted to reach consensus on nomenclature in this area. This article outlines the current status of groin pain nomenclature for the radiologist, highlighting inherent heterogeneity, recent attempts to reach a consensus, the need for a radiological consensus and why imprecise terminology should be avoided when reporting.

Background CTPA is the gold standard investigation for evaluating suspected pulmonary embolism (PE) in the general population however is sometimes considered second line in pregnant and post-partum patients with a normal CXR due to its higher breast dose and the increased radio-sensitivity of breast tissue during this period. Guidelines advocating for scintigraphy over CTPA, however, quote significantly higher breast doses than those achievable with optimised low dose strategies. Defining the radiation dose achievable with a specific low-dose CTPA protocol is therefore imperative. As decreasing dose is associated with increased image noise, demonstrating the image quality and validity of a negative low-dose CTPA in out-ruling PE in this population is necessary. Methods The OPTICA study is a prospective multicentre observational study aiming to validate the clinical utility and safety of an optimised low-dose CTPA protocol in pregnancy. An optimised low-dose CTPA protocol has been agreed across all study sites with equivalent CT capabilities. Pregnant women undergoing CTPA for suspected PE will be included. Independent review of CTPAs by two radiology consultants, image data analysis and 3-month patient follow up will be performed. The primary outcome is the 3-month incidence of VTE in pregnant patients in whom PE was excluded at baseline CTPA. Secondary outcomes will confirm the associated radiation dose and image quality of this protocol. The radiation dose will be calculated using the Monte Carlo method and will include maternal effective, breast and foetal doses. Image quality will be assessed objectively by measuring opacification of the main pulmonary trunk, signal-to-noise and contrast-to-noise ratios and subjectively using a grading scale and inter-reader variability of CTPA results. Conclusion The OPTICA study is the first prospective trial of a low-dose CTPA protocol in the pregnant population. It will provide high-quality evidence defining the achievable dose, image quality and safety of an optimised CTPA for this population. It will assist other institutes with similar CT capabilities in achieving comparable low doses for its patients and provide an evidence base upon which modern CTPA protocols can be appropriately compared to scintigraphy in the pregnant population.

In this paper, we propose a CT imaging algorithm for patients presenting with suspected acute stroke that incorporates automated CT perfusion (CTP) imaging. The algorithm details evaluation of the non-contrast CT (NCCT) for hemorrhage and acute ischemia, calculation of ASPECTS, with performance and interpretation of CTP if appropriate. In particular, we consider the key steps in expeditious interpretation of non-contrast CT and CT angiography in the context of suspected acute ischemic stroke. Given the recent expansion of the "imaging based" treatment window for thrombectomy from 6 to 24 h in the 2018 American Heart Association stroke guidelines, we consider the key criteria in the decision to perform CT perfusion and the patient cohorts in which this might be most helpful. We also describe how imaging findings might be incorporated into the treatment paradigm for suspected with acute ischemic stroke and we allude to some of the most frequently encountered pitfalls associated with CTP which we think will be particularly helpful for radiologists and stroke physicians who are considering adding CT perfusion to their work-up for acute stroke.

Highlights • A patient with a positive chest radiograph had a very high probability (88 %, CI 80–96 %) of having a positive RT-PCR. • This structured approach to chest radiographs in COVID-19 had good interrater reliability with a Fleiss-Cohen-weighted Cohen’s κ of 0.81 (CI 0.78-0.85). • Chest radiographs have a low sensitivity (43 % CI 34–52 %) and a very high specificity (98% CI 96–99 %) in detecting COVID-19., Purpose To date, the majority of chest imaging studies in COVID-19 pneumonia have focused on CT. Evidence for the utility of chest radiographs (CXRs) in this population is less robust. Our objectives were to develop a systematic approach for reporting likelihood of COVID-19 pneumonia on CXRs, to measure the interobserver variability of this approach and to evaluate the diagnostic performance of CXRs compared to real-time reverse transcription polymerase chain reaction (RT-PCR). Method Retrospective review of patients suspected of having COVID-19 pneumonia who attended our emergency department and underwent both CXR and a RT-PCR were included. Two radiologists reviewed the CXRs, blind to the RT-PCR, and classified them according to a structured reporting template with five categories (Characteristic, High Suspicion, Indeterminate, Unlikely and Normal) which we devised. For analysis of diagnostic accuracy, Characteristic and High Suspicion CXRs were considered positive and the remaining categories negative. Concordance between the two assessors was also measured. Results Of 582 patients (51 +/- 20 years), 143/582 (24.6 %) had a positive RT-PCR. The absolute concordance between the two assessors was 71.1 % (414/582) with a Fleiss-Cohen-weighted Cohen’s κ of 0.81 (95 % confidence interval, 0.78-0.85). A patient with a positive CXR had an 88 % (95 % CI 80–96 %) probability of having a positive RT-PCR during a period of high incidence, early in the COVID-19 pandemic. Conclusion Using a structured approach, a positive CXR had a high likelihood of predicting a positive RT-PCR, with good interrater reliability. CXRs can be useful in identifying new cases of COVID-19.

