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PubMedDate not supplied

[Indication for transcranial Doppler studies in transient ischemic attack].

UNLABELLED: The diagnostic procedures for the assessment of transient ischemic attacks (TIA) include both brain imaging (computed tomography, nuclear magnetic resonance) and cerebrovascular investigation by means of ultrasound studies and angiography. Transcranial Doppler sonography (TCD) has not yet become a widely used diagnostic tool, although it allows noninvasive investigation of the intracranial cerebral circulation. The aim of this study was to assess the value of TCD investigation in patients who suffered from TIA. Eighty-one consecutive patients admitted to our General Medicine Department with a diagnosis of TIA underwent cranial computed tomography, ultrasound investigation of the extracranial cerebral arteries, and TCD. RESULTS: 39% of the TCD findings were not significant; TCD findings were highly significant in 18% of the patients with TIA, mainly for intracranial arterial stenoses and symptomatic subclavian steal; the other abnormal TCD findings were nonspecific, but in all these cases TCD yielded information on the efficiency of intracranial collateralization and the mechanisms regulating cerebral hemodynamics. These results suggest that TCD is a useful tool for the assessment of TIA.

Adult↗
PubMed1994

Developmental alterations in the sensitivity of hippocampal NMDA receptors to AP5.

Changes in the properties of the N-methyl-D-aspartate (NMDA) receptor are proposed as a factor in the decrease in synaptic plasticity during maturation of the brain. Alterations in the hippocampal NMDA receptor population were studied during development by comparing competitive antagonist efficacy during a window characterized by hyperexcitability and active synaptogenesis to that seen in a more mature period. A developmental change in the sensitivity of the N-methyl-D-aspartate (NMDA) evoked response to the competitive antagonist D(-)2-amino-5- phosphonopentanoic acid (D-AP5) was observed by whole-cell mode voltage-clamp, intracellular and extracellular recordings in hippocampal slices. These differences were observed in the portions of the hippocampus that contain the terminal axon arbors of the CA3 pyramidal neurons, the synaptic fields of the Schaffer collateral, associational and commissural pathways. The apparent antagonist efficacy was 2-3 times greater in immature slices obtained on postnatal day (PND) 10-16 than that observed in more mature tissue (> PND38). Given the possible role of the NMDA receptor in network plasticity, these observations could indicate a role for the molecular diversity of this important receptor subtype family in the maturation of hippocampal pathways.

2-Amino-5-phosphonovalerate↗
PubMed2004

Changes in the expression of calbindin D-28k in the gerbil hippocampus following seizure.

Previous studies have reported that calbindin D-28k (CB), a calcium-binding protein, containing neurons in the hippocampus play an important role in hippocampal excitability in epilepsy, because CB modulates the free calcium ion during seizure. Hence, in the present study, we investigated changes of CB expression in the hippocampus and its association in the Mongolian gerbil to identify roles of CB in epileptogenesis. CB immunoreactivity in the hippocampus was significantly lower in the pre-seizure group of seizure sensitive (SS) gerbils as compared with those seen in the seizure resistant (SR) gerbils. The distribution of CB immunoreactivity in the hippocampus showed significant difference after seizure on-set in SS gerbils. CB immunoreactivity in the hippocampal CA1, CA2 areas, and subiculum was lowest at 3h after seizure on-set; thereafter, the immunoreactivity became to increase to 12h after seizure on-set. Mossy fibers, Schaffer collaterals and dentate granule cells showed the highest CB immunoreactivity at 3h after seizure on-set; thereafter, the immunoreactivity became to decrease. In the case of the intrinsic and output connections of the hippocampus, a rapid decrease of CB serves an inhibitory function, which regulates the seizure activity and output signals from the hippocampus.

Animals↗
PubMed1999

MR imaging of coarctation of the aorta and its postoperative complications in adults: assessment with spin-echo and cine-MR imaging.

