Right Lobe Function

|LIVER |

Caudo ~ Cranial (CC) length = < 17 cm

Right Lobe

Caudo ~ Cranial (CC) length = < 16 cm
Anterio ~ Posterior (A ~ P) length = < 16 cm

Left Lobe

Width = < 11 cm
Anterio ~ Posterior (A ~ P) length = < 7 cm

Caudate Lobe

Caudo ~ Cranial (CC) length = < 8 cm (5 ~ 8 cm)
Anterio ~ Posterior (A ~ P) length = < 2.5 cm (2.0 ~ 2.5 cm)

Caudate lobe and Right lobe ratio (cc length of caudate lobe/ cc length of right lobe)

> 0.65 = 93 % specific for cirrhosis
> 0.73 = 99 % specific for cirrhosis

Normally Right lobe : Caudate lobe = 3 : 2

Pediatric liver size (up to 12 years) = <
11 cm

Portal vein

Normal diameter = < 13 mm
In portal hypertension = > 13 mm (> 15 mm is suggestive)

Common bile duct (CBD)

Normal diameter in adult = < 7 mm
In elderly (70 yr) & after cholecystectomy = 8 ~ 10 mm

(In case of older patient 1 mm dilatation with each decade after 40 years of age is normal)

Gallbladder

Length = 8 ~ 12 cm
Width = < 5 cm
Distended (mucocele) = Diameter > 5 cm
Normal wall thickness = < 3 mm

Liver Doppler
PSV of portal vein = 13 ~ 23 cm/sec

Congestive index (CI) =

Normal range of CI = 0.070 + 0.029 cm/sec
In cirrhosis CI = 0.171 + 0.075 cm/sec

Hepatic artery
Normal RI = 0.62 + 0.04
After meal = 0.66 + 0.78

|SPLEEN |

Length (L) = < 13 cm
Width (W) = < 6 cm
Anterio-posterior thickness (A ~P) = < 4 cm

Formula of measuring splenic weight = L X W X A~P X 0.43
(Lengths should be in cm and resultant weight unit expressed in gm)

Normal weight: ▪ Male = < 180 gm ▪ Female = < 150 gm

Splenomegaly (irrespective of sex):

▪ Mild = > 200 gm ▪ Moderate = > 500 gm ▪ Severe = > 2000 gm

Splenic index = L X A~P (expressed in no unit)
Normal range of splenic index = < 45 (no unit)

Pediatric spleen size measurement formula (up to 12 years):
Length (L) = 5.5 + (age in year X 0.31) expressed in cm

Example exercise for measuring pediatric spleen of a 10-year old kid:
Length (L) = 5.5 + (10 X 0.31) = 5.5 + 3.1 = 8.6 cm

Subjective assessment of splenomegaly:

▪ If the spleen is crossing the mid-pole of the left kidney, it assumes as enlarged. ▪ If spleen is going out of the window of ultrasound, it assumes as enlarged.

Normal diameter of the splenic vein = < 10 mm
In portal hypertension = > 10 mm

|PANCREAS |

Length (L) = 12.5 ~ 15.0 cm

Maximum anterio-posterior (A~P) diameter:

▪ Head = 3.0 cm ▪ Neck = 1.0 ~ 2.0 cm ▪ Body = 2.5 cm ▪ Tail = 2.0 cm

Normal diameter of pancreatic duct:

▪ Average = 2.0 mm ▪ Head = 3.0 mm ▪ Body = 2.1 mm ▪ Tail = 1.6 mm

Common site for the pancreatic mass = Head

|GIT |

Esophagus

Length (L) = 25 cm
Width (W) = 2.5 ~ 3.0 cm

Stomach

Four coats of the stomach wall:
a. Serous coat – peritoneum
b. Muscular coat – 3 layers (outer longitudinal, middle circular & inner oblique)
c. Submucous coat – connective tissue
d. Mucous coat – mucous membrane

Normal wall thickness = < 5 mm

Hypertrophic pyloric stenosis
Length of pylorus = > 18 mm
Thickness of pyloric muscle = > 4 mm (one wall)