Objectives To investigate the accuracy of Diffusion Weighted Imaging (DWI) using the Readout Segmentation of Long Variable Echo-trains (RESOLVE) sequence in detecting lumbosacral nerve abnormalities. Methods Following institutional ethics committee approval, patients with sciatica-type lower limb radicular symptoms (n = 110) were recruited and prospectively scanned using 3T MRI. Additional participants (n = 17) who underwent neurophysiological testing (EMG/NCV), were also prospectively studied. In addition to routine lumbar spine MRI, a DWI-RESOLVE sequence of the lumbosacral plexus was performed. Two radiologists, blinded to the side of patient symptoms, independently evaluated the MR images. The size and signal intensity changes of the nerves were evaluated using ordinal 4-point Likert-scales. Signal-to-noise ratio (SNR), apparent diffusion coefficient (ADC) and size were measured for affected and normal nerves. Inter-observer agreement was determined with kappa statistics; κ. Results In patients who did not undergo EMG/NCV testing (n = 110), the DWI-RESOLVE sequence detected lumbosacral nerve abnormalities that correlated with symptoms in 36.3% (40/110). This is a similar percentage to patients who underwent EMG/NCV testing, which was positive and correlated with symptoms in 41.2% (7/17). Inter-observer agreement for evaluation of lumbosacral nerve abnormalities was excellent and ranged from 0.87 to 0.94. SNR and nerve size measurements demonstrated statistically significant differences for the L5 and S1 nerves (p value Conclusion The DWI-RESOLVE sequence is a promising new method that may permit accurate detection and localization of lumbar nerve abnormalities in patients with sciatica.

To investigate the impact of parameter optimisation for novel three-dimensional 3D sequences at 1.5T and 3T on resultant image quality.Following institutional review board approval and acquisition of informed consent, MR phantom and knee joint imaging on healthy volunteers (n = 16) was performed with 1.5 and 3T MRI scanners, respectively incorporating 8- and 15-channel phased array knee radiofrequency coils. The MR phantom and healthy volunteers were prospectively scanned over a six-week period. Acquired sequences included standard two-dimensional (2D) turbo spin echo (TSE) and novel three-dimensional (3D) TSE PDW (SPACE) both with and without fat-suppression, and T2∗W gradient echo (TrueFISP) sequences. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured for knee anatomical structures. Two musculoskeletal radiologists evaluated anatomical structure visualisation and image quality. Quantitative and qualitative findings were investigated for differences using Friedman tests. Inter- and intra-observer agreements were determined with κ statistics.Phantom and healthy volunteer images revealed higher SNR for sequences acquired at 3T (p-value0.05). Generally, the qualitative findings ranked images acquired at 3T higher than corresponding images acquired at 1.5T (p 0.05). 3D image data sets demonstrated less sensitivity to partial volume averaging artefact (PVA) compared to 2D sequences. Inter- and intra-observer agreements for evaluation across all sequences ranged from 0.61 to 0.79 and 0.71 to 0.92, respectively.Both 2D and 3D images demonstrated higher image quality at 3T than at 1.5T. Optimised 3D sequences performed better than the standard 2D PDW TSE sequence for contrast resolution between cartilage and joint fluid, with reduced PVA artefact.With rapid advances in MRI scanner technology, including hardware and software, the optimisation of 3D MR pulse sequences to reduce scan time while maintaining image quality, will improve diagnostic accuracy and patient management in musculoskeletal MRI.

Imaging for the diagnosis and follow-up of patients with suspected or confirmed multiple sclerosis is a common scenario for many general radiologists and subspecialty neuroradiologists. The field of MS therapeutics has rapidly evolved with multiple new agents now being used in routine clinical practice. To provide an informed opinion in discussions concerning newer MS agents, radiologists must have a working understanding of the strengths and limitations of the various novel therapies. The role of imaging in MS has advanced beyond monitoring and surveillance of disease activity to include treatment complications. An understanding of the new generation of MS drugs in conjunction with the key role that MR imaging plays in the detection of disease progression, opportunistic infections, and drug-related adverse events is of vital importance to the radiologist and clinical physician alike. Radiologists are in a unique position to detect many of the described complications well in advance of clinical symptoms. Part 1 of this review outlines recent developments in the treatment of MS and discusses the published clinical data on the efficacy and safety of the currently approved and emerging therapies in this condition as they apply to the radiologist. Part 2 will cover pharmacovigilance and the role the neuroradiologist plays in monitoring patients for signs of opportunistic infection and/or disease progression.

