Pretreatment ADC Histogram Analysis as a Prognostic Imaging Biomarker for Patients with Recurrent Glioblastoma Treated with Bevacizumab: A Systematic Review and Meta-analysis.

BACKGROUND: The mean ADC value of the lower Gaussian curve (ADCL) derived from the bi-Gaussian curve-fitting histogram analysis has been reported as a predictive/prognostic imaging biomarker in patients with recurrent glioblastoma treated with bevacizumab; however, its systematic summary has been lacking. PURPOSE: We applied a systematic review and meta-analysis to investigate the predictive/prognostic performance of ADCL in patients with recurrent glioblastoma treated with bevacizumab. DATA SOURCES: We performed a literature search using PubMed, Scopus, and EMBASE. STUDY SELECTION: A total of 1344 abstracts were screened, of which 83 articles were considered potentially relevant. Data were finally extracted from 6 studies including 578 patients. DATA ANALYSIS: Forest plots were generated to illustrate the hazard ratios of overall survival and progression-free survival. The heterogeneity across the studies was assessed using the Cochrane Q test and I2 values. DATA SYNTHESIS: The pooled hazard ratios for overall survival and progression-free survival in patients with an ADCL lower than the cutoff values were 1.89 (95% CI, 1.53-2.31) and 1.98 (95% CI, 1.54-2.55) with low heterogeneity among the studies. Subgroup analysis of the bevacizumab-free cohort showed a pooled hazard ratio for overall survival of 1.20 (95% CI, 1.08-1.34) with low heterogeneity. LIMITATIONS: The conclusions are limited by the difference in the definition of recurrence among the included studies. CONCLUSIONS: This systematic review with meta-analysis supports the prognostic value of ADCL in patients with recurrent glioblastoma treated with bevacizumab, with a low ADCL demonstrating decreased overall survival and progression-free survival. On the other hand, the predictive role of ADCL for bevacizumab treatment was not confirmed.

Sodium MR Neuroimaging.

Sodium MR imaging has the potential to complement routine proton MR imaging examinations with the goal of improving diagnosis, disease characterization, and clinical monitoring in neurologic diseases. In the past, the utility and exploration of sodium MR imaging as a valuable clinical tool have been limited due to the extremely low MR signal, but with recent improvements in imaging techniques and hardware, sodium MR imaging is on the verge of becoming clinically realistic for conditions that include brain tumors, ischemic stroke, and epilepsy. In this review, we briefly describe the fundamental physics of sodium MR imaging tailored to the neuroradiologist, focusing on the basics necessary to understand factors that play into making sodium MR imaging feasible for clinical settings and describing current controversies in the field. We will also discuss the current state of the field and the potential future clinical uses of sodium MR imaging in the diagnosis, phenotyping, and therapeutic monitoring in neurologic diseases.

3D Quantitative Synthetic MRI in the Evaluation of Multiple Sclerosis Lesions.

BACKGROUND AND PURPOSE: Synthetic MR imaging creates multiple contrast-weighted images based on a single time-efficient quantitative scan, which has been mostly performed for 2D acquisition. We assessed the utility of 3D synthetic MR imaging in patients with MS by comparing its diagnostic image quality and lesion volumetry with conventional MR imaging. MATERIALS AND METHODS: Twenty-four patients with MS prospectively underwent 3D quantitative synthetic MR imaging and conventional T1-weighted, T2-weighted, FLAIR, and double inversion recovery imaging, with acquisition times of 9 minutes 3 seconds and 18 minutes 27 seconds for the synthetic MR imaging and conventional MR imaging sequences, respectively. Synthetic phase-sensitive inversion recovery images and those corresponding to conventional MR imaging contrasts were created for synthetic MR imaging. Two neuroradiologists independently assessed the image quality on a 5-point Likert scale. The numbers of cortical lesions and lesion volumes were quantified using both synthetic and conventional image sets. RESULTS: The overall diagnostic image quality of synthetic T1WI and double inversion recovery images was noninferior to that of conventional images (P = .23 and .20, respectively), whereas that of synthetic T2WI and FLAIR was inferior to that of conventional images (both Ps < .001). There were no significant differences in the number of cortical lesions (P = .17 and .53 for each rater) or segmented lesion volumes (P = .61) between the synthetic and conventional image sets. CONCLUSIONS: Three-dimensional synthetic MR imaging could serve as an alternative to conventional MR imaging in evaluating MS with a reduced scan time.

