Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0034065 (pulmonary embolism)
 14,979 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

MRI of lung parenchyma and pulmonary embolism (PE) remains challenging. "Ferrum," a ferric hydroxide sucrose complex used clinically for iron deficiency anemia for more than 40 years, was investigated as a negative MRI contrast agent in five rabbits bearing experimental PE as well as in five normal volunteers. Clots were prepared by spontaneous coagulation of 0.1 ml In-111 labeled autologous red blood cells and introduced through the jugular vein. Scintigraphic imaging permitted anatomical localization of PE in vivo and thereby served as a control for MR imaging. MRI was performed on a 1.5 T GE Signa scanner before and after induction of PE, and before and after the injection of Ferrum. T1-weighted images were obtained continuously for up to 90 min using varying doses of Ferrum. In five normal human volunteers, a single dose of 100 mg each was administered. T1- and T2-weighted spin-echo and gradient-echo images of lung parenchyma were repeatedly obtained before and after agent administration. In rabbit, Ferrum remained in circulation for several hours where it shortened both T1 and T2 of blood, improving the contrast between PE and lung parenchyma (i.e., intravascular compartment). A dose of 3 mg/kg was enough to increase the contrast-to-noise ratio (CNR) between PE and lung parenchyma by almost three fold, substantially improving lesion detectability. CNR increased up to five-fold when the dose was increased up to 20 mg/kg at which point CNR reached a plateau. In humans, T2-weighted spin-echo sequence appeared to be most sensitive to changes in signal-to-noise ratio (SNR) of normal lung parenchyma. Within 60 min after injection of 100 mg of iron, SNR dropped by 34% (p < .025). However, 24 hr later, SNR returned to almost normal. Ferrum increased the contrast between PE and lung parenchyma in the rabbit and decreased the parenchymal SNR in humans in nontoxic doses. These results suggest that Ferrum is worthy of further investigation of PE imaging in humans.
 ...
PMID:Use of Ferrum in MRI of lung parenchyma and pulmonary embolism. 831 63

We report five cases of OVT and review the literature on this disease. Among our patients OVT was not suspected clinically and was diagnosed by CT scanning or MRI. Ultrasound imaging, utilized in three cases, failed to detect OVT. Although this disease usually occurs after delivery, in two cases it was diagnosed before delivery. Of the two postpartum cases, one had a typical presentation and the other was asymptomatic. The final case was diagnosed incidentally 5 months after removal of an ovarian carcinoma. Our experience suggests that this disease may be underdiagnosed. More widespread use of CT scanning and MRI may lead to more frequent diagnosis of OVT. The role that clinically silent OVT may play in peripartum pulmonary embolism should be clarified.
 ...
PMID:Ovarian vein thrombosis. 836 20

In recent years, clinics and radiology of congenital anomalies of the inferior vena cava have increased in importance in planning abdominal surgery, liver or kidney transplantation, or new interventional or diagnostic procedures such as the positioning of inferior vena cava filters to prevent pulmonary embolism, varicocel sclerotherapy and renal venous sampling. In the past, the radiologic assessment of these rare anomalies was performed only with angiography, which remains the most accurate diagnostic method. Today, besides angiography, less invasive examinations can be performed, e.g., US, CT and MRI, with MRA. In the last two years, 5 patients with inferior vena cava anomalies were examined: 3 had double inferior vena cava and 2 azygos continuation. All of them were submitted to US, CT, MRI and MRA and 3 patients underwent also angiography, two of them with double puncture. US can suggest the diagnosis but may be limited by technical factors and in the assessment of the whole inferior vena cava. Enhanced CT can depict anomaly extent, but uses contrast agents and ionizing radiations. Angiography better depicts craniocaudal spread and collateral networks but is an invasive procedure and sometimes needs a double puncture (double inferior vena cava). MRI, with MRA, yields the same information as the other modalities, but without contrast agents or ionizing radiations. The development of velocity encoded sequences will probably make this technique the method of choice in the study of inferior vena cava anomalies. Our study was aimed at reviewing the embryo-genesis of inferior vena cava anomalies and to assess the relative importance of different diagnostic procedures in the diagnosis and staging of these anomalies.
 ...
PMID:[Congenital anomalies of the inferior vena cava: role of imaging]. 855 19