Purpose: Patients with acute pulmonary embolism (PE) can quickly deteriorate and the condition has high mortality due to right ventricular (RV) failure. Immediately available predictors of adverse outcome are of major interest to the treating physician in the acute setting. The purpose of the present study was to evaluate if easily attainable measurements of RV function from the diagnostic computed tomography pulmonary angiography (CTPA) provide information for fast risk stratification in patients with acute PE. Methods: We retrospectively evaluated images from CTPA in 261 patients (age median 60 years, 50% females) enrolled in a prospective study. RV and left ventricular (LV) diameters and their ratio, the presence of septal bowing, contrast reflux in the inferior vena cava, and the diameter of the central pulmonary arteries (PA) were measured. The composite outcome was 5-day severe adverse events including death, acute decompensation, or need for emergent treatment. We used Wilcoxon rank sum test and Fischer’s exact test to test between groups and multivariate logistic regression for prediction. Results: In multivariate analysis, increased diameter of the main PA (OR = 1.08 per 1 mm increase, p = 0.047) and the presence of septal bowing (OR = 2.23, p = 0.055) were associated with severe adverse events. RV/LV > 1 did not predict severe outcomes (OR = 0.73, p = 0.541). Conclusions: Two easily attainable parameters of RV function on CTPA, septal bowing and main PA diameter, are associated with short-term adverse outcomes in patients with acute PE. Further study is required to determine whether these findings can be incorporated into clinical treatment algorithms. Purpose Patients with acute pulmonary embolism (PE) can quickly deteriorate and the condition has high mortality due to right ventricular (RV) failure. Immediately available predictors of adverse outcome are of major interest to the treating physician in the acute setting. The purpose of the present study was to evaluate if easily attainable measurements of RV function from the diagnostic computed tomography pulmonary angiography (CTPA) provide information for fast risk stratification in patients with acute PE. Methods We retrospectively evaluated images from CTPA in 261 patients (age median 60 years, 50% females) enrolled in a prospective study. RV and left ventricular (LV) diameters and their ratio, the presence of septal bowing, contrast reflux in the inferior vena cava, and the diameter of the central pulmonary arteries (PA) were measured. The composite outcome was 5-day severe adverse events including death, acute decompensation, or need for emergent treatment. We used Wilcoxon rank sum test and Fischer’s exact test to test between groups and multivariate logistic regression for prediction. Results In multivariate analysis, increased diameter of the main PA (OR = 1.08 per 1 mm increase, p = 0.047) and the presence of septal bowing (OR = 2.23, p = 0.055) were associated with severe adverse events. RV/LV > 1 did not predict severe outcomes (OR = 0.73, p = 0.541). Conclusions Two easily attainable parameters of RV function on CTPA, septal bowing and main PA diameter, are associated with short-term adverse outcomes in patients with acute PE. Further study is required to determine whether these findings can be incorporated into clinical treatment algorithms.

To qualitatively assess the legibility of radiopaque patient identification stickers and their effect on image quality. These stickers are intended for use as a part of a patient registration and identification pack utilized in a mass casualty incident (MCI), to prevent errors in correlating patients with their diagnostic imaging and reports. Four different prototype designs of stickers with radiopaque identification numbers which are legible on radiographs and CT were created. These were affixed to head and thorax phantoms and scanned using standard imaging protocols. Images were reviewed qualitatively for legibility and the presence of image degradation due to the radiopaque sticker materials using Likert scales by four radiologists and four emergency physicians. All four prototypes were confidently legible on forehead, shoulder and sternum on CT on topogram and reconstructed images. Sticker positioning over the temple resulted in unreliable legibility on topogram. All prototypes were confidently legible on shoulder and sternum on CT and radiographs. Significant image degradation was reported on radiographs with sticker position over the sternum. The preferred anatomic position was the forehead. In a mass casualty incident, radiopaque patient identification stickers affixed to injured patients may help to ensure confidence in the correlation between patients and their imaging. Tested prototypes were found to be easily legible without substantial degradation of image quality. Preferred anatomical position and construction material was established. Consideration should be given to addition of such radiographic identity aides to MCI patient registration packs.

Background Ambulatory management of isolated acute deep venous thrombosis (DVT) is the recommended standard of care in selected populations. However, in practice a significant number of patients continue to be managed as in-patients. Objectives In this study we aimed to evaluate acute DVT treatment pathways in our emergency department (ED) in practice and to identify barriers to outpatient management. Methods This study was a cross-sectional analysis of prospectively collected data pertaining to consecutive patients presenting to the ED of a large, city center, academic teaching hospital over a 46 week period who were diagnosed with DVT. Results Implementation of an outpatient care pathway led to the majority of patients presenting with DVT in our institution being treated without hospital admission. Forty percent (31/78) of patients with DVT were treated with a direct oral anticoagulant (DOAC) as an outpatient in line with international best practice guidelines. Conclusion The study provides a clear picture of the clinical profile and management of patients in clinical practice. Due to the lack of resources and supported infrastructure it is difficult to effectively implement outpatient venous thromboembolism (VTE) management to its full potential. Directing resources towards strategies which facilitate outpatient DVT treatment among vulnerable patient groups could represent a means of reducing hospital admissions for DVT in urban centers. Our study highlights the success and clinical limitations of the outpatient treatment model, which should become standard as part of wider VTE care.

