15 Characterization and Detection of Renal Tumors

Transcription

1 Chrteriztion n Detetion of Renl Tumors Chrteriztion n Detetion of Renl Tumors Emilio Qui CONTENTS 15.1 Introution Dynmi Phses in Renl Prenhym Enhnement After Miroule Injetion Snning Moes Contrst Enhnement Ptterns in Soli Renl Tumors After Miroule Injetion Benign Soli Renl Tumors Emryonl Metnephri Aenom Angiomyolipom Renl Onoytom Mlignnt Soli Renl Tumors Soli Renl Cell Crinom Renl Metstsis Contrst Enhnement Ptterns in Cysti Renl Tumors After Miroule Injetion Benign Cysti Renl Tumors Mlignnt Cysti Renl Tumors Clinil Results Detetion of Renl Tumors When Shoul Miroule-Bse Agents Be Employe? 242 Referenes Introution Bseline gry-sle ultrsoun (US), whih my e supplemente y spekle- n noise-reuing tehniques suh s tissue hrmoni imging n ompoun imging (Cluon et l. 2002), is relile imging tehnique for the erly ignosis of renl tumors (Hélénon et l. 2001). ) Soli renl tumors. Bseline gry-sle US my revel vrious eho ptterns whih re onsiere essentil in the hrteriztion of soli renl tumors. A hypoehoi pperne, sometimes with eviene of n nehoi rim or smll intrtumorl ysts, is E. Qui, MD Assistnt Professor of Riology, Deprtment of Riology, Cttinr Hospitl, University of Trieste, Str i Fiume 447, Trieste, Itly frequently oserve in renl ell rinom, while homogeneously right n wege-shpe pperne, with eviene of posterior ousti showing, is onsiere typil for renl ngiomyolipom (Ymshit et l. 1992; Hélénon et l. 1997, 2001; Jinzki et l. 1997). Some typil US ptterns hve lso een esrie for renl onoytom, suh s the presene of entrl sr tht ppers s stellte hypoehoi re n the sene of hemorrhge n nerosis (Hélénon et l. 2001). Nevertheless, seline US hs low ury in the hrteriztion of renl msses, espeilly if smller thn 4 m in imeter, sine enign n mlignnt tumors frequently present similr pperne (Corres et l. 1999). In ft, pproximtely 30% of smll renl ell rinoms pper s hyperehoi msses (Formn et l. 1993), while typil isohypoehoi n slightly hyperehoi ngiomyolipoms ount for 6% n 29% respetively (Hélénon et l. 2001). Furthermore, even enign n mlignnt renl msses >4 m my present similr pperne, n lrge renl ell rinoms n resemle lrge ngiomyolipoms on seline US (lrge renl ell rinoms usully isply heterogeneous pperne ue to intrtumorl nerosis, lifitions, n hemorrhge, while lrge ngiomyolipoms my lso pper heterogeneous owing to soli, ipose, n hemorrhgi omponents). Power Doppler n olor Doppler US my revel ifferent vsulr ptterns in renl tumors. Jinzki et l. (1998) ientifie four vsulr ptterns relevnt to lesion hrteriztion. Intrtumorl (pttern 1) or penetrting (pttern 2) vessels were esrie s typil for enign renl tumors, n in prtiulr for ngiomyolipom, while peripherl (ptterns 3) or mixe penetrting n peripherl (pttern 4) vessels were onsiere typil for renl ell rinoms, even though they oul lso e oserve in 20% of renl ngiomyolipoms. Even though the esription of these vsulr ptterns represents first enevor to ifferentite the ifferent histotypes of renl tumors using olor n power Doppler, this tehnique oes not signifintly

2 224 E. Qui improve US pilities in the hrteriztion of renl tumors (Hélénon et l. 2001). This is euse enign n mlignnt renl tumors my present similr vsulr rhiteture on olor n power Doppler US (Kier et l. 1990; Corres et l. 1999). ) Cysti renl tumors. Renl ysti tumors hve een lssifie oring to their ompute tomogrphy (CT) pperne (Bosnik 1986; Isrel n Bosnik 2003). Type 1 re simple enign ysts ontining flui with the ttenution of wter n hving thin wlls without sept or lifition, while type 2 re minimlly omplite ysts. These msses re enign ysti lesions tht my ontin hirline-thin sept, fine lifition in the wlls or sept, or short segment of slightly thikene lifition. Miniml enhnement of hirlinethin, smooth septum or wll is sometimes present. Ctegory 2F (F mens follow-up) lesions re more omplex ysts tht nnot e lssifie either s tegory 2 or s tegory 3 ysts. These ysts my ontin n inrese numer of sept n n inrese mount of lifitions, whih my e thiker n noulr (Isrel n Bosnik 2003). Type 3 re ineterminte ysti msses sine their enignity or mlignny nnot e etermine with imging stuies. These lesions hve thik peripherl wlls or sept, my pper hyperense, n my ontin either smll or lrge mounts of lifition. Enhnement of the wll or sept n e lerly ppreite on ontrst mteril-enhne CT. If finings re equivol or suspiious, follow-up in 3 6 months with renl CT is reommene (Zgori 2000). Type 4 re ysti renl tumors. Ctegory 4 lesions re mlignnt ysti msses ontining either smll or lrge mounts of lifition within thik, enhning irregulr wll or septum. Enhning soft tissue omponents re present jent to or extening from, ut re inepenent of, the wll or septum. Type 1 or 2 ysts n type 4 ysts, respetively enign n mlignnt, re hrterize y seline US (Hélénon et l. 2001). When the imging fetures on CT re equivol for enign versus mlignnt ysti renl msses, US my further show the internl rhiteture of the ysti renl mss (Zgori 2000). Clifition in ysti renl mss is not s importnt in ignosis s the presene of ssoite enhning soft tissue elements (Isrel n Bosnik 2003). Color signl sturtion, motion n looming rtifts, insensitivity to the flow of pillry vessels, n limite sensitivity to the signl proue y miroule-se gents represent importnt limittions of olor Doppler US. Miroule-se ontrst gents n eite US ontrst-speifi moes hve een introue to overome the limittions of seline gry-sle n olor Doppler US Dynmi Phses in Renl Prenhym Enhnement After Miroule Injetion The injetion of iointe or prmgneti ontrst gents shows ifferent phses of nephrogrphi progression, inluing the vsulr (15 25 s), the ortiomeullry or ortil nephrogrphi (25 80 s), the nephrogrphi or iffuse nephrogrphi ( s), n the exretory (3 5 min post injetion) phses. A hyperttenuting ortil nephrogrm with ortiomeullry ifferentition is otine uring the ortiomeullry phse, while homogeneous nephrogrm n e otine uring the nephrogrphi phse. Unlike ontrst gents employe in CT or mgneti resonne (MR) imging, whih present n interstitil phse, miroules remin entirely intrvsulr n my e onsiere s pure loo pool gents whih re not exrete y the kineys n present neither nephrogrphi nor n exretory phse. Renl ortex rpily enhnes from 15 to 20 s fter miroule injetion, while the vessels of the renl meull re progressively fille from 30 to 35 s n ompletely fille from 40 to 50 s fter miroule injetion. This is euse the renl meull hs lower glol perfusion thn renl ortex (out 400 vs 190 ml/min per 100 g of renl tissue). For these resons, it is pproprite to ientify, fter miroule injetion, n erly or rteril ortiomeullry phse (from 20 to 40 s) with ortiomeullry ifferentition n lte ortiomeullry phse (from 45 to 120 s) with homogeneous enhnement in oth renl ortex n meull Snning Moes Eh renl tumor must unergo preliminry snning y seline gry-sle n olor Doppler US, inluing with the employment of spekle-reuing tehnique suh s tissue hrmoni imging or ompoun imging (Cluon et l. 2002). Bseline olor Doppler US is performe y using slow-flow settings (pulse repetition frequeny 800 1,500 Hz, wll filter

