Computed Tomography Magnetic Resonance Imaging Research Articles

Isolated sulfite oxidase deficiency.

Isolated sulfite oxidase deficiency (ISOD) is a life-threatening, autosomal recessive disease characterized by severe neurological impairment. As no long-term effective treatment is available, distinction from other treatable diseases, such as molybdenum cofactor deficiency (MoCD) type A, should be made. We reviewed 47 patients (45 previously reported in the literature). Cases were reviewed for consanguinity, sex, age at onset, death, clinical findings (including spasticity, seizures, psychomotor retardation, feeding difficulties, ectopia lentis, microcephaly), laboratory findings [urinary sulfite, S-sulfocysteine (in plasma and urine), plasma cystine, total homocysteine, uric acid, and oxypurines in urine] and radiological findings (including cerebral/cerebellar atrophy, cystic white matter changes, ventriculomegaly). We also aligned the published SUOX gene mutations to the reference sequence NM_000456.2. Onset occurred mostly during the first 72h of life (57%) and within the first year of life in all but two patients (96%). All patients presented with neurological abnormalities, such as neonatal axial hypotonia and/or peripheral hypertonia (100%), (pharmacoresistant) seizures (84%), or developmental delay (97%). Feeding problems were also common. As found in our review, measurement of homocysteine in plasma, amino acids in plasma/urine, and sulfite in fresh urine supports the diagnosis of ISOD. Analysis of uric acid (plasma) and oxypurines (urine) is useful to rule out MoCD. In all patients in whom brain magnetic resonance imaging/computed tomography (MRI/CT) was performed, brain abnormalities were found. The purpose of this literature review is to provide a thorough overview of clinical, neuroimaging, biochemical, and genetic findings of patients with ISOD.

CT MR image registration for 3D image based treatment planning in cervical cancer brachytherapy – An initial experience

The use of image registration is relevant in radiotherapy centres with good access to computed tomography (CT) and limited access to magnetic resonance (MR) imaging. This presentation outlines recent work on commissioning and bringing into clinical use CT MR image registration to facilitate 3 dimensional image based treatment planning in cervical cancer high dose rate brachytherapy. CT MR compatible ring and tandem applicators are required for this dual imaging approach. X-ray catheters and MR line markers were fitted into the applicators as appropriate for the imaging modality. Applicator reconstruction, dose prescription, organ at risk (OAR) contouring and optimisation were performed on the CT images. Contouring of the high risk clinical target volume was performed on the MR images. Image registration involved identifying and marking three corresponding points on the ring and tandem applicator on both the CT images and the MR images. The average error associated with the registration in all three patients involved in this study was less than 1 mm. Treatment plans were generated that complied with published dose volume parameters for the target and OAR dose constraints [1] , [2] . CT MR image registration was shown to be feasible for delivering high quality cervical cancer brachytherapy treatments and shows a distinct improvement on CT only treatments.

A clinical study of cerebral venous thrombosis

Background: Cerebral venous thrombosis (CVT) is an uncommon form of stroke, usually affecting young population. Clinical features of CVT are diverse, and for this reason, high degree of clinical suspect is mandatory to diagnose the conditions. The objectives of the study were to analyse the commonest clinical modes of presentation, possible etiologies, and to evaluate clinical outcome.Methods: This study was prospective, clinical study was conducted on 40 patients during the period of September 2010 to September 2011 in the Department of Emergency, Institute of Internal medicine at Government General Hospital (GGH), Chennai. All the patients included in the study were subjected to neuroimaging techniques like Computed tomography (CT), magnetic resonance imaging (MRI) along with magnetic resonance venography (MRV) according to guidelines and standard protocol.Results: Majority of the patients involved in the study were in the age group of 15-35 years contributing to 75%. Male: female ratio was 1.5: 1. Headache was the most common presenting symptom seen in 36 (87.5%) cases followed by convulsions in 32 (80%) patients. Altered sensorium was observed in 26 (65%), focal deficits in 22 (55%), and 18 (45%) had fever. Two of them had ear discharge and another with diarrhea. Cranial nerve involvement in 35% and pappiledema was noted in 20% of patients. Out of 40, 17 (42.5%) patients were anemic. Eighteen (18) patients who were suspected of meningitis underwent CSF analysis. Abnormality was seen in 10 patients with pleocytosis being the maximum. On CT scan, haemorrhagic infarct was seen in 22 (55%) cases followed by edema in 8 (20%) and 10% showed normal CT picture. On MRI scan, superior sagittal sinus thrombosis was observed in 24 (60%) patients followed by transverse sinus in 20 (50%) patients. Etiology factor were identified in 25 (62.5%) of patients and in 15 (37.5%) cases risk factors could not be identified. The mortality rate in the study was 20%.Conclusions: The clinical symptoms of CVT are not specific, as a result of chances of misdiagnosis tends to be more. CT scan and MRI along with MRV can improve the precision of CVT diagnosis.