Myelin and Axonal Damage in Normal-Appearing White Matter in Patients with Moyamoya Disease.

BACKGROUND AND PURPOSE: Although chronic ischemia is known to induce myelin and axonal damage in animal models, knowledge regarding patients with Moyamoya disease is limited. We aimed to investigate the presence of myelin and axonal damage in Moyamoya disease and their relationship with cognitive performance. MATERIALS AND METHODS: Eighteen patients with Moyamoya disease (16-55 years of age) and 18 age- and sex-matched healthy controls were evaluated with myelin-sensitive MR imaging based on magnetization transfer saturation imaging and 2-shell diffusion MR imaging. The myelin volume fraction, which reflects the amount of myelin sheath; the g-ratio, which represents the ratio of the inner (axon) to the outer (axon plus myelin) diameter of the fiber; and the axon volume fraction, which reflects axonal components, were calculated and compared between the patients and controls. In the patients with Moyamoya disease, the relationship between these parameters and cognitive task-measuring performance speed was also evaluated. RESULTS: Compared with the healthy controls, the patients with Moyamoya disease showed a significant decrease in the myelin and axon volume fractions (P < .05) in many WM regions, while the increases in the g-ratio values were not statistically significant. Correlations with cognitive performance were most frequently observed with the axon volume fraction (r = 0.52-0.54; P < .03 in the right middle and posterior cerebral artery areas) and were the strongest with the g-ratio values in the right posterior cerebral artery region (r = 0.64; P = .004). CONCLUSIONS: Myelin-sensitive MR imaging and diffusion MR imaging revealed that myelin and axonal damage exist in patients with Moyamoya disease. The relationship with cognitive performance might be stronger with axonal damage than with myelin damage.

MRI Findings of Immune Checkpoint Inhibitor-Induced Hypophysitis: Possible Association with Fibrosis.

BACKGROUND AND PURPOSE: Hypophysitis is one of the well-known adverse effects of immune checkpoint inhibitors. Immune checkpoint inhibitor-induced hypophysitis frequently causes irreversible hypopituitarism, which requires long-term hormone replacement. Despite the high frequency and clinical significance, characteristic MR imaging findings of immune checkpoint inhibitor-induced hypophysitis have not been established. In the present study, we aimed to review and extract the MR imaging features of immune checkpoint inhibitor-induced hypophysitis. MATERIALS AND METHODS: This retrospective international multicenter study comprised 20 patients with melanoma who were being treated with immune checkpoint inhibitors and clinically diagnosed with immune checkpoint inhibitor-induced hypophysitis. Three radiologists evaluated the following MR imaging findings: enlargement of the pituitary gland and stalk; homogeneity of enhancement of the pituitary gland; presence/absence of a well-defined poorly enhanced area and, if present, its location, shape, and signal intensity in T2WI; and enhancement pattern in contrast-enhanced dynamic MR imaging. Clinical symptoms and hormone levels were also recorded. RESULTS: Enlargement of the pituitary gland and stalk was observed in 12 and 20 patients, respectively. Nineteen patients showed poorly enhanced lesions (geographic hypoenhancing lesions) in the anterior lobe, and 11 of these lesions showed hypointensity on T2WI. Thyrotropin deficiency and corticotropin deficiency were observed in 19/20 and 12/17 patients, respectively, which persisted in 12/19 and 10/12 patients, respectively, throughout the study period. CONCLUSIONS: Pituitary geographic hypoenhancing lesions in the anterior lobe of the pituitary gland are characteristic and frequent MR imaging findings of immune checkpoint inhibitor-induced hypophysitis. They reflect fibrosis and are useful in distinguishing immune checkpoint inhibitor-induced hypophysitis from other types of hypophysitis/tumors.

