OznurL.Konu@1Ay@egüIOzdemirAlaaddinAkkayaGoncaErba@Had çelikSedatI@lk

OBJECTIVE. The objectiveof this studywas to determinethe normal rangeof dimensions for the liver, spleen, and kidney in healthy neonates, infants, and children.

SUBJECTS AND METHODS. This prospectivestudyinvolved307 pediatricsubjects(169 girls and 138 boys) with normalphysicalor sonographicfindingswho were examinedbecauseof problems unrelated to the measuredorgans.The subjects were 5 days to 16 yearsold. All measured organs were sonographically normal. At least two dimensions were obtamed for each liver, spleen, and kidney. Relationships of the dimensions of these organs withsex, age, body weight, height, and body surface area were investigated. Suggested limits ofnormal dimensions were defined.

RESULTS. Dimensionsof themeasuredorganswerenotstatisticallydifferentin boysandgirls.Longitudinaldimensionsof all threeorgansshowedthe bestcorrelationwith age,bodyweight, height, and body surface area. Height showed the strongest correlation of all. Thiscorrelationwasa polynomialcorrelation.

CONCLUSION. Determinationof pathologicchangesin sizeof theliver,spleen,andkidney necessitates knowing the normal range of dimensions for these organs in healthy neonates,infants, and children. Presented data are applicable in daily routine sonography. Body height

should be considered the best criteria to correlate with longitudinal dimensions of these organs.

S onography provides a quick assessment of visceral organ di

mensions without any risk ofradiation. The normal range of visceral organsizes in adults and children determined with

sonography has been reported elsewhere [ I—¿�13]. However, available data are limited forthe liver and the spleen in children, whichcauses difficulty in defining hepatomegalyand splenomegaly sonographically.

Our purposewas primarily to documentthe normal range of dimensions of the liverin children. The relationship of each dimensionwith sex,age,body weight, height,andbody surface area was determined. A similarevaluation was done for the spleen and thekidney at the same time.

We prospectively examined 307 pediatric sub

jects ( 169 girls and 138 boys) with sonography. The

rangeof agewasfromfull-termnewborns(5 days)to 16 years. Patients who did not have normal

growth curves (who were not in the third to 97thpercentiles)were not includedin the study.Anothermajor criterion for selection of children was having

no clinically or sonographically pathologic findings

related to the studied organs. Most children were

completely healthy. although some were undergoing follow-up for a disease unrelated to the measured organs, such as hip dysplasiaor undescendedtestes. No child had a history of oncologic, hemato

logic, or traumatic conditions. Some children with

urinarytract infectionwereincludedin the study,butonly liverandspleendimensionswererecordedinthosepatients.Wealsodidnotrecorddimensionsof a number of spleens for which abdominal gas

distentionpreventedreliablesize measurements.Allmeasuredorganshada normalpositionandshapeand normalecho texture.

We used high-resolution real-time sonographic

scanners (SSA 270A; Toshiba, Tokyo, Japan; and

EUB-5l5 and EUB-5l5A; Hitachi, Tokyo, Japan)with 3.5-MHz convextransducers.Patientshadneither preparation nor sedation.

Liver measurements were performed in all sub

jects(n= 307).In asubjectlying in thesupineposition, longitudinaland anteroposteriordimensionswereobtainedin themidclavicularandmidsagittal

ReceivedMarch30,1998;acceptedafterrevisionJune17,1998.

1All authors: Department of Radiology, School of Medicine,GaziUniversity,Besevier,06510,Ankara,Turkey.Address Subjects and Methodscorrespondenceto 0. L Konu@.

AJR1998;1711693—1698

0361—803X/98/1716—1693

©AmericanRoentgenRaySociety

AJR:171,December1998 1693

Normal Liver, Spleen, and KidneyDimensions in Neonates, Infants,and Children: EvaluationwithSonography

Height.85.77.81.50Age.82.71.78.47Weight.80.73.74.49Surface

area.83.75.78.45

BodyParameterLongitudinalTransverseHeight

AgeWeight

Surfacearea.88

.84

.84

.86.70

.67

.69

.70

Posterior Anterior

__________Correladon Coefficients for I,1q@@Kidney Dimensions as

Revealedby Sonographyin F279 PediatrIc Subjects j

BodyParameterRightKidneyLeftKidney@Long.

