shu-508 and Acute-Disease

Color-coded perfusion maps can be calculated from ultrasound harmonic gray-scale imaging data after ultrasound contrast agent bolus injection to analyze brain tissue perfusion. First reports indicate that this method can display cerebral perfusion deficits in acute ischemic stroke. We performed a prospective patient study to evaluate this approach.. Thirty consecutive patients suffering from acute middle cerebral artery infarction who presented to our department within 12 hours after symptom onset were investigated with ultrasound perfusion harmonic imaging (PHI) after Levovist bolus injection. Color-coded perfusion maps were calculated from the ultrasound data. In addition, the original gray-scale images were analyzed in cine mode. Findings were compared with those of cranial CT.. All 30 patients suffered from acute ischemic stroke of the middle cerebral artery territory (median National Institutes of Health Stroke Scale score, 16 points). Twenty-three of the 30 patients (76.7%) had sufficient PHI insonation conditions. In 19 of these 23 patients (82.6%), a marked deficit in contrast enhancement could be visualized by initial PHI with the color-coded parameter images and cine-mode images. In 17 of the 23 (73.9%), the perfusion deficit was found on the parameter images. The area of hypoperfusion in the initial PHI investigation corresponded to the definite area of infarction in follow-up cranial CT. In 3 of 23 patients (13.0%), a perfusion deficit could be demonstrated in PHI, although the supplying artery was found patent by transcranial color-coded duplex sonography.. With PHI, it is possible to display cerebral perfusion deficits in acute ischemic stroke. PHI yields additional information on the perfusion state of the human brain compared with extracranial and transcranial color-coded duplex sonography.

Topics: Acute Disease; Adult; Aged; Brain; Brain Ischemia; Contrast Media; Echoencephalography; Female; Humans; Image Processing, Computer-Assisted; Infarction, Middle Cerebral Artery; Male; Middle Aged; Polysaccharides; Predictive Value of Tests; Prospective Studies; Sensitivity and Specificity; Severity of Illness Index; Stroke; Tomography, X-Ray Computed

The aim of the present study was to assess the use of an echo-enhancing agent (Levovist; Schering AG) in equivocal carotid bifurcation ultrasound studies and compare the information obtained with digital subtraction angiography (DSA). Contrast-enhanced carotid ultrasound studies were performed on 30 carotid bifurcations in 28 patients. The standard carotid ultrasound examinations were considered equivocal for two reasons: apparent acute internal carotid artery occlusions (n = 10), and possibly patent but critically stenosed internal carotid arteries with the residual flow lumen being incompletely visualized (n = 20). All patients underwent subsequent carotid digital subtraction angiography. All patients with apparent acute carotid occlusions (n = 10) were correctly characterized on contrast-enhanced ultrasound when compared with DSA. The majority were complete occlusions (n = 8) although in two cases there were critical carotid stenoses requiring surgical endarterectomy. In the 'incompletely visualized lumen' group (n = 20), the majority (n = 16) were correctly characterized on contrast enhanced ultrasound: 13 cases of critically stenotic but patent internal carotid arteries, two cases without a haemodynamically significant stenosis and one case of a carotid occlusion with patent vasa vasorum. One of the critical carotid stenoses was prospectively reported as occluded on the 'gold standard' angiography. In three cases the flow lumen was still incompletely visualized due to calcified plaque despite an echo-enhancing agent; angiography revealed no significant stenosis in all cases. There was one false negative for internal carotid occlusion. This occurred early in the series and could be considered to be a technical error. Importantly, there were no false positives for carotid occlusion. Contrast-enhanced carotid ultrasound significantly improves diagnostic confidence in equivocal carotid ultrasound studies. In appropriate clinical settings this may reduce the need for subsequent carotid angiography.