To evaluate the ability of ECG-gated spin-echo (SE)-MR imaging vs. cine-MR imaging to assess coarctation of the aorta, 11 patients aged 15-45 years, with known or suspected coarctation of the aorta, and five patients suspected of re-stenosis or postoperative false-aneurysms after coarctation repair were examined by multisection SE-MR imaging and single-section multiphase cine-MR imaging on a 1.0 Tesla device. Aortography was performed in 15, and surgery in 14 of these 16 patients. Qualitatively, the location, severity, and length of the coarctation were shown in all cases with MR imaging, as well as the relationship with the arteries arising from the aortic arch. The respective sensitivities and specificities in the assessment of severity of stenoses were 86% and 100% for SE MR images, and 100% and 100% for cine-MR images. Cine-MR imaging was superior to SE imaging in stenosis diameter assessment with contrast angiography as reference, as well as to identify the site of leakage in cases of postoperative pseudoaneurysm. Pre-stenotic dilation or post-stenotic aneurysm, collateral channels, and associated malformations were better identified on SE images. Quantitatively, a better stenosis diameter correlation was found between cine-MR images and angiography than between SE-MR images and angiography (r=0.99 vs. r=0.78; p=0.001 vs. p=0.004), related to overestimation of stenoses with SE-MR imaging. The use of a combination of spin-echo and cine-MR imaging correlates well with conventional angiographic findings in this small series of patients with coarctation of aorta or postoperative pseudoaneurysmal complications. Cine-MRI can provide anatomic information that is equivalent to angiography for surgical planning.

Adolescent↗
PubMed2002

The early magnetic resonance imaging features of the knee in juvenile idiopathic arthritis.

AIMS: Early diagnosis of juvenile idiopathic arthritis (JIA) facilitates earlier more aggressive therapy, and improved outcome. Recognition of the features of early, untreated JIA on magnetic resonance imaging (MRI) will improve disease detection and expedite treatment. This study aims to highlight the relevant MRI features. METHODS: MRI examinations of the knee joint were performed on 11 children with clinically confirmed, early, untreated JIA. The MRI images were obtained at a mean of 2 months after symptom onset and independently evaluated by two consultant paediatric radiologists. RESULTS: Abnormalities were found on all MRI examinations. Synovial hypertrophy, joint effusions, popliteal lymph nodes and soft tissue swelling were present in all patients. Gadolinium DTPA enhancement improved the detection of synovial hyperplasia. Metaphyseal splaying and condylar overgrowth were seen in five cases (41%), oedema of the lateral collateral ligament in two cases (18%) and superficial cartilage thinning in one case. Bony erosions and deep cartilage destruction were not demonstrated. CONCLUSION: MRI of the knee joint identifies early joint changes which are distinct from those in later disease. The presence of these features should alert the radiologist to the possible diagnosis of JIA and post gadolinium DTPA sequences should be performed. Gadolinium DPTA enhancement increases the sensitivity for the detection of inflammatory changes in JIA.

Adolescent↗
PubMed1988

Regulation of glutamate and aspartate release from slices of the hippocampal CA1 area: effects of adenosine and baclofen.