Small Bowel (Duodenum, Jejunum & Ileum)

Length (L) = 6 meter
Diameter = 4 cm (2.5 cm at lower end)
Normal wall thickness = < 3 mm

Large Bowel

The colon
Length (L) = 1.5 meter
Diameter = 6 cm
Normal wall thickness = < 5 mm

In Crohn’s diseae:
(The lesion usually involves the distal ileum and colon)

Thickness of the affected bowel segment = > 5 mm

Rectum
Length = 12 cm

The Appendix

Length = 9 cm
Diameter = 5 mm
Diameter in acute appendicitis = > 6 mm (outer wall ~ outer wall)

|KIDNEY |

Length (L) = < 12 cm
Width (W) = < 6 cm
Anterio-posterior thickness (A~P) = < 3 cm
(Difference of kidney length should not be > 2 cm in normal adult)

Normal weight = 120 ~ 170 gm

Cortex and medulla ratio

< 30 years : cortex : medulla = 2.0 : 1.0
30 ~ 50 years : cortex : medulla = 1.6 : 1.0
> 50 years : cortex : medulla = 1.0 : 1.0

Ureter

Normal diameter = < 5 mm

Pediatric kidney size measurement

Formula

a) For the children over one year of age Kidney length (in cm) = 6.79 + (0.22 X age in year)

Example exercise of a kid of 10 year: Kidney length = 6.79 + (0.22 X age in year) = 6.79 + (0.22 X 10) = 6.79 + 2.2 = 8.99 cm

b) For the children less than one year of age Kidney length (in cm) = 4.98 + (0.155 X age in month)

Example exercise of a kid of 10 month: Kidney length = 4.98 + (0.155 X age in month) = 4.98 + (0.155 X 10) = 4.98 + 1.55 = 6.5 cm

Note: Asymmetry in renal lengths exceeding 5 mm in infants and 10 mm in older children should raise the suspicion of an underlying problem even if both kidneys are within the normal range.
Normal renal pelvic diameter in fetus

▪ 15 ~ 20 weeks = &lt; 4 mm ▪ 20 ~ 30 weeks = &lt; 8 mm ▪ &gt; 30 weeks = &lt; 10 mm

Prostate

Measurement of weight = L X W X A~P X 0.55 (expressed in gm)
Normal weight = &lt; 30 gm
(If any measurement appears more than 37 mm, it assumes prostate is enlarged)

Urinary bladder

Normal wall thickness = 3 mm (in distended
bladder = 6 mm (in partially filled bladder)
Thickened bladder wall = > 4 mm
(In pediatric patient a PMR more than 30 ml is generally considered as pathological)
Kidney Doppler

Renal artery

PSV = 60 ~ 140 cm/sec (< 180 cm/sec)

Resistive index (RI) = 0.56 ~ 0.70
Pulsatility index (PI) = 0.70 ~ 1.40

In obstructive uropathy RI = > 0.7

|UTERUS |

Size
Neonatal (at birth) = 3.5 cm

Adult (nullipara)

Length (L) = 6 ~ 9 cm (mean 7.5 cm)
Width (W) = 3 ~ 5 cm (mean 4 cm)
Anterio-posterior thickness (A~P) = 2 ~ 3 cm (mean 2.5 cm)

Adult (multipara)

Length (L) = 9 ~ 11 cm (mean 10 cm)
Width (W) = 4 ~ 6 cm (mean 5 cm)
Anterio-posterior thickness (A~P) = 3 ~ 4 cm (mean 3.5 cm)

(Uterine size in length becomes enlarged for 1 cm for each delivery up to three deliveries)

Ratio of body with cervix

In infant body : cervix = 1 : 2
In adult body : cervix = 2 : 1

Hypoplastic uterus

Length of uterus in adult = < 5.5 cm (with normal body & cervix ratio)