Trans.Long.Trans.Height.94

.86.93.85E@Age.91

.84.90.83Weight.89

.82.88.79Surface

area.91.83.91.80Note—Long.=longitudinal,Trans.=transverse.

(7IuI:@Right@ Left

Konu@etal.

planes for the right and left lobes. “¿�Midsagiualplane―means that the plane passes through thexiphoid process. In both planes, the upper margin ofthe liver was defined as the uppermost edge underthe dome of the diaphragm, whereas the lower margin was defined as the lowermost edge of the lobe(Fig. 1).

Spleen measurements were performed in 169girls and 130 boys (n = 299). Longitudinal andtransverse dimensions in the coronal plane wereobtained with the subject in the supine or slightlyrightlateraldecubitusposition.Longitudinalsizemeasurement was performed between the most superomedial and the most inferolateral points of thespleen. The transverse dimension was measuredbetween the hilum and the most superolateral margin ofthe spleen (Fig. 2).

Kidney measurements were performed in 155girlsand 124boys(Fl= 279). Longitudinalandtransverse dimensions of both kidneys were obtamedinthecoronalplanepassingthroughtherenal hilum with subjects in the supine or slightlyrightor leftlateraldecubituspositions(Fig.3).

To determine reproducibility. each measurement of each organ was repeated at least threetimes, and the most repeated value was recorded.Data obtained from the measurements were classifled into I I age groups. Relationships of all dimensions with sex, age. height. weight. and bodysurface area were statistically analyzed. Body surface area was derived using the patient's heightand weight from the nomogram modified from thedataof E. Boydby C. D. WestI 141.All measurements were plotted as a function of age in months,body weight, height, and body surface area. Typesof relationships and regression lines were obtainedfor the various sets of data using the least squaresmethod. The mean. minimum, and maximumvalue; fifth and 95th percentiles: and standard deviationswerecalculated(Excel5.0: Microsoft.Redmond, WA). The lowermost and uppermostlimitsof normalfor eachagegroupweresuggested and were derived using the previous zero orfive integer values below the fifth percentile, and

the next zero or five integer values above the 95thpercentile, considering also the mean, minimum,and maximum values of normal [I 1.

Results

No statistically significant differences werefound betweenthe two sexesin any agegroupfor any measured organ dimension (t test, p>.05).Therefore, all datawere rearrangedwithout being separatedaccording to sex.

Compared with the anteroposterior and

transverse dimensions, all longitudinal di

mensions of each organ showed the highest

correlation with the body parameters(i.e.,age, height, weight, and body surface area)

(Tables 1—3).Among the body parameters,height was the one best correlated with thelongitudinal dimension of each organ. Bodysurface area, age, and weight followedheight, in that order. Correlation coefficientsare presented in Tables 1—3.On regressionanalysis, the relationship between the longitudinal dimensions and height was of thepolynomial type for each organ (Figs. 4—8).

Longitudinal dimensions of the right lobeof the liver, the spleen, and both kidneys,with corresponding values of patient heightin selected age groups, are presented in Tables 4-7. Mean, minimum, and maximumvalues; fifth and 95th percentile values; standard deviations; and suggestedlimits of normal are also given. Other dimensions arepresented in graphic form (Figs. 4—8).Thedimensions of the left lobe of the liver, except those taken in infancy, poorly correlatedwith body parameters.

Significant differenceswere found betweenthe longitudinal sizes of the right and left kidneys (t test, p < .05). For this reason, findings

Jver I Imenslons asRevealed by Sonography In

I Pediatric Subjects

RightLobe Left LobeBodyParameter

Long. AP Long. AP

Note—Long.=longitudinal,AP=anteroposterior.

;orrelatlonCoefficientsforpleen Dimensions as

Revealedby SonographyIn9 PediatrIcSubjects

A BFig.1.—Diagramsshowhowlongitudinalandanteroposteriordimensionsofliverlobesweremeasured. Fig.2.—DiagramshowshowIonA,Livermeasurementswereperformedatmidclavicularandmidlinesagittalplanes. gitudinalandtransversedimenB,Longitudinalandanteroposteriordimensionsof rightandleftlobesweremeasured. sionsofspleenweremeasuredin

coronal section passing throughsplenichilum.

Fig.1—Diagramshowshow longitudinalandtransversedimensionsof kidney were measuredincoronalsectionpassingthrough renalhilum.

