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Biomedical subjects

C C Jaffe

Publications and source records attributed to C C Jaffe.

At least 55 records · Page 3Linked to original sources
PubMed1983

Fluoroscopic dose reduction using a digital television noise-reduction device.

A digital video image processor, connected to a video system in a conventional pediatric fluoroscopy room, was used to determine whether the device could provide satisfactory fluoroscopic images during routine examinations when the x-ray tube was operated at substantially lower than normal radiation-dose levels. A 50% reduction resulted in image quality which was indistinguishable from conventional fluoroscopic views.

Child↗
PubMed1982

A controlled evaluation of the risk of bacterial endocarditis in persons with mitral-valve prolapse.

The absence of controlled evidence and the high prevalence of mitral-valve prolapse have created substantial uncertainty about whether this condition is an important risk factor for bacterial endocarditis. We evaluated this risk in a case-control study of hospital inpatients who had undergone echocardiography and who lacked any known cardiovascular risk factors for endocarditis, apart from mitral-valve prolapse and isolated mitral-regurgitant murmurs. Thirteen (25 per cent) of 51 patients with endocarditis had mitral-valve prolapse, as compared with 10 (seven per cent) of the 153 matched controls without endocarditis. For the 51 matched case-control sets, the odds ratio (8.2; 95 per cent confidence interval, 2.4 to 28.4) indicated a substantially higher risk of endocarditis for people with mitral-valve prolapse than for those without it. This association remained statistically significant when parenteral drug abuse and routine antibiotic prophylaxis preceding dental work and other forms of instrumentation were taken into account. Furthermore, the risk may be higher than is indicated by this study, since 46 per cent of the controls underwent echocardiography for clinically suspected mitral-valve prolapse, suggesting an overrepresentation of mitral prolapse in the control group. The results support the contention that mitral-valve prolapse is a significant risk factor for bacterial endocarditis.

Adult↗
PubMed1982

Fetal echocardiography for evaluation of in utero congestive heart failure.

Thirteen fetuses with nonimmune hydrops (22 to 39 weeks of gestation) were evaluated with two-dimensional and M-mode echocardiography. Ten fetuses had cardiovascular abnormalities resulting in heart failure, and three had noncardiac causes of hydrops. In three cases, hydrops was caused by supraventricular tachycardia. One of these fetuses responded to cardioversion at birth, another responded to transplacental digoxin therapy, and the third died with atrial flutter and high-grade atrioventricular block before delivery. There were no cases of "idiopathic" hydrops. Our results show that fetal echocardiography is useful in determining cardiac causes of in utero heart failure resulting in hydrops fetalis. The fetal echocardiogram may also be used in monitoring transplacental therapy of heart failure.

Adolescent↗
PubMed1982

The effect of a television digital noise reduction device on fluoroscopic image quality and dose rate.

In conventional fluoroscopy, the current, and therefore the dose rate, is usually determined by the level at which the radiologist visualizes a just tolerable amount of photon "mottle" on the video monitor. In this study, digital processing of the analogue video image reduced noise and generated a television image at half the usual exposure rate. The technique uses frame delay to compare an incoming frame with the preceding output frame. A first-order recursive filter implemented under a motion-detection scheme operates on the image of a point-by-point basis. This effective motion detection algorithm permits noise suppression without creating noticeable lag in moving structures. Eight radiologists evaluated images of vesicoureteral reflux in the pig for noise, contrast, resolution, and general image quality on a five-point preferential scale. They rated the digitally processed fluoroscopy images equivalent in diagnostic value to unprocessed images.

Animals↗
PubMed1982

Evaluation of gynecologic pelvic masses by ultrasound and computed tomography.

In a prospective study, computed tomography (CT) and ultrasound scanning of the pelvis were performed for 50 patients having clinically suspected pelvic masses or recurrence of known pelvic malignancy. On the basis of these scan images, an attempt was made to characterize pelvic masses on the basis of benign or malignant character and organ of origin. The presence of recurrent tumor in patients previously treated for pelvic malignancy was assessed, and the presence of abdominal metastatic disease was evaluated for all patients. CT was successful in a higher proportion of cases in detecting abdominal metastatic disease due to bowel gas's degrading the abdominal ultrasound scan images. In characterizing suspected pelvic masses and evaluating the presence of recurrent tumor, both CT and ultrasound scanning were accurate in approximately two-thirds of cases. The significant proportion of incorrect results indicates that neither technique is sufficiently accurate to preclude pathologic diagnosis of a pelvic mass or to substitute for exploratory surgery to assess recurrence of pelvic malignancy.

Female↗
PubMed1981

Sonographic transducer performance cannot be evaluated with clinical images.