Glutamate and/or aspartate is the probable transmitter released from synaptic terminals of the CA3-derived Schaffer collateral, commissural, and ipsilateral associational fibers in area CA1 of the rat hippocampal formation. Slices of the CA1 area were employed to test the effects of adenosine- and gamma-aminobutyrate (GABA)-related compounds on the release of glutamate and aspartate from this projection. Under the conditions of these experiments, the release of glutamate and aspartate evoked by 50 mM K+ was more than 90% Ca2+-dependent and originated predominantly from the CA3-derived pathways. Adenosine reduced the K+-evoked release of glutamate and aspartate by a maximum of about 60%, but did not affect the release of GABA. This action was reversed by 1 microM 8-phenyltheophylline. The order of potency for adenosine analogues was as follows: L-N6-phenylisopropyladenosine greater than N6-cyclohexyladenosine greater than D-N6-phenylisopropyladenosine approximately equal to 2-chloroadenosine greater than adenosine much greater than 5'-N-ethylcarboxamidoadenosine. 8-Phenyltheophylline (10 microM) by itself enhanced glutamate/aspartate release, whereas dipyridamole alone depressed release. These results support the view that adenosine inhibits transmission at Schaffer collateral-commissural-ipsilateral associational synapses mainly by reducing transmitter release and that these effects involve the activation of an A1 receptor. Neither adenosine, L-N6-phenylisopropyladenosine, nor 8-phenyltheophylline affected the release of glutamate or aspartate evoked by 10 microM veratridine. The differing effects of adenosine compounds on release evoked by K+ and veratridine suggest that A1 receptor activation either inhibits Ca2+ influx through the voltage-sensitive channels or interferes with a step subsequent to Ca2+ entry that is coupled to the voltage-sensitive Ca2+ channels in an obligatory fashion. Neither baclofen nor any other agent active at GABAB or GABAA receptors affected glutamate or aspartate release evoked by elevated K+ or veratridine. Therefore, either baclofen does not inhibit transmission at these synapses by depressing transmitter release or else it does so in a way that cannot be detected when a chemical depolarizing agent is employed.

Adenosine↗
PubMed2005

Local anaesthetic infiltration increases the accuracy of assessment of ulnar collateral ligament injuries.

OBJECTIVE: To assess the effectiveness of a systematic examination of the ulnar collateral ligament (UCL) of the thumb metacarpophalangeal joint (MCPJ) prior to and post infiltration of local anaesthetic. METHODS: During the study period from 24 October 2001 to 22 February 2002, 51 patients with clinical signs suggestive of UCL injuries were identified prospectively from initial ED attendances and attendances at a subsequent review clinic. Patients were formally assessed a mean of 6.6 days post injury. A single ED Senior House Officer carried out examination before and after direct infiltration of local anaesthetic around the site of injury. Stress radiography was also performed as the 'gold standard' diagnostic test of UCL instability. RESULTS: Forty-seven patients were enrolled in the study. When reviewed by the single observer, examination prior to and post local anaesthetic infiltration revealed a degree of joint stability in 28% (95% CI 16-43%) and 98% (95% CI 88-100%) cases, respectively, compared to the gold standard. Post infiltration, this technique had a specificity of 100% (95% CI 94-100%) and a sensitivity of 87.5% (95% CI 74-95%) (P < 0.001). Stress radiography offered additional information in one patient. A total of eight patients previously underdiagnosed in the ED were found to have unstable thumb MCPJs. CONCLUSION: This simple technique improves assessment of suspected UCL injuries approximately 1 week post injury. Further studies are indicated to determine its effectiveness in the ED immediately post injury.

Adolescent↗
PubMed1990

Descending neurons supplying the neck and flight motor of Diptera: physiological and anatomical characteristics.

In Diptera, dorsal neuropils of the pro-, meso-, and metathoracic ganglia supply motor neurons to neck and flight muscles. Motor circuits are supplied by more than 50 pairs of descending neurons (DNs) whose dendritic trees in the brain are restricted to dorsal neuropils of the deutocerebrum where they are grouped together into discrete clusters. Each cluster is visited by wide-field motion-sensitive neurons and by morphologically small-field retinotopic elements. This organization suggests that flight descending neurons should respond to complex stimuli reflecting panoramic movement and small-field motion. Intracellular recordings, combined with dye filling, confirm this. Certain descending neurons responding to visual flow fields terminate bilaterally in superficial pterothoracic neuropils, at the level of indirect (power) flight muscle motor neurons. Other DNs terminate laterally, and provide segmental collaterals to areas containing neck and direct (steering) flight muscle motor neurons. Such DNs are activated by wide-field directional stimuli corresponding to pitch, roll, or yaw, and to small-field stimuli. Appropriate directional mechanosensory stimuli also activate dorsal descending neurons. The significance of dorsal descending neurons for the control of flight is discussed and compared with studies on course deviation neurons in other insects. It is suggested that, in Diptera, dorsal descending neurons may separately be involved in the control of velocity, stabilization, and steering manoeuvres.