1694 AJR:171,December 1998

0 20 40 60 80 100 120 140 160 180 200

Height(cm)

120j—-••—@——.@—100

@ .-@. . .@ 4@ ..—@

ght(cm)Hei

EEa..a,C•¿�C

.C@,

0 20 40 0 20 40 60 80 100 120 140 160 180 200

Height(cm)

60 80 100120Height

(cm)140 160 180 200

Sonography of Liver, Spleen, and Kidney Dimensions in Children

Fig.4.—Scatterdiagramshows longitudinal(•)and anteroposterior (0)dimensions of right lobeof liver plotted againstheights of patients. Notethat longitudinal dimensions of right lobe arelonger than anteropostenor dimensions and thisdifference increaseswithheight.

for the right and left kidneysarepresentedseparately in Tables 6 and 7 and in Figures 7 and 8.

Discussion

In the literature, studies about normal liverand spleen dimensions in children are rare,especially for the liver. Most studies do not

organs without the risk of ionizing radiation.Organ volumes or ratios obtained by usingvarious organ dimensions and body surface areas are already used in correlation with bodyparameters to describe the normal dimensionsandto measurethe degreeof pathologic deviation from normal. However, those techniquesare time-consuming and impractical in dailyuse. On the other hand, either one or more ofthe longitudinal, anteroposterior, and transversedimensionsof theseorgansaremeasuredaspart of routine abdominalsonographicscanning. Therefore, use of these measurementsseems more practical for purposes of determining “¿�normal:'Any other data, when neces

sary to combine with the above measurements,

should also be easily obtainable. Age, bodyweight, andheight aresuchparameters.

We did not find any significant differencein measured organ sizes between the twosexesof any age group (t test, p > .05). Thisfinding is similar to the findings of others [2—7, 10—12].Therefore, sex certainly is not a

120 200

Height(cm)

include enough children to separate the sub

jects into appropriate age groups [1—9].Westudied many children of all ages, and to our

knowledge, this study covers the largest series of pediatric liver and spleendimensions.

Sonographyis a simpleandreliableway tovisualize and to measure abdominal visceral

Fig.5.—Scatterdiagramshowslongitudinal(•)andanteroposterior(o) dimensions of left lobe of liver plotted against heights of patients. Note that longitudinaldimensions of left lobe are shorter than anteroposterior dimensions at patientheightsof lessthan 70cm but longer at patient heightsof morethan 70cm.

Fig.6.—Scatterdiagramshowslongitudinal(•)andtransverse(0) dimensionsofspleenplottedagainstheightsofpatients.

Fig.1.—Scatterdiagramshowslongitudinal(•)andtransverse(o) dimensionsofright kidneyplotted againstheightsof patients.

Fig.8.—Scatterdiagramshowslongitudinal(•)andtransverse(0) dimensionsofleft kidneyplottedagainstheightsof patients.Leftkidneydimensionsarelongerthanrightkidneydimensions,asseenincomparisonwithFigure7.

AJR:171,December1998 1695

BodyHeight(cm)No.Age

Range(mo)MeanSD.

.Minimum. MaximumPercentileSuggested

LimitsofNormal5th95thLowermostUppermost47—64

54—7365—78

71—92

85—109

100—130110—131

124—149

137—153

143—168

152—17553

402018

27

3038

30

16

23

121—3

4—67—912—30

36—59

60—8384—107

108—131

132—155

156—179

180—20064

737985

86

100105

105

115

118

12110.4

10.88.010.0

11.8

13.610.6

12.5

14.0

14.6

11.745

446867

69

7381

76

93

87

10090

92100104

109

125128

135

137

137

14148

537068

63

7790

83

95

94

10482

869098

105

124123

128

136

136

13940

456065

65

7075

75

85

85

9590

95100105

115

125130

135

140

140

145L.ongitu4l

SubjectsInal

Dimen‘ons ofSplei Versus Height and Age

LongitudinalDimensions(mm)ofSpleenBody

Height(cm)No.Age

Range(mo)MeanSD.