3 Chrteriztion n Detetion of Renl Tumors 225 of 50 Hz, high levels of olor versus eho priority, n olor persistene). Color gin is vrie ynmilly uring the exmintion to enhne olor signls n voi exessive noise, with the size of the olor ox eing juste to inlue the entire lesion in the fiel of view. Spetrl nlysis of entrl n peripherl tumorl vessels is performe y pulse Doppler to revel ontinuous venous or pulstile rteril flows. After seline ssessment, the employment of ontrst-speifi US moes with miroules my provie importnt itionl finings relevnt to renl tumor hrteriztion. As in the snning of fol liver lesions (Hrvey et l. 2000), high or low ousti power moe insontion my e employe. ) Destrutive high ousti power intermittent moe. The high ousti power moe hs to e employe with ir-fille miroule ontrst gents. When insonte with high ousti power (mehnil inex, MI>0.8 1), miroules ollpse, prouing high-intensity, ron trnsient signl whih my e etete using eite ontrst-speifi tehniques. Before miroule injetion, suitle ousti winow offering the est visuliztion of the renl mss on the xil or longituinl plne hs to e ientifie with one single fous elow the tumor. During reth-hol, ifferent high ousti power trins of four to six US pulses re trnsmitte intermittently y using mnul (every s) or ECG-triggere insontion to minimize miroule rupture. High ousti power insontion hs the vntge of prouing high-intensity hrmoni signls, though it hs severl rwks, e.g., intermittene of insontion, tehnil iffiulty of performne, n high iniene of rtifts. ) Nonestrutive low ousti power ontinuous moe. Renl msses re insonte ontinuously uring oth the erly n the lte ortiomeullry phse in rel time y employing low ousti power moe to hieve miroule resonne with proution of hrmoni frequenies. The low ousti power moe hs to e employe with perfluororon- or sulfur hexfluorie-fille miroule ontrst gents, suh s SonoVue (BR1, Bro, Miln, Itly), Definity (DMP 115, Du Pont Merk, Billeri, USA), n Optison (FS069, evelope y Moleulr Biosystem In., Sn Diego, CA; istriute y Amershm Helth In., Prineton, NJ). These gents hve een reporte to inrese ignosti onfiene in the hrteriztion of renl tumors, to improve renl lesion onspiuity, n to effetively elinete tumorl mirovessels (Brr et l. 2001; Corres et l. 2001). The low ousti power moe is tehnilly more simple to perform thn the high ousti power moe sine the sonologist my hnge trnsuer position uring snning n my perform rel-time sweep without the risk of losing the orret snning plne. Moreover, the low ousti power moe llows more effetive suppression of the kgroun signl rising from the ntive tissues n seletive visuliztion of miroules with reue frequeny of rtifts. However, the low ousti power moe hs lower signl to noise rtio n offers limite visiility of the eep prenhyml regions ue to US signl ttenution Contrst Enhnement Ptterns in Soli Renl Tumors After Miroule Injetion Different ontrst enhnement ptterns my e oserve in oth soli n ysti renl tumors. Both in enign n in mlignnt soli renl tumors, four funmentl ptterns of ontrst enhnement my e visulize (Fig. 15.1): () sent, no ifferene in renl tumor pperne efore n fter miroule injetion; () otte, tiny seprte spots istriute throughout the lesion; () iffuse homogeneous, involving the entire lesion with the sme eho intensity throughout the lesion, or () iffuse heterogeneous, involving the entire lesion. The ehogeniity of renl tumors on seline gry-sle US n the tumorl vsulrity n stining fter miroule-se ontrst gent injetion hve to e ompre with the jent kiney. Tumors with homogeneous or slightly heterogeneous eho intensity istriution re efine s hyper-, iso-, or hypoehoi (or hyper-, iso-, or hypovsulr) epening on whether they isply similr or lower ehogeniity reltive to the jent renl prenhym. In the other ses, renl tumors re efine s heterogeneous Benign Soli Renl Tumors Emryonl Metnephri Aenom Emryonl metnephri enom is rre enign renl tumor whih shows heterogeneous pperne