Animals↗
PubMed1997

Localization of NADPH-diaphorase containing neurons in the spinal dorsal horn and spinal sensory ganglia of the turtle Chrysemys d'orbigny.

NADPH-diaphorase positive (NDP) neurons and nerve fibers were found in the spinal dorsal horn (DH) and sensory ganglia of the turtle Chrysemys d'orbigny. Three well-defined types of NDP neurons were found in the DH: (a) elongated nerve cells with two radially arranged dendritic branches, (b) neurons with rostrocaudal dendritic branches, (c) bitufted neurons with two, practically symmetric branches that project to the ipsilateral and contralateral dorsal horns. A combination of the techniques that reveal NADPH-diaphorase activity with the horseradish peroxidase transganglionic labeling of the dorsal root collaterals, suggested that NDP neurons of the DH are second-order cells of the spinal sensory pathway. NDP neurons were also found in the spinal sensory ganglia at all metameric levels. Our findings indicate that the DH of turtles, like that of mammals, contains both the enzymatic machinery and the neural connections required to postulate the participation of nitric oxide in "plastic phenomena" such as hyperalgesia and central sensitization. Two other alternatives or complementary hypotheses are discussed: (a) NDP neurons in the DH and sensory ganglia may represent specific cell populations involved in the processing of sensory visceral information; (b) NADPH-diaphorase reactivity may indicate sustained levels of neuronal activity.

Afferent Pathways↗
PubMed2005

Activation of group I metabotropic glutamate receptors depresses recurrent inhibition of motoneurons in the neonatal rat spinal cord in vitro.

This study examined whether activation of group I metabotropic glutamate receptors (mGluRs) could modulate synaptic inhibition of spinal motoneurons in the neonatal rat isolated spinal cord. Recurrent inhibitory postsynaptic potentials (IPSPs) generated by Renshaw cells were evoked via antidromic stimulation of motor axon collaterals and recorded intracellularly from lumbar motoneurons. The selective agonist of group I mGluRs DHPG (5 micromol L-1) depressed the recurrent IPSP, an effect prevented by the selective antagonist AIDA (500 micromol L-1). The depression by DHPG was use-independent and could be partly counteracted by increasing stimulus strength. Paired pulse depression observed at <or=50-ms intervals was blocked by DHPG in an AIDA-sensitive manner. These results suggest that, in the presence of DHPG, smaller recurrent IPSPs can contribute to the excitatory action of mGluR activation on spinal networks, including the generation of synchronous oscillations recorded from motoneurons.

Analysis of Variance↗
PubMed2003

Transanal laser Doppler flowmetry to assess microcirculation in the upper rectum during abdominal aortic aneurysmectomy.

PURPOSE: Fatal ischemic colitis can develop after abdominal aortic aneurysmectomy. We investigated the effectiveness of transanal laser Doppler flowmetry (LDF) for assessing microcirculation in the rectal mucosa during aneurysm repair. METHODS: The subjects were 17 patients who underwent abdominal aortic aneurysmectomy. A Doppler laser and Doppler probe were mounted on a rectoscope, which was inserted into the anus, and rectal flux values were obtained by a flowmeter. RESULTS: The mean flux value during aortic clamping was 146 +/- 35.6 perfusion units (PU) in patients with sufficient collateral circulation to the upper rectum and 58.3 +/- 19.4 PU in patients with insufficient collateral circulation ( P << 0.01). The LDF values and inferior mesenteric artery stump pressure measurements were well correlated ( r = 0.86). CONCLUSION: Transanal rectal LDF is useful for continuously assessing microcirculation in the rectal mucosa during abdominal aneurysmectomy, and the data obtained with this method may reflect whether a collateral pathway to the upper rectum exists.