Traitement ablatif pour cancer du rein : modalités d’évaluation pré-, per-, post-intervention et prise en charge adaptée

Ablative treatment (AT) rise is foreseen, validation of steps to insure good proceedings is needed. By looking over the process of the patient, this study evaluates the requirements and choices needed in every step of the management. We searched MEDLINE®, Embase®, using (MeSH) words and we looked for all the studies. Investigators graded the strength of evidence in terms of methodology, language and relevance. Explanations of AT proposal rather than partial nephrectomy or surveillance have to be discussed in a consultation shared by urologist and interventional radiologist. Per-procedure choices depend on predictable ballistic difficulties. High volume, proximity of the hilum or of a risky organ are in favor of general anesthesia, cryotherapy and computed tomography/magnetic resonance imaging (CT/MRI). Percutaneous approach should be privileged, as it seems as effective as the laparoscopic approach. Early and delayed complications have to be treated both by urologist and radiologist. Surveillance by CT/MRI insure of the lack of contrast-enhanced in the treated area. Patients and tumors criteria, in case of incomplete treatment or recurrence, are the key of the appropriate treatment: surgery, second session of AT, surveillance. AT treatments require patient's comprehension, excellent coordination of the partnership between urologist and radiologist and relevant choices during intervention.

Increasing Rates of Imaging in Failed Back Surgery Syndrome Patients: Implications for Spinal Cord Stimulation

Background: Failed back surgery syndrome (FBSS) has a high incidence following spinal surgery, is notoriously refractory to treatment, and results in high health care utilization. Spinal cord stimulation (SCS) is a well-accepted modality for pain relief in this population; however, until recently magnetic resonance imaging (MRI) was prohibited due to risk of heat conduction through the device. Objectives: We examined trends in imaging use over the past decade in patients with FBSS to determine its impact on health care utilization and implications for patients receiving SCS. Study Design: Retrospective. Setting: Inpatient and outpatient sample. Methods: We identified patients from 2000 to 2012 using the Truven MarketScan database. Annual imaging rates (episodes per 1000 patient months) were determined for MRI, computed tomography (CT) scan, x-ray, and ultrasound. A multivariate Poisson regression model was used to determine imaging trends over time, and to compare imaging in SCS and non-SCS populations. Results: A total of 311,730 patients with FBSS were identified, of which 5.17% underwent SCS implantation (n = 16,118). The median (IQR) age was 58.0 (49.0 – 67.0) years. Significant increases in imaging rate ratios were found in all years for each of the modalities. Increases were seen in the use of CT scans (rate ratio [RR] = 3.03; 95% confidence interval [CI]: 2.79 – 3.29; P < 0.0001), MRI (RR = 1.73; 95% CI: 1.61 – 1.85; P < 0.0001), ultrasound (RR = 2.00; 95% CI: 1.84 – 2.18; P < 0.0001), and x-ray (RR = 1.10; 95% CI: 1.05 – 1.15; P < 0.0001). Despite rates of MRI in SCS patients being half that in the non-SCS group, these patients underwent 19% more imaging procedures overall (P < 0.0001). SCS patients had increased rates of x-ray (RR = 1.27; 95% CI: 1.25 – 1.29), CT scans (RR = 1.32; 95% CI: 1.30 – 1.35), and ultrasound (RR = 1.10; 95% CI: 1.07 – 1.13) (all P < 0.0001). Limitations: This study is limited by a lack of clinical and historical variables including the complexity of prior surgeries and pain symptomatology. Miscoding cannot be precluded, as this sample is taken from a large nationwide database. Conclusions: We found a significant trend for increased use of advanced imaging modalities between the years 2000 and 2012 in FBSS patients. Those patients treated with SCS were 50% less likely to receive an MRI (as expected, given prior incompatibility of neuromodulation devices), yet 32% and 27% more likely to receive CT and x-ray, respectively. Despite the decrease in the use of MRI in those patients treated with SCS, their overall imaging rate increased by 19% compared to patients without SCS. This underscores the utility of MR-conditional SCS systems. These findings demonstrate that imaging plays a significant role in driving health care expenditures. This is the largest analysis examining the role of imaging in the FBSS population and the impact of SCS procedures. Further studies are needed to assess the impact of MRI-conditional SCS systems on future trends in imaging in FBSS patients receiving neuromodulation therapies.