4 226 E. Qui Fig The ifferent ptterns of ontrst enhnement whih my e oserve in soli renl tumors fter the injetion of miroule-se gents. sent, otte, iffuse homogeneous, iffuse heterogeneous. Fig Emryoni metnephri enom. Bseline US n Power Doppler US. A heterogeneous soli lrge renl mss (rrowhes) is ientifie t the upper pole of the right kiney with peripherl n penetrting vessels on Power Doppler US., Contrst-speifi moe: Pulse Inversion Moe (Philips-ATL, WA, USA) with high ousti power insontion fter ir-fille miroule injetion. Diffuse heterogeneous ontrst enhnement (rrowhes) is emonstrte uring the rteril phse () n ereses uring the lte phse (). on seline US (Fig. 15.2), with mixe rteril vessel istriution on olor Doppler US (Fig. 15.2). After miroule injetion, emryonl metnephri enom emonstrtes heterogeneous ontrst enhnement uring the rteril n lte phses (Fig. 15.2,) Angiomyolipom Epiemiology n histopthologi fetures. Angiomyolipom is reltively unommon renl tumor, with prevlene of 0.3% to 3%, n it ours more ommonly in women thn in men (Isrel n Bosnik 2003). Angiomyolipom ontins smooth musle, vsulr, lipomtous, n myeloi elements (Shermn et l. 1981; Wgner et l. 1997) in ifferent proportions. It usully ppers s n expnsive unifol lrge tumor whih looks yellowish on setion when the ft omponent is preominnt, white if the musulr omponent is preominnt, or re when the vsulr omponent is preominnt ( hemorrhgi pttern my then e present) (Hrtmn 2001).

5 Chrteriztion n Detetion of Renl Tumors 227 Bseline US n olor Doppler US. Angiomyolipoms smller thn 3 m typilly pper hyperehoi n homogeneous, with shrp mrgins (Formn et l. 1993; Jinzki et l. 1998; Ymshit et l. 1992; Pozzi Muelli n Lotelli 2002). Lrge ngiomyolipoms my isply heterogeneous pperne ue to soli, ipose, n hemorrhgi omponents. The presene of posterior ousti showing my suggest ngiomyolipom (Ymshit et l. 1992; Hélénon et l. 1997; Jinzki et l. 1997). Color Doppler US revels penetrting, peripherl, or mixe peripherl n intrtumorl istriution, with preominne of the mixe istriution in typil hypervsulr ngiomyolipoms. Multimolity imging CT n MR imging. The CT ignosis of ngiomyolipom is relte to the ientifition of ft within the lesion (Pozzi Muelli n Lotelli 2002). Angiomyolipoms lrger thn 3 m usully emonstrte preominnt hypoense ft omponent on nonenhne CT, with low ontrst enhnement of the soli peripherl or entrl omponent (spring the ft omponent) fter iointe ontrst gent injetion. Angiomyolipoms smller thn 3 m present low-gre ontrst enhnement uring the rteril n lte phses, ppering hypoense in omprison with the jent enhning renl prenhym. Differentil ignosis etween typil ngiomyolipoms n nonftty renl tumors is not lwys solve even y CT n MR imging (Pretorius et l. 2000). Atypil ngiomyolipoms with sene of ft omponent ount for out 5% of ses (Pozzi Muelli n Lotelli 2002) n usully pper iso- or slightly hyperense ompre to the jent kiney on nonenhne CT. A similr pttern my e oserve in omplite enign ysts (hemorrhgi, protein-rih, or geltinous), renl metstsis, n renl ell rinom. Atypil hypervsulr ngiomyolipoms isply iffuse ontrst enhnement fter the injetion of iointe or prmgneti ontrst gents, n omplite enign ysts my e exlue in this wy. Contrst-enhne US. Typil hyperehoi homogeneous or slightly heterogeneous ngiomyolipoms typilly isply persistent otte ontrst enhnement (Fig. 15.3) (Qui et l. 2003,), with n isoehoi (isovsulr) pperne ompre to the jent enhning renl prenhym, prtiulrly if high ousti power insontion is employe. Using low ousti power insontion, more effetive suppression of the kgroun hyperehoi pperne is hieve, n ngiomyolipoms usully pper hypoehoi ompre to the jent kiney fter miroule injetion (Fig. 15.3). Atypil ngiomyolipoms show iffuse ontrst enhnement with hypervsulr pperne uring the rteril phse (Figs. 15.4, 15.5), with (Fig. 15.4) or without (Fig. 15.5) progressive reution of ontrst enhnement in the lte phse. This ontrst enhnement pttern is use y the hypervsulr nture of most typil ngiomyolipoms Renl Onoytom Epiemiology n histopthologi fetures. Renl onoytoms (2 3% of renl tumors) re enign tumors rising from proximl tuulr epithelil ells tht n e trete y lol exision or heminephretomy. Their preopertive ifferentition from renl ell rinom is very importnt. Onoytom is hrterize y lrge ells with smll, uniform, roun nulei n n unnt eosinophili ytoplsm. It ppers rown on setion owing to the lipohromi pigment of mitohonri, with or without lifitions; usully nerosis n hemorrhge re sent, n there is firomyxoi strom in the entrl sr (Amin et l. 1997). Bseline n olor Doppler US. The presene of entrl sr ppering s stellte hypoehoi re n the sene of hemorrhge n nerosis re onsiere typil in renl onoytom (Hélénon et l. 2001). Lrge onoytoms with stellte hypoehoi entrl re my lso isply entrl spoke-wheel shpe istriution of tumor vessels on olor Doppler US (Hélénon et l. 2001). Multimolity imging CT n MR imging. The lssi ngiogrphi finings esrie for renl onoytom, inluing spoke-wheel shpe pttern, homogeneous nephrogrm, n shrp, smooth rim (Amos et l. 1978; De Crli et l. 2000; Hjri et l. 2001), my e oserve on ontrst-enhne CT. On ontrst-enhne CT sns, iffuse homogeneous ontrst enhnement throughout the tumor n entrl, shrply mrginte, stellte re of low ttenution re foun in 70 80% of lesions (Dvison et l. 1993). Nevertheless, res of erese ttenution ifferent from the stellte entrl re, whih re usully foun in renl ell rinom, my e oserve in out 20 30% of onoytoms (Dvison et l. 1993), n prtiulrly those lrger thn 3 m. Rrely,