Topics: Acute Disease; Aged; Aged, 80 and over; Angiography, Digital Subtraction; Carotid Artery, Internal; Carotid Stenosis; Contrast Media; Female; Humans; Injections, Intravenous; Male; Middle Aged; Polysaccharides; Prospective Studies; Ultrasonography, Doppler, Color

Ultrasonography (US) is a well-established method used to assess the brain-supplying arteries in the acute stroke setting. However, several technical and anatomic limitations are known to reduce its diagnostic accuracy and confidence level. Echocontrast agents (ECA) are known to improve the signal-to-noise ratio by enhancing the intensity of the reflecting Doppler signal. We undertook this prospective study to evaluate the diagnostic value of ECA in a consecutive, nonselected cohort of acute stroke patients with insufficient native US investigations.. During a 1-year period, 25 patients were examined within 48 hours of the onset of stroke. The need for ECA was due to an insufficient transtemporal (n=18), transforaminal (n=4), or extracranial (n=3) imaging of arteries potentially involved in the ischemic event. In 12 patients, a diagnostic suspicion could natively be raised, whereas in the other 13 patients, the strongly reduced image quality did not allow for any neurovascular conclusions. Four grams of Levovist was injected at a concentration of 200 mg/mL and 400 mg/mL for the extracranial and transcranial insonations, respectively. The effect of the echocontrast enhancement was assessed with respect to (1) signal enhancement, (2) image quality, (3) final diagnostic confidence, and (4) the need for additional neurovascular imaging methods.. In all but one patient (96%), a strong signal enhancement was noted, leading to a moderate (n=11) or strong improvement (n=10) of the transcranial image quality. Thus in a total of 18 patients (72%), the echoenhancement provided a neurovascular diagnosis of sufficient confidence. This led to the confirmation of the previously suspected findings and disclosed three further occlusions and four stenoses of the intracranial arteries. In contrast, for the three extracranial examinations the image quality was not sufficiently improved because of persistent color artifacts derived from adjacent neck vessels. Besides the seven patients with inconclusive examinations, five patients with conclusive echoenhanced US studies (48% in total) demanded additive neurovascular imaging studies, based on the clinical decision of the attending physicians. This led to confirmation of all high-confident sonographic diagnoses.. In summary, in approximately three fourths of our acute stroke patients with insufficient native US investigations, echocontrast enhancement enabled a reliable neurovascular diagnosis, allowing the cancellation of additive neurovascular imaging procedures in half of our cohort. Our preliminary results suggest that ECA can reasonably support the early cerebrovascular workup in the acute stroke setting.

Topics: Acute Disease; Adult; Aged; Aged, 80 and over; Cerebral Angiography; Cerebrovascular Disorders; Contrast Media; Diagnostic Imaging; Female; Follow-Up Studies; Humans; Image Enhancement; Image Processing, Computer-Assisted; Magnetic Resonance Angiography; Male; Middle Aged; Pilot Projects; Polysaccharides; Sensitivity and Specificity; Tomography, X-Ray Computed; Ultrasonography, Doppler, Transcranial

We sought to evaluate the diagnostic value of echo-enhanced transcranial color-coded duplex sonography (TCCD) and the clinical relevance of vascular pathology assessed by sonography for early clinical outcome in acute ischemic stroke.. We present 23 consecutive patients with an anterior circulation stroke in whom clinical examination, CT, and ultrasonography were performed within 5 hours after the onset of symptoms. Transcranial Doppler sonography (TCD) and unenhanced and contrast-enhanced TCCD (Levovist, 4 g, 300 mg/mL) were compared for their ability to detect middle cerebral artery (MCA) occlusion and flow velocity reduction suggesting hemodynamic impairment in the MCA distribution pathway. Sonographic examination times were registered. Baseline clinical characteristics and CT findings were assessed. Neurological deficit was quantified according to the National Institutes of Health Stroke Scale score, with an early clinical improvement defined as decrease of the score by 4 or more points or a complete resolution of the deficit on day 4.. Contrast-enhanced TCCD enabled diagnosis of intracranial vascular pathology in 20 affected hemispheres, whereas unenhanced TCCD and TCD were conclusive in 7 and 14 hemispheres, respectively (P=0.0001). Contrast-enhanced TCCD was superior in evaluating distal carotid (carotid-T) occlusion and differentiating major vessel occlusions from patent arteries with flow velocity diminution. Mean examination time for enhanced TCCD ranged from 5 to 7 minutes, depending on the number of investigated vessels (without or with MCA branches). Logistic regression selected a patent MCA without reduced blood flow velocity as the only independent predictor for an early clinical improvement (P<0.01).. Contrast-enhanced TCCD is a promising tool for early prognosis in anterior circulation stroke. It is considered superior to unenhanced TCCD and TCD.