White Matter Abnormalities in Multiple Sclerosis Evaluated by Quantitative Synthetic MRI, Diffusion Tensor Imaging, and Neurite Orientation Dispersion and Density Imaging.

BACKGROUND AND PURPOSE: A number of MR-derived quantitative metrics have been suggested to assess the pathophysiology of MS, but the reports about combined analyses of these metrics are scarce. Our aim was to assess the spatial distribution of parameters for white matter myelin and axon integrity in patients with relapsing-remitting MS by multiparametric MR imaging. MATERIALS AND METHODS: Twenty-four patients with relapsing-remitting MS and 24 age- and sex-matched controls were prospectively scanned by quantitative synthetic and 2-shell diffusion MR imaging. Synthetic MR imaging data were used to retrieve relaxometry parameters (R1 and R2 relaxation rates and proton density) and myelin volume fraction. Diffusion tensor metrics (fractional anisotropy and mean, axial, and radial diffusivity) and neurite orientation and dispersion index metrics (intracellular volume fraction, isotropic volume fraction, and orientation dispersion index) were retrieved from diffusion MR imaging data. These data were analyzed using Tract-Based Spatial Statistics. RESULTS: Patients with MS showed significantly lower fractional anisotropy and myelin volume fraction and higher isotropic volume fraction in widespread white matter areas. Areas with different isotropic volume fractions were included within areas with lower fractional anisotropy. Myelin volume fraction showed no significant difference in some areas with significantly decreased fractional anisotropy in MS, including in the genu of the corpus callosum and bilateral anterior corona radiata, whereas myelin volume fraction was significantly decreased in some areas where fractional anisotropy showed no significant difference, including the bilateral posterior limb of the internal capsule, external capsule, sagittal striatum, fornix, and uncinate fasciculus. CONCLUSIONS: We found differences in spatial distribution of abnormality in fractional anisotropy, isotropic volume fraction, and myelin volume fraction distribution in MS, which might be useful for characterizing white matter in patients with MS.

Improving the Quality of Synthetic FLAIR Images with Deep Learning Using a Conditional Generative Adversarial Network for Pixel-by-Pixel Image Translation.

BACKGROUND AND PURPOSE: Synthetic FLAIR images are of lower quality than conventional FLAIR images. Here, we aimed to improve the synthetic FLAIR image quality using deep learning with pixel-by-pixel translation through conditional generative adversarial network training. MATERIALS AND METHODS: Forty patients with MS were prospectively included and scanned (3T) to acquire synthetic MR imaging and conventional FLAIR images. Synthetic FLAIR images were created with the SyMRI software. Acquired data were divided into 30 training and 10 test datasets. A conditional generative adversarial network was trained to generate improved FLAIR images from raw synthetic MR imaging data using conventional FLAIR images as targets. The peak signal-to-noise ratio, normalized root mean square error, and the Dice index of MS lesion maps were calculated for synthetic and deep learning FLAIR images against conventional FLAIR images, respectively. Lesion conspicuity and the existence of artifacts were visually assessed. RESULTS: The peak signal-to-noise ratio and normalized root mean square error were significantly higher and lower, respectively, in generated-versus-synthetic FLAIR images in aggregate intracranial tissues and all tissue segments (all P < .001). The Dice index of lesion maps and visual lesion conspicuity were comparable between generated and synthetic FLAIR images (P = 1 and .59, respectively). Generated FLAIR images showed fewer granular artifacts (P = .003) and swelling artifacts (in all cases) than synthetic FLAIR images. CONCLUSIONS: Using deep learning, we improved the synthetic FLAIR image quality by generating FLAIR images that have contrast closer to that of conventional FLAIR images and fewer granular and swelling artifacts, while preserving the lesion contrast.