6 228 E. Qui e Fig e Angiomyolipom with otte ontrst enhnement. Bseline olor Doppler US. A hyperehoi n homogeneous lrge renl mss (rrows) with peripherl vessels is ientifie., Contrst-speifi moe: Cene Contrst Pulse Sequene (Siemens-Auson, CA, USA) with low ousti power fter the injetion of sulfur hexfluorie-fille miroules. A hypoehoi (hypovsulr) pperne with otte ontrst enhnement (rrows) is emonstrte uring oth the rteril () n the lte () phse., e Contrst-enhne CT: persistent hypoense pperne of the tumor in oth the ortiomeullry () n the tuulr phse (e) with ft ensity pperne (rrows). Fig Angiomyolipom with iffuse homogeneous ontrst enhnement. Bseline US. Homogeneous hyperehoi lesion (rrows) with wege-shpe onnetion to the renl prenhym., Contrstspeifi moe: Contrst Tune Imging (Esote, Geno, Itly) with low ousti power fter the injetion of sulfur hexfluorie-fille miroules. The lesion revels iffuse n homogeneous ontrst enhnement (rrows) with hypervsulr pperne uring the rteril phse () tht persists into the lte phse ().

7 Chrteriztion n Detetion of Renl Tumors 229 ft omponent my e ientifie (Hélénon et l. 1997). Diffuse homogeneous enhnement hs lso een esrie on G-DTPA enhne MR imging (Eilenerg et l. 1990). Contrst-enhne US. After the injetion of miroule-se ontrst gent, renl onoytom shows persistent iffuse homogeneous ontrst enhnement, with hypervsulr pperne, in the erly ortiomeullry phse. The enhnement progressively elines uring the lte ortiomeullry phse, resulting in hypovsulr pperne (Fig. 15.6) Mlignnt Soli Renl Tumors Soli Renl Cell Crinom Epiemiology n histopthologi fetures. Soli renl ell rinom is the most ommon mlignny of the kiney n ounts for 2% of ll ners (Sheth et l. 2001). Vrious histopthologi sutypes of mlignnt soli renl prenhym tumors hve een esrie: (1) ler ell (70 80%), (2) ppillry ell (10 15%), (3) grnulr ell (5%), (4) hromophoe ell (5%), (5) sromtoi ell (1 2%), (6) olleting ut rinom, n (7) meullry rinom (1 2%). Types 1 4 usully present n expnsile growth pttern while types 5 7 usully show n infiltrtive pttern (Storkel et l. 1997; Oyen 1998; Oyen et l. 2001; Pikhrt et l. 2000). Bseline US n olor Doppler US. Most soli renl ell rinoms smller thn 3 m pper hypoehoi on seline US, with pproximtely 30% ppering s hyperehoi msses (Formn et l. 1993). Presene of n nehoi rim or smll intrtumorl ysts my suggest renl ell rinom (Ymshit et l. 1992; Hélénon et l. 1997; Jinzki et l. 1997). Soli renl ell rinoms lrger thn 3 m usully pper heterogeneous on seline US. Renl ell rinoms preominntly present rteril vessels with mixe istriution on olor Doppler US (Fig. 15.7). Fig Angiomyolipom with iffuse homogeneous ontrst enhnement. Bseline US n olor Doppler US. A hypoehoi exophyti renl mss (rrows) is ientifie t the upper pole of the right kiney. Arteril intrtumorl n penetrting vessels re ientifie on olor Doppler US., Contrst-speifi moe: Pulse Inversion Moe (Philips-ATL, WA, USA) with high ousti power fter the injetion of ir-fille miroules. The renl tumor (rrows) shows iffuse n homogeneous ontrst enhnement uring the rteril phse (), while ontrst enhnement progressively ereses in the lte phse (). Biopsy revele ngiomyolipom with prevlent vsulr omponent.

8 230 E. Qui e f g h Fig h. Renl onoytom. Bseline US n Power Doppler US. Longituinl sn shows heterogeneous n hypoehoi lesion (rrows) with peripherl n intrtumorl vessels., Contrst-speifi moe: Contrst Tune Imging (Esote, Geno, Itly) with low ousti power fter the injetion of sulfur hexfluorie-fille miroules. Diffuse homogeneous ontrst enhnement (rrows) with hypervsulr pperne is ientifie in the rteril phse (); the enhnement erese uring the lte phse, with hypovsulr pperne (). e T2-weighte n f h G-BOPTA-enhne T1-weighte MR sequenes. The renl tumor (rrows) ppers hypointense on the T2-weighte sequene (e). Contrst enhnement is evient uring the ortiomeullry phse (f) n ereses in the tuulr (g) n exretory (h) phses.

9 Chrteriztion n Detetion of Renl Tumors 231 Fig Renl ell rinom of the ler ell type with iffuse homogeneous ontrst enhnement. Bseline US n Power Doppler US. Longituinl sn shows hyperehoi n slightly heterogeneous lesion (rrows) with peripherl n intrtumorl vessels., Contrst-speifi moe: Contrst Tune Imging (Esote, Geno, Itly) with low ousti power fter the injetion of sulfur hexfluorie-fille miroules. Diffuse homogeneous ontrst enhnement, with hypervsulr pperne (rrows), is ientifie in the rteril phse () n is seen to erese in the lte phse (). Presene of intrtumorl rteriovenous shunts is suggestive of renl ell rinom (Hélénon et l. 2001), even though ngiomyolipoms my revel the sme pttern. Lrge (>4 m) renl ell rinoms typilly show heterogeneous pperne ue to intrtumorl nerosis, lifitions (Hélénon et l. 2001), n hemorrhge. Multimolity imging CT n MR imging. Most renl ell rinoms re soli lesions with ttenution vlues of 20 HU or greter on nonenhne CT (Silvermn et l. 1994). An inrese of HU on CT (Hrtmnn et l. 1988; Mki et l. 1999) n of 15% signl intensity on MR imging (Ho et l. 2002) within renl lesion fter the intrvenous ministrtion of ontrst gent hs generlly een epte s threshol for ontrst enhnement. The emonstrtion of enhnement is onsiere relile sign of vsulr renl tumor even though it is not onsiere sign of mlignny. Nevertheless, in renl ell rinom ontrst enhnement on CT or MR imging is usully iffuse n intense, spring neroti intrtumorl res (Soyer et l. 1997). An exeption is the ppillry ell sutype, whih ppers hypovsulr on ontrst-enhne CT or MR imging (Choyke et l. 1997, 2003). Distint res of ft my e present s well. Cysti res my preominte so tht the tumor presents frnk ysti pperne. Contrst-enhne US. After miroule injetion, soli renl ell rinoms smller thn 3 m show iffuse (Fig. 15.7), homogeneous or heterogeneous ontrst enhnement (Fig. 15.8) uring the erly ortiomeullry phse, often with hypervsulr pperne. The enhnement is limite to the soli vile regions, spring intrtumorl vsulr neroti, hemorrhgi, or ysti omponents n therey inresing their onspiuity (Fig. 15.8). Renl ell rinoms pper isovsu-