Magnetic resonance and computed tomography image fusion technology in patients with Parkinson's disease after deep brain stimulation

Electrode position after deep brain stimulation (DBS) for Parkinson's disease (PD) needs to be confirmed, but there are concerns about the risk of postoperative magnetic resonance imaging (MRI) after DBS. These issues could be avoided by fusion images obtained from preoperative MRI and postoperative computed tomography (CT). This study aimed to investigate image fusion technology for displaying the position of the electrodes compared with postoperative MRI. This was a retrospective study of 32 patients with PD treated with bilateral subthalamic nucleus (STN) DBS between April 2015 and March 2016. The postoperative (same day) CT and preoperative MRI were fused using the Elekta Leksell 10.1 planning workstation (Elekta Instruments, Stockholm, Sweden). The position of the electrodes was compared between the fusion images and postoperative 1–2-week MRI. The position of the electrodes was highly correlated between the fusion and postoperative MRI (all r between 0.865 and 0.996; all P<0.001). The differences of the left electrode position in the lateral and vertical planes was significantly different between the two methods (0.30 and 0.24mm, respectively, both P<0.05), but there were no significant differences for the other electrode and planes (all P>0.05). The position of the electrodes was highly correlated between the fusion and postoperative MRI. The CT-MRI fusion images could be used to avoid the potential risks of MRI after DBS in patients with PD.

PP.29.28] SERUM PROTEINS INTERPLAYING WITH ISCHEMIC STROKE - A LC/MS HUMAN PROTEOMIC STUDY FOR BIOMARKERS AND POTENTIAL DRUG TARGETS

Objective: The aim of this study was to identify potential proteins-candidates for biomarkers and drug targets of acute ischemic stroke. Design and method: There were 32 patients at age of 29–80 years with diagnosed ischemic stroke were included into the study group. The control group was constituted of 30 volunteers demographically matched with study group. Patients enrolled on the study group presented clinical symptoms of stroke lasting no longer than 24 hours, confirmed by trained neurologists examination or new brain ischemia visible in MR/CT (magnetic resonance imaging / computed tomography). The analysis of plasma proteome was performed using liquid chromatography–mass spectrometry. Results: We managed to identify 10 proteins which serum concentrations significantly differ from observed in healthy controls – complement factor B, apolipoprotein A-I, fibronectin, alpha-2-HS-glycoprotein, alpha-1B-glycoprotein, heat shock cognate 71 kDa protein/heat shock-related 70 kDa protein 2, thymidine phosphorylase, cytoplasmic tryptophan--tRNA ligase, ficolin-2, beta-Ala-His dipeptidase. Conclusions: Listed proteins should be considered as risk factors or markers of ischemic stroke. Further clinical validation of these proteins should define their role in differential diagnostics and monitoring course of the ischemic stroke as well as in designing novel therapies.

Medial Proximal Femoral Angle better than Neck-Shaft Angle? Influence of Rotation on the Anteroposterior Radiograph

AbstractNeck-shaft angle (NSA) and medial proximal femoral angle (MPFA) describe the geometry of the proximal femur, but they are influenced by rotation. The MPFA is closer to the right angle and therefore assumed to be less influenced. This hypothesis was tested with a mathematical approach to compare the effects of rotation and their clinical relevance on both angles. We developed a three-dimensional (3D) geometrical model representing projectional radiography of the femoral axes under rotation and derived a mathematical equation. For validation purposes, we experimentally simulated projectional radiography and compared the results to those of the equation (five different inclinations of the femoral neck (IFN) each in 13 different rotations). The validated equation was used to determine the influence of rotation (–60° to +60°) on normal valued NSA and MPFA. The mean absolute difference between calculated and experimentally measured values was 0.6° (standard deviation [SD] 0.5; 0.0–2.2). The mean calculated difference between true and projected NSA was 7.1° (SD 7.1; 0.0–22.0), and for the MPFA, it was –1.9° (SD 2.2; –7.4 to 0.0). Clinically relevant deviations (≥5°) occurred at ≥30° external or ≥ 40° internal rotation for the NSA, for the MPFA at 60° external rotation. Mathematical modeling of radiographic projection of the IFN is possible to a high level of accuracy. Our results indicate that the NSA is significantly more susceptible to deviations caused by rotation than the MPFA. Clinicians must be aware of rotational influences in radiographic projection and possibly should use the MPFA instead of the NSA. The rotational influence during X-ray imaging must be controlled accurately, and femoral torsion should be quantified in computed tomography/magnetic resonance imaging (CT/MRI) scans if possible. 3-D bone models reconstructed from digital image data can be a future option for measuring true angles. Level of evidence was basic research.

