Ultrasound diagnostics in phlebology*

Transcription

1 Review Article 270 Ultrsound dignostics in phleology* Correct use of terms E. Mendoz 1 ; J. Schimmelpfennig 2 ; L. Schimmelpfennig 2 1 Venenprxis, Wunstorf, Germny; 2 MVZ Gefäßmedizin, Burgerch, Germny Keywords Duplex ultrsound, Doppler, CDU, PW duplex, B-mode flow, vricosis Summry Since the introduction of the Doppler effect into clinicl prctice for the dignosis of vsculr nd crdic diseses, the technology hs developed considerly. From the pencil proe (CW Doppler) to lck nd white duplex, PW Doppler, which ws incorported into B-mode imge, to colour duplex ultrsound (CDU) nd eyond to more recent developments, such s power duplex nd B-mode flow imging. These terms re frequently confused with ech other nd medicl reports refer to CDU s venous Doppler or ultrsound of the leg veins. This short outline ttempts to clrify ech term riefly in words nd imges. Correspondence to Dr. Erik Mendoz Venenprxis Speckenstr. 10, D Wunstorf, Germny E-mil: erik.mendoz@t-online.de Ultrsound B-mode imge Using ultrsound, tissue slice is visulised in greyscle. This does not require the Doppler effect ( Fig. 1). * This rticle contins text sections from Mendoz E, Duplexsonogrphie der oerflächlichen Beinvenen in: Phleologischer Bildtls [ Duplex ultrsound scnning of the superficil leg veins in: Phleology Imging Atls ] Re E, Stücker M, Vivitl pulishing house, 2015, y courtesy of the Vivitl pulishing house, Cologne Schlüsselwörter Duplexsonogrphie, Doppler, FKDS, PW-Duplex, B-Flow, Vrikose Zusmmenfssung Seit der Doppler-Effekt für die Dignostik von Gefäß- und Herzerkrnkungen in der Klinik eingesetzt wurde, ht sich die Technik strk weiter entwickelt. Von der Stiftsonde (CW- Doppler) zum Schwrzweiß-Duplex, dem PW- Doppler, der in ein B-Bild eingereitet wurde, is hin zur frkodierten Duplex-Sonogrphie (FKDS) und drüer hinus zu neueren Entwicklungen wie dem Power-Duplex und dem B-Flow. Immer wieder werden diese Begriffe verwechselt und die FKDS in Arztriefen ls Venendoppler ezeichnet oder ls Ultrschll der Beinvenen. Dieser kurze Üerlick versucht, in knppen Worten und Bildern Klrheit zu jedem Begriff zu schffen. Ultrschlldignostik in der Phleologie* Korrekte Verwendung der Begriffe Phleologie 2015; 44: Received: August 2, 2015 Accepted: August 14, 2015 CW-Doppler Continuous Wve Doppler: The first ppliction of the Doppler effect in the dignostics of flow velocities in the humn ody is still used tody in the form of pencil proe or pocket Doppler ( Fig. 2). Continuous trnsmission nd reception of Doppler signl. All flow signls long the penetrtion depth of the Doppler em re registered nd simultneously trnsmitted. It is not possile to determine the tissue depth of the flow registered nor cn it e scertined whether mesurement ws performed in one or more vessels. Nowdys, much more precise mesuring instruments re ville in phleology (simultneous imging nd flow curve), so tht the CW Doppler is no longer of ny rel significnce. The CW Doppler proe is, however, still importnt in determining the closing pressures t the nkle nd scertining the nkle-rchil index when excluding rteril occlusive disese, which could present contrindiction for compression. PW-Doppler Pulsed wve Doppler: Mesures the flow velocity t specific point (unlike continuous wve, in which the Doppler mesurement records ll lood flows on its em) ( Fig. 3). The echo is trnsmitted s pulse from the proe nd the nswering signl is nticipted. It is therey possile to determine the tissue depth from which the response is trnsmitted nd ssign the flow velocities to n exct point. This llows mesurement of the lood flow t previously selected point in the B-mode imge. Although modern ultrsound equipment still offers the option of n isolted PW Doppler curve, the isolted curve without the B-mode imge is now used only rrely, thnks to the fr more prcticl PW duplex ppliction (see elow). PW-Duplex A comintion of B-mode imge nd PW Doppler in the sme imge. Also clled lck nd white duplex, to distinguish it from colour duplex ultrsound. In the B-mode imge, n re is selected in which the flow is mesured (indicted y red Schttuer 2015 Phleologie 5/2015

