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