From 1980 to 1992 we followed 12 patients with cardiac myxomas for an average of 4.4 years (8 months-11 years). Presenting symptoms were neurological in four patients (hemiparesis, aphasia, visual field deficits, progressive dementia or vertigo), progressive dyspnoea in six, pulmonary embolism in one, and peripheral arterial or renal emboli in three. The diagnosis was suspected clinically in 11 patients. It was confirmed by echocardiography in ten and by thoracic CT in one. All these patients had cardiac surgery. One diagnosis was made at autopsy; the patient died unexpectedly during surgery for emboli to the leg arteries. At follow-up, two additional patients had died, one from myocardial infarction and one from rhabdomyosarcoma. Only one of the nine surviving patients had recurrent symptoms after cardiac surgery. His dementia continued to progress. The patients without new symptoms after cardiac surgery had normal MRI of the brain or residual ischaemic lesions. MRI of the patient with progressive dementia showed multiple cerebral lesions with a bright centre and a dark rim on T1- and T2-weighted spin-echo images. On CT there were many calcified lesions. CT, MR angiography and contrast angiography revealed multiple fusiform aneurysms. The rare occurrence of progressive neurological symptoms after myxoma resection with multiple cerebral lesions and aneurysms should suggest myxoma metastases to the brain.
 ...
PMID:Cardiac myxomas: a long term study. 856 32

Acute pulmonary embolism is a medical emergency and diagnostic certitude must be obtained as early as possible. In clinically serious situations, spiral CT is a reliable diagnostic tool. It provides direct signs of embolism with visualisation of thrombi in the pulmonary arteries as far as the segmental branches and its diagnostic value does not change in cases of pulmonary parenchymal involvement. In emergencies, spiral CT should replace pulmonary angiography, which is more costly and associated with greater morbidity and mortality. Other methods, in particular MRI, which is totally innocuous, could play an important role in the diagnostic strategy of acute pulmonary embolism in the near future.
 ...
PMID:[New imaging techniques in pulmonary embolism]. 881 34

The accurate assessment of pulmonary perfusion is especially important in the evaluation of patients with suspected pulmonary embolism, a common and potentially lethal disorder that can be treated by aggressive anticoagulation. In this study, we demonstrate for the first time the use of MR to image pulmonary perfusion in humans by using dynamic imaging after contrast administration. The technique, which uses an inversion recovery turbo FLASH sequence with ultrashort TE (1.4 ms) and 1-s temporal resolution, was tested in a series of eight healthy subjects and in a porcine model of pulmonary embolism. After the administration of gadopentetate dimeglumine in humans and animal models, there was serial enhancement of the systemic veins, right atrium, right ventricle, and pulmonary arteries. The pulmonary arterial tree was visualized beyond the segmental branches, followed by a gradual diffuse increase in signal intensity of the lung parenchyma over a period of 4.0-7.0 s. Pulmonary circulation times ranged from 3.0-3.4 s. Whereas a high dose (20 or 40 ml) of contrast agent tended to produce the most intense parenchymal enhancement, a low dose (5 ml) was best for showing recirculation. In the animal model, a perfusion defect due to a pulmonary embolus was clearly shown and confirmed by cine angiography. It is concluded that MRI of lung perfusion is feasible. With further development, perfusion MRI could eventually have a significant clinical role in the diagnostic evaluation of pulmonary embolism.
 ...
PMID:Pulmonary perfusion: qualitative assessment with dynamic contrast-enhanced MRI using ultra-short TE and inversion recovery turbo FLASH. 889

Takayasu's disease involves the pulmonary vessels in over 50% of cases. However, primary lesions of the pulmonary arteries are very rare. The authors report the cases of a 34 year-old Caucasian woman presenting with clinical and radiological signs of acute pulmonary embolism, but in whom the pulmonary angiography showed stenotic and occlusive lesions of the right pulmonary artery. MRI provided an accurate diagnosis by showing typical thickening of the pulmonary arterial walls.
 ...
PMID:[Localised primary lesion of the right pulmonary artery in Takayasu's disease]. 895 49

