Journal of Neuro-Ophthalmology, March 1986, Volume 6, Issue 1

Correlative study of the computed tomographic, ultrasonographic, and pathological characteristics of cavernous versus capillary hemangiomas of the orbit.

Pathologic and ultrasonographic features of cavernous and capillary hemangiomas were correlated with the computed tomographic (CT) characteristics of these two tumors to show that these hemangiomas can be differentiated by their contrast enhancement characteristics. Specifically, all five cases of adult cavernous hemangiomas were enhanced proportionately less than extraocular muscles, whereas capillary hemangiomas were enhanced proportionately more than extraocular muscles. The capillary hemangioma that demonstrated the lowest relative enhancement was in an older child, it may have represented a more mature form of a capillary hemangioma. We correlated these CT findings with the ultrasonographic and pathologic features to explain the differences in these CT characteristics.

Correlative Study of the Computed T0l11ographic, Ultrasonographic, and Pathological Characteristics of Cavernous Versus Capillary Helnangiomas of the Orbit E\"l'l~' n Lllpe/. SkiM, \1.1 I., Robert M. QUl'nLer, \ 1.1l. , S,mdr,l t-:rc1l.ier B~'rnl" and Virgil E. F, 'kIM, \1.1>" f'h.l>. 1'.lth"ll1~k .md ullr.1'o'II1\'~r.lphl" ",,,t u r...... ,t ,,1\ ,·rn. 'II' .Ind ',lpdl.H\· h'·II1.ln~ll1l11.1'o \\\'r,' l"rrd.ll ..d \\llh Ih.· (llll1pUkd t"II1"gr,lphll' (. II '·h.lI..It'lI·l'I ... II,·... "I Ih ...... , t\\I' IUIl1,'r~ III ,h"I\ Ih.11 lhl"l' hl·II1.111.\,;111111.1'o ,,111 b,' dllh'r' l'nll,lkd l'\' Ihur ,','ntr.I 1 .. nh,IIl(I·nll'nl ,h,1r,I(lt-n,III'" Sf'I·'lli...III~·. ,Ill 11\',· ,',1 ," ,'I .Idull (.1\·I·rn"l1'" hnll.\lI-gillll1, l'" 1I','r,' "nh,ll1(I'd pn'p"rllt,n.lld\· k ...... Ih.1I1 "'lr,l­1'( lIl,H Illll ...(!e.... \\'hl'f,·.b '''If'IiI.Ir~' hl'lll,ln~hlnl.l'" \l,'r,' <'nh,ln,,'d prllp"rllllll.lll'l.l· nHH,' th.11l ,·,tr.H'(uI.H Illu ...d ...... TIl<' (,lpill.u~· hl'Ill,lIlgil1111,1 th,ll d"I1lI)Il,tr.lll'li Ihl' Ill\\"l·~t f.. l.lIl\'l· "nh,1I1(1'IlWllt \\ ,1' III .\11 "kkr (hild. II moll' h,l\·'· r'Trl·..."nkd .1 Illllr,' Ill,llur,' h'rl\l lit ,1 (,lpill.H.\· hl·m,lnglllll1,l. \V" (lIrrd.lIn! 111<'''''' CI IlIldlng' \\"llh till' llllr,b'''lll~r.lphl( .1Ild p.1lh"llIgl( ll',lllln" III "'pl,llll Ill<' dilll·rl·n(l·... in th,·... l· CT (h,H,l(kn'lll, f'rllill lht' I ),'p.lrtl1h·nl III l~,ldl'lhl~\ _ L·JlI\\'P.. lt\ "I \11,\l11i ""'dllllli pi \l,·dl\lllt', llu\t,,',l\ \It \ll.lIllll.h,k"'lln .\h'Jlhlll,d Ml'lltl.oI l "I1I1'r, ~lt.1I11l. 1,1",,,1., ,\..,Idn'" \ urrt·... p\llh,l\·rh.l' ,1I1d n'prll11 n,·qlh· .. t.... 1\, l),- I, \1 t.!ul'llu·r .Il l.t·p.lrlllh'l1t HI I\'ldhdll)!.