10 232 E. Qui Fig Renl ell rinom of the ler ell type with iffuse heterogeneous ontrst enhnement. Bseline US n olor Doppler US. Axil sn shows heterogeneous lesion (rrows) with peripherl n intrtumorl vessels., Contrstspeifi moe: Contrst Tune Imging (Esote, Geno, Itly) with low ousti power fter the injetion of sulfur hexfluoriefille miroules. Diffuse heterogeneous ontrst enhnement (rrows) is ientifie in the rteril phse (), n ereses uring the lte phse (). lr or slightly hypovsulr reltive to the jent renl prenhym, with progressive reution of ontrst enhnement in the lte ortiomeullry phse (Figs. 15.7, 15.8). If tumorl thromus is present in the renl vein or inferior ven v, it my show ontrst enhnement (Corres et l. 1999, 2003). At ojetive nlysis of ontrst enhnement, renl ell rinoms isplye signifintly higher eho intensity enhnement uring oth the rteril n the lte phse ompre to enign renl tumors (Qui et l. 2003). Contrst-enhne US my e even more sensitive thn ontrst-enhne CT in showing ontrst enhnement in soli renl tumors (Fig. 15.9), ue to the high sensitivity of US ontrst-speifi moes to the hrmoni signl proue y miroule insontion. Ppillry ell-type rinoms prevlently isplys sent or slight ontrst enhnement fter miroule injetion (Figs , 15.11), with hypovsulr pperne reltive to the jent renl prenhym, s is lso seen on ontrstenhne CT or MR imging (Herts et l. 2002). CT my ifferentite type 3 hyperense ysts from hyperense renl ell rinom y emonstrting ontrst enhnement fter the injetion of n iointe ontrst gent, while US my ifferentite type 3 hyperense ysts from iso-hyperense hypovsulr tumors y reveling ysti nehoi pttern (30 50% of ses) or soli ehoi pttern (Fig ) Renl Metstsis The frequeny of metstses to the kiney in ner ptients is 7 13% in lrge utopsy series (Brken et l. 1979; Pikhrt et l. 2000). Renl metstses re usully etete lte in the ourse of the mlignny n re usully multifol (Choyke et l. 1987). Metstses rising from olon, lung, n rest rinom n melnom my involve the kiney. As with lymphom, renl metstses n isply either n expnsile or n infiltrtive growth pttern (Choyke et l. 1987; Pikhrt et l. 2000). However, the most frequent pttern is tht of multiple isrete ilterl lesions. Solitry exophyti

11 Chrteriztion n Detetion of Renl Tumors 233 e f g Fig g. Higher sensitivity of US ontrst-speifi moes fter the injetion of miroule-se gents in the etetion of ontrst enhnement, in omprison with ontrst-enhne CT. Bseline US n Power Doppler US. Longituinl sn showing hyperehoi renl mss (rrows) with peripherl n intrtumorl vessels., Contrst-speifi moe: Contrst Tune Imging (Esote, Geno, Itly) with low ousti power fter the injetion of sulfur hexfluorie-fille miroules. Diffuse ontrst enhnement (rrows) is ientifie in the erly ortiomeullry phse () n ereses uring the lte ortiomeullry phse (), with onsequent hypovsulr pperne of the tumor. e g Contrst-enhne CT. Renl tumor (rrow) oes not isply signifint ontrst enhnement fter iointe ontrst gent injetion. Histologi nlysis of the surgil speimen revele renl ell rinom of the ler ell type.

12 234 E. Qui e f g h

13 Chrteriztion n Detetion of Renl Tumors 235 Fig h. Asent enhnement in soli ppillry ell type rinom. Bseline US n power Doppler US. A hyperehoi exophyti lesion (rrows) is ientifie in the left kiney with no vsulr signl t power Doppler nlysis., Contrst-speifi moe: Contrst Tune Imging (Esote, Geno, Itly). No ontrst enhnement is ientifie fter the injetion of sulfur hexfluorie-fille miroules t low ousti power insontion, with persistent hypovsulr pperne (rrows). e h. Nonenhne (e) n ontrst-enhne (f h) CT. The renl tumor (rrows) shows slight ontrst enhnement fter iointe ontrst gent injetion, with persistent hypovsulr pperne. Soli ppillry renl ell rinom ws revele fter surgil resetion. Fig Hypovsulr pperne of smll soli ppillry ell type rinom. Bseline US revels smll (1.5-m) hyperehoi tumor (rrow) in the left kiney. After injetion of the miroule-se gent, the renl tumor (rrow) ppers hypovsulr ompre to the jent kiney. Nonenhne CT isplys hyperense tumor (rrow). The tumor ppers hypovsulr on ontrst-enhne CT uring the ortiomeullry phse, fter the injetion of iointe ontrst gent. Soli ppillry renl ell rinom ws revele fter surgil resetion.

