3. Transverse cerebellar diameter measurement (TCD) : The cerebellar view is obtained by rotating the transducer in the axial plane centered on the thalamus to show the cerebellar hemispheres. This view shows the cerebellum, the cistern magna and the cavum septum pellucidi. The cerebellum characteristically appears as two lobules in either side of midline in the posterior cranial fossa. The widest diameter of the cerebellum is measured(16).
Fig. 5: Ultrasonographic Measurement of Transverse cerebellar Diameter
Table 5: Predicted Menstrual Age for Transverse Cerebellar Diameter (TCD) measurements (29) TCD (mm) Menstrual Age (weeks) TCD (mm) Menstrual Age (weeks)
14 15.2 35 29.2
15 15.8 36 30.0
16 16.5 37 30.6
17 17.2 38 31.2
18 17.9 39 31.8 …show more content…
It lies dorsal to the pons and the medulla, separated from them by fourth ventricle. Cerebellum is separated from the cerebrum by a fold of duramater called the tentorium cerebelli. The cerebellum consists of a midline part called the vermis and two lateral hemispheres. It is roughly spherical but somewhat constricted in its median region and flattened, the greatest diameter being transverse.
The cerebellum develops from the dorsolateral part of the alar lamina of the metencephalon. In the embryo cerebellum appears at the end of the fifth week as a swelling overriding the fourth ventricle.
Since cerebellum lies in the posterior cranial fossa, surrounded by the dense petrous ridges and the occipital bone so it can withstand deformation by extrinsic pressure better than the parietal bones. The fetal cerebellum can be visualized with ultrasound easily. Therefore imaging the posterior fossa is becoming an integral part of many routine fetal sonogram. Several authors working on transverse cerebellar diameter (TCD) have correlated it well with gestational age, even in the presence of growth retardation and found it as a better marker for GA estimation as compared to other clinical and biometric
Fig. 5: Ultrasonographic Measurement of Transverse cerebellar Diameter
Table 5: Predicted Menstrual Age for Transverse Cerebellar Diameter (TCD) measurements (29) TCD (mm) Menstrual Age (weeks) TCD (mm) Menstrual Age (weeks)
14 15.2 35 29.2
15 15.8 36 30.0
16 16.5 37 30.6
17 17.2 38 31.2
18 17.9 39 31.8 …show more content…
It lies dorsal to the pons and the medulla, separated from them by fourth ventricle. Cerebellum is separated from the cerebrum by a fold of duramater called the tentorium cerebelli. The cerebellum consists of a midline part called the vermis and two lateral hemispheres. It is roughly spherical but somewhat constricted in its median region and flattened, the greatest diameter being transverse.
The cerebellum develops from the dorsolateral part of the alar lamina of the metencephalon. In the embryo cerebellum appears at the end of the fifth week as a swelling overriding the fourth ventricle.
Since cerebellum lies in the posterior cranial fossa, surrounded by the dense petrous ridges and the occipital bone so it can withstand deformation by extrinsic pressure better than the parietal bones. The fetal cerebellum can be visualized with ultrasound easily. Therefore imaging the posterior fossa is becoming an integral part of many routine fetal sonogram. Several authors working on transverse cerebellar diameter (TCD) have correlated it well with gestational age, even in the presence of growth retardation and found it as a better marker for GA estimation as compared to other clinical and biometric