Neuroimaging in staging patients with lung cancer

Background to the audit: It is important to detect brain metastases in patients with newly diagnosed advanced lung cancer intended for curative treatment. To this end, the National Institute for Health and Care Excellence (NICE) suggests considering magnetic resonance imaging (MRI) or computed tomography (CT) head especially in stage III disease and the Scottish Intercollegiate Guidelines Network (SIGN) 2014 recommends contrast CT head or MRI in N2 disease. It is also important to use resources appropriately, SIGN also recommends that stage I-II do not require such imaging unless clinically indicated.

External ventricular drain causes brain tissue damage: an imaging study.

An external ventricular drain (EVD) is used to measure intracranial pressure (ICP) and to drain cerebrospinal fluid (CSF). The procedure is generally safe, but parenchymal sequelae are reported as a possible side effect, with variable incidence. We investigated the mechanical sequelae of EVD insertion and their clinical significance in acute brain-injured patients, with a special focus on hemorrhagic lesions. Mechanical sequelae of EVD insertion were detected in patients by computed tomography (CT) and magnetic resonance imaging (MRI), performed for clinical purposes. In 155 patients we studied the brain tissue surrounding the EVD by CT scan (all patients) and MRI (16 patients); 53 patients were studied at three time points (day 1-2, day 3-10, >10days after EVD placement) to document the lesion time course. Small hemorrhages, with a hyperdense core surrounded by a hypodense area, were identified by CT scan in 33 patients. The initial average (hyper-+hypodense) lesion volume was 8.16ml, increasing up to 15ml by >10days after EVD insertion. These lesions were not accompanied by neurologic deterioration or ICP elevation. History of arterial hypertension, coagulation abnormalities and multiple EVD insertions were significantly associated with hemorrhages. In 122 non-hemorrhagic patients, we detected very small hypodense areas (average volume 0.38ml) surrounding the catheter. At later times these hypodensities slightly increased. MRI studies in 16 patients identified both intra- and extracellular edema around the catheters. The extracellular component increased with time. EVD insertion, even when there are no clinically important complications, causes a tissue reaction with minimal bleedings and small areas of brain edema.

Pulmonary 3He Magnetic Resonance Imaging Biomarkers of Regional Airspace Enlargement in Alpha-1 Antitrypsin Deficiency

Thoracic x-ray computed tomography (CT) and hyperpolarized 3He magnetic resonance imaging (MRI) provide quantitative measurements of airspace enlargement in patients with emphysema. For patients with panlobular emphysema due to alpha-1 antitrypsin deficiency (AATD), sensitive biomarkers of disease progression and response to therapy have been difficult to develop and exploit, especially those biomarkers that correlate with outcomes like quality of life. Here, our objective was to generate and compare CT and diffusion-weighted inhaled-gas MRI measurements of emphysema including apparent diffusion coefficient (ADC) and MRI-derived mean linear intercept (Lm) in patients with AATD, chronic obstructive pulmonary disease (COPD) ex-smokers, and elderly never-smokers. We enrolled patients with AATD (n = 8; 57 ± 7 years), ex-smokers with COPD (n = 8; 77 ± 6 years), and a control group of never-smokers (n = 5; 64 ± 2 years) who underwent thoracic CT, MRI, spirometry, plethysmography, the St. George's Respiratory Questionnaire, and the 6-minute walk test during a single 2-hour visit. MRI-derived ADC, Lm, surface-to-volume ratio, and ventilation defect percent were generated for the apical, basal, and whole lung as was CT lung area ≤-950 Hounsfield units (RA950), low attenuating clusters, and airway count. In patients with AATD, there was a significantly different MRI-derived ADC (P = .03), Lm (P < .0001), and surface-to-volume ratio (P < .0001), but not diffusing capacity of carbon monoxide, residual volume or total lung capacity, or CT RA950 (P > .05) compared to COPD ex-smokers with a significantly different St. George's Respiratory Questionnaire. In this proof-of-concept demonstration, we evaluated CT and MRI lung emphysema measurements and observed significantly worse MRI biomarkers of emphysema in patients with AATD compared to patients with COPD, although CT RA950 and diffusing capacity of carbon monoxide were not significantly different, underscoring the sensitivity of MRI measurements of AATD emphysema.