14 236 E. Qui metstses re more ommon in ptients with olon ner, n perinephri tumor extension is typil of melnom (Pikhrt et l. 2000). The presene of n ssoite exophyti omponent, ysti nerosis, hemorrhge, or lifition on CT epens on the nture of the unerlying primry tumor. Renl metstses o not isply ontrst enhnement on either ontrst-enhne CT/MR imging (Choyke et l. 1987; Pikhrt et l. 2000) or ontrst-enhne US (Qui et l. 2003). In prtiulr, fter miroule injetion, renl metstses pper persistently hypovsulr ompre to the jent renl prenhym n their visiility is improve (Fig ) Contrst Enhnement Ptterns in Cysti Renl Tumors After Miroule Injetion Contrst-enhne US is vlule tool to ientify ontrst enhnement in the peripherl wll or intrtumorl sept of ysti renl tumors. This is ue to the high sensitivity of the ontrst-speifi moe to the hrmoni signls proue y miroules. As result, ontrst-enhne US is proly even more effetive thn ontrst-enhne CT n MR imging in the etetion of ontrst enhnement in ysti renl tumors. Miroule-se ontrst gents hve een shown to improve the hrteriztion of renl ysts n typil ysti renl msses y reveling ifferent enhnement ptterns(kim et l. 1999; Qui et l. 2003,). After miroule injetion vriety of ontrst enhnement ptterns my e oserve in ysti renl tumors (Fig ): () sent, no ifferene efore n fter miroule injetion; () ontinuous or () isontinuous peripherl rim-like enhnement in ysti lesion with or without intrtumorl sept; () peripherl noulr enhnement limite to the peripherl wll n to the noulr ppillry enoysti omponents; (e) peripherl wll n septl enhnement; or (f) iffuse noulr n septl enhnement with noulr omponents oth in the peripherl wll n in the intrtumorl sept. Fig Renl metstsis. Bseline US. A heterogeneous mss (rrows) is ientifie t the upper right renl pole. Contrst-speifi moe: Contrst Tune Imging (Esote, Geno, Itly) with low ousti power fter the injetion of sulfur hexfluorie-fille miroules. A persistent sene of ontrst enhnement with hypovsulr pperne (lrge rrow) is ientifie (), n there is eviene of itionl smll hypovsulr lesions (smll rrows) in the lte ortiomeullry phse (, ).

15 Chrteriztion n Detetion of Renl Tumors 237 e f Fig f. The ifferent ptterns of ontrst enhnement in ysti renl tumors: sent (oserve in simple renl ysts), ontinuous rim-like peripherl enhnement, isontinuous rim-like peripherl enhnement, noulr peripherl enhnement, e peripherl wll n septl enhnement, f iffuse noulr n septl enhnement Benign Cysti Renl Tumors Complex renl inflmmtory or hemorrhgi ysts. Inflmmtory or hemorrhgi ysts my show type 3 pttern oring to the Bosnik lssifition (1986), onsisting in thik peripherl wll hrterize y sene of vsulr signls or y few spots on seline olor Doppler US or in orpusulr hyperehoi ense ontent. After miroule injetion, enign renl ysts with ehoi ontent isply sent (Fig ) or ontinuous/ isontinuous peripherl rim-like (Fig ) ontrst enhnement in oth the rteril n the lte ortiomeullry phse. Multiloulr ysti nephrom. Multiloulr ysti nephrom is n unommon neoplsm ompose of multiple, vrily size ysts with prominent sept (Hrtmn 1989). The ysts ontin nonhemorrhgi flui n o not ommunite with eh other. Clifition is only unommonly present in the yst wll n sept. This tumor is hrterize y ense peripherl firous psule. The ysts re line y uoil epithelil ells tht projet into the yst lumen. The septl strom is ompose of loose onnetive tissue with sprse ellulrity. Typilly, no ontrst enhnement is ientifie in intrtumorl sept on ontrst-enhne CT (Hrtmn 1989; Dll Plm et l. 1990). Multiloulr ysti nephrom my isply ontinuous or isontinuous peripherl rim-like ontrst enhnement in the thik peripherl wll (Fig ) fter miroulese ontrst gent injetion Mlignnt Cysti Renl Tumors Cysti renl ell rinom. Cler ell n ppillry ell type rinoms my present ysti pttern (Roerts et l. 1997). Cysti ler ell rinoms ten to e lrge, roune, or polyloulr lesions (Hrtmn 1989). Cysti renl ell rinom my pper s ysti lesion with ehoi ontent or thik peripherl wll or s pseuoysti tumor with thik, irregulr peripherl wll or peripherl ehoi murl noules. The peripherl wll or the murl noules usully isply some rteril flow signls on olor Doppler US. Typilly, intense ontrst enhnement is ientifie in intrtumorl sept n murl noules on ontrst-enhne CT (Hrtmn 1989; Dll Plm et l. 1990). After miroule injetion, ysti renl ell rinom shows isontinuous peripherl rimlike (Fig ) or peripherl noulr (Fig ) or iffuse noulr n septl (Fig ) ontrst enhnement. In pseuoysti renl tumors, etter

16 238 E. Qui Fig Renl hemorrhgi yst with sene of ontrst enhnement fter miroule injetion. Bseline US n olor Doppler US. An exophyti lesion with ehoi ontent (rrow) is ientifie in the left kiney on seline US (); it oes not present vsulr signl on olor Doppler US (). Contrst-speifi moe: Pulse Inversion Moe (Philips-ATL, WA, USA). No ontrst enhnement is ientifie (rrow) fter the injetion of sulfur hexfluorie-fille miroules t low ousti power insontion. This ehvior llows ifferentition of this orpusulr yst from soli renl tumor. Fig Renl inflmmtory yst with rim-like ontinuous peripherl enhnement. Bseline US. A hypoehoi exophyti lesion (rrows) is ientifie t the right kiney. Contrst-speifi moe: Pulse Inversion Moe (Philips-ATL, WA, USA). Peripherl wll enhnement is ientifie fter the injetion of ir-fille miroules t intermittent high ousti power insontion. Nonenhne CT n ontrst-enhne CT. A renl lesion (rrows) isplys peripherl ontrst enhnement fter iointe ontrst gent injetion. An inflmmtory ysti lesion ws ignose t histologi nlysis of the surgil speimen.