Adult↗
PubMed2002

Alterations of intestinal motor responsiveness in a model of mild mesenteric ischemia/reperfusion in rats.

In this study we investigate the changes in intestinal motor responsiveness after mild mesenteric ischemia/reperfusion in anaesthetized rats. Motor responsiveness to pharmacological/electrical stimulation was studied in isolated ileum excised from sham-operated rats or animals which underwent occlusion of superior mesenteric artery (1 h) plus interruption of collateral blood flow and reperfusion for 0, 24, 72 h. Only 24 h reperfusion resulted in a significant suppression in acetylcholine induced contractile response and in indomethacin induced relaxation. In the presence of adrenergic and cholinergic blockade a greater relaxant response to field stimulation (trains 10 s every min, 120 mA, 1 ms and 10 Hz) was unmasked in all groups except 24 h reperfused rats. Such effect was sensitive to N(G)-Nitro-L-arginine methyl ester (NOS unselective inhibitor) and the proteolytic enzyme alpha-chymotrypsin but resistant to aminoguanidine (iNOS selective inhibitor). In conclusion, in this rat model, intestinal mild ischemia/24 h reperfusion induces reversible changes in enteric motility attributable to a decrease in eicosanoids, nitric oxide and neuropeptides availability.

Acetylcholine↗
PubMed1998

Photodynamic therapy of intracranial tissues: a preclinical comparative study of four different photosensitizers.

OBJECTIVE: The effectiveness of four different photosensitizers for intracranial photodynamic therapy (PDT) of normal brain tissues and an intracranial tumor was investigated in rabbits, using the photodynamic threshold model. SUMMARY: PDT is currently being investigated as an adjuvant treatment to surgical resection and/or radio chemotherapy of intracranial neoplasms. While possible neurotoxic side effects of the treatment have been noted, only limited preclinical data quantifying the response of intracranial normal and tumor tissues following PDT are available. MATERIALS AND METHODS: The photodynamic threshold dose values for the four photosensitizers, Photofrin, 5-aminolevulinic acid (ALA)-induced Protoporphyrin IX (PpIX), Tin Ethyl Etiopurpurin (SnET2), and chloroaluminum phthalocyanine (AlClPc), were determined using measured light fluence distributions, photosensitizer concentration in tissue, and histologically-determined extent of necrosis following PDT. These measurements were made in normal rabbit brain and in an intracranially-implanted carcinoma (VX2). RESULTS: For Photofrin, AlClPc, and SnET2 (in an emulsion delivery vehicle) normal grey and white matter were very sensitive to PDT, showing a significantly lower threshold dose value than VX2-tumor. For ALA-induced PpIX and SnET2 (in liposome) very little or no white matter damage was observed. Additionally, ALA-PpIX showed significantly lower concentration in white matter than in cortex and tumor. Normal brain structures lacking a blood-brain barrier showed high uptake of all photosensitizers and, hence, are at risk of collateral damage during PDT. CONCLUSIONS: For clinical PDT of most adult intracranial neoplasms ALA-induced PpIX appears to be promising, and SnET2 (liposomal) has potential for selective tumor destruction with relative sparing of white matter. Other normal brain structures and, for the other photosensitizers, also white matter are at risk of collateral damage, if exposed to light during PDT.

Animals↗
PubMed1989

Sensitivity and neural organization of the cat cornea.