Effect of Gadolinium on the Estimation of Myelin and Brain Tissue Volumes Based on Quantitative Synthetic MRI.

BACKGROUND AND PURPOSE: The effect of gadolinium on the estimation of myelin has not been reported. The aim of the current study was to investigate the effects of gadolinium on automatic myelin and brain tissue volumetry via quantitative synthetic MR imaging. MATERIALS AND METHODS: The study included 36 patients who were referred for brain metastases screening, and quantitative synthetic MR imaging data before and after gadolinium-based contrast agent administration were analyzed retrospectively. Brain metastases were detected in 17 patients. WM volume, GM volume, CSF volume, non-WM/GM/CSF volume, myelin volume, brain parenchymal volume, myelin fraction (myelin volume/brain parenchymal volume), and intracranial volume were estimated. T1 and T2 relaxation times, proton density, and myelin partial volume per voxel averaged across the brain parenchyma were also analyzed. RESULTS: In patients with and without metastases after gadolinium-based contrast agent administration, measurements of WM and myelin volumes, and myelin fraction were significantly increased (+26.65 and +29.42 mL, +10.14 and +12.46 mL, +0.88% and +1.09%, respectively), whereas measurements of GM, CSF, brain parenchymal, and intracranial volumes were significantly decreased (-36.23 and -34.49 mL, -20.77 and -18.94 mL, -6.76 and -2.84 mL, -27.41 and -21.84 mL, respectively). Non-WM/GM/CSF volume did not show a significant change. T1, T2, and proton density were significantly decreased (-51.34 and -46.84 ms, -2.67 and -4.70 ms, -1.05%, and -1.28%, respectively) after gadolinium-based contrast agent administration, whereas measurements of myelin partial volume were significantly increased (+0.78% and +0.75%, respectively). CONCLUSIONS: Gadolinium had a significant effect on the automatic calculation of myelin and brain tissue volumes using quantitative synthetic MR imaging, which can be explained by decreases in T1, T2, and proton density.

Automated brain tissue and myelin volumetry based on quantitative MR imaging with various in-plane resolutions.

BACKGROUND AND PURPOSE: Segmented brain tissue and myelin volumes can now be automatically calculated using dedicated software (SyMRI), which is based on quantification of R1 and R2 relaxation rates and proton density. The aim of this study was to determine the validity of SyMRI brain tissue and myelin volumetry using various in-plane resolutions. METHODS: We scanned 10 healthy subjects on a 1.5T MR scanner with in-plane resolutions of 0.8, 2.0 and 3.0mm. Two scans were performed for each resolution. The acquisition time was 7-min and 24-sec for 0.8mm, 3-min and 9-sec for 2.0mm and 1-min and 56-sec for 3.0mm resolutions. The volumes of white matter (WM), gray matter (GM), cerebrospinal fluid (CSF), non-WM/GM/CSF (NoN), brain parenchymal volume (BPV), intracranial volume (ICV) and myelin were compared between in-plane resolutions. Repeatability for each resolution was then analyzed. RESULTS: No significant differences in volumes measured were found between the different in-plane resolutions, except for NoN between 0.8mm and 2.0mm and between 2.0mm and 3.0mm. The repeatability error value for the WM, GM, CSF, NoN, BPV and myelin volumes relative to ICV was 0.97%, 1.01%, 0.65%, 0.86%, 1.06% and 0.25% in 0.8mm; 1.22%, 1.36%, 0.73%, 0.37%, 1.18% and 0.35% in 2.0mm and 1.18%, 1.02%, 0.96%, 0.45%, 1.36%, and 0.28% in 3.0mm resolutions. CONCLUSION: SyMRI brain tissue and myelin volumetry with low in-plane resolution and short acquisition times is robust and has a good repeatability so could be useful for follow-up studies.

Analysis of White Matter Damage in Patients with Multiple Sclerosis via a Novel In Vivo MR Method for Measuring Myelin, Axons, and G-Ratio.

