Quiz case: a clinical reasoning challenge in the emergency stroke setting.

A right-handed woman in her 80s was admitted to the emergency department 1 h after sudden-onset global aphasia and right-sided hemiparesis. Medical history included arterial hypertension, dyslipidemia, hyperuricemia, aortic stenosis, osteoporosis, and recent pulmonary embolism. Medication consisted of apixaban, bisoprolol, hydrochlorothiazide, allopurinol, fenofibrate, and vitamin D. Vital parameters (blood pressure, heart rate, body temperature, oxygen saturation) and glycemia were all within normal range. Electrocardiogram showed a first-degree atrioventricular block. The patient was promptly transported to the emergency computed tomography (CT) scanner. Non-contrast brain CT revealed a unilateral hyperdensity in the left caudate and lentiform nuclei. No other intracranial lesion was visualized. Laboratory studies were not yet available at the time of imaging. What is your diagnosis?

The practice of emergency radiology throughout Europe: a survey from the European Society of Emergency Radiology on volume, staffing, equipment, and scheduling.

OBJECTIVES: To obtain information from radiology departments throughout Europe regarding the practice of emergency radiology METHODS: A survey which comprised of 24 questions was developed and made available online. The questionnaire was sent to 1097 chairs of radiology departments throughout Europe using the ESR database. All data were collected and analyzed using IBM SPSS Statistics software, version 20 (IBM). RESULTS: A total of 1097 radiologists were asked to participate, 109 responded to our survey. The response rate was 10%. From our survey, 71.6% of the hospitals had more than 500 beds. Ninety-eight percent of hospitals have an active teaching affiliation. In large trauma centers, emergency radiology was considered a dedicated section. Fifty-three percent of institutions have dedicated emergency radiology sections. Less than 30% had all imaging modalities available. Seventy-nine percent of institutions have 24/7 coverage by staff radiologists. Emergency radiologists interpret cross-sectional body imaging, US scans, and basic CT/MRI neuroimaging in more than 50% of responding institutions. Cardiac imaging examinations/procedures are usually performed by cardiologist in 53% of institutions, while non-cardiac vascular procedures are largely performed and interpreted by interventional radiologists. Most people consider the European Diploma in Emergency Radiology an essential tool to advance the education and the dissemination of information within the specialty of emergency radiology. CONCLUSION: Emergency radiologists have an active role in the emergency medical team. Indeed, based upon our survey, they have to interact with emergency physicians and surgeons in the management of critically ill patients. A broad skillset from ultrasonography and basic neuroimaging is required. KEY POINTS: • At most major trauma centers in Europe, emergency imaging is currently performed by all radiologists in specific units who are designated in the emergency department. • Radiologists in the emergency section at present have a broad skillset, which includes cross-sectional body imaging, ultrasonography, and basic neuroimaging of the brain and spine. • A dedicated curriculum that certifies a subspecialty in emergency radiology with a diploma offered by the European Society of Emergency Radiology demonstrates a great interest by the vast majority of the respondents.

Treatment of a mycotic abdominal aortic aneurysm with the jailing technique.

PURPOSE: We explored an innovative technique in treating mycotic aortic aneurysms. CASE REPORT: A patient presenting with severe back pain, vague abdominal pain, weight loss and decline in general health, was diagnosed with a contained-rupture of a suprarenal mycotic aortic aneurysm, as a complication of spondylodiscitis. Since the patient's health condition was too poor to perform an open aortic repair, we choose an alternative treatment option by coiling the aneurysm with the jailing technique. CONCLUSION: We observed a good clinical outcome.

Dedicated sub 0.1 mSv 3DCT using MBIR in children with suspected craniosynostosis: quality assessment.