Fractures of the trapezium are rarely diagnosed on plain radiographs after acute wrist trauma. High-resolution cross-sectional imaging identifies fractures of the trapezium as the most common radiographically occult carpal bone fracture. We review the fracture frequency, mechanisms and patterns of trapezium fractures. Cone beam CT was performed in patients with suspected radiographically occult radiocarpal fracture following acute injury. The frequency of carpal bone fractures was assessed and compared. Ninety-three radiographically occult wrist fractures were identified in 166 patients with acute trauma and negative radiographs. The trapezium was the most frequently fractured carpal bone, making up 20.4% of wrist fractures. Seventy-nine percent of trapezium fractures involved the volar ridge. The scaphoid was the clinically suspected fractured bone at initial assessment in 84% of patients with trapezium fractures. Fractures of the trapezium in acute wrist trauma are much more common than described in the literature. If initial radiographs are negative, a fracture of the trapezium is more likely to be present than one of the scaphoid, despite high levels of clinical suspicion for scaphoid injuries. Awareness of the types and mechanisms of trapezium fracture is important. Cross-sectional imaging should be considered in all cases of post-traumatic wrist pain with negative radiographs.

Computed tomography pulmonary angiogram (CTPA) provides a volumetric assessment of clot burden in acute pulmonary embolism (PE). However, it is unclear if clot burden is associated with right-sided heart strain (RHS) or adverse clinical events (ACE). We prospectively enrolled Emergency Department patients with PE (in CTPA) from 2008 to 2011. We assigned 1 to 9 points as clot burden score, based on whether emboli were saddle, central, lobar, segmental, and subsegmental. We evaluated a novel score (the "CT-PASS") based on the sum (in millimeters) of the largest filling defects in the right and left pulmonary vasculature. Our primary outcome was RHS, defined by imaging (echocardiography or CTPA) or cardiac biomarkers. Our secondary outcomes included 5-day ACE. We included 271 patients (50% women), with a mean age of 59 ± 17 years. Based on CTPA, 131 patients (48%) had central PE (clot burden score ≥5 points). The median CT-PASS was 9.1 mm (interquartile range 4.9 to 16.4). In univariate analysis, higher clot burden (highest quartile CT-PASS) was associated with RHS (p = 0.003). In multivariate analysis, after adjusting for RHS, age, and gender, central PE (odds ratio [OR] 2.92, 95% confidence interval [CI] 1.10 to 7.81) and CT-PASS20 mm (OR 3.54, 95% CI 1.39 to 8.97) were significantly associated with ACE. However, this association of central PE with ACE was not statistically significant after excluding patients with shock index1 (OR 2.56, 95% CI 0.62 to 10.64). In conclusion, highest quartile CT-PASS was associated with RHS and central PE and ACE, but this association was not statistically significant in hemodynamically stable PE [corrected].

OBJECTIVE. Spinal injections are common pain management procedures using corticosteroids and local anesthetics. Most corticosteroid preparations are particulate suspensions, such as methylprednisolone acetate and triamcinolone acetonide. In the cervical spine, particulate corticosteroids have been linked to catastrophic complications, including blindness, paralysis, and death. Serious neurologic injuries have also been reported at the thoracic, lumbar, and sacral levels. CONCLUSION. Nonparticulate preparations, such as dexamethasone, are safer but have shorter-lived antiinflammatory effects. Local anesthetics are often mixed with corticosteroids in pain management procedures. Although everyday risks are minimal, injection techniques should take into account neural and cardiac toxicities. In this article, we discuss the potential for serious adverse events associated with injected medications. We review the current literature to make conclusions on medication combinations that balance safety and efficacy.

There has been a year on year increase in imaging requests at our academic institution. The iRefer guidelines are produced by the Royal College of Radiologists in the UK and are designed to prevent inappropriate imaging and radiation exposure. They have been available to general practitioners and hospital physicians in Ireland since March 2015. Our aims were to determine the proportion of inappropriate imaging referrals pre- and post-guideline introduction and to calculate the cost and dose estimates for inappropriate scans. A retrospective review of 1124 radiographs was performed with reference to a validated audit template. Emergency department, in-patient, and general practitioner referrals were reviewed. Cost and cumulative dose estimates were calculated for inappropriate referrals taking into account salaries, average time spent performing/reporting radiographs, and median effective dose values. The introduction of the iRefer guidelines has not significantly affected the proportion of inappropriate radiograph referrals at our institution, 42% pre-introduction and 43% post-introduction. We identified 784 inappropriate referrals across 6 radiograph subtypes, imparting a total median effective dose of 65.1 mSv to patients. The time spent performing inappropriate abdominal and spinal radiographs in 2017 yielded an estimated cost of €8036.40. A significant amount of inappropriate radiographs continue to be requested and performed, exposing patients to needless ionizing radiation and wasting staff members time at a financial cost. Interventions are needed to decrease inappropriate referrals.