.Minimum. MaximumPercentileSuggested

LimitsofNormal5th95thLowermostUppermost48—64

54—73

65—7871—9285—109

100—130110—131

125—149

137—153

143—168

152—17552

39

181827

3036

29

17

21

121—3

4—6

7—912—3036—59

60—8384—107

108—131

132—155

156—179

180—20053

59

637075

8485

86

97

101

1017.8

6.3

7.69.68.4

9.010.5

10.7

9.7

11.7

10.333

45

505460

6165

64

72

84

8871

71

778691

100102

114

100

120

12040

47

535561

7069

70

81

85

8865

67

748288

100100

100

108

118

11530

40

455055

6065

65

75

80

8570

75

808595

105105

110

115

120

120

@I•LongltudSubjects@nal

Dimen@ronsof RightKidney VersusHeight andAgeLongitudinal

Dimensions(mm)of RightKidneyBody

Height(cm)No.Age

Range(mo)MeanSD.

.Minimum. MaximumPercentileSuggested

Limits ofNormal5th95thLowermostUppermost48—64501—3505.838664058356554—73394—6535.341665064407065—78177—9595.250705266457071—921812—30613.455665565507585—1092236—59675.1577759755580100—1302660—83745.5628365836085110—1313284—107806.6689370916595124—14927108—131807.06996698965100137—15315132—155896.2811028210070105143—16822156—179945.9831058510275110152—17511180—200927.0801078310275110

Konu@etal.

ILongitudinalDimensionsofRightLobeofUverVersusHeightandAgeSubjects LongitudinalDimensions(mm)of RightLobeof Liver

1696 AJR:171,December 1998

•¿�I@1:1@@LongItudInaIDimensionsof Left KidneyVersusHeight andAgeSubjectsLongitudinal

Dimensions (mm) of LeftKidneyBody

Height(cm)No.Age

Range(mo)MeanSD-

-Minimum. MaximumPercentileSuggested

LimitsofNormal5th95thLowermostUppermost48—64

54—7365—78

71—9285—109

100—130

110—131

124—149

137—153

143—168

152—17550

3917

1822

26

32

27

15

22

111—3

4—67—9

12—3036—59

60—83

84—107

108—131

132—155

156—179

180—20050

5661

6671

79

84

84

91

96

995.5

5.54.6

5.34.5

5.9

6.6

7.4

8.4

8.9

7.539

4454

5461

66

71

71

71

83

8761

6868

7577

90

95

99

104

113

11642

4754

5761

70

73

75

77

84

9059

6468

7276

87

93

97

102

110

11035

4045

5055

60

65

65

70

75

8065

7075

8085

95

100

105

110

115

120

Sonography of Liver, Spleen, and Kidney Dimensions in Children

determining factor for organ dimensions inthe pediatric agegroup.

In most other studies, sizes between thefifth and the 95th percentile were the accepted normal limits [2, 3, 5, 6, 8—10,13].However, this practice results in approximately 10% of children with normal visceralorgan sizes falling outside these limits [1 1].Besides, although plus or minus two SDs arethe accepted equivalents of the fifth and 95thpercentile values statistically [15], somestudies were basedon plus or minus one SD[7]. For this reason,we preferredto definethe normal lowermost and uppermost longitudinal dimensions of the studied organs using the method originally described by

Rosenberget al. [ 11in 1991.We foundthatheightshowsthebestcorre

lation with any one of the mentioned organdimensions. Body surface area also shows ahigh correlation with organ dimensions, butto a lesser degree. However, its derivation isnot as practical as height. For those reasons,we preferred not to use body surface area instandard tables and graphics. Age and bodyweight are not as important as height andbody surface area.Therefore, when decidingif sonographically obtained dimensions of anorgan are normal, patient height should bethe primary concern.

The liver is an organ of complex shapeand varies widely from patient to patient.Our wide range of normal dimensionssupports this opinion. However, it is necessaryto have references for normal liver dimensions in the pediatric age group.

The findings of various similar studiesdiffer somewhat from eachother and from ours.Deligeorgis et al. [12] performed a study with

direct roentgenography in 350 children to establish normal liver dimensions. They foundsignificantly longer dimensions than we did.The reason for the difference is obviously themagnification factor on radiographs.