Topics: Acute Disease; Aged; Aged, 80 and over; Arterial Occlusive Diseases; Cerebral Arteries; Cerebrovascular Disorders; Contrast Media; Diagnostic Imaging; Female; Humans; Image Enhancement; Male; Middle Aged; Polysaccharides; Prognosis; Reproducibility of Results; Sensitivity and Specificity; Time Factors; Ultrasonography, Doppler, Color; Ultrasonography, Doppler, Transcranial

The effect of transmyocardial laser revascularization (TMLR) on microperfusion and oxygen supply was studied in an acute ischemia model, using 35 pigs, with 13 serving as controls.. Measurement of tissue oxygen tension was compared with the semiquantitative measurement of microperfusion using contrast echocardiography and infrared laser Doppler. All methods were used before and after coronary occlusion and after TMLR. Effects were measured in the ischemic area and in two ischemia independent areas.. At baseline, oxygen partial pressure was 54.2 +/- 15.7 mmHg and decreased to 2.8 +/- 1.4 mmHg ( P < 0.05) after occlusion. After TMLR, oxygen tension increased to 27.3 +/- 8.5 mmHg ( P < 0.05) in the ischemic area, indicating a significant effect of TMLR on microperfusion and oxygen tension. Changes in regional oxygen tension corresponded to Levovist density changes in contrast echocardiography and changes in microperfusion measured by infrared laser Doppler.. Our data indicate that measurement of tissue oxygen tension is a suitable experimental tool to assess the effect of TMLR on myocardial perfusion, which cannot be discriminated using clinical imaging methods.

Topics: Acute Disease; Animals; Contrast Media; Coronary Circulation; Disease Models, Animal; Echocardiography; Electrochemistry; Ion-Selective Electrodes; Laser Therapy; Laser-Doppler Flowmetry; Lasers, Excimer; Male; Microcirculation; Myocardial Ischemia; Myocardial Revascularization; Myocardium; Oxygen; Partial Pressure; Polysaccharides; Reproducibility of Results; Swine

Occlusion of the internal carotid artery (ICA) and stroke may be the consequence of either local thrombosis due to atherosclerosis or massive embolism. Up to date, there are only few reports of subsequent recanalization.. We report 12/76 cases of acute ICA occlusion leading to ischemic stroke, in which early recanalization was identified. Ultrasound and stroke MRI findings, therapeutic options, and outcome are described.. 10/12 patients showed an- or hypoechogenic morphology of occlusion. While in 7/12 cases complete recanalization was seen, in 5/12 patients partial recanalization with filiform flow (4) or residual high-grade stenosis (1) was detected. 10/12 patients had territorial or subcortical infarction, while two showed small cortical lesions only. In 7/12 cases, a potential cardiac source of embolism was found. Five patients received tPA; four patients underwent early carotid endarterectomy of the partially recanalized ICA within 48 hours. In the 10-day follow-up examination 10/12 patients showed clinical improvement as measured by the NIHSS.. Spontaneous recanalization after occlusion of the ICA may occur and might be more frequent than hitherto assumed. Echogenicity analysis and serial examinations of symptomatic ICA occlusion is useful for identifying a patient subgroup that might benefit from further therapy.

Topics: Acute Disease; Aged; Carotid Artery, Internal; Carotid Stenosis; Contrast Media; Female; Gadolinium DTPA; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Polysaccharides; Remission, Spontaneous; Stroke; Ultrasonography, Doppler, Duplex