\ ,1,·11111. llll\-l·r.... lt\' \)1 .\II."," 0." h....1..I .\1<-.1 .. III". f' \ I II.., 111"""11. ~h.llll1. II ;~IIII U 0., 1\ l-l )rbildl hL'll1dngi\In1.l:--. Ih~' m'I..1 (ammOn pri­Illdr~' Ilrbltdl tUlllllf (I). ,H~' de':<aibed p.lthologi­(, 111\' ,b ~'d\'l'rmlU", l'r (,lpill,u\' ht:'mangiomas. C\,nill ... il>n in the Illt:r,ltur~' ~'\I"b because 'I)me au­tlwr' (\lll ... idl·r tlw::,-t.· t~'rL''' \.i hemangil)mas to be di,:<tln(l pathlllll~l(al t·ntitit' ... (2/ while lIther au­tl1l'h It.·t·1 thdl ,1 (.1\'t.·rnL1U:-- ht'mangil)ma ma~' rep­rl''' t'nt a Il1 11 fl' n1,ltllrL' illrll1 lIt a (apillary heman­gl\ lm,l 11.:>.'tJ. ..;ltlll1l1gh the <1~t:' oi presentation IwJp" tIl dbtinglll ... h ,1 c,lpi!I.lr~· twm a (<1\'ernous hl·01.1ngil 101,1 (:i.h). il \\'\llIld be uSt'tul il a radio­gr, lphl'- diitt'rl'nthltit1l1 bt'twt't'n tht'5e two tumors (l'lIld bt' 61,lbli"ht.'d. sin'-t' t',l(h ma\" requirt' dii­It.' rt'nt thL'r,l~'t'lIll( nW,1"lIres. 5peciiicall~', ca\'­l'flHl1l5 h t'01,l n g I\1111,1 S ,1ft' t fe,l It'd su rgica II y \\'ht·n·.l" .-.lpdI.H~· ht'n1,ln~II)01,'5 are usually trt"lkd n1<'l1l.-.11"· \,'ith "tt'wids it Ihere is no e\'i­dl'l1( l' lIt "!-'llnt,1Ill'111l" rt'sll!util)ll, "\llhllll~h tilt' ,lll~i\lgrams \It tht'se lesions differ, \\'1lh '-,lpill.u\' ht'll1,1Jl.~iI1Il1a5 denlllllstrating a \'ery \',15I'lIl,lf p,1tkrn with dirt'ct Mlt'rial leeders and (,l\'l'rllllll, hl'1l1.111~illm,'5 i,liling III lill with con­Ir. 1,,1 nlt'dillll1 Itlll\IWill~ .111 Mtt'rial injection (2,7), a II' ... " il1\·,l;.l\·I' n1l'lh\ld ni diliert'ntiation would .-k.HI~' 1'1' lk:--ir,lblt'. l)rbital t'd1ll~raphy has been lI"I'd in ,11) ,1t1l'nlpl III diiit'rt'nti,ltt' these types of hl·nl.ln~1\lnl,15 \:-'-ILll. Thl' SlhXt'SS of this approach I;.. h\l\\'t·\'l'r. \'l'ry dl'pt'ndl:'nt uplln the experience III llll' 1I1Ir,'511I1l1p,'pher. Tht' (llmputed Illmo­gr, lphi.- (IT) .-h.1f,lLtt'ristics llf each 01 these types \11 IWl11.mgiunl.1s .nt' based mainlv on the fact that ",'pill.H~· Iw01angitlnlclS tend to' be larger, more puurly l'nc.1psulated, and more invasive than cav­l'r1hlllS hl'nlangiomas (l,2). but a comparative ,m,'l\'sis llf the CT enhancing characteristics of c,.\ \,TRNl )L/:; \':;, l-:\I 'll/.:\/n III:MI\NG/OMI\$ /5 these ht'm<1n~i\lm,l:- h,lS nul. l\l uur klHl\\'I\'dgv, been peri~mlled. Our \lbjell in this rq~\'rt. IIwrl'l Il!"l', i~ tIl l\'!T\'­lllte patIHll~lgil,11 :-tudics with l" I .11ld ultr,JSlllllHI iindings in .ll1 .1 Ill'l11pl til :-llllW th.lt ~"lpill.H\' .lI1d ~"'\"l'rlHlUS lWI11,lll~i\ll11,IS III 1111' I'rbit 111.1\' h\' dil­it'rt'nti, lll'd