To assess the benefits and complications of developing a practice of single-stage primary ureteral stenting in a university hospital. A practice change developed from the traditional practice of multi-stage stenting to single-episode stent placement. To evaluate this change of practice, we retrospectively analysed data of 70 patients who underwent primary tubeless antegrade ureteric stenting and compared this group to the previous 54 patients who had a covering nephrostomy. There was an overall success rate of 91.3% (85/93 stents having had tubeless antegrade stenting). There were no major and 33 minor complications. The comparative group of 54 patients whose stents had a covering nephrostomy had a median length of stay of 13.2 days compared to 7.4 days for the tubeless group. Single-stage primary ureteric stenting is a safe practice to employ and has universal benefits for both the patient and the health service.

Purpose The study sought to determine the frequency of nonthromboembolic imaging abnormalities in pregnant women referred for computed tomography pulmonary arteriography (CTPA). Materials and Methods CTPA studies on 100 consecutive pregnant women performed over a 5-year period were reviewed independently by 2 radiologists, with conflicts resolved by consensus. Age range was 18-43 years (mean 28 years). The presence or absence of pulmonary embolism and of nonthromboembolic imaging abnormalities was recorded. These were graded as A if the abnormalities were thought to provide potential alternative explanations for acute symptoms, B if findings were incidental that required clinical or radiologic follow-up, and C if the findings did not require further action. Results Pulmonary embolism was seen in 5 women. In 2 of these additional findings of consolidation and infarction were seen. Ninety-five women did not have pulmonary embolism. Eleven women (12%) had grade A abnormalities; 6 cases of consolidation, 2 cases of lobar collapse, and 3 cases of heart failure with pleural effusions. One woman had a grade B abnormality due to the presence of pulmonary nodules. Ten women had incidental grade C abnormalities. Conclusion Pulmonary embolism occurs in 5% of pregnant women referred for CTPA. In pregnant women without embolism on CTPA, potential alternative causes for patient symptoms are seen on CT in 12% of cases.

To describe and evaluate a novel technical development to improve detection of intracranial vessel occlusions using multiphase CT angiography (MPCTA). The institutional ethics committee approved the study. Fifty patients (30 consecutive distal (M2 or smaller) anterior circulation occlusions, ten M1 occlusions, ten cases without occlusion) presenting with suspected AIS who underwent MPCTA were included. Post-processing of MPCTA studies created “subtraction” and “delayed enhancement” (DE) datasets. Initially, non-contrast CT and MPCTA studies for each patient were evaluated. Readers' confidence, speed and sensitivity of detection of intracranial vessel occlusions were recorded. After an interval of at least 4 weeks, readers were provided with post-processed images and studies were re-evaluated. While the sensitivity of detection of intracranial vessel occlusions was equal for both conventional MPCTA and subMPCTA, the mean time taken to identify a vessel occlusion decreased by 64 % using subMPCTA (16 s vs. 45 s with conventional MPCTA) (p

An understanding of the new generation of MS drugs in conjunction with the key role MR imaging plays in the detection of disease progression, opportunistic infections, and drug-related adverse effects is of vital importance to the neuroradiologist. Part 1 of this review outlined the current treatment options available for MS and examined the mechanisms of action of the various medications. It also covered specific complications associated with each form of therapy. Part 2, in turn deals with the subject of pharmacovigilance and the optimal frequency of MRI monitoring for each individual patient, depending on his or her unique risk profile. Special attention is given to the diagnosing of progressive multifocal leukoencephalopathy in patients treated with natalizumab as this is a key area in which neuroradiologists can contribute to improved patient outcomes. This article also outlines the aims of treatment and reviews the possibility of "no evidence of disease activity" becoming a treatment goal with the availability of more effective therapies. Potential future areas and technologies including image subtraction, brain volume measurement and advanced imaging techniques such as double inversion recovery are also reviewed. It is anticipated that such advancements in this rapidly developing field will improve the accuracy of monitoring an individual patient's response to treatment.

BACKGROUND AND PURPOSE: Multiphase CTA, a technique to dynamically assess the vasculature in acute ischemic stroke, was primarily developed to evaluate collateral filling. We have observed that it is also useful in identifying distal anterior circulation occlusions due to delayed anterior circulation opacification on multiphase CTA, an observation we term the “delayed vessel sign.” We aimed to determine the usefulness of this sign by comparing multiphase CTA with single-phase CTA. MATERIALS AND METHODS: All 23 distal anterior circulation occlusions during a 2-year period were included. Ten M1-segment occlusions and 10 cases without a vessel occlusion were also included. All patients had follow-up imaging confirming the diagnosis. Initially, the noncontrast CT and first phase of the multiphase CTA study for each patient were blindly evaluated (2 neuroradiologists, 2 radiology trainees) for an anterior circulation occlusion. Readers' confidence, speed, and sensitivity of detection were recorded. Readers were then educated on the “delayed vessel sign,” and each multiphase CTA study was re-examined for a vessel occlusion after at least 14 days. RESULTS: There was significant improvement in the sensitivity of detection of distal anterior circulation vessel occlusions (P < .001), overall confidence (P < .001), and time taken to interpret (P < .001) with multiphase CTA compared with single-phase CTA. Readers preferred MIP images compared with source images in >90% of cases. CONCLUSIONS: The delayed vessel sign is a reliable indicator of anterior circulation vessel occlusion, particularly in cases involving distal branches. Assessment of the later phases of multiphase CTA for the delayed vessel sign leads to a significant improvement in the speed and confidence of interpretation, compared with single-phase CTA.