To evaluate the potential diagnostic advantages of the contrast agent Levovist for signal enhancement of small adjoining fetal vessels and to study the effect of Levovist before and during acute fetal hypoxia on the fetal circulation and the fetal blood flow velocities.. A prospective, randomized study was performed in 12 fetal sheep before and during acute fetal hypoxia produced by complete occlusion of the maternal common iliac artery. Two groups of animals were studied, comprising animals with (study group, n = 6) and without (control group, n = 6) Levovist. In the study group, Levovist was administered intravenously by a pump (modified IVAC P 4000, Schering, Berlin). Duration and intensity of signal enhancement were measured in the fetal aorta, the common carotid artery and the ophthalmic artery of both groups before and during hypoxia. Concurrently, fetal heart rates as well as systolic and diastolic blood flow velocities in all three vessels were recorded in both groups.. The increased signal intensity of up to 15 dB in the study group resulted in improved differentiation and imaging quality of adjoining small fetal vessels when compared with the control group. Neither before nor during acute hypoxia, significant differences of the fetal heart rate and the systolic and diastolic blood flow velocities were observed between the two groups (p > 0.05). In the study group, no emboli were caused by Levovist in any fetal tissue or in the placenta.. The contrast agent Levovist improves the detection and accuracy of monitoring flow velocities in small fetal vessels by increasing the intensity of the Doppler signal without affecting fetal heart rate or fetal blood flow velocities.

Topics: Acute Disease; Animals; Blood Flow Velocity; Contrast Media; Disease Models, Animal; Female; Fetal Blood; Fetal Heart; Fetal Hypoxia; Fetus; Heart Rate, Fetal; Placental Circulation; Polysaccharides; Pregnancy; Prospective Studies; Random Allocation; Sheep; Ultrasonography, Doppler, Duplex; Ultrasonography, Prenatal

To determine the value of power Doppler (PD) ultrasonography (US) and contrast-enhanced power Doppler (CEPD) US in the diagnosis of acute appendicitis and the prediction of histopathologic stages.. 50 patients with suspected acute appendicitis were evaluated by the same radiologist with PD US and CEPD US. Air micro bubbles stabilized by a granulate of "galactose and palmitic acid" were used as a contrast medium for sonography with the concentration of 400 mg/ml. PD US and CEPD US results were later correlated with the surgical and histopathologic findings. PD US and CEPD US findings were considered positive for appendicitis; if there was depiction of hyperemia in the wall of the appendix or if there was depiction of prominent peripheral vascularity when compared with normal soft tissues; and negative if both hyperemia and peripheral hyperemia were not prominent.. Of the 50 patients, 35 patients had histopathologically proven acute appendicitis. CEPD US showed prominent hyperemia in the appendiceal vessels or feeding vessels of the inflamed appendix, and resistance index (RI) calculations were easier. There was statistically significant difference between mean RI values of the normal appendix, suppurative appendicitis and gangrenous appendicitis. PD US has accuracy of 80%, sensitivity of 74% and CEPD US has 98%, and 100% in the diagnosis of acute appendicitis. CEPD US identified 100% of suppurative appendicitis and gangrenous appendicitis.. CEPD US is a promising method in the diagnosis of acute appendicitis and determination of the inflammation stage.

Topics: Acute Disease; Adolescent; Adult; Appendicitis; Appendix; Child; Child, Preschool; Contrast Media; Female; Humans; Male; Middle Aged; Polysaccharides; Predictive Value of Tests; Sensitivity and Specificity; Ultrasonography, Doppler

The value of stress harmonic power Doppler imaging (HPDI) for the evaluation of myocardial perfusion has never been assessed in patients after acute coronary syndrome (ACS).. To evaluate the agreement between stress HPDI and single photon emission computed tomography (SPECT) imaging for the assessment of myocardial perfusion after unstable angina or myocardial infarction.. Thirty patients with a recent ACS underwent HPDI and SPECT. Images were obtained at rest and during dipyridamole infusion (0.56 mg/kg over 4 min). Apical two- and four-chamber views were used for HPDI. Ten myocardial segments were scored for myocardial perfusion. Semiquantitative and quantitative video intensity analysis with background subtraction were performed.. Concordance by patients between quantitative HPDI and SPECT was 76% (kappa=0.40, Phi=0.46) for normal versus abnormal perfusion. When semiquantitative analysis was used, concordance was 72% (kappa=0.42, Phi=0.46). Agreement between methods was best in the left anterior descending artery territory for quantitative (80%) (kappa=0.60, Phi=0.60) and semiquantitative analysis (78%) (kappa=0.51, Phi=0.60) for normal versus abnormal perfusion. Discrepancies between HPDI and SPECT were most important in the circumflex territory, with a concordance of 59% (kappa=0.22) for identification of normal perfusion versus irreversible and reversible defects.. These results suggest that HPDI can detect myocardial perfusion at rest and during pharmacological stress in patients after a recent ACS. Given the suboptimal agreement with SPECT, further advances are required before the routine use of contrast echocardiography is possible for the assessment of myocardial perfusion.

