A novel biopsy method to increase yield of subcutaneous abdominal adipose tissue.

Collection of abdominal subcutaneous adipose tissue (SAT) for research testing is traditionally performed using punch biopsy or needle aspiration techniques, yielding small amounts of very superficial SAT (100-500 mg). Although liposuction techniques can be used to obtain large amounts of SAT, these approaches can compromise the integrity of the adipose tissue. Therefore, we investigated a novel method using a 6-mm Bergström side-cutting biopsy needle to acquire suitable amounts of intact abdominal SAT for multiple complex studies such as flow cytometry, RNA extraction, ex vivo expression of molecular and post-translational protein mediators, and histology. Fifty biopsies were obtained from 29 participants using a Bergström biopsy needle, applying transient manual suction and shearing large pieces of fat within the inner-cutting trochar. Eighteen of the biopsies were performed under ultrasound guidance, whereby we successfully sampled deep SAT (dSAT) from below Scarpa's fascia. The average weight of SAT sampled was 1.5 ± 0.4 g. There was no clinically important bleeding or ecchymosis on the abdominal wall and no infection occurred with this procedure. The 6-mm Bergström biopsy needle yielded substantially more SAT than what has been obtained from superficial procedures and, for the first time, allowed sampling of dSAT by a percutaneous approach.

Imaging of the internal carotid artery: the dilemma of total versus near total occlusion.

PURPOSE: To evaluate ultrasonography (US) and magnetic resonance (MR) angiography in the differentiation between occlusion and near occlusion of internal carotid artery (ICA). MATERIALS AND METHODS: Consecutive patients with occlusion or near occlusion of ICA at catheter angiography and who underwent MR angiography and US were included. MR angiography and US were compared with catheter angiography, the standard, for the ability to help distinguish occlusion from near occlusion. Noninvasive examinations were evaluated for the ability to classify near occlusions as having severe focal stenosis with distal luminal collapse versus diffuse nonfocal disease. The 95% CIs were calculated. RESULTS: In 55 of 274 patients with 548 ICAs, catheter angiography depicted 37 total occlusions and 21 near occlusions. US depicted all total occlusions; MR angiography depicted 34 (92%) (95% CI: 0.78, 0.98). US depicted 18 (86%) of 21 (95% CI: 0.64, 0.97) near occlusions; MR angiography depicted all (100%). Of 18 vessels that were determined to be patent at US, 17 (94%) (95% CI: 0.73, 0.99) were classified as having focal stenosis or diffuse disease. Because flow gaps were identified in vessels with focal and diffuse disease, MR angiography was not effective in helping to differentiate these lesions. CONCLUSION: Assuming US is the initial imaging examination, when occlusion is diagnosed, MR angiography can depict it. If occlusion is confirmed, no further imaging is necessary. US performed well in helping to differentiate vessels with focal severe stenosis from those with diffuse disease. MR angiography added little in this group. Catheter angiography remains beneficial for vessels with diffuse nonfocal narrowing.

Sonographic contrast agents in vascular imaging.

The use of ultrasound contrast agents for peripheral vascular imaging has not been adapted widely worldwide and remains experimental in the United States. Nevertheless, there is considerable interest in contrast agents, because they potentially might offer substantial benefits for peripheral vascular imaging. This article reviews the status of ultrasound contrast agents. It includes a thorough discussion of the types of agents that are available or are under development and an assessment of the desirable properties of an ideal contrast agent. The interaction of these agents with ultrasound is considered next, including consideration of the advantages of harmonic imaging with contrast. Finally, the potential clinical benefits of contrast, as revealed by the authors experience and published data, are reviewed for a variety of cerebral, peripheral, and abdominal vascular applications. These include the carotid arteries, transcranial Doppler, extremity arteries and veins, the renal arteries, and hepatic vessels.

Ability to use duplex US to quantify internal carotid arterial stenoses: fact or fiction?