The innervation of the adult cat cornea was investigated both psychophysically and histologically. Mean corneal touch threshold (CTT) for 25 adult domestic cats was 43 +/- 9 mg in the center of the cornea and 100 +/- 32 and 94 +/- 33 mg in the superior and inferior cornea, respectively. Gold chloride impregnation showed that the cat cornea is innervated by 16-20 radial nerve trunks that enter the mid-posterior stroma at various sites around the corneal circumference. As these trunks travel anteriorly toward the center of the cornea they give off collaterals that form the anterior stromal and subepithelial plexus. Fibers from the subepithelial plexus penetrate the epithelial basement membrane and give off numerous long fibers that ramify in the basal epithelial layer. Intraepithelial terminals arise from these, penetrating between the epithelial cells, ending with a terminal enlargement at the wing cell level. A distinct pattern of neural organization was found in the periphery of the cat cornea. This consisted of finer nerve fibers that entered the cornea at the subepithelial and basal epithelial levels at numerous sites around the corneal circumference. These fibers branched after a short distance in the cornea and appeared to innervate the anterior stroma and epithelium in the periphery of the cornea. This study thus provides direct evidence of two types of neural organization in the cornea of the domestic cat. Stromal nerves appear to be the main source of innervation to the epithelium in the center of the cornea while conjunctival nerves supply the peripheral epithelium.

Animals↗
PubMed1994

GABA synapses formed in vitro by local axon collaterals of nucleus accumbens neurons.

GABAergic medium-spiny neuron axons not only form the principal projections of the nucleus accumbens (nAcc) but also branch locally in a dense network overlapping their own dendrites, suggesting that their recurrent synapses mediate the major information processing functions of the nAcc. We used postnatal nAcc cultures to study these synapses individually. In culture, as in the intact nAcc, medium-spiny neurons account for over 95% of the cells and are GABAergic. Strikingly, these neurons showed a spike afterhyperpolarization (AHP) that was largely blocked by the GABAA antagonist bicuculline. The bicuculline-sensitive AHP occurred without or with latency, and met criteria for monosynapticity; consistent with this, dye fills showed the presence of recurrent axons and a low incidence of dye coupling. Blockade of Ca2+ influx eliminated this autaptic PSP, while TTX almost completely eliminated it, indicating that it is due to exocytic GABA release principally at axodendritic contacts. While blocking GABAB receptors had no direct effect on the autaptic PSP, activating these receptors with baclofen produced presynaptic inhibition, as well as directly mediated hyperpolarization; together, these actions increased the signal-to-noise ratio in the cellular response to synaptic inputs. Bicuculline also increased the signal-to-noise ratio; in addition, it induced burst firing and depolarization inactivation. In contrast, the indirect GABA agonist flurazepam and the GABA uptake blocker nipecotic acid each enhanced autaptic PSPs. Since autapses formed in vitro appear to be functionally equivalent to synapses between neighboring medium-spiny neurons that receive similar inputs, these results bear on the function of intrinsic GABA synapses in the intact nAcc. Thus, intrinsic GABA synapses are likely to regulate the signal-to-noise ratio in nAcc information processing and may be important targets for the modulatory actions of endogenous neurotransmitters and drugs.

Animals↗
PubMed1985

Spectral analysis of hippocampal EEG in the freely moving rat: effects of centrally active drugs and relations to evoked potentials.

Hippocampal EEG signals derived from chronically implanted electrodes in the freely moving rat were recorded before and after administration of centrally acting drugs, and analyzed by power and coherence spectra. Eserine, ether or urethane induced a low frequency (3-6 c/sec) theta power and coherence peak in the immobile rat, which was sensitive to atropine or scopolamine. After phencyclidine, theta that occurred during walking (7-8 c/sec) was virtually abolished by atropine while in the normal rat, absolute theta power was not affected by atropine. The residue spectrum, defined as the EEG spectrum with the theta harmonics removed, was sensitive to centrally acting drugs. Ether, urethane and pentobarbital suppressed fast waves of 50-100 c/sec, and under some conditions, enhanced 15-50 c/sec waves. Eserine enhanced (30-60 c/sec) fast waves during walking while atropine suppressed fast waves and increased irregular slow activity (less than 30 c/sec). The main effects of drugs and behavior on the residue spectra and on the average evoked potentials following stimulation of the Schaffer collaterals could be explained by a previously proposed model (Leung 1982) which suggests a continuum of hippocampal 'activation' (tonic input) under the various conditions.