Post-menopausal uterus

Smaller size with normal body & cervix ratio

Cervix

Normal length = 2.5 ~ 4.5 cm (in reproductive age) = 2.1 ~ 2.6 cm (in post-menopausal state)
Cervical incompetence = < 2.5 cm in length
(Elongated cervix > 4.5 cm may be a cause of infertility)

Endometrium

Normal thickness
a.
In pre-menopausal women ▪ In proliferative phase = 2 ~ 8 mm ▪ During ovulation = 13 mm ▪ Secretory phase = 8 ~ 14 mm

b. In postmenopausal women ▪ With hormone therapy = &lt; 8 mm ▪ Without hormone therapy = &lt; 5 mm
Endometrial hyperplasia

Endometrial thickness = &gt; 14 mm (in pre-menopausal women) = &gt; 8 mm (in postmenopausal women)

Gynae Doppler

|Status |Ovarian Artery |Uterine Artery |
|Different phases/stages |RI |PI |Velocity |
|
|Early proliferative phase |0.65 ~ 0.70 |1.80 ~ 2.20 |20 cm/s |1.45 ~ 1.90 |
|Late proliferative phase |0.55 ~ 0.60 |1.00 ~ 1.30 |40 cm/s |1.50 ~ 2.30 |
|Secretory phase |0.60 ~ 0.65 |1.30 ~ 1.80 | |1.55 ~ 2.90 |
|Non-conception |0.60 ~ 0.70 |1.80 ~ 2.20 | |2.75 ~ 4.95 |
|Post-menopausal |0.60 ~ 1.00 |1.30 ~ 4.00 | |1.80 ~ 3.80 |

Ovarian mass

Resistive index (RI) = < 0.4 suggestive of malignant = 0.4 ~ 0.5 suggestive of intermediate (suspicious) = > 0.5 suggestive of benign

|OBSTETRICS |

Embryonic stage = Up to 10 weeks of gestational age
Fetus = > 10 weeks of gestational age

Mean Sac Diameter (MSD) in TAS (Transabdominal sonography)
At 20 mm size = Yolk sac must be present
At 25 mm size = Embryo must be present

Blighted ovum

Neither yolk sac nor embryo is present within the gestational sac when – ▪ In transvaginal sonography (TVS) MSD measures = > 16 mm ▪ In transabdominal sonography (TAS) MSD measures = > 25 mm

Yolk Sac

▪ Normal diameter = < 6 mm ▪ Normally seen = 5 ~ 12 weeks of gestational age ▪ Wall = Thin and regular ▪ Content = Anechoic ▪ Diameter > 6 mm and/or persistence after 12 weeks of gestational age may be due to chromosomal abnormality) ▪ In case of monochorionic monoamniotic twin pregnancy low-level echoes can be seen inside yolk sac, which is due to thick fluid content to provide nutrient for two developing fetus from one yolk sac) ▪ Number of yolk sac indicates number of zygote

Placenta

Start developing = At 7 ~ 8 weeks of gestational age
Thickness in mm = Corresponds with gestational age in weeks
Thickened placenta = > 50 mm
Thin placenta = Thickness is 2.5 cm or less at/after 35 weeks of gestational age
Low-lying placenta = Cervical end of the placenta lying 2.5 cm vicinity of internal os

Causes of thickened placenta:

▪ Diabetes mellitus ▪ Fetal hydrops ▪ Fetal infection (e.g. Cytomegalovirus) ▪ Chromosomal abnormality (especially triploidy)

Placental grading:

|Features |Latest Grading |Old Grading |
|Cervical end of the placenta |2.5 cm within the vicinity of the |5 cm within the vicinity of the internal |
| |internal os = Low-lying |os = Type I placenta praevia |
|Placenta just touching the internal os |Marginal placenta praevia |Type II placenta praevia |
|Placenta partially covers the os |Partial placenta praevia |Type III placenta praevia |
|Placenta completely covers the internal |Complete placenta praevia |Type IV placenta praevia |
|os | | |

Placental maturity:

▪ Grade – 0 ▪ Grade – I ▪ Grade – II ▪ Grade – III

Amniotic fluid

Contents:

a. Water = 98% ~ 99%
b. Organic components i. Protein (50%) ii. Others (50%) o Carbohydrate o Fat o Enzymes o Hormones o Pigments
c. Inorganic constituents – inorganic salts

Volume:

At 10 weeks = 25 ml 20 weeks = 350 ml 35 weeks = 1000 ml 43 weeks = 250 ml (peaks at 36 weeks)

Source:

In early pregnancy : Amniotic membrane, transudate from mayernal blood
From 2nd trimester : Fetal kidney starts to contribute (about 500 ml/day).