Objective: The “delayed vessel sign” refers to the presence of relative unilateral delayed enhancement of a vessel or vessels in the anterior circulation on delayed phases of a multiphase CTA (MPCTA) distal to the point of vessel occlusion. We aimed to determine if educating radiologists on the “delayed vessel sign” would improve sensitivity, confidence and speed in the detection of distal anterior circulation vessel occlusions in the suspected stroke patient. Methods: Non-contrast CT (NCCT) and MPCTA studies of 53 individual patients, who presented with signs/symptoms of acute anterior circulation stroke, were retrospectively selected by an independent radiologist. 15 cases without a vessel occlusion, 15 cases with a M1 occlusion and 23 cases with a distal anterior circulation (A2/M2/M3) occlusion were included. Initially, NCCT and single phase CTA (SPCTA) studies were independently interpreted by four observers (two neuroradiologists, two radiology trainees) and observers’ confidence (scale 1-5), speed and sensitivity of detection were recorded. Observers were then educated on the “delayed vessel sign” and each study was re-examined after an interval of at least 14 days. Results: There was a significant improvement in the sensitivity of detection of distal anterior circulation vessel occlusions on MPCTA compared to SPCTA (p=0.0003) and this was also true for M1 occlusions (p=0.045). Overall confidence was 4.0 for SPCTA and 4.88 with MPCTA (p Conclusion: The “delayed vessel sign” is a reliable indicator of ipsilateral vessel occlusion, and is particularly useful in cases involving distal MCA branches where the occlusion is not easily identified on the initial angiographic phase. We have found this sign facilitates the rapid on-table confirmation of acute ischemic stroke, even when small vessels are involved and the clinical diagnosis is uncertain.

Several factors have been associated with mortality in the months after PE. Factors associated with short-term clinical deterioration or need for hospital-based intervention are less well known.We prospectively enrolled consecutive emergency department patients with PE and recorded clinical, biomarker and radiographic data. We assessed hospitalised patients daily to identify clinical deterioration or need for hospital-based intervention for 5 days after PE. We captured postdischarge events via 5-day and 30-day interviews. We used univariate and multivariable models to assess associations with clinical deterioration, severe clinical deterioration and 30-day all-cause mortality. We also assessed the test characteristics of three published clinical decision rules.We enrolled 298 patients with PE: mean age 59 (SD±17) years; 152 (51%) male and 268 (90%) white race. 101 (34%) patients clinically deteriorated or required a hospital-based intervention within 5 days, and 197 (66%) did not. 27 (9%) patients suffered severe clinical deterioration and 12 died within 30 days. Factors independently associated with clinical deterioration were hypotension (p=0.001), hypoxia (p0.001), coronary disease (p=0.004), residual deep vein thrombosis (p=0.006) and right heart strain on echocardiogram (p0.001). In contrast, factors associated with 30-day all-cause mortality were active malignancy (p0.001) and congestive heart failure (p=0.009). The sensitivity of clinical decision rules was moderate (39-80%) for 5-day clinical deterioration but higher (67-100%) for 30-day mortality.Most patients do not clinically deteriorate after PE diagnosis. Several factors are associated with short-term clinical deterioration, but these factors differ from those associated with 30-day mortality.

To investigate optimised isotropic 3D turbo spin echo (TSE) and gradient echo (GRE)-based pulse sequences for visualisation of articular cartilage lesions within the knee joint. Optimisation of experimental imaging sequences was completed using healthy volunteers (n=16) with a 3-Tesla (3T) MRI scanner. Imaging of patients with knee cartilage abnormalities (n=57) was then performed. Acquired sequences included 3D proton density-weighted (PDW) TSE (SPACE) with and without fat-suppression (FS), and T2*W GRE (TrueFISP) sequences, with acquisition times of 6:51, 6:32 and 5:35 min, respectively. One hundred sixty-one confirmed cartilage lesions were detected and categorised (Grade II n=90, Grade III n=71). The highest sensitivity and specificity for detecting cartilage lesions were obtained with TrueFISP with values of 84.7% and 92%, respectively. Cartilage SNR mean for PDW SPACE-FS was the highest at 72.2. TrueFISP attained the highest CNR means for joint fluid/cartilage (101.5) and joint fluid/ligament (156.5), and the lowest CNR for cartilage/meniscus (48.5). Significant differences were identified across the three sequences for all anatomical structures with respect to SNR and CNR findings (p-value

Keywords: caudate and putamen; collapsin response mediator protein 5 (CRMP5); 18-fluorodeoxyglucose positron emission tomography (18FDG PET) brain; paraneoplastic Parkinsonism