17 Chrteriztion n Detetion of Renl Tumors 239 e Fig e. Renl multiysti nephrom with ontinuous rim-like peripherl enhnement. Bseline US n olor Doppler US. Longituinl sn shows ysti renl mss with intrtumorl sept n eviene of vessels (rrows) in the peripherl wll. Contrst-speifi moe: Contrst Tune Imging (Esote, Geno, Itly) with low ousti power fter the injetion of sulfur hexfluorie-fille miroules. Peripherl ontrst enhnement is ientifie in the peripherl wll (rrows), without eviene of septl enhnement., e Contrst-enhne CT. Peripherl wll ontrst enhnement is ientifie fter iointe ontrst gent injetion (rrows), without eviene of tumorl sept. elinetion etween the soli n the liqui intrtumorl omponents is possile fter miroule injetion (Fig ) Clinil Results Vrying ontrst enhnement ptterns my e ientifie in oth mlignnt n enign renl tumors. Despite this, the ignosti performne of US in the ignosis of mlignny hs not een shown to inrese signifintly fter miroule injetion (Qui et l. 2003). This is euse the pperne of renl tumors on seline US, whether soli or ysti, is often hrteristi (Qui et l. 2003), s in the se of hyperehoi renl ngiomyolipom, lrge heterogeneous renl ell rinom, multiloulr ysti nephrom, n multiseptte ysti renl ell rinom with murl noules (Hélénon et l. 2001). The injetion of miroule-se gents my improve renl tumor hrteriztion on the sis of the ontrst enhnement pttern, e.g., otte or iffuse homogeneous enhnement in enign lesions, iffuse heterogeneous enhnement in mlignnt lesions, n sene of enhnement in renl metstses. Nevertheless, soli enign n mlignnt renl tumors my present n ientil pperne fter miroule injetion. For this reson, renl tumor hrteriztion still relies on ontrst-enhne helil CT or MR imging (Zgori 2000), whih lso llows stging ssessment. Contrst-enhne US hs some vntges over seline olor n power Doppler US, suh s the sene of motion n looming rtifts n reue epenene of the signl on the epth of the renl tumor. Contrst-enhne US my llow istintion etween those renl tumors whih shoul e hrterize y ross-setionl imging n those whih n e exhustively hrterize y US, e.g., typil ngiomyolipom, hemorrhgi or hyperehoi ysts simulting soli renl tumor, or simple or enign minimlly omplite renl ysts. When iffuse homogeneous or heterogeneous ontrst enhnement is ientifie in soli renl tumor or peripherl

18 240 E. Qui Fig Cysti renl tumor with isontinuous rim-like peripherl enhnement. Bseline US n olor Doppler US. A hypoehoi exophyti lesion (rrow) is ientifie t the right kiney with some vessels in the peripherl ehogeni omponent. Contrst-speifi moe: Pulse Inversion Moe (Philips-ATL, WA, USA). Peripherl wll enhnement (rrow) is ientifie fter the injetion of ir-fille miroules t intermittent high ousti power insontion. Contrst-enhne CT. Peripherl ontrst enhnement limite to the peripherl thikene wll (rrow) is ientifie fter iointe ontrst gent injetion. Cysti renl ell rinom of the ler ell type ws ignose t histologi nlysis of the surgil speimen. Fig Cysti renl ell rinom with noulr peripherl enhnement., Contrst-speifi moe: Contrst Tune Imging (Esote, Geno, Itly) with low ousti power insontion fter the injetion of sulfur hexfluorie-fille miroules. Contrst enhnement (rrows) is emonstrte in the soli peripherl noulr omponent of the tumor., Contrstenhne CT. Peripherl ontrst enhnement (rrow) is ientifie in the peripherl tumorl noules, while the rest of the lesion presents ysti pperne.

19 Chrteriztion n Detetion of Renl Tumors 241 e Fig e. Cysti renl ell rinom. Diffuse noulr n septl enhnement. Bseline US n olor Doppler US. A omplex ysti renl mss shows thikene peripherl wll n tumorl sept with eviene of vessels (rrow). Contrstspeifi moe: Contrst Tune Imging (Esote, Geno, Itly) with low ousti power fter the injetion of sulfur hexfluoriefille miroules. Diffuse septl n peripherl wll enhnement is emonstrte fter miroule injetion., e Contrstenhne CT. Peripherl wll n septl enhnement (rrows) is ientifie fter iointe ontrst gent injetion. e f Fig f. Cysti renl ell rinom with enhnement in the soli omponent. Bseline US. A heterogeneous renl mss (rrows) isplys peripherl hyperehoi omponent n entrl hypoehoi omponent. Contrst-speifi moe: Pulse Inversion Moe (Philips-ATL, WA, USA) with high ousti power insontion fter the injetion of ir-fille miroules. Peripherl ontrst enhnement is revele in the soli tumorl omponent (rrows), llowing etter ifferentition from the ysti tumorl omponent. Non-enhne CT n -f ontrst-enhne CT. Peripherl ontrst enhnement is ientifie in the peripherl soli omponent (rrow) of the ysti tumor, whih ppers progressively more evient from the ortiomeullry () to the tuulr (e) n exretory (f) phses.