Somefindings arecontradictoryevenwithinonestudy.Forexample,in thestudyof Holderetal. [2], which included 185children,sonographically measureddimensionsof the liver are anaverageof 4 cm smaller than the samedimensions measured scintigraphically. Our sonographicallymeasuredliver dimensionsarelargerthan those of Holder et al. The reason is probably their techniqueof measurement.They usedlinear transducersand performed the measurements in a sagittal plane passing through themidpoint of the liver's right and left margins.Linear transducers,becauseof the interpositionof lung betweenthe dome of the liver and theanteriorabdominalwall, preventsomeof thesuperior portion of the liver from being observed.This effect,asHolder admits,resultsin the “¿�observed―lung—liverborder'sbeingdeterminedasthe superior margin of the liver, and consequently in the liver's being measuredashavingsmaller longitudinal dimensions than the liverswe measured.Convex probes,such as the onewe used, prevent this complication. Besides, unlike Holderet al.,we believethatthemidpoint ofthe liver's right and left margins cannot be re

ferred to as a standard sagittal plane because the

left lobe in particular differs in extensionandsize from one personto anotherand with age.Instead, midsagittal and midclavicular planesseem more appropriate for longitudinal liver size

measurements. In spite of these technical differ

ences, Holder et al. also concluded that height isthe best-correlatedbody parameterwith liverlongitudinal dimensions.

In the study of Markisz et al. [4] that included 116 children, liver and spleen dimensions obtained with scintigraphic methods

also exceeded ours. Those authors used volume measurements and found a high linearcorrelation between the volumes of theseorgans and patient weights. Correlations with

age were lessevident. Patient height or organdimensionswere not consideredin their studyand limits of normal cannot be derived. Fromthe study of Markisz et al. (like the study ofHolder et al. [2]), we conclude that scinti

graphically obtained organ sizes are largerthan sonographically obtained ones. Therefore, differences in organ size are probablydue to the difference of imaging techniques.

In 1983, Niederau et al. [13] described astudy of normal liver dimensions in 1000adult patients. Sonographically, their studyshowed smaller values than ours. This difference is probably the result of the sametechnical reason we discussed with respect to thestudy of Holder et al. [2]. Niederau et al.noted that organ sizes increased with heightand body surface area in adults.

In 1983, Dittrich et al. [3] also usedsonography to study liver dimensions in 194children. Although they reported smaller dimensions than we did, Dittrich et al. notedthe best correlation was found between liverdimensions and height, which is a linear correlation. They found also a high correlation

with body surface area, but in their studyonly height was used as a reference parameter for further analysis.

Normal spleen dimensions and volumestandards have been investigated by only afew researchers.Rosenberget al. [1] studiednormal spleen longitudinal dimensions in

AJR:171,December1998 1697

Konu@et al.

8). This finding is similar to the findings ofDinkel et al. [10]. In the infancyperiod,theanteroposterior dimension of the left lobe ofthe liver may be somewhat longer than thelongitudinal dimension. With aging, thesephenomena change and the longitudinal dimension of the left lobe becomes longer than

the anteroposteriordimension except inobese persons [13]. We observed the samephenomenon in infants. Anteroposterior dimensionsof theleft liver lobeswerefoundtobe somewhat longer than the longitudinal dimensions. The reason is that the intraabdominal visceral organs are larger in childrenthan in adults when compared with totalbody volume. This finding leads to the conclusion that measurements of the midclavic

ular and midsagittal longitudinal dimensionssuffice to estimate the liver size in most children, and that measurements of anteroposterior dimensions, particularly of the left lobe,must be obtained only in infants.

Data of normal visceral organ sizes according to age have been given in table form in

several previous studies [1, 7]. However, theselected age groups in those studies present awide range like 5 years, as in the studies ofRosenberg et al. [1] and Dremsek et al. [7]

(whereas our selected age groups had an age

range of 3 months or 2 years). In other studies,

data were given only in graphic form [2—6,10]. We present our data both in tabular andgraphic forms with the aim ofenabling a morepractical evaluation during a sonographic examination.

Establishing normal parameters is mandatory for defining the pathologic changes insize of the liver, spleen, and kidneys in routine sonographic examinations of children.

The methodsof measurementand analysiswe used in this study are standardizedandeasy to apply. Findingsare handy and reliable and are suitable particularly for sonography units and pediatric departments withlarge numbers of patients.

Longitudinal dimension and patient heightare the most important determining factors oforgan size among studied dimensions andbody parameters. Therefore, any specificlongitudinal dimension should primarily becorrelated with patient height, and findings

should be compared with tables and graphicsof normal parameters.