OBJECTIVE: To retrospectively compare image quality of a lowered dose CT protocol to a standard CT protocol in children with suspicion of craniosynostosis. METHODS: Forty-eight patients (age 0- 35 months), who presented with a cranial deformity underwent cranial 3D CT to assess sutural patency: between 2009 - 2010, 24 patients were imaged with a standard protocol (CTDIvol 32.18 mGy), from 2011-2012, 24 underwent a low dose protocol (0.94 mGy) combined with iterative reconstruction. Image quality was evaluated by both expert reading and objective analysis. Differences were assessed by independent t-test and Mann-Whitney U test, interreader agreement by Cohen's Kappa test. RESULTS: Effective dose of the low dose protocol was 0.08 mSv, corresponding to a reduction of 97 %. Image quality was similar in both groups in terms of overall diagnostic acceptability, objective noise measurements, subjective cranial bone edge sharpness and presence of artefacts. For objective sharpness of cranial bone-brain interface and subjective perception of noise, the images of the low dose protocol were superior. For all evaluated structures, interreader agreement was moderate to almost perfect. CONCLUSION: In the diagnosis of craniosynostosis in children with cranial deformities, a dedicated sub 0.1 mSv cranial 3DCT protocol can be used without loss in image quality. KEY POINTS: 3DCT is used for the diagnosis of craniosynostosis. Imaging protocols should be optimized to minimize radiation exposure to children. Combining 80 kVp with iterative reconstruction can help to reduce dose. A sub 0.1 mSv cranial 3DCT protocol can be used without loss of diagnostic quality.

Development and Pilot Testing of 24/7 In-Ambulance Telemedicine for Acute Stroke: Prehospital Stroke Study at the Universitair Ziekenhuis Brussel-Project.

BACKGROUND: In-ambulance telemedicine is a recently developed and a promising approach to improve emergency care. We implemented the first ever 24/7 in-ambulance telemedicine service for acute stroke. We report on our experiences with the development and pilot testing of the Prehospital Stroke Study at the Universitair Ziekenhuis Brussel (PreSSUB) to facilitate a wider spread of the knowledge regarding this technique. METHODS: Successful execution of the project involved the development and validation of a novel stroke scale, design and creation of specific hardware and software solutions, execution of field tests for mobile internet connectivity, design of new care processes and information flows, recurrent training of all professional caregivers involved in acute stroke management, extensive testing on healthy volunteers, organisation of a 24/7 teleconsultation service by trained stroke experts and 24/7 technical support, and resolution of several legal issues. RESULTS: In all, it took 41 months of research and development to confirm the safety, technical feasibility, reliability, and user acceptance of the PreSSUB approach. Stroke-specific key information can be collected safely and reliably before and during ambulance transportation and can adequately be communicated with the inhospital team awaiting the patient. CONCLUSION: This paper portrays the key steps required and the lessons learned for successful implementation of a 24/7 expert telemedicine service supporting patients with acute stroke during ambulance transportation to the hospital.

Contrast agent and radiation dose reduction in abdominal CT by a combination of low tube voltage and advanced image reconstruction algorithms.

OBJECTIVES: To assess image quality in abdominal CT at low tube voltage combined with two types of iterative reconstruction (IR) at four reduced contrast agent dose levels. METHODS: Minipigs were scanned with standard 320 mg I/mL contrast concentration at 120 kVp, and with reduced formulations of 120, 170, 220 and 270 mg I/mL at 80 kVp with IR. Image quality was assessed by CT value, dose normalized contrast and signal to noise ratio (CNRD and SNRD) in the arterial and venous phases. Qualitative analysis was included by expert reading. RESULTS: Protocols with 170 mg I/mL or higher showed equal or superior CT values: aorta (278-468 HU versus 314 HU); portal vein (205-273 HU versus 208 HU); liver parenchyma (122-146 HU versus 115 HU). In the aorta, all 170 mg I/mL protocols or higher yielded equal or superior CNRD (15.0-28.0 versus 13.7). In liver parenchyma, all study protocols resulted in higher SNRDs. Radiation dose could be reduced from standard CTDIvol = 7.8 mGy (6.2 mSv) to 7.6 mGy (5.2 mSv) with 170 mg I/mL. CONCLUSION: Combining 80 kVp with IR allows at least a 47 % contrast agent dose reduction and 16 % radiation dose reduction for images of comparable quality. KEY POINTS: • There is a balance between image quality, contrast dose and radiation dose. • Iterative reconstruction has a major, positive impact on this balance. • Both contrast dose and radiation dose can be reduced in abdominal CT. • The trade-off can be quantitatively described by a 3D model. • Contrast and radiation dose can be tailored according to specific safety concerns.