h\' llwir l\llltr.lst \'IlIl.lIH'I'IlWIlI d1.lT",I\·' teristics. MATERIALS A 0 METHODS CT SC,ll1::; III .111 p.ltiCllh 1\'lth Ilrl,it,11 IWIll.IIl­~ i\ll11,lS ,It till' B,bC\llll l'.llllwr L~'\' Illstitull' lWl1l \<.lSI tll I<)S3 IHT\' rl'\'il'\\,ed, ,ll1d 1m'" thl,sv p,l­tit'l1ts \\'lw Iud hl'I'1l 1',\.lIl1illl'd I\'itll high-r sulu­tilll1 LT utillLin~ ,1 CE SSllll SC,lIlIWr .1I1d orbital t'(hll~r.lphy I\'ert' ilH'ludl'd in this stud~·. Tlll'n.' II".1S ,I Illt,11 lli nint' p,ltit'nts: fi\'e with c.H'I'rnllUs ht'm,lnglllm.ls 1'1 tIlt' llrblt .1I1d i1llir I,'ith ~"'piIIMY ht'm,ln~illlll,b Ili tl1l' IHbil. linic,ll d,lt.1 \\'I'rt Ilbt.lirlt'd irolll the p.1ti~'nts' hllspit.,l rt'(l'rds. r.1tlwlllgic,11 d,lt,1 \\'~'re llbtained iwm " rt,,'il'\\' III spt:'Limt:'ns .1t tilt:' B<1SLllm Palmer Eye Institult:' p.1thL)111g~' lab~HlItlln'. c.wt:'rnl1us hem(lngillma$ \\·t'fe identiiied by their Llinical pre­$ entation and pdthLllogical iindings. Capillary hemangillmas \\'ere idl'ntifi d by th ir clinical pr ­sentation and chJractt'ristic echllhraphic iindings. Echograph\' was perfllrmed utilizing bl1th A­mode and B-mllde ultrasllund, A-ml,dt' t'chog­raphy \\'as perillrmed \'ia tran -ocular and para­llcular appfllaches u. ing the Kretztechnik 1200­mA tandardized A-scan unit (Slmometrics Inc., :\e\\' York, \fY) I,'ith an 8-MHz contact trans­ducer. The B-mude Ocuscan 400 unit with a 10­\ IHz contact tran.,duct'r and a Medsonic nondi­rectional Doppler transducer wert' .11'u ulilized. Specific e:\aminatilll1 ll'chniqut,,> l'mpit'yed f(lf le­sion differentiation were quantitative, topo­graphic, and kinetic echugraphy. Quantitative standardized A-scan echography was used to as­sess a lesion's internal structure, n,-f1ectivity, and sound attenuation. Topographic qu,llitil'" included location, shape, .,izE', and surfclCl' ch,uacll'ristics (borders), B-scan echugraphy wa:-- usdul in dl'm­onstrating the location and slh1pe ui thl' mbit.ll mass. A lesion's ~pecific bounJari\'s ,lnd burdt'rs were most accurately establishl'd with I\-SC,1I1 echography (9-11). Kim'tic l'chugr.lphy dell-r­mined the vascularity of tht., ma '. Intl'rnal vascu­larity was demonstrated with stand,Hdi/.l'd l\-scal1 and Doppler (12) echllgraphy, Highly v,lscul.u le­sions show fast spontanl'ous flicking \,i the in­ternal lesion spikes wherea,> stagn,lJ)t blood pro­duces no spike movement. Although spl'clr,ll ,1Ihllysis W,lS nul pl'rformed, audible evaluation of tl1l' Ouppler sign,11 was recorded 1I -ing a Mini Volsun h,lJ)d-lwld nondirectjona) unit. With CT, tlw urbil:-. were studied at 5-mm in­ll'rv, 11s bllth bdorl' ,lnd aftl'r infusion uf Cllntrast