20 242 E. Qui or septl ontrst enhnement is ientifie in ysti renl tumor, the tumor hs to e further exmine y ontrst-enhne CT or MR imging Detetion of Renl Tumors Bseline US. In ition to some tehnil n ntomil ftors tht my lter US performne, the etetility of renl tumors epens minly on the size, lotion, n ehogeniity of the lesion, with hyperehoi renl tumors eing more esily visile. The min limittions of seline US in the etetion of renl tumors relte to smll isoehoi intrprenhyml tumors n tumors of polr origin with extrrenl growth tht my e osure y owel gs. Bseline US is less urte thn ontrst-enhne CT in emonstrting smll renl msses, prtiulrly when they re smller thn 3 m (Zgori 2000). Among smll renl ell rinoms (3 m or less), 23 46% of soli tumors re iso- or hypoehoi ompre with norml renl prenhym (Hélénon et l. 2001). Bseline olor Doppler seems not to inrese signifintly the etetion rte of smll tumors (Hélénon et l. 2001). Contrst-enhne CT n MR. Contrst-enhne CT is onsiere relile tehnique for the etetion of renl tumors (Jmis-Dow et l. 1996; Szolr et l. 1997; Zgori 2000). All renl msses n e etete y CT. Approximtely 15% of renl msses etete on CT re enign, while the remining 85% re mlignnt tumors (Zgori 2000). For the urte etetion of renl msses, the nephrogrphi n exretory phses re optiml (Szolr et l. 1997; Yuh n Cohn 1999; Zgori 2000). The nephrogrphi n exretory phse imges pper of similr vlue, ut oth re superior to ortiomeullry phse imges in terms of ility to etet n hrterize renl msses. The ortiomeullry phse shoul lso e inlue for stging (Kopk et l. 1997; Zgori 2000). Some ignosti pitflls hve een esrie for ontrst-enhne CT (Kopk et l. 1997; Szolr et l. 1997). The prinipl ignosti iffiulties re enountere in the presene of smll hypervsulr renl ell rinoms with similr ontrst enhnement to renl ortex, whih my e mistken for norml prenhym in the ortiomeullry phse, n entrlly lote tumors, whih my e mistken for norml hypottenuting renl meull (Yuh n Cohn 1999). Most stuies inite tht MR imging is omprle to CT for the etetion of renl msses (Semelk et l. 1992; Zgori 2000). Contrst-enhne US. The prinipl limittion of ontrst-enhne US in the etetion of renl msses is tht miroule-se gents emonstrte only the ortiomeullry phse without the possiility of nephrogrphi phse. Sine renl ell rinoms present similr ontrst enhnement to the jent renl prenhym uring the rteril ortiomeullry phse, they eome less evient fter miroule injetion. Even though some stuies seem to show n improvement in the etetion of renl msses fter miroule injetion (Jenett et l. 2000), mlignnt renl tumors re usully iffiult to etet. The only exeption my e renl hypovsulr metstses, whih present persistent hypoehoi pperne fter miroule injetion (Qui et l. 2003) n pper s hypoehoi efets in the enhning renl prenhym When Shoul Miroule-Bse Agents Be Employe? In typil ngiomyolipom, seline US llows orret hrteriztion (Hélénon et l. 2001). Sine the ignosti performne of US in respet of mlignny hs not een shown to improve signifintly fter miroule injetion (Qui et l. 2003), miroule-se gents shoul e employe only in selete other ses, e.g., to ssess tumorl vsulrity, to etermine the extent of tumorl neroti nonenhning res (Fig ), or to ientify ontrst enhnement in the tumorl thromus. Every soli renl tumor whih is ineterminte on oth seline US n ontrst-enhne CT or MR imging hs to e remove. Miroulese gents re lso useful in ifferentiting renl tumors from pseuotumors suh s hypertrophi olumn of Bertin. In pseuotumors, internl n peripherl vsulture exhiits smooth n homogeneous rnhing (Corres et l. 1999). Simple (type 1) or minimlly omplite (type 2) renl ysts re relily ssesse y seline US. Miroule-se gents shoul e employe to ifferentite hemorrhgi n inflmmtory renl ysts (Figs , 15.15) from soli renl tumors. Ineterminte renl ysts (type 3) shoul lwys e ssesse fter miroule injetion to ientify septl or murl

21 Chrteriztion n Detetion of Renl Tumors 243 Fig Lrge renl soli tumor tht is extensively neroti n isplys n infiltrting growth pttern., Heterogeneous iffuse ontrst enhnement (rrowhes) is ientifie fter miroule injetion, with entrl hypovsulr neroti regions (rrow)., Contrst-enhne CT isplys the tumor (rrows) in the upper left renl pole () with infiltrting growth towrs the jent renl prenhym () n omplete thromosis of the left renl vein (rrows). noule ontrst enhnement, whih is typil of mlignnt ysts. If these finings re ientifie, the renl yst shoul e further exmine y ontrstenhne CT. In overt mlignnt renl ysts (type 4), miroules shoul e employe in selete ses, e.g., to istinguish soli from ysti, neroti, nonenhning omponents (Fig ). In renl tumor etetion, miroules shoul e employe only to etet renl metstses, whih pper hypoehoi ompre to the jent renl prenhym on ontrst-enhne US. Referenes Amos MA, Bosnik MA, Vlensi QJ (1978) Angiogrphi ptterns in renl onoytoms. Riology 129: Amin MB, Crotty TB, Tikoo SK, Frrow GM (1997) Renl onoytom: repprisl of morphologi fetures with liniopthologi finings in 80 ses. Am J Surg Pthol 21:1-12 Brr RG, Roin ML, Peterson C (2001) Definity-enhne ultrsoun imging of the kiney in ptients with ineterminte msses: vlue of ontrst hrmoni imging with olus n infusion ministrtion. Riology [Suppl] 221:316 Bosnik MA (1986) The urrent riologil pproh to renl yst. Riology 158:1-10 Brken RB, Chi G, Johnson DE, Lun M (1979) Seonry renl neoplsms: n utopsy stuy. South Me J 72: Choyke PL, White EM, Zemn RK (1987) Renl metstses: liniopthologi n riologi orreltion. Riology 162: Choyke PL, Wlther MM, Glenn GM et l (1997) Imging fetures of hereitry ppillry renl ners. J Comput Assist Tomogr 21: Choyke PL, Glenn GM, Wlther MM et l (2003) Hereitry renl ners. Riology 226:33-46 Cluon M, Trnqurt F, Evns DH et l (2002) Avnes in ultrsoun. Eur Riol 12:7-18 Corres JM, Hélénon O, Moreu JF (1999) Contrst-enhne ultrsonogrphy of ntive n trnsplnte kiney iseses. Eur Riol 9 [Suppl 3]:S394-S400 Corres JM, Cluon M, Lesvre A et l (2001) Contrstenhne sonogrphy of renl msses using FSO69: quntifition of the enhnement with Pulse Inversion Imging. Riology [Suppl] 221:316 Corres JM, Cluon M, Trnqurt F, Hélenon O (2003) Contrst-enhne ultrsonogrphy: renl pplitions. J Riol 84: Dll Plm L, Pozzi Muelli F, Di Donn A, Pozzi Muelli R (1990) Cysti renl tumors: US n CT finings. Urol Riol 12:67-73 Dvison AJ, Hyes WS, Hrtmn DS (1993) Renl onoytom n rinom: filure of ifferentition with CT. Riology 186: De Crli P, Viiri A, Lmnn L, Cntini R (2000) Renl ono-

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