Body packing: a review of general background, clinical and imaging aspects.

To avoid detection at border crossings or airport customs, drug trafficking is increasingly performed by intra-corporeal concealment. Body packers may ingest packets of varying size and containing varying drugs (mostly cocaine, heroin and cannabis) mixed with other compounds, while body pushers will insert packets in the rectum or vaginal cavity. Body packing may lead to potential life-threatening complications with acute overdose syndromes after packet rupture and intestinal obstruction with possible ensuing bowel rupture being the most significant complications. Physicians including radiologists should be aware of the capabilities of imaging techniques to screen for presence of drug packets as well as the potential complications. Although conventional radiography has long been and still is the most important imaging modality for screening for presence of intestinal packets, the better test characteristics in conjunction with the decreasing radiation exposure, will likely render computed tomography (CT) more important in the future. For imaging of symptomatic patients, CT already is the modality of choice. Besides these modalities, ultrasound and magnetic resonance imaging will be discussed in this paper, together with more general background and clinical information.

Pulmonary disease in cystic fibrosis: assessment with chest CT at chest radiography dose levels.

PURPOSE: To investigate a computed tomographic (CT) protocol with iterative reconstruction at conventional radiography dose levels for the assessment of structural lung abnormalities in patients with cystic fibrosis ( CF cystic fibrosis ). MATERIALS AND METHODS: In this institutional review board-approved study, 38 patients with CF cystic fibrosis (age range, 6-58 years; 21 patients <18 years and 17 patients >18 years) underwent investigative CT (at minimal exposure settings combined with iterative reconstruction) as a replacement of yearly follow-up posteroanterior chest radiography. Verbal informed consent was obtained from all patients or their parents. CT images were randomized and rated independently by two radiologists with use of the Bhalla scoring system. In addition, mosaic perfusion was evaluated. As reference, the previous available conventional chest CT scan was used. Differences in Bhalla scores were assessed with the χ(2) test and intraclass correlation coefficients ( ICC intraclass correlation coefficient s). Radiation doses for CT and radiography were assessed for adults (>18 years) and children (<18 years) separately by using technical dose descriptors and estimated effective dose. Differences in dose were assessed with the Mann-Whitney U test. RESULTS: The median effective dose for the investigative protocol was 0.04 mSv (95% confidence interval [ CI confidence interval ]: 0.034 mSv, 0.10 mSv) for children and 0.05 mSv (95% CI confidence interval : 0.04 mSv, 0.08 mSv) for adults. These doses were much lower than those with conventional CT (median: 0.52 mSv [95% CI confidence interval : 0.31 mSv, 3.90 mSv] for children and 1.12 mSv [95% CI confidence interval : 0.57 mSv, 3.15 mSv] for adults) and of the same order of magnitude as those for conventional radiography (median: 0.012 mSv [95% CI confidence interval : 0.006 mSv, 0.022 mSv] for children and 0.012 mSv [95% CI confidence interval : 0.005 mSv, 0.031 mSv] for adults). All images were rated at least as diagnostically acceptable. Very good agreement was found in overall Bhalla score ( ICC intraclass correlation coefficient , 0.96) with regard to the severity of bronchiectasis ( ICC intraclass correlation coefficient , 0.87) and sacculations and abscesses ( ICC intraclass correlation coefficient , 0.84). Interobserver agreement was excellent ( ICC intraclass correlation coefficient , 0.86-1). CONCLUSION: For patients with CF cystic fibrosis , a dedicated chest CT protocol can replace the two yearly follow-up chest radiographic examinations without major dose penalty and with similar diagnostic quality compared with conventional CT.

Colovesical Fistula as a Late Complication of Ingestion of a Foreign Body.

Teaching point: Ingestion of a foreign body is a rare cause of a colovesical fistula.

Subclinical epileptiform activity in the Alzheimer continuum: association with disease, cognition and detection method.