l1l<1tl'ri.ll in the axic)1 planl', and only afll'r infusion lli Clll'lr,lst Ilwdillm in the cmon(,1 planl' (drip in­lusiun with I'll! rnl (,O'y, meglumine iothalamate in iive ,1dults ,1l1d 2.2 ml/kg bllilis injection in iour childrl'n), Since an Ilbjt'ctiVl' oi this investigation W.1S to diift'rl'nti,l!l' the enh,1l1cing characteristic pf capill.uy from cavernous hemilngioma and be­C, lUSl', in this retrospective study, case,> were no klnger retrievable un m,lgnelic tap, we dl'vised a melhod to cllmpull' T <1bsorptiun value,> dirt'ctly imm the -ray film. A densitllmet r wa u eel to measure optical densities (00) of the varitlus had found on the gray 'calt: at the left ide llf each CT scan. Each shade corresponds to a CT ab orpti n value, which i' fixed bv the CT h:~vel and the window width, For each sepMate scan, I,ve con trueted a graph relating the ODs oi the various shades in the gray scale with their corresponding CT ab- )rpti n value (Fig. 1). Thus, a CT number could be obtained ior any point on the can by -imply FIG. 1. Graph relating the optical densities (00) 01 the various shades in the gray scale (ordinate) with their corresponding CT absorption values (abscissa). Each shade corresponds to a CT absorption value fixed by a CT level (+ 009 in this figure) and a CT window width (100 in this figure), If, .... ;../.\1,//.1/ FIG. 2. A capillary hemangioma In a '·month-old In· fant who demonstlated rapid growth of a red spot on the left eyelid (case 6\ ThiS eventually encompassed the left Sid of Ih neck, fac ,and h ad FIG. 3. Echography of orbital hemangiomas, Para­ocular A-mode echography Top: of a cavernous hem· angioma showlI1g uniformly high reflectivity. Para­ocular A-mode echography Bottom: of a caprllary hemangioma shOWing a varrable pattern of reflectivity (see the DISCUSSion for explanation of differences) RE L:LT 1',II'\'t! \ l'1'\ l', ... iI\· III del J,lllll1, ... 111 t' Ih.· d\·11,1I1'ic.,. III mlll"l"n lIl'lIl1lf,I"'1 I11t'dllll1l 1<iI' ,1dult~ )l1d chrl­df,' n \\,'1',' dilll'rl'nl, L'\ Ilbl,llllil1g .)11 Jilt 'rn,ll 'UI1­trld ,II d ,I rl'l .. ll\ t' \ ,duL', dJlIl'rL'n(l''' in lhe 1111'11111.1 ... lit "ntf,,,",1 I11l'dlUIll c1dmll1r"lr,ltI1l11 wert' 11111)11111/ ..1 1111' h••" '11.1/ rl·'lI,d" III n,n,· p, II 'nh I\'ith llr· bll.d h '111,111;";11'111"'" \\t'rt' rt·\ 1l'1\'l'd fT,\b!t> I), Cal'­L'rllI> U'" 1H'I)),lngIl 1J))ol'" (11 Ih ' IIr!:>ll ('t"currt'd ,du­... 1\ .,It In ,1.1 u II ... f'rl''''''1 tint.; 1\ Ilh ... 