Pulmonary embolism shows a high mortality especially for the difficulty in establishing an early correct diagnosis. The pathophysiology and thus the clinical manifestations of pulmonary embolism (PE) are essentially conditioned by three factors: the size of the embolus, the pre-existing cardiorespiratory condition, the release caused by the embolus, of some substances or the activation of reflexes which tend to worsen the purely mechanical consequences of PE. The clinical manifestations resulting from the combination of these factors result in three clinical patterns: acute cor pulmonare, pulmonary infarction, acute dyspnea. PE symptoms may be absent in a moderate percentage of cases and if present, they are nonspecific. Some laboratory tests were shown to be of no diagnostic accuracy, as enzyme determination, a sign of necrosis, blood gas analysis, and determination of alveolar arterial oxygen gradient. Among blood coagulation tests, D-dimer determination was shown to be of some relevance. However, at present, it cannot be used to confirm the diagnostic suspicion of PE. Among the instrumental cardiologic procedures, while ECG has a poor diagnostic reliability, transesophageal echocardiography in central embolism may be able to visualize the embolus and to accurately assess the hemodynamic effects, supplying sufficient information for PE therapy. Even if imaging procedures as pulmonary angiography and more recently CT or MRI are the most reliable diagnostic tools, the diagnostic suspicion of PE in subjects at risk, the use of the examined methods and the search in these patients for the presence of lower limb deep vein thrombosis, often asymptomatic, may increase the number of treated patients thus decreasing the mortality of this disease.
 ...
PMID:Clinical and instrumental diagnosis of pulmonary embolism. 906 54

Nuclear medicine procedures and mainly perfusion lung scanning (often associated with ventilation lung scanning), after thirty years still play a major role in the diagnosis of pulmonary embolism. International study groups with accurate statistical methods have shown their efficacy in the diagnosis and follow-up, in reducing the clinical uncertainty, in directing the therapy and in lowering health care costs. The major limitation of nuclear medicine procedures lies in the high percentage of patients for whom intermediate or indeterminate probability is reported. However this percentage is steadily decreasing based on: patient clinical preselection; improved procedures and especially an extensive use of D-SPET with a three-head gamma camera; the combination with other advanced diagnostic imaging procedures (HRCT, fast-CT, MRI); suitable diagnostic algorithms for nuclear medicine procedures which should consider laboratory data (D-dimer, TAT) and the study of deep vein thrombosis; the use of artificial intelligence; the introduction of radiopharmaceuticals which enable direct scanning of the intravasal embolus (as P180 polypeptide) in combination with perfusion scanning which shows the hemodynamic alterations.
 ...
PMID:The role of nuclear medicine in pulmonary embolism. 906 56

The technological progress in Computed Tomography (CT) (spiral and electron beam) and Magnetic Resonance Imaging (MRI fast sequences) has stimulated their interest in the diagnosis of acute and chronic pulmonary embolism (PE). They are noninvasive procedures able to identify thrombi up to the level of segmental pulmonary branches. This result, albeit not ideal, is significant, in view of the lower clinical relevance of peripheral emboli as compared to more central locations, especially in the absence of peripheral venous thrombosis. Spiral CT allows satisfactory assessment of pulmonary branches with high sensitivity (65-100%), specificity (89-96%), positive predictive value (95%) and negative predictive value (80-100%) in the diagnosis of PE. MRI with spin-echo sequences has also a satisfactory sensitivity (75-90%), specificity (up to 100%), positive predictive value (86%) and negative predictive value (85%). Recently, MR angiography was shown to be able to depict smaller pulmonary branches (6th and 7th generation), even if its efficacy in the identification of emboli has not been demonstrated as yet. CT and MRI are bound to play an increasingly relevant role in the diagnosis of PE.
 ...
PMID:Pulmonary embolism: the role of computed tomography and magnetic resonance imaging. 906 57


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>