2 271 E. Mendoz, J. Schimmelpfennig, L. Schimmelpfennig: Ultrsound dignostics in phleology circle in Fig. 4). The flow curve cn thus e precisely ssigned to n ntomicl re. The user cn select whether the B-mode imge ppers on the left side or upper hlf of the screen nd the derived flow curve on Fig. 1 The imge shows trnsverse section through the inner thigh with visulistion of the gret sphenous vein s lck point in the fscil ed. The gret sphenous vein is mesured in the imge. the right hlf of the imge (in tht cse with shorter course, Fig. 4) or on the lower hlf of the screen (in tht cse with longer curve, Fig. 4). Colour duplex ultrsound (CDU) Converts informtion from PW Doppler to colour for ll points visulised in window. Movements towrds the proe re coded in red nd those wy from the proe re in lue ( Fig. 5). This coding llows much more rpid ssignment of lood flows, prticulrly t the confluence of severl vessels. It does, however, require higher computer processing cpcity s the PW Doppler dt hve to e cquired from reltively lrge re nd trnslted into colour. On older equipment, therefore, this cn result in loss of informtion in the cse of slow refluxes. For documenttion purposes, it is not suitle for imge cquisition, s only film would document the course of the flow over the time xis, nd thus revel the presence of reflux. The disdvntge of CDU is looming the spred of colour eyond the edges of T. 1 Overview of the terminology used in ultrsound dignostics Arevition CW Doppler PW Doppler Blck nd white duplex or PW duplex CDU Triplex Power duplex B-mode flow Imge No Full nme Continuous wve Doppler, pencil proe Pulsed wve Doppler Pulsed wve Doppler with simultneous B-mode imge Colour duplex ultrsound Use in phleology Replced y duplex in venous dignostic procedures, optiml for mesuring the nkle-rchil index Mesurement of flow curves in vessels previously determined in the B-mode imge Mesures flow curves in defined vessels Flow mesurements in ll vessels in the selected imge section, colour-coded PW mesurement Flow mesurement in colour nd showing the flow curve Serches for vsculr flow signls without flow indiction in CDU Dignoses very smll thromi or very discrete vlvulr insufficiency Advntges Inexpensive to cquire, smll formt Exct loction of the flow to e mesured Exct visulistion of the vessel nd the flow, the only instrument ville for documenting reflux Convenient overview of vsculr segment or fscicle Better orienttion Cn lso record very slow lood flows, regulrly ville in ll modern CDU equipment Cn lso record slower lood flows without spreding eyond the vessel Disdvntges The flow mesured cnnot e ssigned precisely to one vessel Risk of wole without simultneous imging (duplex) More time-consuming thn colour duplex ultrsound Not suitle for documenting flow curve, looming with colour spreding eyond the vessel Slower visulistion due to high demnd on computer processing cpcity No informtion on flow direction, looming Expensive to cquire Phleologie 5/2015 Schttuer 2015

