ADVANCED USG LOUNGE

SPIRAL CT MRI PET-CT CENTRE SEC 44 –C CHANDIGARH

www.spiralctmricentre.com

Dr Arun Gupta Director imaging Dr Rakhee gupta Dr R K S Gandhi Dr Vinayak Mittal Dr Ritesh Mahajan

SONO EMBRYOLOGY

SONO EMBRYOLOGY

VITTELOINTESTINAL DUCT

VITELLOINTESTINAL DUCT /YOLK STALK

OMPHALOMESENTERIC DUCT

The endodermal connection between the mid-gut and the

yolk sac. During embryonic disc folding (human week 3) this structure is initially a

broad open connection which is then restricted to a narrow tube and

finally closed between the mid-gut and the

yolk sac.

Yolk sacembroy

YOLK SAC ATTTACHED TO EMBROY THROUGH VITTELOINTESTINAL DUCT

The constituents of the vitelline duct

vitelline veins ( Paired) (omphalomesenteric vein,The blood vessels

which form in the yolk sac and have a blood flow towards the embryo. Derived from the extra-embryonic mesoderm surrounding the endoderm of the yolk sac.

vitelline arteries ( Paired) . (omphalomesenteric artery The blood

vessels which form in the yolk sac and have a blood flow away from embryo. Derived from the extraembryonic mesoderm surrounding the endoderm of the yolk sac.

Vitellogenesis The term refers to the formation of yolk.

Doppler values of Vitelline artery

Low velocity No diastolic flow PSV : 5.8

+_1.7cm/sec PI : 3.24 +_.94

3D Rendered image

Fetal anomaly series ………..

ARACHNOID CYST

Arachnoid cyst …..a brief

Arachnoid cysts are benign intracranial non communicating

collections in the arachnoid memberane. USUALLY STABLE CAN OCCUR INTRACRANIALLY OR IN SPINAL CANAL ALSO. EVEN IF LARGE ( RARELY CAUSE SYMPTOMS)

MID LINE CYSTS MAY LEAD TO PITUITARY DYSFUNCTION. MAY INTERFERE WITH CSF CIRCULATION.

COMMON LOCCATIONS ARE :1. SYLVIAN FISSURE / TEMPORAL FOSSA2. POSTERIOR FOSSA 3. ALONG CEREBERAL CONVEXITY4. MIDLIINE ( SUPRASELLAR)

ARACHNOID CYST ………….

FETAL MR IMAGE

CSF SIGNAL LARGE CYSTIC LESION IN THE LEFT TEMPORO-PARIETAL REGION ( SYLVIAN FISSURE CONFINES)/SUPRASELLAR / POSTERIOR FOSSA REGION.

( NEARLY OCCUPYING ALL THE COMMON SITES WHERE

ARACHNOID CYST IS PRESENT )

Fetal MR and Multiplanar USG Reformation.

FETAL MR SAGITTAL IMAGE

MASS EFFECT IS APPRECIATED ON BRAIN STEM INDENTATED ALONG THE VENTRAL SURFACE

USG SECTIONAL PLANE IMAGING OF LARGE INTRACRANIAL CYST

Coronal images ….Fetal MR / USG

NORMAL VERMIS / CEREBELLAR HEMISHERE( RULES OUT DANDY-WALKER MALFORMATION)

USG ( CORONAL PLANE )

DIFFERENTIAL DIAGNOSIS FOR ARACHNOID CYST

MIDLINE Cavum veli interpositi Aneurysm of vein of

galen ( Midline cysts may

accompany corpus callosum dysgenesis so in supratentorial cysts corpus callosum should be assessed) .

Posterior fossa : Dandy walker

malformation Inferior vermian

hypoplasia Mega cisterna

magna Blake’s pouch

cysts

DEPENDS ON POSITION

Diagnostic Ultrasound

4th Edition

Carol M. Rumack

Stephanie R. Wilson

J. William Charboneau

Deborah Levine

References