Comparison of 3D bone models of the knee joint derived from CT and 3T MR imaging

PurposeTo examine whether magnetic resonance (MR) imaging can offer a viable alternative to computed tomography (CT) based 3D bone modeling. MethodsCT and MR (SPACE, TrueFISP, VIBE) images were acquired from the left knee joint of a fresh-frozen cadaver. The distal femur, proximal tibia, proximal fibula and patella were manually segmented from the MR and CT examinations. The MR bone models obtained from manual segmentations of all three sequences were compared to CT models using a similarity measure based on absolute mesh differences. ResultsThe average absolute distance between the CT and the various MR-based bone models were all below 1mm across all bones. The VIBE sequence provided the best agreement with the CT model, followed by the SPACE, then the TrueFISP data. The most notable difference was for the proximal tibia (VIBE 0.45mm, SPACE 0.82mm, TrueFISP 0.83mm). ConclusionsThe study indicates that 3D MR bone models may offer a feasible alternative to traditional CT-based modeling. A single radiological examination using the MR imaging would allow simultaneous assessment of both bones and soft-tissues, providing anatomically comprehensive joint models for clinical evaluation, without the ionizing radiation of CT imaging.

Permanent prostate brachytherapy postimplant magnetic resonance imaging dosimetry using positive contrast magnetic resonance imaging markers

PurposePermanent prostate brachytherapy dosimetry using computed tomography-magnetic resonance imaging (CT-MRI) fusion combines the anatomic detail of MRI with seed localization on CT but requires multimodality imaging acquisition and fusion. The purpose of this study was to compare the utility of MRI only postimplant dosimetry to standard CT-MRI fusion-based dosimetry. Methods and MaterialsTwenty-three patients undergoing permanent prostate brachytherapy with use of positive contrast MRI markers were included in this study. Dose calculation to the whole prostate, apex, mid-gland, and base was performed via standard CT-MRI fusion and MRI only dosimetry with prostate delineated on the same T2 MRI sequence. The 3-dimensional (3D) distances between seed positions of these two methods were also evaluated. Wilcoxon-matched-pair signed-rank test compared the D90 and V100 of the prostate and its sectors between methods. ResultsThe day 0 D90 and V100 for the prostate were 98% versus 94% and 88% versus 86% for CT-MRI fusion and MRI only dosimetry. There were no differences in the D90 or V100 of the whole prostate, mid-gland, or base between dosimetric methods (p > 0.19), but prostate apex D90 was high by 13% with MRI dosimetry (p = 0.034). The average distance between seeds on CT-MRI fusion and MRI alone was 5.5 mm. After additional automated rigid registration of 3D seed positions, the average distance between seeds was 0.3 mm, and the previously observed differences in apex dose between methods was eliminated (p > 0.11). ConclusionsPermanent prostate brachytherapy dosimetry based only on MRI using positive contrast MRI markers is feasible, accurate, and reduces the uncertainties arising from CT-MRI fusion abating the need for postimplant multimodality imaging.

The Role of PET Scanning in the Evaluation of Patients With Kidney Disease.

Patients with underlying kidney disease are often required to undergo imaging for a variety of purposes including diagnosis and prognosis. A test that is being increasingly used with for this group of patients is the positron emission test (PET) scan. In addition, combining the nuclear medicine technique (PET) with computed tomography scan allows additional imaging advantages over either alone. These imaging modalities are commonly used for a number of extrarenal indications (ie, cancer, coronary artery disease, central nervous system disease, infectious diseases, and others). They have also been used for diagnosis of acute tubulointerstitial nephritis, evaluation and management of retroperitoneal fibrosis, identifying infection within kidney and liver cysts, and distinguishing complex kidney cysts from kidney cancer in patients with underlying CKD. We will review PET scan utility in patients with kidney disease.