BACKGROUND AND PURPOSE: Myelin and axon volume fractions can now be estimated via MR imaging in vivo, as can the g-ratio, which equals the ratio of the inner to the outer diameter of a nerve fiber. The purpose of this study was to evaluate WM damage in patients with MS via this novel MR imaging technique. MATERIALS AND METHODS: Twenty patients with relapsing-remitting MS with a combined total of 149 chronic plaques were analyzed. Myelin volume fraction was calculated based on simultaneous tissue relaxometry. Intracellular and CSF compartment volume fractions were quantified via neurite orientation dispersion and density imaging. Axon volume fraction and g-ratio were calculated by combining these measurements. Myelin and axon volume fractions and g-ratio were measured in plaques, periplaque WM, and normal-appearing WM. RESULTS: All metrics differed significantly across the 3 groups (P < .001, except P = .027 for g-ratio between periplaque WM and normal-appearing WM). Those in plaques differed most from those in normal-appearing WM. The percentage changes in plaque and periplaque WM metrics relative to normal-appearing WM were significantly larger in absolute value for myelin volume fraction than for axon volume fraction and g-ratio (P < .001, except P = .033 in periplaque WM relative to normal-appearing WM for comparison between myelin and axon volume fraction). CONCLUSIONS: In this in vivo MR imaging study, the myelin of WM was more damaged than axons in plaques and periplaque WM of patients with MS. Myelin and axon volume fractions and g-ratio may potentially be useful for evaluating WM damage in patients with MS.

Effectiveness of early administration of tranexamic acid in patients with severe trauma.

BACKGROUND: A reduction in mortality with the early use of tranexamic acid has been demonstrated in severely injured patients who are bleeding. However, the modest treatment effect with no reduction in blood transfusion has raised concerns. The aim of the present study was to estimate the effectiveness of regular use of tranexamic acid in severely injured patients. METHODS: This multicentre observational study used retrospectively collected data from consecutive injured patients (Injury Severity Score at least 16) treated in 15 Japanese academic institutions in 2012. A propensity score-matched analysis compared patients who did or did not receive tranexamic acid administration within 3 h of injury. Study outcomes included 28-day all-cause and cause-specific mortality, and need for blood transfusion. RESULTS: Of 796 eligible subjects, 281 were treated with tranexamic acid. Propensity score matching selected a total of 500 matched subjects (250 in each group). Tranexamic acid administration was associated with lower 28-day mortality (10·0 versus 18·4 per cent; difference -8·4 (95 per cent c.i. -14·5 to -2·3) per cent) and lower 28-day mortality from primary brain injury (6·0 versus 13·2 per cent; difference -7·2 (-12·3 to -2·1) per cent). However, there was no significant difference between groups in the need for blood transfusion (33·2 versus 34·8 per cent; difference -1·6 (-9·9 to 6·7) per cent). CONCLUSION: Early tranexamic acid use was associated with reduced mortality in severely injured patients, in particular those with a primary brain injury.

Synthetic MRI in the Detection of Multiple Sclerosis Plaques.

BACKGROUND AND PURPOSE: Synthetic MR imaging enables the creation of various contrast-weighted images including double inversion recovery and phase-sensitive inversion recovery from a single MR imaging quantification scan. Here, we assessed whether synthetic MR imaging is suitable for detecting MS plaques. MATERIALS AND METHODS: Quantitative and conventional MR imaging data on 12 patients with MS were retrospectively analyzed. Synthetic T2-weighted, FLAIR, double inversion recovery, and phase-sensitive inversion recovery images were produced after quantification of T1 and T2 values and proton density. Double inversion recovery images were optimized for each patient by adjusting the TI. The number of visible plaques was determined by a radiologist for a set of these 4 types of synthetic MR images and a set of conventional T1-weighted inversion recovery, T2-weighted, and FLAIR images. Conventional 3D double inversion recovery and other available images were used as the criterion standard. The total acquisition time of synthetic MR imaging was 7 minutes 12 seconds and that of conventional MR imaging was 6 minutes 29 seconds The lesion-to-WM contrast and lesion-to-WM contrast-to-noise ratio were calculated and compared between synthetic and conventional double inversion recovery images. RESULTS: The total plaques detected by synthetic and conventional MR images were 157 and 139, respectively (P = .014). The lesion-to-WM contrast and contrast-to-noise ratio on synthetic double inversion recovery images were superior to those on conventional double inversion recovery images (P = .001 and < 0.001, respectively). CONCLUSIONS: Synthetic MR imaging enabled detection of more MS plaques than conventional MR imaging in a comparable acquisition time. The contrast for MS plaques on synthetic double inversion recovery images was better than on conventional double inversion recovery images.