PURPOSE: To determine if duplex ultrasonography (US) can help predict the degree of internal carotid arterial (ICA) stenosis. MATERIALS AND METHODS: ICA peak systolic velocity (PSV) and the ratio of the PSV in the ICA to that in the ipsilateral common carotid artery (VICA/VCCA) were compared with the degree of arteriographically measured stenosis. ICAs were arteriographically subgrouped at 10% incremental levels of stenosis and broader ranges. Mean PSV, VICA/VCCA, and SDs were calculated for each category. Histograms showing the numbers of stenotic ICAs in subgroups and for vessels with stenoses of greater than or equal to or less than 70% narrowing were constructed. The number of vessels correctly subgrouped with typical Doppler US thresholds was calculated. RESULTS: Mean PSV and VICA/VCCA increased with stenosis level (P < .01); SDs were wide. Histograms showed Doppler US values in the central groups across all disease levels. Histograms differentiating at least or less than 70% stenosis showed minimal overlap. PSV and VICA/VCCA helped classify, respectively, 185 and 181 of 204 vessels with stenoses of less than 50%, 15 and 21 of 46 vessels with stenoses of 50%-69%, and 73 and 67 of 84 vessels with stenoses of 70% or greater. When classifying stenoses as 69% or less or 70% or more, PSV and VICA/VCCA were correct in 90.6% and 90.3% of vessels. CONCLUSION: Doppler US is excellent for classifying stenoses as above or below a single degree of severity but does not function well in stenosis subclassification.

Doppler sonographic parameters for detection of carotid stenosis: is there an optimum method for their selection?

OBJECTIVE: A wide range of Doppler threshold values for carotid stenosis is found in the literature. We undertook this study to compare methods of derivation and to determine if an optimum strategy of threshold selection exists for a high-risk population. MATERIALS AND METHODS: From the sonograms of all patent internal carotid arteries, peak systolic velocity in the internal carotid artery (ICA(PSV)) and the ratio of peak systolic velocity in the internal carotid artery to that of the common carotid artery (ICA(PSV)/ CCA(PSV)) were compared with the percentage of angiographically determined stenosis. Receiver operating characteristic curves were generated for levels of stenosis > or =60% and > or =70%. Doppler thresholds were chosen on the basis of maximum accuracy and on the basis of > or =90% sensitivity and specificity. Patients were then segregated into symptomatic and asymptomatic cohorts, and the above process was repeated. An effectiveness analysis was also conducted using various Doppler thresholds. Thresholds derived using these three methods were compared and optimal values chosen. RESULTS. Of 333 carotid arteries that fit inclusion criteria, 132 were found in asymptomatic patients and 201 in symptomatic patients. Maximum accuracy, > or =90% sensitivity and specificity, and effectiveness analysis each produced different ranges of thresholds. We chose final thresholds that maintained patient outcome profiles. For asymptomatic patients at the > or =60% stenosis level, thresholds were ICA(PSV) = 200 cm/sec and ICA(PSV)/CCA(PSV) = 3.0. For symptomatic patients with stenosis > or =70%, thresholds were ICA(PSV) = 175 cm/sec and ICA(PSV)/CCA(PSV) = 2.5. CONCLUSION: Considerable latitude exists in the choice of carotid Doppler thresholds. We propose a rational strategy for threshold selection based on a combination of three commonly used methods. Our observations indicate that it appears advisable to consider symptomatic and asymptomatic patients separately and to apply appropriately derived thresholds.

Transvaginal saline hysterosonography: characteristics distinguishing malignant and various benign conditions.