Topics: Acute Disease; Aged; Aged, 80 and over; Contrast Media; Coronary Circulation; Coronary Disease; Echocardiography; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Polysaccharides; Radiopharmaceuticals; Research Design; Syndrome; Tomography, Emission-Computed, Single-Photon

Initial reports indicate that cerebral perfusion deficits in acute ischemic stroke might be detectable by means of transcranial harmonic imaging after an ultrasound contrast agent (UCA) bolus injection. Twenty-four patients with acute middle cerebral artery (MCA) infarction were investigated twice with perfusion harmonic imaging (PHI) after Levovist (Schering, Berlin, Germany) bolus injection no longer than 12 h after symptom onset. The findings were compared with those of cranial computed tomography (CCT). All 24 patients suffered from acute ischemic stroke of the MCA territory (median National Institutes of Health Stroke Scale score: 15 points). Corresponding to the area of infarction in follow-up CCT, a marked contrast deficit was visualized in 19 of 24 patients by initial PHI, which had a sensitivity and specificity of 86.4% and 96.2%, respectively, for predicting the occurrence and localization of a definite infarction in the midthalamic plane. The area of hypoperfusion in the initial PHI investigation correlated with the definite area of infarction in follow-up CCT (r=0.66, p<0.01). When time-intensity curves of both hemispheres were compared, the areas under the curve were significantly less in the symptomatic brain regions (p=0.01). With PHI and UCA bolus injection, it is possible to assess cerebral perfusion deficits that correlate with the definite area of infarction in acute ischemic stroke patients.

Topics: Acute Disease; Adult; Aged; Artifacts; Contrast Media; Female; Follow-Up Studies; Humans; Image Processing, Computer-Assisted; Infarction, Middle Cerebral Artery; Male; Microcirculation; Middle Aged; Polysaccharides; Sensitivity and Specificity; Tomography, X-Ray Computed; Ultrasonography, Doppler, Transcranial

To evaluate in a prospective multicentre setting the feasibility of transcranial colour coded duplex sonography (TCCS) for examination of the middle cerebral artery (MCA) in patients with acute hemispheric stroke, and to assess the validity of sonographic findings in a subgroup of patients who also had a correlative angiographic examination.. TCCS was performed in 58 consecutive patients within six hours of the onset of a moderate to severe hemispheric stroke. Ultrasound contrast agent (Levovist) was applied if necessary. Thirty two patients also had computed tomography angiography (n=13), magnetic resonance angiography (n=18), or digital subtraction angiography (n=1). In 14 of these patients, both the sonographic and corresponding angiographic examination were performed within six hours of stroke onset (mean time difference between TCCS and angiography 0.8 hours). Eighteen patients, in whom angiography was carried out more than 24 hours after stroke onset, had a follow up TCCS for method comparison (mean time difference 6.1 hours).. Initial unenhanced TCCS performed 3.4 (SD 1.2) hours after the onset of symptoms depicted the symptomatic MCA mainstem in 32 patients (55%) (13 occlusions, one stenosis, 18 patent arteries). After signal enhancement, MCA status could be determined in 54 patients (93%) (p<0.05), showing an occlusion in 25, a stenosis in two, and a patent artery in 27 patients. In 31 of the 32 patients who had correlative angiography, TCCS and angiography produced the same diagnosis of the symptomatic MCA (10 occlusions, three stenoses, 18 patent arteries); TCCS was inconclusive in the remaining one.. TCCS is a feasible, fast, and valid non-invasive bedside method for evaluating the MCA in an acute stroke setting, particularly when contrast enhancement is applied. It may be a valuable and cost effective alternative to computed tomography and magnetic resonance angiography in future stroke trials.