BACKGROUND AND PURPOSE: Transforaminal CS injections have been associated with severe adverse CNS events, including brain and spinal cord infarction. Our purpose was to describe the static and dynamic microscopic appearances of CS preparations, with an emphasis on their potential to cause adverse central nervous system events by embolic mechanisms during transforaminal injection. MATERIALS AND METHODS: Pharmaceutical preparations of nondilute injectable CSs were used after appropriate mixing: MPA (40 mg/mL), TA (40 mg/mL), and DSP (8 mg/2 mL). For dynamic imaging, a novel methodology was devised to replicate the flow of crystals within spinal cord arterioles. In addition, CS preparations were mixed with plasma to assess for changes in crystal size, morphology, and tendency to aggregate. RESULTS: The CS preparations MPA and TA are composed of crystals of varying sizes. MPA crystal size range was 0.4–26 μm (mean, 6.94 μm), TA crystal size range 0.5–110 μm (mean, 17.4 μm), and DSP did not contain any significant crystals or particles. There was no change in the crystal morphology or propensity to aggregate after mixing with local anesthetic. After mixing with plasma, the crystals also were unchanged; however, there was a significant reduction in the size of aggregates. On dynamic imaging, these aggregates were proved to maintain their integrity and to act as potential embolization agents. CONCLUSIONS: MPA and TA have a substantial risk of causing infarction by embolization if inadvertently injected intra-arterially at the time of TFESI. DSP is completely soluble and microscopically has no potential to obstruct arterioles. When performing cervical TFESI procedures, the administration of insoluble CSs should be avoided.

This article reviews the potential use of a combination of whole-body imaging and targeted contrast agents in improving diagnostics, with a particular focus on oncology imaging. It looks at the rationale for nanoparticles and their development as targeted contrast agents. It subsequently describes many of the advances made thus far in developing tissue-specific contrast agents capable of targeting tumors that combined with whole-body imaging may enable superior cancer detection and characterization.

Molecular imaging has the potential to transform the field of diagnostic imaging through enabling far more detailed investigation and characterisation of disease processes than is currently possible. Magnetic resonance imaging (MRI) is capable of three-dimensional non-invasive imaging of opaque tissues at near cellular resolution. Among the imaging techniques available today, MRI has, perhaps, the greatest potential to exploit the possibilities that molecular imaging presents. Nanoparticles are the focus of intense research, due to a wide variety of potential applications in the biomedical, optical, and electronic fields. In this article we examine the progress made in the development of nanoparticles as targeted contrast agents for molecular magnetic resonance imaging. In particular, we will examine the potential of antibody-targeted liposomes (immunoliposomes) as vehicles for delivering MRI contrast agents to cellular biomarkers, thus enabling visualisation of structures and processes at the molecular level. We will address some of the challenges that must be faced by researchers in this field before the progress made in the laboratory can be translated into improved clinical diagnostics and therapeutics.

Groin pain is a commonly encountered problem in musculoskeletal radiology. The diagnosis can be difficult to establish, based on the complex interconnected anatomy at the pubic symphysis and surrounding structures. The differential diagnosis is therefore broad, and diagnostic imaging is crucial in reaching the correct diagnosis, thus allowing appropriate therapy to be instituted. This article reviews the relevant anatomy and differential diagnoses encountered in overuse injuries of the groin. The common mechanisms of injury, presenting symptoms, and imaging findings for each diagnosis are addressed.

Corticosteroids and local anesthetics are some of the most commonly administered medications in radiology departments. These medications have marked variability in their formulations, which may increase their adverse event profile for specific procedures. In particular, certain corticosteroid preparations are associated with adverse central nervous system (CNS) sequelae. This is most likely due to distal embolization by particulate formulations. Nonparticulate steroid formulations are not associated with such events. Local anesthetics have severe CNS and cardiac adverse effects if injected intravascularly and have recently been associated with intraarticular chondrolysis if used in large doses. This review discusses these medications with particular emphasis on their established and postulated adverse effects. The administering radiologist should be aware of these potential effects and how best to reduce their occurrence.

Aim To evaluate the efficacy of ultrasound-guided percutaneous drainage of symptomatic meniscal cysts. Materials and methods Patients with lateral knee joint tenderness and swelling and confirmed meniscal cyst on magnetic resonance imaging (MRI) were consecutively enrolled for ultrasound-guided percutaneous cyst aspiration. Cysts were injected with local anaesthetic and steroid before completion of procedure. All 18 patients (all male, average age 33 years) were subsequently followed up (average time 10 months) and meniscal cyst symptoms assessed by questionnaire. Fischer's exact test used to analyse the data. Results In every case the procedure was well tolerated, and each patient indicated that they would be willing to have a repeat procedure in the future. Ten patients reported complete resolution of symptoms secondary to therapeutic cyst aspiration and had resumed participation in high-performance sport. Two patients reported a satisfactory sustained response, reporting only occasional “twinges of pain”. In the remaining six patients, symptoms returned after an initial pain-free period. The pain-free period ranged from 1–8 weeks. In this study, patient outcome did not significantly correlate with any meniscal cyst characteristic. Conclusion Ultrasound-guided percutaneous aspiration of meniscal cysts is a well-tolerated, simple, and safe procedure. In this small patient series, it was associated with positive early results with favourable outcomes in the mid to long-term. It should be considered in patients unsuitable for surgical debridement or as an interim therapy if surgery is delayed or postponed.