BACKGROUND: Epileptic seizures are an established comorbidity of Alzheimer's disease (AD). Subclinical epileptiform activity (SEA) as detected by 24-h electroencephalography (EEG) or magneto-encephalography (MEG) has been reported in temporal regions of clinically diagnosed AD patients. Although epileptic activity in AD probably arises in the mesial temporal lobe, electrical activity within this region might not propagate to EEG scalp electrodes and could remain undetected by standard EEG. However, SEA might lead to faster cognitive decline in AD. AIMS: 1. To estimate the prevalence of SEA and interictal epileptic discharges (IEDs) in a well-defined cohort of participants belonging to the AD continuum, including preclinical AD subjects, as compared with cognitively healthy controls. 2. To evaluate whether long-term-EEG (LTM-EEG), high-density-EEG (hd-EEG) or MEG is superior to detect SEA in AD. 3. To characterise AD patients with SEA based on clinical, neuropsychological and neuroimaging parameters. METHODS: Subjects (n = 49) belonging to the AD continuum were diagnosed according to the 2011 NIA-AA research criteria, with a high likelihood of underlying AD pathophysiology. Healthy volunteers (n = 24) scored normal on neuropsychological testing and were amyloid negative. None of the participants experienced a seizure before. Subjects underwent LTM-EEG and/or 50-min MEG and/or 50-min hd-EEG to detect IEDs. RESULTS: We found an increased prevalence of SEA in AD subjects (31%) as compared to controls (8%) (p = 0.041; Fisher's exact test), with increasing prevalence over the disease course (50% in dementia, 27% in MCI and 25% in preclinical AD). Although MEG (25%) did not withhold a higher prevalence of SEA in AD as compared to LTM-EEG (19%) and hd-EEG (19%), MEG was significantly superior to detect spikes per 50 min (p = 0.002; Kruskall-Wallis test). AD patients with SEA scored worse on the RBANS visuospatial and attention subset (p = 0.009 and p = 0.05, respectively; Mann-Whitney U test) and had higher left frontal, (left) temporal and (left and right) entorhinal cortex volumes than those without. CONCLUSION: We confirmed that SEA is increased in the AD continuum as compared to controls, with increasing prevalence with AD disease stage. In AD patients, SEA is associated with more severe visuospatial and attention deficits and with increased left frontal, (left) temporal and entorhinal cortex volumes. TRIAL REGISTRATION: Clinicaltrials.gov, NCT04131491. 12/02/2020.

Microtrabecular Fracture with Intramedullary Fat Globules.

Teaching Point: In rare cases, trauma may result in intramedullary fat globules which have a characteristic aspect both on MRI and dual-energy CT.

Traumatic Retroclival Subdural Hematoma.

Teaching Point: Retroclival subdural hematoma is a rare type of extra-axial hematoma after craniocervical trauma.

Stent appearance in a novel silicon-based photon-counting CT prototype: ex vivo phantom study in head-to-head comparison with conventional energy-integrating CT.

BACKGROUND: In this study, stent appearance in a novel silicon-based photon-counting computed tomography (Si-PCCT) prototype was compared with a conventional energy-integrating detector CT (EIDCT) system. METHODS: An ex vivo phantom was created, consisting of a 2% agar-water mixture, in which human-resected and stented arteries were individually embedded. Using similar technique parameters, helical scan data was acquired using a novel prototype Si-PCCT and a conventional EIDCT system at a volumetric CT dose index (CTDIvol) of 9 mGy. Reconstructions were made at 502 and 1502 mm2 field-of-views (FOVs) using a bone kernel and adaptive statistical iterative reconstruction with 0% blending. Using a 5-point Likert scale, reader evaluations were performed on stent appearance, blooming and inter-stent visibility. Quantitative image analysis was performed on stent diameter accuracy, blooming and inter-stent distinction. Qualitative and quantitative differences between Si-PCCT and EIDCT systems were tested with a Wilcoxon signed-rank test and a paired samples t-test, respectively. Inter- and intra-reader agreement was assessed using the intraclass correlation coefficient (ICC). RESULTS: Qualitatively, Si-PCCT images were rated higher than EIDCT images at 150-mm FOV, based on stent appearance (p = 0.026) and blooming (p = 0.015), with a moderate inter- (ICC = 0.50) and intra-reader (ICC = 0.60) agreement. Quantitatively, Si-PCCT yielded more accurate diameter measurements (p = 0.001), reduced blooming (p < 0.001) and improved inter-stent distinction (p < 0.001). Similar trends were observed for the images reconstructed at 50-mm FOV. CONCLUSIONS: When compared to EIDCT, the improved spatial resolution of Si-PCCT yields enhanced stent appearance, more accurate diameter measurements, reduced blooming and improved inter-stent distinction. KEY POINTS: • This study evaluated stent appearance in a novel silicon-based photon-counting computed tomography (Si-PCCT) prototype. • Compared to standard CT, Si-PCCT resulted in more accurate stent diameter measurements. • Si-PCCT also reduced blooming artefacts and improved inter-stent visibility.

