La Radiologia medica
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La Radiologia medica · Jul 2003
Comparative StudyGadobenate dimeglumine (Gd-DTPA) vs gadopentetate dimeglumine (Gd-BOPTA) for contrast-enhanced magnetic resonance angiography (MRA): improvement in intravascular signal intensity and contrast to noise ratio.
The purpose of this study was to compare contrast enhanced MR angiography (MRA) with gadopentetate dimeglumine (Gd-DTPA) to MRA with gadobenate dimeglumine (Gd-BOPTA), a high relaxivity paramagnetic contrast agent. ⋯ The greater relaxivity of Gd-BOPTA, at lower doses, compared with Gd-DTPA, provides higher intravascular signal and signal to noise ratio. Gd-BOPTA appears to be an optimal contrast agent for contrast enhanced MRA.
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La Radiologia medica · May 2003
Contrast medium injection optimisation in spiral CT for the diagnosis of pulmonary embolism.
Spiral CT, normally a highly accurate diagnostic method to diagnose pulmonary embolism, has its weak point in the synchronisation of contrast medium (CM) injection and the start of the acquisition, essential to obtain optimal vascular enhancement. The aim of this paper is to introduce a method to control the CM injection based on the enhancement of blood vessels in the diagnosis of pulmonary embolism. ⋯ In order to be diagnostically useful, spiral CT requires good vascular enhancement and synchronisation of the start of acquisitions with the highest concentration of CM, as an incorrect scan delay will lead to artefacts and interpretation errors. The proposed method allows correct timing of the CM injection. The diagnostic bolus is preceded by a slow-flow timing bolus that is intercepted by the electronic trigger, which starts the scan when the CM passes into the right heart and pulmonary arteries. The slow-flow bolus volume was 30 ml injected at 1.5 ml/s, whereas the volume of the real bolus was 100 ml, injected at 4.5 ml/s. Monitor scans were performed with the trigger ROI centred on the right heart (trigger value set at 30/35 HU). The time needed for the complete spiral CT exam did not exceed 30 min. The first low-flow bolus injection takes approximately 10 min, but this time becomes shorter as the operator's experience grows. The correct positioning of the ROI on the right heart is the most time-consuming step in the procedure. The procedure was well accepted by all patients with no complaints due to the CM or to the duration of the procedure. There is a high level of concordance between arterial enhancement and image quality. In conclusion, the proposed method is simple, easy to reproduce, and does not give rise to interpretation problems. It is well accepted by patients and suffers few limitations, mainly represented by patients with severe cardiac arrhythmia.
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La Radiologia medica · Mar 2003
Capsulo-labro-ligamentous lesions of the shoulder: evaluation with MR arthrography.
The aim of the study was to analyse the accuracy of MR arthrography in the evaluation of capsulo-labro-ligamentous lesions of the shoulder in patients with glenohumeral joint instability. ⋯ In many cases of subacute glenohumeral joint lesions with intracapsular fluid, MR may accurately evaluate capsulo-labral-ligamentous lesions. Indeed, the examination of lesions is limited by the absence of the natural contrast determined by fluid; in such cases, intra-articular injection of gadolinium contrast is necessary. MR arthrography evaluates the degree of capsulo-labro-ligamentous tears and may guide the surgical approach.
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La Radiologia medica · Jan 2003
Progressive worsening of idiopathic pulmonary fibrosis. High resolution computed tomography (HRCT) study with functional correlations.
To evaluate the usefulness of the high-resolution computed tomography (HRCT) visual score in idiopathic pulmonary fibrosis (IPF) and its correlation with respiratory function tests. ⋯ IPF exhibited a progressive deterioration both in HRCT extent of disease and lung function impairment. There is a significant correlation between HRCT visual score and lung function tests both at diagnosis and at follow-up. The HRCT study is able to identify and quantify anatomic IPF and also to evaluate the progression of the disease. In clinical practice, the HRCT visual score of disease extent can be used in association with function tests to monitor IPF evolution, and to evaluate prognosis and therapy. In the future, helical CT with 3D model construction will provide a more precise IPF quantification with automatic score.