Utility of a Multiparametric Quantitative MRI Model That Assesses Myelin and Edema for Evaluating Plaques, Periplaque White Matter, and Normal-Appearing White Matter in Patients with Multiple Sclerosis: A Feasibility Study.

BACKGROUND AND PURPOSE: T1 and T2 values and proton density can now be quantified on the basis of a single MR acquisition. The myelin and edema in a voxel can also be estimated from these values. The purpose of this study was to evaluate a multiparametric quantitative MR imaging model that assesses myelin and edema for characterizing plaques, periplaque white matter, and normal-appearing white matter in patients with MS. MATERIALS AND METHODS: We examined 3T quantitative MR imaging data from 21 patients with MS. The myelin partial volume, excess parenchymal water partial volume, the inverse of T1 and transverse T2 relaxation times (R1, R2), and proton density were compared among plaques, periplaque white matter, and normal-appearing white matter. RESULTS: All metrics differed significantly across the 3 groups (P < .001). Those in plaques differed most from those in normal-appearing white matter. The percentage changes of the metrics in plaques and periplaque white matter relative to normal-appearing white matter were significantly more different from zero for myelin partial volume (mean, -61.59 ± 20.28% [plaque relative to normal-appearing white matter], and mean, -10.51 ± 11.41% [periplaque white matter relative to normal-appearing white matter]), and excess parenchymal water partial volume (13.82 × 103 ± 49.47 × 103% and 51.33 × 102 ± 155.31 × 102%) than for R1 (-35.23 ± 13.93% and -6.08 ± 8.66%), R2 (-21.06 ± 11.39% and -4.79 ± 6.79%), and proton density (23.37 ± 10.30% and 3.37 ± 4.24%). CONCLUSIONS: Multiparametric quantitative MR imaging captures white matter damage in MS. Myelin partial volume and excess parenchymal water partial volume are more sensitive to the MS disease process than R1, R2, and proton density.

Clinical evaluation of acute phase nystagmus associated with cerebellar lesions.

OBJECTIVES: To determine the characteristics of acute phase nystagmus in patients with cerebellar lesions, and to identify a useful indicator for differentiating central lesions from peripheral lesions. METHODS: Acute phase nystagmus and the appearance of neurological symptoms were retrospectively investigated in 11 patients with cerebellar stroke. RESULTS: At the initial visit, there were no patients with vertical nystagmus, direction-changing gaze evoked nystagmus or pure rotatory nystagmus. There were four cases with no nystagmus and seven cases with horizontal nystagmus at the initial visit. There were no neurological symptoms, except for vertigo and hearing loss, in any cases at the initial visit. The direction and type of nystagmus changed with time, and neurological symptoms other than vertigo appeared subsequently to admission. CONCLUSION: It is important to observe the changes in nystagmus and other neurological findings for the differential diagnosis of central lesions.

Clinical study of tympanostomy tube placement for patients with intractable Ménière's disease.