The role of CT imaging for management of COVID-19 in epidemic area: early experience from a University Hospital.

BACKGROUND: To evaluate the clinical value of the chest CT scan compared to the reference standard real-time polymerase chain reaction (RT-PCR) in COVID-19 patients. METHODS: From March 29th to April 15th of 2020, a total of 240 patients with respiratory distress underwent both a low-dose chest CT scan and RT-PCR tests. The performance of chest CT in diagnosing COVID-19 was assessed with reference to the RT-PCR result. Two board-certified radiologists (mean 24 years of experience chest CT), blinded for the RT-PCR result, reviewed all scans and decided positive or negative chest CT findings by consensus. RESULTS: Out of 240 patients, 60% (144/240) had positive RT-PCR results and 89% (213/240) had a positive chest CT scans. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of chest CT in suggesting COVID-19 were 100% (95% CI: 97-100%, 144/240), 28% (95% CI: 19-38%, 27/240), 68% (95% CI: 65-70%) and 100%, respectively. The diagnostic accuracy of the chest CT suggesting COVID-19 was 71% (95% CI: 65-77%). Thirty-three patients with positive chest CT scan and negative RT-PCR test at baseline underwent repeat RT-PCR assay. In this subgroup, 21.2% (7/33) cases became RT-PCR positive. CONCLUSION: Chest CT imaging has high sensitivity and high NPV for diagnosing COVID-19 and can be considered as an alternative primary screening tool for COVID-19 in epidemic areas. In addition, a negative RT-PCR test, but positive CT findings can still be suggestive of COVID-19 infection.

64-Slice CT angiography of the abdominal aorta and abdominal arteries: comparison of the diagnostic efficacy of iobitridol 350 mgI/ml versus iomeprol 400 mgI/ml in a prospective, randomised, double-blind multi-centre trial.

PURPOSE: The purpose of this study was to assess the influence of iodine concentration on diagnostic efficacy in multi-detector-row computed tomography (MDCT) angiography of the abdominal aorta and abdominal arteries. METHODS: IRB approval and informed consent were obtained. In this double-blind trial, patients were randomised to undergo MDCT angiography of the abdominal arteries during administration of iobitridol (350 mgI/ml) or iomeprol (400 mgI/ml). Each centre applied its own technique for delivery of contrast medium, regardless of iodine concentration. Diagnostic efficacy, image quality, visualisation of the arterial wall and arterial enhancement were evaluated. A total of 153 patients received iobitridol and 154 received iomeprol. RESULTS: The ability to reach a diagnosis was "satisfactory" to "totally satisfactory" in 152 (99.3%) and 153 (99.4%) patients respectively. Image quality was rated as being "good" to "excellent" in 94.7 and 94.8% segments respectively. Similar results were observed for image quality of arterial walls (84.3 vs. 83.2%). The mean relative changes in arterial enhancement between baseline and arterial phase images showed no statistically significant differences. CONCLUSION: This study demonstrated the non-inferiority of the 350 versus 400 mgI/ml iodine concentration, in terms of diagnostic efficacy, in abdominal MDCT angiography. It also confirmed the high robustness and reliability of this technique across multi-national practices.

