Presentazione sul tema: "5° CORSO NAZIONALE CONGIUNTO ULTRASONOLOGIA VASCOLARE"— Transcript della presentazione:
15° CORSO NAZIONALE CONGIUNTO ULTRASONOLOGIA VASCOLARE BERTINORO, MARZO 20075° CORSO NAZIONALE CONGIUNTOULTRASONOLOGIA VASCOLAREDIAGNOSI E TERAPIADIAGNOSTICA CON APPARECCHIAD ULTRASUONIECOCOLORDOPPLER, POWERDOPPLERED ANGOLO DI INCIDENZAD. Righi
4PER VALUTARE IL GRADO DI STENOSI DEVO CONOSCERE LA VELOCITA’ DEL SANGUEPER VALUTARE LA VELOCITA’ DEL SANGUEDEVO CONOSCERE L’ ANGOLOTRA IL FASCIO ULTRASONORO ED IL FLUSSO
5L’ angolo di insonazione è l’ angolo tra il trasduttore (la sonda) e le strutture da esplorare, nel nostro caso i vasi.Influenza la maniera in cui i vasi in esplorazione sono visualizzati.La correzione d’ angolo è necessario per avere una valutazione corretta delle velocità misurate con il doppler pulsato.Non si rende necessaria solo quando il vaso è a zero gradi rispetto al cursore ed alla linea guida.
11E’ UNA ED UNA SOLA PER VALUTARE IL GRADO DI STENOSI POSSO VARIARE LA DIREZIONE DEL FASCIO DI ULTRASUONIUTILIZZANDO I COMANDI DELLA MACCHINAO MUOVENDO LA SONDAMA LA RETTA PARALLELA AL FLUSSOE’ UNA ED UNA SOLAED UNO ED UNO SOLO E’ QUINDI L’ ANGOLOTRA IL FASCIO ULTRASONORO ED IL FLUSSO
14NELL’ ESECUZIONE DI UN ESAME DOPPLER PW MEDIANTE DUPLEX ANGOLO:NELL’ ESECUZIONE DI UN ESAMEDOPPLER PW MEDIANTE DUPLEXCONVIENE MANTENERLO TRA 45° E 60°NON SUPERARE MAI I 60°90° - 61° = ERRATO60° = OTTIMALE59° - 1°= GIUSTO
15The results of the study were published in the Journal of Vascular Surgery (“JVS”).in an article entitled, “Reliability of Extracranial Carotid Artery Duplex Ultrasound Examinations: Value of Vascular Laboratory Accreditation,” authored by O. William Brown, M.D., et.al.The objective of the study reported in this article was to evaluate the reliability of carotid duplex ultrasound testing performed by unaccredited vascular laboratories and to assess the clinical impact on patient management. The study found that of the 174 patients referred for surgical evaluation for carotid endarterectomy, 88 patients (51%) were found to have less than the 60% percent or higher stenosis that had been diagnosed by unaccredited vascular laboratories. The overestimation of stenosis by the unaccredited laboratory was attributed to technical errors (19 arteries), use of B-mode image data alone without the use of velocity criteria for confirmation of the lesion (36 arteries), and use of inappropriate velocity criteria (49 arteries). Because of the study, more than half of all patients who participated in this sub-group were spared the risks of an unnecessary surgery to "correct" a condition that did not exist.Correlating data in all patients with a subsequent evaluation (angiography, MRA, or surgery) supported the findings of the accredited laboratories.
17MEDIA: 210 cm/secDoppler Velocity Criteria Based on Receiver Operating Characteristic Analysis for the Detection of Threshold Carotid StenosesChi-Shin Hwang, MD Wen-Yi Shau, MD, PhD Charles H. Tegeler, MDJournal of Neuroimaging Vol 12 No 2 April 2002
19-POWER-POWER DOPPLER-POWER MAP-AMPLITUDE MAP-DOPPLER POWER MODE-COLOR ANGIOGRAPHY
20RIFERISCE NON ALLA FREQUENZA MEDIA DEL SEGNALE DOPPLER IL COLORE DI UN PIXEL SIRIFERISCE NON ALLA FREQUENZAMEDIA DEL SEGNALE DOPPLEROTTENUTO DA QUELLA PARTEDELL’ IMMAGINE, MA ALLA SUAAMPIEZZA O POWER.VIENE RAPPRESENTATO CONUN SOLO COLORE OMOGENEO.
28Power and VeloPowerAs the Power mode is more sensitive than Color mode, it is used to assess the vascular system of tissues and organs, especially in places with slow or weak flow.Directional Power or VeloPower combines the PD sensitivity to slow flows, with an option fordetecting the flow direction. As the power of the reflected signal is independent of its direction,Power is less sensitive to Doppler angle and therefore offers an increased sensitivity in thedetection of low flow.Power Mode VeloPower
29Ultraschall Med 1999 Aug;20(4):137-43 [Area reduction in carotid stenosis of the internal carotid artery].Lyrer P, Bont A, Marugg A, Operschall C, Radu EWNeurologische Universitatsklinik, Abteilung zerebrale Ultraschalldiagnostik,Basel.In 58 patients who suffered from 60 moderate to severe ICA stenoses, B-mode sonography combined with CDE -coded duplex sonography was applied to measure the extent of the stenosis by determining the residual lumen width.CONCLUSIONS: Determination of the degree of stenosis based on CDE alone is not reliable enough to allow orrect diagnosis of severe carotid artery stenosis.
30Purdue University • Department of Animal Sciences • Lilly Hall