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Biomedical subjects

L A Mack

Publications and source records attributed to L A Mack.

134 records · Page 8Linked to original sources
PubMed1980

Evaluation of fetal intracranial anatomy by static and real-time ultrasound.

Improvements in ultrasound technology have now made possible detailed visualization of fetal intracranial anatomy. Structures such as the midbrain, thalami, and lateral ventricles can be routinely imaged. Measurements of the ratio between lateral ventricular width and cerebral hemispheric width demonstrate a steady decrease from a mean of 56% at 15 wk gestation to 28% at term reflecting the relatively more rapid growth of the cerebral hemispheres as compared with the cerebral ventricles. Application of this new ultrasound data greatly facilitates accurate and consistent biparietal diameter estimations and early diagnosis of fetal hydrocephalus and other fetal cranial anomalies. This article describes the axial fetal cranial anatomy as demonstrated sonically and includes a table for normal fetal ventricular size at various gestational ages, based on evaluation of 196 normal fetuses. Some of the more common fetal cranial anomalies amenable to ultrasound diagnosis in utero are discussed.

Brain↗
PubMed1980

Ultrasound evaluation of cystic intracranial lesions in the neonate.

Ultrasound detected cystic intracranial lesions in 18 infants. Lesions included porencephaly (6 infants), hydranencephaly (1 infant), a quadrigeminal cyst (1 infant), Dandy-Walker syndrome (1 infant), and cavum septi pellucidi and Vergae (9 infants). Cystic lesions of the infant brain can be delineated accurately with ultrasound and distinguished from normal ventricular structures.

Brain Diseases↗
PubMed1979

B-mode echoencephalography in the normal and high risk infant.

Commercially available high resolution, contact, gray scale imaging systems can now dependably visualize the normal and abnormal ventricular system as well as some other intracranial structures in all newborns. On 25 normal infants and 41 high risk infants, 135 B-mode echoencephalograms were performed. The technique for obtaining these scans is described. The normal lateral ventricle at the midbody in term infants is 0.9--1.3 cm wide (mean, 1.1 cm). Normal ratio of lateral ventricle to hemisphere is 28% (range, 24%--30%). High risk premature infants have a ratio of 31% (range, 24%--34%). The demonstration of hydrocephalus and cystic intracranial masses is reliable and the correlation with computed tomography is excellent. Postoperative or high risk infants can be repeatedly evaluated without radiation, at a lower cost, and more rapidly with ultrasound than with computed tomography. Ventricular size can be closely monitored and shunt failure detected at any early stage.

Cerebral Hemorrhage↗
PubMed1978

Ultrasonic evaluation of the pancreas.

With the advent of new gray scale imaging techniques, ultrasound plays a major role in the diagnosis of pancreatic lesions. As a noninvasive, nonionizing, accurate, and inexpensive diagnostic modality that directly images the pancreatic gland, ultrasound can be used as a primary screening tool. It is helpful in confirming the diagnosis of acute pancreatitis and in detecting and following pseudocysts and other complications. Neoplasms can be detected with a high rate of accuracy, and by assessing the presence of ascites or metastatic foci in the liver, ultrasound can aid in the staging of the neoplastic process. Bowel gas and obesity remain serious limitations to adequate examination, and in these patients computed tomography offers a complementary modality.

Acute Disease↗
PubMedDate not supplied

MR imaging of accessory soleus muscle.

The accessory soleus muscle is an unusual anatomical variant that may present as a mass in the distal calf or medial ankle region. On both magnetic resonance (MR) and ultrasound, this variant has appearances similar to adjacent normal muscle. The diagnosis can be strongly suggested by typical location and by both echo texture and MR signal pattern of striated muscle.

Adult↗
PubMedDate not supplied

Antenatal ultrasonic evaluation of acardiac monsters.

Acardiac monster represents a rare but serious complication of monozygotic twin pregnancy. Antenatal recognition is important because of accompanying obstetrical problems, including polyhydramnios, dystocia, and uterine rupture. While pathologic findings are varied, characteristic sonographic findings allow accurate prenatal diagnosis. Acardia must be distinguished from sacrococcygeal teratoma, omphalocele and macerated fetus.

Abnormalities, Multiple↗