Post-stroke infections associated with spleen volume reduction: A pilot study.

BACKGROUND: Spleen volume reduction followed by re-expansion has been described in acute ischemic stroke in both animal and human studies. Splenic contraction might be partially due to sympathetic hyperactivity and might be accompanied by release of splenocytes in the peripheral circulation, leading to immunodepression. AIMS: To investigate whether spleen volume changes in the first week after stroke are associated with post-stroke infections, changes in lymphocytes count and autonomic dysfunction. METHODS: In patients with acute ischemic stroke, spleen sizes were calculated from abdominal CT images on day one and day seven. Spleen size reduction was defined as > 10% spleen size reduction between day one and day seven. Post stroke infections were diagnosed during the first seven days after stroke onset using the modified criteria of the US Center of Disease Control and Prevention. We assessed the time course of leukocyte subsets and analysed pulse rate variability (PRV) indices. RESULTS: Post-stroke infections occurred in six out of 11 patients (55%) with spleen size reduction versus in five out of 27 patients (19%) without spleen size reduction (p = 0,047). Spleen size reduction was associated with a drop in lymphocytes and several lymphocyte subsets from admission to day one, and a higher NIHSS at admission and at day three (p = 0,028 and p = 0,006 respectively). No correlations could be found between spleen volume change and PRV parameters. CONCLUSION: Post-stroke infections and a drop in lymphocytes and several lymphocyte subsets are associated with spleen volume reduction in acute ischemic stroke.

Improving the diagnosis of peripheral arterial disease in below-the-knee arteries by adding time-resolved CT scan series to conventional run-off CT angiography. First experience with a 256-slice CT scanner.

PURPOSE: Run-off Computed Tomography Angiography (run-off CTA) of the lower extremities has become the method of choice for the diagnostic imaging of patients suffering from peripheral arterial disease (PAD). However, it remains a challenging radiological examination with a considerable risk of non-diagnostic image quality for the assessment of below-the-knee arteries. In this study, we investigate the diagnostic benefit of adding time-resolved CT scan series to the standard run-off CTA by performing repeated axial acquisitions over the calves of the patient during a second bolus of iodinated contrast injection. MATERIALS AND METHODS: This prospective study included 20 patients (9 male, 11 female; mean age 66.1 ± 14.9 years) who received a standard run-off CTA and an additional time-resolved CT scan series after a 10 min delay. The time-resolved series consisted of 18 repeated axial acquisitions over the calves directly below the knee with a 2 s interphase delay. For both series, two observers independently assessed the anterior tibial, posterior tibial and peroneal arteries of both legs for following criteria: arterial enhancement, presence and degree of stenosis, the confidence of grading, degree of stenosis and venous overlay. Quantitative assessment of arterial enhancement was performed by measuring the mean CT values (HU) in all arteries. Radiation exposure was quantified by the effective dose. RESULTS: A total of 118 arteries were assessed. The observer study showed that the additional time-resolved series improved both arterial enhancement (64% considered optimal enhanced versus 44%) and diagnostic confidence (59% considered as certain versus 33%) for the assessment of arterial stenosis (all p < 0.05). Venous overlay reduced from 15% to 6%. In all three arteries, the measured contrast enhancement by CT values (HU) was considerably higher (average 48%, p < 0.05) with the time-resolved series. The time-resolved series had an effect on stenosis classification (p = 0.03): a higher number of arteries were graded as having a non-significant stenosis (78.8% versus 71.2%). The interobserver variability in stenosis classification improved from κ = 0.39 to κ = 0.61. The mean effective dose was 5.1 ± 1.3 mSv for the run-off CTA and 0.2 ± 0.07 mSv for the time-resolved series. Per patient, a total volume of 140 mL contrast agent was injected. CONCLUSION: A dynamic CT scan protocol with repeated axial series can be added to a standard helical run-off CTA sequence for the lower extremities within the same CT examination, and it increases image quality and diagnostic confidence for the assessment of presence and degree of arterial stenosis in below-the-knee arteries.