Real-time Sector Scanner Research Articles

Attenuation of ultrasound in normal liver and diffuse liver disease in vivo.

Preliminary results of in vivo attenuation measurements of the liver have been obtained in 39 normal patients and in 35 patients with diffuse liver disease. A modified real-time sector scanner incorporating an online attenuation measurement method was used. The value of attenuation in normal liver was estimated as 0.52 +/- 0.03 dB/cm/MHz, measured at 3 MHz. Significantly higher attenuation values were obtained from patients with alcoholic and cardiac cirrhosis, and following hepatic artery infusion with chemotherapeutic agents. Lower values were obtained from patients with biliary cirrhosis, chronic active hepatitis, and diffuse infiltration by lymphoma or leukemia. Fatty infiltrated livers showed a wide range of values of 0.37-0.66 dB/cm/MHz. The results suggest that estimates of attenuation coefficients are useful in detecting the presence of diffuse liver disease.

Attenuation of ultrasound in normal liver and diffuse liver disease in vivo

Preliminary results of in vivo attenuation measurements of the liver have been obtained in 39 normal patients and in 35 patients with diffuse liver disease. A modified real-time sector scanner incorporating an on-line attenuation measurement method was used. The value of attenuation in normal liver was estimated as 0.52 ± 0.03 dB/cm/MHz, measured at 3 MHz. Significantly higher attenuation values were obtained from patients with alcoholic and cardiac cirrhosis, and following hepatic artery infusion with chemotherapeutic agents. Lower values were obtained from patients with biliary cirrhosis, chronic active hepatitis, and diffuse infiltration by lymphoma or leukemia. Fatty infiltrated livers showed a wide range of values of 0.37 – 0.66 dB/cm/MHz. The results suggest that estimates of attenuation coefficients are useful in detecting the presence of diffuse liver disease.

Examination of the infant hip with real-time ultrasonography.

Examination of the infant hip with a real-time sector scanner permits accurate and reliable determination of the anatomic structures and relationships of the hip joint. A technique using two transducer orientations has been found most effective. In 100 hip examinations, the method failed to differentiate an abnormal hip in only one instance.

Soft tissue anatomy of the tongue and floor of the mouth: An ultrasound demonstration

Ultrasound technology has not been used extensively in the study of normal and abnormal oral physiology and speech. Features such as soft tissue detail, real-time motion display, and subject safety make ultrasound ideal for imaging the tongue and the floor of the mouth. This study demonstrates visualization of the muscles of the tongue and floor of the mouth for a normal subject using ultrasound imaging. By employing submandibular transducer placement of real-time sector scanners, tongue anatomy and motion were continuously visualized in sagittal or coronal planes. In addition to the entire tongue surface, much of the intrinsic anatomy was identified including: the genioglossus, geniohyoid, mylohyoid, and digastric muscles; fascial boundaries such as the median fibrous septum, floor intermuscular septum, and paramedian septums; and the hyoid bone. A tongue excised from a human cadaver was scanned using ultrasound and dissected to confirm the anatomy seen in the live tongue. Tongue surface shape and configuration of the intrinsic tissue structures were observed and compared for the phonemes /k/, /u/, and /i/. Anatomical landmarks in the resting and speaking tongue are discussed as well as applications in the fields of speech science and speech pathology.

Ultrasound imaging system combining static B‐scan and real‐time sector scanning capability

A standard articulated B-scan arm provides positional and directional information for a transducer at its end, based on relative angular displacements of the separate arm segments. A real time scanner, preferably one having a fixed transducer and a fixed oscillating mirror, is freely attachable or detachable from the scan arm. The probe itself is operable either in a real time sector scan or in a static B-scan mode.

Ultrasonography of choledocholithiasis.

In a retrospective study of patients with ultrasonographically demonstrable choledocholithiasis, 81 stones were demonstrated in 46 patients. The majority of the stones were between 5 and 10 mm in diameter; the smallest was 2 mm and the largest 23 mm. Of the 81 stones, 64 demonstrated acoustical shadowing; 56 were located in the distal segment of the common bile duct. Stones in the common bile duct are best demonstrated by sagittal sections with the patient in the right anterior oblique position. It is possible but more difficult to demonstrate stones within a normal-sized common bile duct. Several possible sources of confusion in the diagnosis of common bile duct stones are discussed. Ultrasonography of the common bile duct is best performed with a high-resolution real-time sector scanner. The accuracy and frequency of detection of common bile duct stones have increased significantly with the advances in technology and improvement in resolution of the mechanical sector real-time scanners.

Clinical Applications of High Resolution Real Time Sector Scanning

SUMMARYA commercially available high resolution real time sector scanner was clinically evaluated over a 6 month period in a teaching hospital. The instrument was found to be suitable as a “stand alone” scanner for most small parts applications. Studies performed on this scanner complemented compound water path ultrasonic investigation of the breast and testes. The advantages and limitations of scanning with this type of instrument are discussed.