1111\'''' f'l'ugre ...... l\·t· Llnd,l 'r,d f'n'plll ... '.... ,lplll,1ry IIrbil,ll h,'I)),)n· 1.;"'111,1'" \\,'11' ,'1'11 111 Inl,ll11-. Ill' LhiILil n, and 111 'tl\(> •• , Ill' ,,, ..., thL' h '1ll.lngllllll,,,", i"I1111n ... tr, L·d ,1 dr.i1l1"tll hl'll\\'lh ~") lL'rn i'lg 21, \ . .rnd 1"I1)",lt 1IIt')""I1I'hr,,~ hi ...IUell'·"; ~h"\\'ed dill '1' 'nl "hM,) 'It'rr"ll' I, 'I' "1I'L'rl1,lu,; ,lnd c.lpil­I, H\ 11l'm,1I1gl'lIn..... FI\' l,I':o ' ......h )\\'L'd it pattern lIn"'I"'[ 'nt I\'llh ,)\ 'rn,lU'" IWI11,lIl,l:llIl))ih ilnd I 'ur Aq,' '~ .... w ,.,.kc:. 7 \N+:-t3'~ s ri1.Lln 115­" ar<, h Y"(ir~ .1 yf'fU, '") Y'''tU~ 2 v~ar' I "~1r S TABLE 1. D, '1I1ogrrlf1hfC ltlld F F F rr l,lkll1h ,)n ~ \I) 1ll1\''''lIrl'I1\1'I\1 ,!lId 11ll'11 u'n\'t'rl1l1g lhl'" Inll' ,1 <.. , IHlllll'I'" "'11\1'''' thl'>lI.'h till' mldl'"r- 11"n ,'I ht' lunlt'! ... \\'t'I'" 1',ll'tllll'llt'd 1111,' "Il,.i1k, ,H \h '\11 ~ 11Illt\""Ul't'l Will \\.,.., ..H,lm"d I,ll \'dd ... m.dl "I't',\ 1\ ,thm tl,,' ... 11\1' ,llld .I 1111',111 m \1"'111"" Illt'nl llwn ,,1 It 1I1"lt'c1. I hi" Ill,',I'" II' '11"'"1 ~'rl'l ,,\11 \\',h nl'Ll' ...... .I1'\ b' ,HI"'" "'1'1111' .1 Ill, ,11',"1 111 Iht' lum,'I'''' ,,1"'1\' 'd hl,~11 'I' d ")-.11\ 1111',hllrt'Ill'l1t ... th,lI) 'Itl1n ,Hl\'''' " ...... ','n In hh" .f ,)l1d ; rllh.ll1t 'l1wnl III ,·.Ith 'I blt,1i IWI11.1l1hlllm,l \\',1'" '('Ill~',ll't'd 1\ Ith tl1.11 III 111"111,11 Inlr,l"rL'll,,1 ... llll·­IUft ·... , ,'\'" 1 umll\,l, \\ c' .In,ll\ zl'd tlh' 'nh,l 11 tt'll1 ,'11 I I.t till' nll'dl, I I' 'dll" 1l111"d ' 11',' 11 lh ' U11 !I 1\', 01\' 'd 'VL' ,)nd h,I\\' It ,) \'alll' 1\1 lIn,I\', Thll:-, t',)'h IIfbll,ll h't'fl),1I1gi' )111,1 had ,) t,lmputt·t! \ ,llu.· lit r 'I.Hi\,' t·n· halK 'Illen!. 111 th,,,, 1,):-hil'Il, d, t, l"lild L..,· ,','111' 11 1 .. II I 1'1" CAVElmOLlS VS. C,.\flIlL ..\ln IlLMANClOMAS /9 • normal orbital vascular structures such as the mt'­dial rectus muscle, whereas capillary hem,'n­giomas were enhanced mor than thilt musrk (Figs. 7 and 8). Therefore, th . description Ilf a l',lV­emous hemangioma as an enhancing Il'sion m,ly be misleading because it suggests an enh,lnrl.'nll'nt FIG. 6. Capillary hemangioma of the patient shown In Fig, 2. a: Plain CT scan shows a large lesion pro­ducing a mass effect on the hypopharynx, It extends into the lett orbit and Intracranially to the lett cavernous sinus and left tentorial leaf. b: Pre-contrast administration CT. c: Post-contrast administra­tion CT. greater than that of normal orbital structure. Sinn' lW\l different method5 Ilf contrast adminis­tr< lti(lll wen:- lIst:'d (in ,1dlllts vs. in infants), th en­han..: ement \If n\lrmal rectus mus..:!\:' tissue al 0 servl,d as an internal standard control (see Mate­rinls and Methods). The differences in enhance- 20 C. L.. SKLAI< 1:'1' At. o o o o • • •• • { 1.5 -..z=....