OBJECTIVE: To evaluate the effectiveness of tympanostomy tube placement in controlling symptoms of intractable Ménière's disease. METHODS: Fifteen patients with intractable Ménière's disease underwent tympanostomy tube placement in the affected ear. Post-operative changes in vertigo attacks and hearing level were recorded, and were evaluated according to American Academy of Otolaryngology-Head and Neck Surgery criteria. RESULTS: At 12 months after treatment, 3 patients (20 per cent) showed complete control of vertigo, 7 (47 per cent) showed substantial control and 2 (13 per cent) showed limited control; 3 patients (20 per cent) required other treatment. At 24 months after treatment, 7 patients (47 per cent) showed complete control of vertigo, 3 (20 per cent) showed substantial control and 1 (7 per cent) showed limited control; 1 patient required other treatment 15 months after tympanostomy tube placement. CONCLUSION: There is no definite pathophysiological explanation for the effect of tympanostomy tube placement in reducing vertigo attacks. This treatment is not effective for all patients with intractable Ménière's disease. However, tympanostomy tube placement might be an additional surgical therapeutic option to consider prior to contemplating other, more invasive treatments.

A case of pulmonary oedema induced by suffocation.

A 57-year old female civilian was suffocated by an intruder The victim (experienced severe dyspnoea) but violently resisted the assault. Two hours after this event, on admission to a Trauma Centre, she demonstrated left facial swelling with low percutaneous oxygen saturation. Chest X-ray and computed tomography demonstrated pulmonary oedema. This improved dramatically within a short time and she was discharged on the 5th hospital day. Pulmonary oedema induced by suffocation has been reported only rarely. The possible mechanisms by which pulmonary oedema might form after the relief of airway obstruction are discussed.

Measurement of short-chain fatty acids in human faeces using high-performance liquid chromatography: specimen stability.

BACKGROUND: Short-chain fatty acids such as lactic acid produced by the intestinal bacterial flora have various physiological actions involved in health, and it is important to determine the concentrations of faecal short-chain fatty acids and evaluate their relationship with large intestinal diseases. In this study, we evaluated the highly selective and sensitive simultaneous measurement of both volatile and non-volatile short-chain fatty acid hydrazides using high-performance liquid chromatography (HPLC). MATERIALS AND METHODS: Faeces treated with ethanol were used as analytic samples. Short-chain fatty acids were measured as fatty acid hydrazides by HPLC. RESULTS: For 12 types of short-chain fatty acid, the results regarding linearity, recovery tests and reproducibility were favourable. Faeces treated with ethanol could be stored at room temperature. DISCUSSION: The stability of short-chain fatty acids in faeces at room temperature was statistically analysed. Faeces stored without treatment with ethanol showed increases/decreases in the concentrations of short-chain fatty acids, which may be due to assimilation by intestinal bacteria. However, specimen in 70% ethanol and stored in room temperature exhibited no substantial changes in concentrations of short-chain fatty acids up to seven days.

A case of pulmonary oedema induced by suffocation / Un caso de edema pulmonar inducido por sofocación

A 57-year old female civilian was suffocated by an intruder. The victim (experienced severe dyspnoea) but violently resisted the assault. Two hours after this event, on admission to a Trauma Centre, she demonstrated left facial swelling with low percutaneous oxygen saturation. Chest X-ray and computed tomography demonstrated pulmonary oedema. This improved dramatically within a short time and she was discharged on the 5th hospital day. Pulmonary oedema induced by suffocation has been reported only rarely. The possible mechan-isms by which pulmonary oedema might form after the relief of airway obstruction are discussed.

Una ciudadana de 57 años fue sofocada por un intruso. La víctima experimentó una disnea severa, pero resistió violentamente el ataque. Dos horas después de este acontecimiento, al ser ingresada en un Centro de Traumas, se le observó hinchazón en el lado izquierdo de la cara, con una baja saturación percutánea de oxígeno. La radiografía del pecho y la tomografía computarizada mostraron un edema pulmonar. Este cuadro clínico mejoró dramáticamente en corto tiempo, y fue dada de alta al quinto día de su hospitalización. El edema pulmonar inducido por sofocación ha sido raramente reportado. Se discuten los posibles mecanismos por los cuales el edema pulmonar podría formarse después de desbloquearse la obstrucción de la vía respiratoria.