A 56-year-old man presented with an 8-month history of lower back pain radiating down the posterior aspect of the thighs bilaterally and a 5-month history of perianal paresthesia. These symptoms markedly increased in severity 1 day before admission and were associated with difficulty passing urine. Examination revealed reduced sensation in an S2–S4 distribution. Magnetic resonance imaging of the spine showed a T1 hypointense (Fig. 1), T2 hyperintense (Fig. 2) central mass within the sacral anterior epidural space which was eroding into the posterior aspect of the S1, S2, and S3 vertebral bodies and causing severe stenosis of the S1 and S2 sacral foramina bilaterally. Further to these investigations, a biopsy was conducted under computed tomography guidance. The histologic diagnosis was chordoma. This patient

To prospectively evaluate a dedicated extremity cone-beam CT (CBCT) scanner in cases with and without orthopedic hardware by (1) comparing its imaging duration and image quality to those of radiography and multidetector CT (MDCT) and (2) comparing its radiation dose to that of MDCT. Written informed consent was obtained for all subjects for this IRB-approved, HIPAA-compliant study. Fifty subjects with (1) fracture of small bones, (2) suspected intraarticular fracture, (3) fracture at the site of complex anatomy, or (4) a surgical site difficult to assess with radiography alone were recruited and scanned on an extremity CBCT scanner prior to FDA approval. Same-day radiographs were performed in all subjects. Some subjects also underwent MDCT within 1 month of CBCT. Imaging duration and image quality were compared between CBCT and radiographs. Imaging duration, effective radiation dose, and image quality were compared between CBCT and MDCT. Fifty-one CBCT scans were performed in 50 subjects. Average imaging duration was shorter for CBCT than radiographs (4.5 min vs. 6.6 min, P = 0.001, n = 51) and MDCT (7.6 min vs. 10.9 min, P = 0.01, n = 7). Average estimated effective radiation dose was less for CBCT than MDCT (0.04 mSv vs. 0.13 mSv, P = 0.02, n = 7). CBCT images yielded more diagnostic information than radiographs in 23/51 cases and more diagnostic information than MDCT in 1/7 cases, although radiographs were superior for detecting hardware complications. CBCT performs high-resolution imaging of the extremities using less imaging time than radiographs and MDCT and lower radiation dose than MDCT.

CT Pulmonary Angiogram (CTPA) provides a volumetric assessment of clot burden associated with acute pulmonary embolism (PE). However, it is unclear if clot burden is associated with right heart strain (RHS) or clinical deterioration. We prospectively enrolled Emergency Department patients with PE

The glenohumeral joint enables tremendous range of motion at the expense of stability. Functional stability is maintained by the synchronous coordination of complex static and dynamic structures. Symptomatic glenohumeral instability most often results from injury to the inferior labral-ligamentous complex, the primary passive stabilizer of the shoulder. This article reviews the structures important in glenohumeral stabilization and illustrates their normal appearances and the abnormalities associated with anterior, posterior, and multidirectional instability. These lesions are discussed in the context of therapeutic decision making.

To demonstrate incidental findings and scoliosis on whole-body MRI (WBMRI) in patients with neurofibromatosis type 1 and 2 (NF1NF2, respectively), and schwannomatosis.Institutional review board approval and written informed consent were obtained for this prospective HIPAA-compliant study. A total of 247 subjects (141 with NF1, 55 with NF2, 51 with schwannomatosis; 132 women (53.5%); mean age, 41 years, range, 18-97 years) underwent WBMRI using coronal STIR (TR/TE: 4190/111 ms, TI: 150 ms) and T1-weighted images (TR/TE: 454/10 ms), 10-mm slice thickness, imaging time ~40 min. Images were reviewed for the presence of incidental findings, outside of nerve sheath tumors. The presence of scoliosis was recorded and curve morphology was assessed and quantified.Incidental findings other than scoliosis were recorded in 104/247 (42%) patients, most often affecting the musculoskeletal system (65/247 patients, 26%). We found 16/247 (6.5%) significant incidental findings likely to affect clinical management, including avascular necrosis of bone in eight patients (five with NF2), eight insufficiency fractures, and four non-neurogenic neoplasms (Hodgkin's lymphoma, liposarcoma, dermoid cyst, large uterine myoma requiring excision). Scoliosis was seen in 50/247 patients (20%), including 8/55 with NF2 (15%) and 11/51 with schwannomatosis (22%).Incidental findings in the neurofibromatoses frequently involve the skeleton. Given the relatively high incidence of unsuspected osteonecrosis and stress fractures, close attention to the skeleton on WBMRI is advised. In addition, knowledge of common incidental findings can help clinicians prepare patients who undergo WBMRI for potential unexpected findings.