Topics: Acute Disease; Adult; Aged; Contrast Media; Feasibility Studies; Female; Humans; Male; Middle Aged; Polysaccharides; Reproducibility of Results; Stroke; Ultrasonography, Doppler, Transcranial

The purpose of this study was to evaluate the ability of pulse inversion harmonic imaging with or without microbubble ultrasonographic contrast agent in depicting renal parenchymal changes in acute pyelonephritis. The study population included 30 patients with acute pyelonephritis and 10 healthy volunteers. Pulse inversion harmonic imaging with or without contrast agent was compared with conventional ultrasonography and tissue harmonic imaging in terms of detection and conspicuity of renal abnormalities. The detection and conspicuity of renal parenchymal abnormalities in acute pyelonephritis on tissue harmonic imaging, pulse inversion harmonic imaging, and contrast-enhanced pulse inversion harmonic imaging were significantly better than those on conventional ultrasonography. In 2 of 10 healthy volunteers all 4 techniques yielded false-positive diagnoses of parenchymal abnormalities. In conclusion, tissue harmonic imaging and pulse inversion harmonic imaging are sensitive techniques for depicting renal parenchymal lesions in acute pyelonephritis. Despite relatively lower specificities and negative predictive values, these techniques are thought to be useful for the depiction of subtle parenchymal changes in acute pyelonephritis.

Topics: Acute Disease; Adult; Aged; Contrast Media; False Positive Reactions; Female; Humans; Male; Middle Aged; Polysaccharides; Predictive Value of Tests; Pyelonephritis; Reproducibility of Results; Sensitivity and Specificity; Tomography, X-Ray Computed; Ultrasonography

A case of a successful systemic thrombolysis of an acute middle carotid artery occlusion is reported. The case underlines the role of contrast-enhanced transcranial color-coded duplex sonography as a noninvasive technique for rapid diagnosis of vessel occlusion in acute stroke. The diagnostic potential of transcranial color-coded duplex sonography for indication and monitoring of intravenous systemic thrombolytic therapy is demonstrated.

Topics: Acute Disease; Brain Ischemia; Carotid Artery Diseases; Cerebral Arteries; Cerebrovascular Circulation; Cerebrovascular Disorders; Contrast Media; Fibrinolytic Agents; Follow-Up Studies; Humans; Image Enhancement; Male; Middle Aged; Polysaccharides; Thrombolytic Therapy; Thrombosis; Tissue Plasminogen Activator; Ultrasonography, Doppler, Duplex; Ultrasonography, Doppler, Transcranial

To compare the usefulness of conventional color Doppler ultrasound (US), unenhanced and contrast material-enhanced power Doppler US, and radionuclide imaging in a model of acute testicular torsion.. Twenty rabbits underwent unilateral 360 degree testis torsion and contralateral orchiopexy. Gray-scale, color Doppler, and unenhanced and contrast-enhanced power Doppler US were performed 4-6 hours later. The side of torsion was determined, and intratestis flow was graded. Within 2 hours of US, technetium-99m pertechnetate was intravenously administered, the rabbits were killed, and the testes excised for radionuclide imaging.. Intratestis perfusion was detected in 85% of torsed testes at US and radionuclide imaging. The side of torsion was correctly diagnosed in 25% of cases with radionuclide imaging and in 60% of cases with US. Power Doppler US demonstrated significantly greater intratestis flow in pexed than in torsed testes. Although the numbers of correct diagnosis with the three US modalities were similar, flow grades within torsed and normal testes were significantly different.. Perfusion to torsed and normal testes was demonstrated equally well with color Doppler US, power Doppler US, and radionuclide imaging. Doppler US better depicted differences in intratesticular flow between torsed and normal testes.

Topics: Acute Disease; Animals; Contrast Media; Male; Polysaccharides; Rabbits; Radionuclide Imaging; Regional Blood Flow; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Spermatic Cord Torsion; Testis; Time Factors; Ultrasonography, Doppler, Color