A wide variety of in vitro tests, some too sophisticated to perform in a clinical setting, is available to provide information on the performance of sonographic transducers. However, it is a common belief among many clinicians that clinically generated in vivo images are a necessary and sufficient test of sonographic image quality. In order to examine the sensitivity and reliability of quality judgments made from clinical images, some transducers that failed elaborate in vitro tests were used to create clinical scans. In a discrimination test between clinical images created by normal and abnormal transducers, a panel of experienced sonographers was unable to consistently identify scans made by transducers with major flaws in the beam uniformity when the defect occurred only in the near field. The study confirms that rigorous in vitro tests provide unique information on transducer performance and can reveal performance flaws that are overlooked in routine clinical images.

Humans↗
PubMed1980

Physical factors influencing numerical echo-amplitude data extracted from B-scan ultrasound images.

The replacement of analog-scan converters by digital-scan converters in commercially available B-scan ultrasound equipment provides easily available numerical echo-amplitude data from regions or organs of interest, once the image has been created. These values vary with, and are influenced by, a variety of physical variables, including transducer power output, time-gain compensation, signal threshold, preprocessing digital signal level assignment, frequency, and acoustic beam width. Unless vigorous efforts are made to standardize these variables, clinical reports using numerical analysis as disease descriptors should be viewed critically.

Acoustics↗
PubMed1980

Prenatal echocardiography.

Congenital cardiac defects are not common, but their serious consequences make early detection and treatment essential. In developing a set of workable criteria for selective screening of serious abnormalities, the authors used commercially available ultrasound equipment in more than 500 high-risk pregnancies. Possible future applications include elucidation of causes of fetal cardiac defects.

Echocardiography↗
PubMed1980

Technical factors influencing the imaging of small anechoic cysts by B-scan ultrasound.

Ultrasound examination of small cysts in vivo and in vitro has demonstrated that several factors can interfere with recognition of their true anechoic nature. Reverberation and the effects of the beam width can interact with adjacent acoustic reflectors to produce artifactual echoes. Sonic enhancement in distal tissues varies with time gain compensation, frequency, and the position of the focal zone. If the operator is aware of this problem, he can compensate for these effects and thereby improve diagnostic accuracy.

Cysts↗
PubMed1980

Sonographic tissue texture: influence of transducer focusing pattern.

The ultrasonic beam profile pattern is not accurately known for most transducers in clinical use. A simple scan of an easily available phantom permits the clinician to determine the focusing pattern of his own transducer and equipment. Disregarding other operator-controllable parameters such as the time-gain compensation, output, and system sensitivity, the true echo pattern of a tissue is not accurately represented until the distance of the region of narrowest beam focus is reached. The fine speckled echo pattern commonly seen in uniform organs near the transducer is largely artifactual due to interference phenomena in the near field of the acoustic beam. Closest approximation of true texture is not displayed until near the depth at which the narrowest focus occurs. Beyond that depth, broad, coarser patterns can be expected.

Humans↗
PubMed1980

A radiographic and echocardiographic approach to cyanotic congenital heart disease.

An updated, systematic approach to the diagnosis of cyanosis in the infant or child has been presented. It involves the use of clinical data (to establish the presence of cyanosis), radiographic information (to assess lung parenchyma, pulmonary vascularity, and certain key, border-forming, cardiac structures), and M-mode and cross-sectional echocardiographic data (the source of detailed intracardiac anatomic information). Specific radiographic and echocardiographic features of the 10 most common cyanotic congenital heart lesions have been presented. Using this approach, one should be able to diagnose accurately the cyanotic infant or child. Further planning for cardiac catheterization and angiocardiography can then be accomplished with an informed and rational point of view.

Adolescent↗
PubMed1980

Echocardiographic studies of the human fetus: prenatal diagnosis of congenital heart disease and cardiac dysrhythmias.

During obstetrical ultrasound examinations, 200 M-mode and 35 real-time two-dimensional echocardiographic studies were performed on 180 fetuses of high-risk pregnancies. Fetal gestational ages ranged from 18 to 41 weeks. M-mode "sweeps" demonstrating mitral- and septal-aortic fibrous continuity were obtained in 115 studies. Paradoxic septal motion in 50 fetuses suggested relarive right ventricular volume loading. Congenital cardiac malformations were accurately diagnosed in a 34-week fetus with pulmonary atresia and hypoplastic right ventricle and in a 28-week fetus with a univentricular heart. Congenital complete atrioventricular block was diagnosed in a 28-week fetus and atrial flutter with variable atrioventricular block was diagnosed in a 38-week fetus. The use of echocardiographic studies to evaluate cardiac structure and rhythm in utero assists in counseling prospective parents and in planning postnatal management for their offspring.

Arrhythmias, Cardiac↗