(Fetal swallowing of amniotic fluid starts at 11 ~ 13 weeks. At later stage of pregnancy fetus swallows about 400 ml/day)

Assessment:

Subjective assessment = Eye ball assessment (needs experience and orientation)

Objective assessment

a) Maximum vertical pocket measurement (Chamberlain Method)
b) Measurement of AFI (Phelan Method)

Maximum vertical pocket measurement (Chamberlain Method)

Interpretation: Normal range 2 ~ 8 cm

< 1 cm = Severe oligohydramnios
1 ~ 2 cm = Significant oligohydramnios
2 ~ 8 cm = Normal
8 ~ 12 cm = Mild polyhydramnios
12 ~ 16 cm = Moderate polyhydramnios
> 16 cm = Severe polyhydramnios

Measurement of AFI (Phelan Method)

Interpretation: Normal range 5.5 ~ 22 cm

< 5.5 cm = Oligohydramnios
5.5 ~ 8 cm = Suspicious for oligohydramnios
8 ~ 22 cm = Normal
> 22 cm = Polyhydramnios

(Dolicocephaly is a common finding in oligohydramnios)

Landmarks for measuring biparietal diameter (BPD)

▪ Falx cerebri ▪ Paired thalami ▪ Cavum septum pellucidum

Landmarks for measurement of abdominal circumference (AC)

▪ Fetal spine ▪ Stomach bubble ▪ Portal sinus

Head circumference (HC) = BPD outer-to-outer X OFD outer-to-outer X 1.57

Cephalic index (CI) =

Normal CI = 0.70 ~ 0.86
Head is dolicocephalic if CI = < 0.70
Head is brachycephalic if CI = > 0.86

Obstetric Doppler

Umbilical artery

S/D Ratio

At 20 weeks = < 4 30 weeks = < 3 35 weeks = < 2.5 term = < 2

Pulsatility index (PI)

At 20 weeks = 1.10 ~ 1.70 (mean 1.35) 28 weeks = 0.80 ~ 1.45 (mean 1.10) 36 weeks = 0.55 ~ 1.20 (mean 0.55)

Uterine artery resistive index (RI)

At 20 weeks = 0.50 ~ 0.76 (mean 0.65) 28 weeks = 0.37 ~ 0.67 (mean 0.53) 36 weeks = 0.35 ~ 0.65 (mean 0.50)

Middle Cerebral Artery (MCA) Pulsatility index (PI)
At 20 weeks = 1.20 ~ 2.10 (mean 1.70) 28 weeks = 1.40 ~ 2.37 (mean 1.90) 36 weeks = 1.20 ~ 2.10 (mean 1.60)

Spectral analysis of umbilical artery
Normal appearance = Saw tooth appearance with good diastolic flow

In IUGR:
Decrease or absent diastolic flow = Indicates feto-placental insufficiency
Reverse diastolic flow = Established IUGR

In term pregnancy
Absence or reverse flow = Indication of immediate delivery by caesarian section

Prepared by:

Dr. Md. Nazrul Islam
Bangladesh
e-mail: [e-mail]

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PV cross sectional area (cm2)

M PV flow velocity cm/sec

PSV = Peak Systolic Velocity
Portal vein area = diameter A X diameter B
PV flow velocity = 0.57 X max. PV velocity (angle 18 mm
▪ Thickness of pyloric muscle = > 4 mm (one wall)

BPD outer-to-outer

OFD

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Values used in ultrasound

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