3 E. Mendoz, J. Schimmelpfennig, L. Schimmelpfennig: Ultrsound dignostics in phleology 272 Fig. 2 With CW Doppler flow curve, the flow direction towrds the proe is positive y definition nd is displyed from the zero line upwrds in the curve, the flow wy from the proe. Fig. 4. PW duplex with verticl prtitioning: B-mode imge left with view of the gret sphenous vein t the inner thigh, where the mesurement window of the PW Doppler is situted (red circle). Visulistion of the flow curve on the right in the imge.. PW duplex with horizontl prtitioning: B-mode imge ove, flow curve elow. In oth imges: Yellow rrow: Rise toe, orthogrde flow, downwrd deflection in the imge, lue rrow: Lower toe, reflux lsting longer thn 0.5 seconds, upwrd deflection. This gret sphenous vein is incompetent, the vlves do not close. This procedure (PW duplex) is the only one pproprite for relile documenttion of reflux, e.g. pre-opertively, s it llows flow long the time xis nd lloction of the flow curve in the imge. Fig. 3 Derived curve in PW Doppler. Firstly, the gret sphenous vein ws visulised in B-mode imge, then the PW Doppler mesurement ws prepred y plcing the mesurement window of the PW Doppler mode in the gret sphenous vein. A switch ws then mde to PW Doppler: The imge creted shows the flow in the gret sphenous vein fter provoction mnoeuvre (rise toe: orthogrde flow, downwrd deflection, flow direction towrds the hert, then lower toe: short ckflow, upwrd deflection until vlve closure, gret sphenous vein competent). the vessel when lood flow is rpid. CDU imging is therefore unsuitle for clculting vsculr dimeters. Triplex Comintion of CDU nd PW trcing in one imge ( Fig. 6). Requires even greter computer processing cpcity from the imging equipment, so tht the curve is usully not visulised so precisely, nor is the colour displyed so clerly. As informtion from the PW curve is clerly more vlule thn tht otined from the colour, the uthors consider tht use of the triplex mode cn proly e dispensed with. The dvntges of either CDU or PW duplex should e exploited. Power-Duplex Enhnces the result of CDU y using other clcultion procedures. The result concentrtes only on the presence of flow nd not on its direction. There is thus only one colour, which ws determined s shde of yellow ( Fig. 7). In modern ultrsound equipment, this mode is highlighted s n option fter switching on the CDU. B-Flow Another technicl enhncement of duplex ultrsound is the B-mode flow. This is not the visile flow in the so-clled erythrocyte sludge in the B-mode imge ( Fig. 8). This develops fter long period of stnding still, possily through the formtion of erythrocyte ggregtes in the slowly flow- Schttuer 2015 Phleologie 5/2015

4 273 E. Mendoz, J. Schimmelpfennig, L. Schimmelpfennig: Ultrsound dignostics in phleology Fig. 5 Longitudinl section of the inner thigh through refluxing perforting vein: The gret sphenous vein runs prllel to the upper edge of the imge. The flow is mesured in the mesurement window (white ox in the imge): This shows red flow with yellow/lue sections due to turulence in the perforting vein re nd red flow in the gret sphenous vein. Fig. 8 B-mode flow (y courtesy of the Springer pulishing house). Longitudinl section through the poplitel cvity with visulistion of smll thromus t vlve cusp in the poplitel vein (rrow). Imge y courtesy of the Springer pulishing house from: Weskott HP, Mendoz E; Ds Ultrschllgerät [The ultrsound unit]; in: Mendoz E; Duplexsonogrphie der oerflächlichen Beinvenen [Duplex ultrsound of superficil leg veins]. Berlin Springer pulishing house 2013) Fig. 6 Triplex visulistion of the reflux curve in gret sphenous vein t the inner thigh. ing or stgnting lood, which ecome visile to the proe nd whose movement cn e visulised like grey cloud in the vein. This option hs to e implemented in the equipment nd is, unfortuntely, still very expensive. It llows exct visulistion of moile fluids without the looming rtefcts tht occur in CDU. Compression ultrsound In order to exclude thromosis, the venous lumen is shown without compression in the left hlf of the imge nd with compression in the right hlf of the imge ( Fig. 9). Fig. 7 Sttus post thromosis in this leg, hrdly ny venous flow is visile in the poplitel cvity (trnsverse section through the poplitel cvity).. using provoction mnoeuvres with CDU,. using provoction mnoeuvres with power duplex. Orthogrde flow Norml flow in the veins: From the superficil veins in the direction of the deep leg veins nd overll towrds the hert. En- Phleologie 5/2015 Schttuer 2015

5 E. Mendoz, J. Schimmelpfennig, L. Schimmelpfennig: Ultrsound dignostics in phleology 274 coded in lue in CDU nd results in downwrd flow in PW Doppler if the proe is held in the usul mnner ( Fig. 3, Fig. 4 nd Fig. 6) Reflux Pthologicl flow due to sence of vlve closure. If the proe is guided in the usul mnner, flow from the deep veins towrds the superficil veins nd the feet is shown in red in CDU, nd results in flow in PW ove the zero line tht persists for longer thn 0.5 seconds up to 1 second ( Fig. 4 nd Fig. 6). Fig. 9 Trnsverse section in B-mode imge t the inner thigh, with visulistion of the gret sphenous vein in the left hlf of the imge with norml contct pressure of the proe. In the right hlf of the imge, contct pressure on the tissue with the proe, the gret sphenous vein is compressed nd cn no longer e visulised, proving tht no lood clot is present there. Schttuer 2015 Phleologie 5/2015