Anesthetics↗
PubMed1992

Effects of intracoronary cromakalim on postischaemic contractile function and action potential duration.

OBJECTIVE: The effects of intracoronary cromakalim (1 microgram.kg-1 x min-1) on postischaemic contractile function and monophasic action potential duration at the 95% repolarisation level (APD95) were assessed in a canine model of stunned myocardium. METHODS: Animals (n = 24) were anaesthetised, subjected to a left thoracotomy, and the left anterior descending coronary artery was isolated. Measurements of segmental shortening and monophasic action potential were taken before drug, after drug, during a 15 min occlusion, and at times following reperfusion. RESULTS: Cromakalim significantly improved reperfusion recovery of function. Both preischaemic and postischaemic myocardial blood flows were increased with cromakalim, although there was no significant change in collateral blood flow during ischaemia relative to vehicle. In the absence of ischaemia, cromakalim reduced APD95 by 8%. There was no change in APD95 with vehicle alone. During coronary occlusion, cromakalim significantly reduced APD95 by 27% as compared with 8% in the vehicle group. APD95 values returned to preocclusion levels within minutes of reperfusion and remained there throughout reperfusion (30 min). Glyburide (3.0 mg.kg-1 intravenously), a blocker of ATP sensitive potassium channels, abolished the APD95 effects of cromakalim. One out of six animals given glyburide survived through reperfusion. In contrast, four out of five of the glyburide+cromakalim treated animals survived through reperfusion. CONCLUSIONS: Cardioprotection with cromakalim is likely to be mediated through activation of ATP sensitive potassium channels, measured as a decrease in action potential duration. Shortening of action potential duration with cromakalim was shown to be augmented in the presence of ischaemia. It is suggested that a possible interrelationship between cardioprotection and action potential duration shortening may exist such that the cardioprotective effects of cromakalim may be selective for ischaemic conditions.

Action Potentials↗
PubMedDate not supplied

The fat pad sign following elbow trauma in adults: its usefulness and reliability in suspecting occult fracture.

OBJECTIVE: An elbow joint effusion with no fracture seen on radiographs after acute trauma has become synonymous with occult fracture. This study evaluates the incidence of fracture in such cases as determined by MR imaging and the predictive value of an elbow joint effusion. METHODS: Twenty consecutive patients whose posttrauma elbow radiographs showed an effusion but no fracture and who were suitable for MR imaging were recruited. The elbow effusion size, represented by anterior and posterior fat pad displacement, was measured from the initial lateral elbow radiograph. Suitable candidates underwent MR imaging using a bone marrow sensitive sequence. The time between injury and MR imaging ranged from 0 to 12 days (mean 4 days). RESULTS: Seventy-five percent of the 20 patients who underwent MR imaging had radiographically occult fractures identified. Some (86.6%) of these fractures were located in the radial head, 6.7% were in the lateral epicondyle, and 6.7% were in the olecranon. Ninety percent had evidence of bone marrow edema. Fifteen percent had collateral ligament disruption identified on MR imaging, and 5% had a loose body. There was no change in patient management as a result of the additional imaging. The anterior fat pad displacement ranged from 5 to 15 mm (mean 9.25), and the posterior fat pad was elevated from 1 to 6 mm (mean 3.2). CONCLUSION: Our data using MR imaging suggests that fat pad elevation in the presence of recent trauma is frequently associated with a fracture. The size of the effusion, anterior/posterior fat pad elevation, or a combination of both does not correspond to the likelihood of an underlying fracture. MR imaging reveals a broad spectrum of bone and soft tissue injury beyond that recognizable on plain radiographs as demonstrated by all patients in this study.

Adipose Tissue↗