References1. RosenbergHK, MarkowitzRI, KolbergH, Park

C, HubbardA, BellahRD.Normalsplenicsizeininfantsand children:sonographicmeasurements.AiR 1991;157:119—121

2. Holder L, Strife J, Padikal TN, Perkins PJ, KerelakesJG. Liversize determinationin pediatricsusing sonographic and scintigraphic techniques.Radiology1975;!17:349—353

3. Dittrich M, Milde S. Dinkel E, Baumann W,Weitzel D. Sonographic biometry of liver andspleen size in childhood. Pediatr Radiol 1983;13:206—211

4. Markisz JA,TrevesST.Davis RT Normal hepaticand splenic size in children: scintigraphic determination.PediatrRadiol 1987;17:273—276

5. Christophe C, Cantraine F, Bogaert C, et al. Ultra

sound: a method for kidney size monitoringinchildren. EurJ Pediatr 1986;145:532—538

6. Han BK, Babcock DS. Sonographic measurements and appearance of normal kidneys in children.AJR1985;145:611—616

7. Dremsek PA, Kritscher H, BöhmG, Hochberger0. Kidneydimensionsin ultrasoundcomparedtosomatometric parameters in normal children. PediatrRadiol 1987;17:285—290

8. RosenbaumDM, KorngoldE, TeeleRL. Sonographic assessment of renal length in normal chilthen.AJR1984;142:467—469

9. SchlesingerAE,EdgarKA,BoxerLA.Volumeofthe spleenin childrenas measuredon CT scans:normal standards as a function of body weight.AJR 1993;160:1107—l109

10. DinkelE, ErtelM, DittrichM, PetersH, BerresM,Schulte-WissermannH. Kidneysizein childhood:sonographicgrowthchartsfor kidneylengthandvolume. PediatrRadiol 1985;15:38—43

11. Zerin JM, Blanc CE. Sonographicassessmentofrenal length in children: a reappraisal. PediatrRadiol 1994;24:l0l—106

12. Deligeorgis D, YannakosD, Doxiadis S. Normalsize of liver in infancy and childhood: x-raystudy.ArchDis Child1973;48:790—793

13. Niederau C, Sonnenberg A, Muller JE, Erckenbrecht JF, ScholtenT, FritschWE Sonographicmeasurements of the normal liver, spleen, pancreas,and portal vein. Radiology 1983;149:537—540

14. Berhman RE, Kliegman R. Nelson essentialsofpediatrics. Philadelphia: Saunders, 1990:712

15. Remington 1W, Schork MA. Statistics with application to the biological and health sciences, 2nded. Englewood Cliffs, NJ: Prentice Hall, 1985:23—43

230 children using sonography.Interestingly,their dimensions are smaller than ours forchildren under the age of 8 years, whereas inchildren over the age of 8 years, the findingsof their study and ours are similar. Theystated that body weight showed the best correlation with spleen length, which was

roughly logarithmic in type. Height and age,in that order, were less well correlated withspleen length.

Schlesinger et al. [9] studied normal spleenvolume in 48 children using CT. These re

searchersfoundthatspleenvolumecorrelatedbetter with body weight than with age. Thebest regressionmodel was a simple linear relationshipof spleenvolumeto bodyweight.

Renal dimensions, as well as cross-sectional areas and volumetric standards of thekidneys, have been investigated by many different authors for pediatric age groups.

Christophe et al. [5] measured kidney

sizes sonographically in 170 children. Valuesof longitudinal kidney dimensionsin theirstudy are also similar to ours. These researchers found a linear relationship betweenrenal length and height. Additionally, theyfound that the longitudinal dimension of thekidneys versus body surface area yielded the

most accurate correlation. However, as theystated, correlating renal length with bodyheight is more practical.

In 1985, Dinkel et al. [10] studied renal dimensions and volumes in 325 children withsonographyandprovidedseparategraphicsforthe right and left kidneys. Correlations of renaldimensionswith body parametersin that studyare similarto our findings,and thoseauthorsstatedthat renal length showeda high correlation with body height. However, in their study,the correlation was a linear relationship. Theseresearchers also found that renal volumeshowed the best correlation with body surfaceareaand showedalmostthe samecorrelationwith body weight. For practicalpurposes,however, they proposed to use the correlation of renalvolumewithbodyweight.

We observed that the increase in the longitudinal dimensions of these organs is much

more rapid during the first years of life,which mirrors the accentuated body growthduringinfancyandearly childhood(Figs.4—

AJR:171,December19981698