Ultrasound probe pressure as a source of error in prostate localization for external beam radiotherapy.

PURPOSE: A pelvic phantom was constructed to evaluate the effect of ultrasound probe pressure during performance of bipolar acquisition technique (BAT) for prostate localization for radiotherapy. METHODS AND MATERIALS: A pelvic phantom of a gelatin mold with a water-filled balloon representing the bladder and rectum and a central encapsulated clay sphere representing the prostate was constructed. This phantom was then scanned using planning computed tomography (CT). The geometric information of the phantom was outlined in two planes. The phantom was then scanned using the BAT system with mild and moderate ultrasound probe pressure. Differences in prostate depth between the CT and BAT systems were displayed. RESULTS: A difference of 1 cm between the phantom surface and the prostate could be produced with moderate ultrasound probe pressure. The differences were similar between the CT- and BAT-generated contours and were dependent on the ultrasound probe pressure. CONCLUSION: Care must be taken not to cause any alteration in prostate localization with increasing ultrasound probe pressure when using BAT localization. Increased probe pressure may introduce errors in prostate localization and under dose the target.

Emergency ultrasound in trauma patients.

US will be used more frequently in the future for the evaluation of traumatized patients. Previously,the main focus of the sonographic examination was for the detection of free fluid. Unstable patients with free fluid often can be triaged to the operation room without further imaging tests. In patients who are more stable or in whom US results are negative, CT is required. Based on recent studies, sonography has a sensitivity rate of approximately 40% in direct detection of solid organ injuries. In the future, however, with the use of contrast-enhanced agents, sonography may more reliably detect solid organ injuries. Within the chest, US has been shown to be helpful in detecting pleural effusions and may be useful in detecting pericardial effusions. US has been shown to be sensitive in detecting pneumothoraces in traumatized patients.

Retained products of conception mimicking a large endometrial AVM: complete resolution following spontaneous abortion.

We report an unusual appearance of retained products of conception that mimicked an arteriovenous malformation. A 38-year-old woman presented with persistent scant vaginal bleeding and declining levels of serum beta-HCG after therapeutic abortion. Sonographic examination revealed a highly vascular lobulated mass, which on spectral Doppler examination showed low resistance and high peak systolic velocity suggestive of arteriovenous shunting. The patient spontaneously passed tissue per vagina, after which the endometrial vascular mass completely disappeared, indicating that the sonographic abnormality was the retained products of conception. The pathologic basis for such a finding is discussed.

Potential pitfalls and methods of improving in utero diagnosis of transposition of the great arteries, including the baby bird's beak image.

OBJECTIVE: The goal of this study was to analyze our recent experience with fetuses with transposition of the great arteries (TGA) to identify potential pitfalls and possible methods to better detect conotruncal anomalies such as TGA. METHODS: We analyzed all nonreferral obstetric ultrasound examinations in which we performed basic, targeted, or formal fetal echocardiography with a newborn diagnosis of TGA. RESULTS: Nine neonates had TGA. Five of these cases were diagnosed prenatally, and 4 of these had complex congenital heart abnormalities. In these 4 cases, there were abnormalities in the cardiac axis (n = 3), abnormal valves or ventricular size (n = 2), and ventricular septal defects (n = 3) that were detected on the 4-chamber view of the heart. In all cases that were not detected prenatally, both prospective and retrospective reviews of the 4-chamber heart appeared normal. The prospective analyses of the outflow tracts were all interpreted as normal, whereas the retrospective review showed subtle abnormalities such as the "baby bird's beak" image. In review of these cases, there was failure to show the "crisscross" relationship of the outflow tracts. In 1 case, 5 short axis views of the heart, retrospectively showed the artery originating from the left ventricle and bifurcated, representing the pulmonary artery. CONCLUSIONS: Transposition of the great arteries may be associated with complex cardiac disease that could be detected on the 4-chamber view of the heart. When the 4-chamber view is normal, it is important to identify the crisscross relationship of the outflow tracts. If this is not done, it is important to document that the pulmonary artery bifurcates and originates from the right ventricle. Five short axis views of the heart may be helpful to detect conotruncal abnormalities.

Sonographic duplication artifact of the spinal cord in infants and children.

OBJECTIVE: To describe the features of sonographic duplication artifacts that we have occasionally seen when imaging the spinal cord of infants and children, mostly with postrepair myelomeningocele. METHODS: Sonography of the spine was performed for the evaluation of neonates with suspected spinal cord abnormalities and of older children in the follow-up of postrepair open-spine defects. RESULTS: Each of our patients had a single spinal cord, but the duplication artifact was seen with 2 brands of scanners and with both linear array and vector array transducers. CONCLUSIONS: The finding of duplication artifacts when imaging the spinal cord of infants and children should be recognized as such and should not be misinterpreted as representing diastematomyelia or diplomyelia.