-:.. -'z"": :z: 1.0 z: .... ....-- -...j ........... 0.5 fh'n.1,'r-,'". I IV 11"hl,11 TllIlh"" IV. B. Saunders, Phila­, h·lph,.l. 1<1:-:;. PI' 11;--132 , 1\\,.1111<'/" 1 .•111.1 l,ll..,lblt'C, f, ,0\,: Ultrastructural compar­",' n "I ,.1f'11I.lr\· .1I1d c.l\'t'rn,lu,; h",mangi,>mas of the orbit, .~I,1r lll",tl""""" 9i: 11+4-11;;03. 1979, .1, .-\~hl,·\'. D I B: [,',III> HI"t,II.I:-:'l'll :I/'I',-arclllrc" ,'f TUn/llrs (;1.r,!,"d l. \',>1 I. Churchill Li\'lnggton. New York. 1978. pp. l>S-.I, ~ ''<If,,-I,,,,·. S. I\\.. I-"'U". R, Y.. Stradtsma, B. R., t!t aL: l.-.l\',·rn,'u~ h,·01.ln!-'lt1mdS ,>t the orbit. lilt. O~Jlrthnln/()1 Oill, 11: ID-12~, 14,1 ;;, liMn". G. j ..•md Jak,'bit!c. f. A.: Cavernous hemangiomas ,'I tIll' ,'rbit. , . .':flIr":'II':O:. 51: 219-228, 1979. n I .lil... B. G.. jak"bit'c. f:. A.. Ellsworth, R. M.. and jones. I. S.: Clpill.JrY ht'mangiomas of the lids and orbit: an anal- REFERENCES that cavernous hemangiomas do not show greater enhancement than do normal vascular orbital tissues. Bv tht:'se criteria, we believe that CT is ca­pable oi difierentiating between cavernous and capillarv hemangi rna oi tht:' orbit; this may be particularly uSt:'iul ",hene\'er orbital echography is not a\·ailable. Although the age at which a heman­gioma KCllr. (Table I) usuall~' serves to clinically differentiate the capillar~' from the cavernous iorm. the sllllL)graphic and CT features presented here can separate these types oi hemangiomas on the basis Llf their imaging charat:teristics. This in­iormatiLm not llnly rna\' be helpful in analyzing the ieatures l11 intrcwrbital masses in patients of an intermediate age (i.e., Lllder children and adoles­cents) but \\'e b lie\'e it furthers our under­st, mding III the nature of these hemangiomas. CAVERNOUS CAPILLU' FIG. 8. Values of relative enhancement fOf cavernous hemangiomas (left) and capillary hemangiomas (right) There IS no Significant overlap in values be· tween these two types of orbital hemangiomas (p < 0.01). • HEMUCIOMA 8l MUSClE 9U :··z II 7:: ::~: :~~ :~~~: .: : : ~:~::. ::::: ::::: : ::::: 6 o CAVERNOUS ].1 'I'll' I' O[ ~ I ~ I I ~ I - . i --5- ­~ 2.0 CAPILLARY ...z....,:.. =- --=1.0 8 CASE NUMBER FIG. 7. Enhancement of cavernous hemangiomas (upper panel) and capillary hemangiomas (lower panel) relative to that of control muscle. Va'ue~ of rei· ative enhancement were computed as described In Materials and Methods, Note that all five cases of cavernous hemangiomas were enhanced less than were their muscle controls whereas the capillary hem­angiomas were enhanced more t.han w:re their muscle controls. Cavernous hemangiomas: x = 0.71: SO = 0.22. Capillary