Pulmonary magnetic resonance imaging is similar to chest tomography in detecting inflammation in patients with systemic sclerosis

Interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are prevalent complications of systemic sclerosis (SSc) and are currently the leading causes of death related to the disease. The accurate recognition of these conditions is therefore of utmost importance for patient management.A study was carried out with 24 SSc patients being followed at the Rheumatology Department of the Hospital de Clínicas of Universidade Federal do Paraná (UFPR) and 14 healthy volunteers, with the objective of evaluating the usefulness of lung magnetic resonance imaging (MRI) when assessing ILD in SS patients. The results obtained with lung MRI were compared to those obtained by computed tomography (CT) of the chest, currently considered the examination of choice when investigating ILD in SS patients.The assessed population was predominantly composed of women with a mean age of 50 years, limited cutaneous SS, and a disease duration of approximately 7 years. In most cases, there was agreement between the findings on chest CT and lung MRI. Considering it is a radiation-free examination and capable of accurately identifying areas of lung tissue inflammatory involvement, lung MRI showed to be a useful examination, and further studies are needed to assess whether there is an advantage in using lung MRI instead of chest CT when assessing ILD activity in SS patients.

Results of a prospective clinical study on the diagnostic performance of standard magnetic resonance imaging in comparison to a combination of 3 T MRI and additional CT imaging in Kienböck's disease

PurposeThis prospective clinical study examined standard wrist magnetic resonance imaging (MRI) examinations and the incremental value of computed tomography (CT) in the diagnosis of Kienböck's disease (KD) with regard to reliability and precision in the different diagnostic steps during diagnostic work-up. Materials and methodsSixty-four consecutive patients referred between January 2009 and January 2014 with positive initial suspicion of KD according to external standard wrist MRI were prospectively included (step one). Institutional review board approval was obtained. Clinical examination by two handsurgeons were followed by wrist radiographs (step two), ultrathin-section CT, and 3T contrast-enhanced MRI (step three). Final diagnosis was established in a consensus conference involving all examiners and all examinations results available from step three. ResultsIn 12/64 patients, initial suspicion was discarded at step two and in 34/64 patients, the initial suspicion of KD was finally discarded at step three. The final external MRI positive predictive value was 47%. The most common differential diagnoses at step three were intraosseous cysts (n=15), lunate pseudarthrosis (n=13), and ulnar impaction syndrome (n=5). A correlation between radiograph-based diagnoses (step two) with final diagnosis (step three) showed that initial suspicion of stage I KD had the lowest sensitivity for correct diagnosis (2/11). Technical factors associated with a false positive external MRI KD diagnosis were not found. ConclusionStandard wrist MRI should be complemented with thin-section CT, and interdisciplinary interpretation of images and clinical data, to increase diagnostic accuracy in patients with suspected KD.

Pitfalls and Rewards for Implementing Ocular Motor Testing in Acute Vestibular Syndrome: A Pilot Project.

Isolated acute vestibular syndrome (iAVS) presentations to the emergency department (ED) pose management challenges, given the concerns for posterior circulation strokes. False-negative brain imaging may erroneously reassure clinicians, whereas HINTS-plus examination outperforms imaging to screen for strokes in iAVS. We studied the feasibility of implementing HINTS-plus testing in the ED, aiming to reduce neuroimaging in patients with iAVS. We launched an institutional Quality Improvement initiative, using DMAIC methodology. The outcome measures [proportion of iAVS subjects who had HINTS-plus examinations and underwent neuroimaging by computed tomography/magnetic resonance imaging (CT/MRI)] were compared before and after the established intervention. The intervention consisted of formal training for neurologists and emergency physicians on how to perform, document, and interpret HINTS-plus and implementation of novel iAVS management algorithm. Neuroimaging was not recommended if HINTS-plus suggested peripheral vestibular etiology. If a central process was suspected, brain MRI/MR angiogram was performed. Head CT was reserved only for thrombolytic time-window cases. In the first 2 months postimplementation, HINTS-plus testing performance by neurologists increased from 0% to 80% (P=0.007), and by ED providers from 0% to 9.09% (P=0.367). Head CT scans were reduced from 18.5% to 6.25%. Brain MRI use was reduced from 51.8% to 31.2%. About 60% of the iAVS subjects were discharged from the ED; none were readmitted or had another ED presentation in the ensuing 30 days. Implementation of HINTS-plus evaluation in the ED is valuable and feasible for neurologists, but challenging for emergency physicians. Future studies should determine the "dose-response" curve of educational interventions.