Correlation of ultrasonic and endocrinologic measurements in human menopausal gonadotropin therapy

Ultrasonographic measurement of follicle growth and estradiol concentrations have been shown to correlate well in spontaneous and Clomid-induced ovulatory cycles. However, little is known about these changes during human menopausal gonadotropin (hMG) therapy. Twenty-five women who did not ovulate when treated with clomiphene were treated with hMG during 70 treatment cycles. Eleven patients had withdrawal bleeding after progesterone administration (group 1) and 14 did not bleed (group 2). Follicle growth was monitored with intermittent serum estrogen determinations and daily ovarian ultrasound with an ADR Model 2140 real-time sector scanner. The mean dominant follicle size at the time of human chorionic gonadotropin (hCG) injection was 21.2 mm ± 0.6 (SEM) and was not different between the two groups. Mean serum estrogen level at the time of hCG injection was 1,121 pg/ml and correlated with follicle volume. At the time of hCG injection in group 2, one dominant follicle was present in 65% and two were present in 35% of the patients. Among those in group 1, two or more dominant follicles were present during all cycles. Mean serum estrogen levels were significantly higher in group 1 patients than those in group 2. This “chemical hyperstimulation” was induced in order to delay ovulation until adequate follicular size had been achieved. All cycles were ovulatory. Five patients in group 1 and eight in group 2 conceived. The use of ultrasound enables the physician to evaluate follicular growth and development daily and thus to individualize treatment and to reduce the need for estrogen monitoring.

Intraoperative localization of subcortical brain tumors

Intraoperative ultrasonography is a potentially useful tool for the neurosurgeon faced with the task of finding and removing small subcortical brain tumors. With the B-mode real-time sector scan equipment now available, satisfactory images of the intracranial contents can be obtained. Others have reported obtaining images by applying the transducer directly to the dura mater or cortex. This carries the risk of pressure damage to the brain. Furthermore, the presence of acoustical noise in the region close to the transducer results in poor image resolution in the superficial region of the cortex. To circumvent these two problems, we have used a saline-filled cylinder placed over the craniotomy site to achieve acoustical coupling. This technique also increases the area of cortex visualized by the pie-shaped beam of the sector scan by separating the transducer from the brain surface. (Neurosurgery 12:189-194, 1983)

Correlation of ultrasonic measurement of ovarian follicle size and serum estradiol levels in ovulatory patients following clomiphene citrate for in vitro fertilization

Ovarian follicle development was investigated in 38 normally cycling women who received clomiphene citrate, 150 mg per day for 5 days, to maximize follicular development. Ultrasonic determination of follicle growth was performed on a daily basis with a real-time sector scanner and correlated with daily concentrations of estradiol (E2) in the peripheral serum as measured by rapid radioimmunoassay. Human chorionic gonadotropin was given to induce ovulation, and the day of injection was considered day 0. Mean concentrations of E2 reached a maximum of 1.150 ± 65 pg/ml on day 0. Mean diameter of the dominant follicle increased to 22.1 ± 0.4 on day 0. When peripheral concentrations of E2 were correlated with diameter and total follicular volume, it was found that plasma E2 levels varied, depending on the number of follicles seen on ultrasound examination, with a mean E2 value of 459 ± 18.9 pg/ml per follicle per day. Multiple growth of follicles occurs with artificial induction of ovulation; therefore, the use of ultrasound is an important parameter to assess follicular maturation and the timing of ovulation more precisely.

Detection of extracerebral fluid collections by real-time sector scanning through the anterior fontanelle.

Real-time sector sonography through the anterior fontanelle has proved useful in detecting extracerebral fluid collections when a water bath is utilized. With this technique, six patients had their extracerebral fluid collections visualized. The role of this procedure in following the course of these patients is discussed.

Monitoring of HMG-stimulated follicular development by real-time ultrasound

Monitoring of human follicular development by real-time ultrasound during HMG—HCG treatment is presented. With the aid of ultrasound monitoring, the ovulation rate is raised to 94.3% (formerly 80% without ultrasound). Serious side effects such as ascites and/or hydrothorax did not occur in this study (1.2% without ultrasound controls). The pregnancy rate was 21 47 (44%) of all hormonally treated patients. By means of real-time sector scan examination, the growing follicle could be detected in 103 106 (97.3%) of HMG—HCG treated cycles. Thus real-time ultrasound examinations provide results comparable to those achieved mostly by time-consuming compound scan in demonstration of the growing follicle.

Medical implications of ultrasonically detected polycystic ovaries.

Polycystic ovaries are usually manifest on an ultrasound study as symmetrically enlarged ovaries containing numerous tiny cysts. The cysts are difficult to detect with conventional contact B-scanners but are readily detected with high-resolution, real-time sector scanners. The cysts range in diameter form 2 to 6 mm and may be arranged in the periphery of an ovary or throughout the parenchyma. In patients with ultrasonically demonstrated polycystic ovaries (aged 15 to 35 years), there is a spectrum of clinical findings. Half the patients have most of the classic signs and symptoms (hirsutism, menstrual irregularity, and obesity) associated with Stein-Leventhal syndrome. Twenty-five percent have variants of the syndrome. In another 25%, no clinical abnormality is evident at the time of an ultrasound examination.

Detection of Dilated Cerebral Ventricles in Infants: A Correlative Study Between Ultrasound and Computed Tomography

Cross-sectional ultrasonic (US) and computed tomographic (CT) scans were obtained to compare their relative accuracies in determining cerebral ventricular size in 20 infants less than one year of age. The goal was to determine whether ultrasound imaging techniques could replace CT in the serial evaluation of the lateral ventricles, particularly in patients with ventricular shunts. The US images were obtained with a servo-controlled real-time sector and trapezoid scanner of the authors' own design. In 85% of the infants, biventricular width by US and CT differed by less than 0.5 cm, and in 95% by less than 1 cm.

Real-time sector scan study of the mitral valve prolapse syndrome.

Real-time sector scan study of the mitral valve prolapse syndrome.