hemangiomas: x = 1.4; SO = 027. ment charac\t'ri -tic' between capillarv and cavernous hemangillmas pnlbably reflect the structural differences between these tWll tumllrs. Arteriography has pre\'it1u 'l~' -hllwn that capil­lary hemangiomas ha\'e direct arterial ieeders, wherea cavernous hell1allgil,mas e'\hibit a . tag­nant circulatilln in their larger \'a 'culM IUlllens (2,7). As a result lli thest' structural differences, contra t medium will not enter the GIVerntlUS \'as­cular lumens ,1S readilv .1S it will enter the \'ascu]ar lumens oi cilpill.uy ill'm'lIlgillll1dS. )i the iOllr capillary hema ngillmas studied, lhe tUIl1Llr that llC­curred in the llldest child (cast' 9) delllllnstrated the lowe·t rt:lativl' enhaIKl'lllt'nl. We postulate that thi capillarv hl'mangiLlI11,l 1l1,1~' h.1\'l' Cllll­tained more ectatic lUIl1l'IlS, with ,1 rl'lative stagna­tion uf blood i1ll\\', ,b ha~ bl'l'n prl'\'illusly de· scribed (2); il~ a fl'sull, it prodUCl'd It's5 CT en­hancl'n1l'nt. We have dl'mon~tr,lted ,1 1l1.uh.ed diiierenct' in thl:: enhallcing ch.u,lrLl'ristics llll CT bdwt'l'n C,1\'­ernous and c.1pill,Hv hl'rn,lllgillnl,lS oi tht:' llrbil. These findings coffel,llt' well with tht' ultr.15lll1l1­graphic and p,llhlllllgiL" difll'rel1cL's b'tWt'l'n t11t'Se two urbital IUrllllrs. In .lddililln, \ t' h,wl:' shll\,vn CA\I[[~ OU:; I':;, C:\I'II/,:I/,) /lJ:MA GfUMA$ 2/ "~" "t Ilw dm".11 1,',11,1"'" .11I.1 Ih,'r"I"'lIl', fl"lIlt- 111 Illl ~.1~"'" l )1'!lt1l"I,1/, 'I. '.'\ II 8b: 7.,0,7<'2, 1"7" - Io.."nlwd,', R, I- .-\rl....,.11 ,·mb"h/.,I""1 "t "tI"I,,1 /1<'111,111' ~1\'nl\'~. 1'llll~ Am l. ),lJrl1jj,{lIh ll :',11 7h: ~h'" ~77. I\I;-S ~, D.I\'I", lo... R , I k",'lill"- I I" 1)"11",, " I , .Ind l.I'I""·, A, S.. Ir .. l:r .Ind ,,(lr.o-,IlIlhlllllll<' dl.I,~Il"'" ,., ',11,'1'111'''' 11I'Il\,III~"'Il\.I' ,11I.1 11"l1l1'h.\I\~II'm.1 "I III<' "rI"1 I ("'''1'''/ / """',\' 01: <l:,_ 104, 1"Sll <l lh>l"lllf' 10.. l' (llI,'"I'I,IIII" 1',I1"~"'1'11\ 1111' 1',1'" "I 11"'11" d'll,'n·nl.ll,,'n I l'//I, (1/"""·",,,/1: n 4", 1"74 III (h'''"l1g, lo... l . I"',·n.1I1, Ill. ,lnd Big.H, F,: C.l\'l'rnllu, Il<'m.lllg'''1l1,'' III 1111' "rb,l. H,'" ()/,I1I/"I1I1111/ 83: 23h-24-l. Ill;; II. (1"""l1g, " l ,: 1,I1"gr,ll'l111 d,IIl'f,'nlioltilln ", v.l'CUIM 111I111'r, ,n II,,' ,,,.bit. In I'", 111/""11" "1",1111,/11111/, Pr/l, , s..,;..>, I M, I h,j,,,'n .Ind II M V,','rro,·,,". Ed" Dr, W Jun". Th" 11.lg,"', I'/HI, pp, 2Hl 241 12, II"rlll', .... " .. ,'nd (;I,o-,'r, I ..... (Irb,IJII,,,u,' d,tf"f\'nltali"n II'llh ,L,nd.rrdlll'li '" hllgr"!,h\' (1/,11/11,,111I,,1,,;.:'/ 90: IIl;" 1 11l1~I, ,,,,n I (I", M'lIn",'p/lllm/III"" VII/ 6, N" I, 1980