Risk factor assessment to predict the likelihood of a diagnosis of metastasis for indeterminate hepatic lesions found at computed tomography in patients with rectal cancer

To assess the significant factors on rectal magnetic resonance imaging (MRI) to predict the likelihood of a diagnosis of metastasis for indeterminate hepatic lesions found at computed tomography (CT) in patients with rectal cancer. A total of 207 patients with rectal cancer who underwent preoperative contrast-enhanced abdominopelvic CT, and rectal and liver MRI were included. Univariate analysis and multivariate logistic regression were used to evaluate the determining factors for the significance of indeterminate hepatic lesions on CT in patients with rectal cancer. Hepatic metastases were diagnosed in 29 (20.9%) of 139 patients who had indeterminate hepatic lesions on preoperative CT obtained for rectal cancer. On univariate analysis, carcinoembryonic antigen level, N stage, mesorectal fascia (MRF) invasion, diameter of superior haemorrhoidal vein, and mesorectal vascular lesion (MVL) grade on rectal MRI (p<0.05) were associated with the possibility of metastasis for indeterminate hepatic lesions on CT. On multivariate analysis, MVL grade and MRF invasion on rectal MRI were independent factors associated with the possibility of metastasis for indeterminate hepatic lesions on CT (p<0.0005 and p=0.0066, respectively). MVL grade and MRF invasion on rectal MRI are independent factors for estimating hepatic metastasis among indeterminate hepatic lesions on CT in patients with rectal cancer.

Ressonância magnética pulmonar é semelhante à tomografia de tórax para detectar inflamação em pacientes com esclerose sistêmica

Interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are prevalent complications of systemic sclerosis (SS) and are currently the leading causes of death related to the disease. The accurate recognition of these conditions is therefore of utmost importance for patient management.A study was carried out with 24 SS patients being followed at the Rheumatology Department of the Hospital de Clínicas of Universidade Federal do Paraná (UFPR) and 14 healthy volunteers, with the objective of evaluating the usefulness of lung magnetic resonance imaging (MRI) when assessing ILD in SS patients. The results obtained with lung MRI were compared to those obtained by computed tomography (CT) of the chest, currently considered the examination of choice when investigating ILD in SS patients.The assessed population was predominantly composed of women with a mean age of 50 years, limited cutaneous SS, and a disease duration of approximately 7 years. In most cases, there was agreement between the findings on chest CT and lung MRI. Considering it is a radiation‐free examination and capable of accurately identifying areas of lung tissue inflammatory involvement, lung MRI showed to be a useful examination, and further studies are needed to assess whether there is an advantage in using lung MRI instead of chest CT when assessing ILD activity in SS patients.

Abstract 38: Brain CT Perfusion is Superior to Non-contrast CT Aspects in the Evaluation of Hyperacute Infarct Volume

Objective: To compare the predictive capacity to detect established infarct in acute anterior circulation stroke between the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) on non-contrast computed tomography (CT) and CT perfusion. Methods: Fifty-nine acute anterior circulation ischemic stroke patients received brain non-contrast CT, CT perfusion and hyperacute magnetic resonance imaging (MRI) within 100 minutes from CT imaging. ASPECTS scores were calculated by 4 independent vascular neurologists, blinded from CT perfusion and MRI data. CT perfusion infarct core volumes were calculated by MIStar software. The accuracy of commonly used ASPECTS cut-off scores and a CT perfusion core volume of ≥ 70 mL to detect a hyperacute MRI diffusion lesion of ≥ 70 ml was evaluated. Results: Median ASPECTS score was 9 (IQR 7-10). Median CT perfusion core volume was 22 ml (IQR 10.4-71.9). Median MRI diffusion lesion volume was 24,5 ml (IQR 10-63.9). ASPECTS score of &lt; 6 had a sensitivity of 0.37, specificity of 0.95 and c-statistic of 0.66 to predict an acute MRI lesion ≥ 70 ml. In comparison, a CT perfusion core lesion of ≥ 70 ml had a sensitivity of 0.76, specificity of 0.98 and c-statistic of 0.92. The CT perfusion core lesion covered a median of 100% of the acute MRI lesion volume (IQR 86-100%). Conclusions: CT perfusion is superior to ASPECTS to predict hyperacute MRI lesion volume in ischemic stroke.