OBJECTIVE: The objective of this study is to establish criteria for distinguishing endometrial polyps, submucosal leiomyomas, endometrial hyperplasia, and endometrial carcinoma on saline hysterosonography. MATERIALS AND METHODS: Sixty-three saline hysterosonograms with histologic confirmation were retrospectively analyzed. We found 26 endometrial polyps, 16 submucosal leiomyomas, three endometrial hyperplasias, one abnormal endometrium associated with a sloughed polyp, one pseudopolyp, and three endometrial carcinomas; 15 sonograms revealed no abnormality. In two patients, sonography revealed both polyps and submucosal leiomyomas. The sonographic appearance of these abnormalities was analyzed to define criteria for their diagnosis. RESULTS: Twenty-five of 26 polyps were uniformly echogenic with smooth borders and either had a stalk or formed acute angles with underlying endometrium. Sixteen of 16 submucosal leiomyomas showed heterogeneous echogenicity; however, 13 were sessile and three were pedunculated. Endometrial hyperplasia was manifested by wall thickening in two patients and tiny polypoid excrescences in one patient. In all patients with endometrial carcinoma, the endometrial cavities were poorly distensible despite successful cervical os cannulation. All patients with abnormalities other than endometrial carcinoma had fully distensible uterine cavities. CONCLUSION: Malignant and various benign endometrial conditions may be accurately distinguished on saline hysterosonography. Uniformity of echogenicity distinguished all polyps from submucosal leiomyomas, but the angulation formed with the endometrial wall by the intracavitary mass did not distinguish all polyps from submucosal leiomyomas. Lack of distensibility of the endometrial canal is a potential sign of endometrial carcinoma.

Effect of US contrast agents on spectral velocities: in vitro evaluation.

PURPOSE: To evaluate the effect of ultrasonographic (US) contrast agents on measurements of peak velocity with spectral Doppler US in stenotic and nonstenotic flow states. MATERIALS AND METHODS: Nonpulsatile flow was established in a flow phantom with 0%, 50%, 75%, and 90% stenoses. SH U 508A, perflenapent emulsion, and perfluorohexane emulsion were the contrast agents evaluated. Before and after administration of each contrast agent, two peak velocity measurements obtained proximal to, at the site of, and distal to the stenosis in each vessel model were averaged. The percentage difference in peak velocity after contrast agent administration was calculated for each site interrogated. The mean, SD, and coefficient of variation of the percentage difference in peak velocity were calculated. RESULTS: Percentage differences in peak velocity after contrast agent administration at different sample volume sites were not significantly different irrespective of the degree of stenosis or the contrast agent evaluated. CONCLUSION: The contrast agents evaluated do not produce a statistically significant increase in peak velocity. If this result is corroborated in clinical practice, contrast agents can be used without reevaluating existing Doppler US thresholds for stenosis.

Disclosure of results of sonographic examinations to patients by sonologists.

OBJECTIVE: The aim of this study was to assess if patients prefer to talk with a sonologist concerning the results of sonographic examinations. MATERIALS AND METHODS: The study involved outpatients who underwent diagnostic sonography. Technologists offered patients the chance to speak with a sonologist about the results of their sonograms. If requested, a sonologist reviewed the results, and if the study showed an abnormality, its significance was discussed. No treatment recommendations were offered. Patients then filled out a questionnaire. RESULTS: Of the 391 outpatients given the choice, 348 (89%) requested a consultation and 207 of those (60%) returned the completed questionnaire. Of the 207 patients completing the questionnaire, 94% preferred receiving the results from the sonologist rather than from their referring physician. CONCLUSION: We propose a revision of the traditional role of the office-based sonologist to one in which he or she will function as a consultant to both the patient and the patient's physician.

Significance of fetal intracardiac echogenic foci in relation to trisomy 21: a prospective sonographic study of high-risk pregnant women.

OBJECTIVE: The aim of the study was to determine if an association exists between intracardiac echogenic foci in the second-trimester fetus and trisomy 21. SUBJECTS AND METHODS: Over a 2-year period, targeted fetal sonography was performed for various indications in 1593 second-trimester high-risk pregnant women. Presence or absence of echogenic foci was recorded for each fetus. Amniocentesis for karyotype analysis was performed in 901 subjects immediately after sonography. The findings of these 901 subjects formed the basis of this report. RESULTS: Intracardiac echogenic foci were present in the left ventricle of 24 (3%) of the 901 fetuses. Three (13%) of these 24 fetuses had trisomy 21; no chromosomal abnormalities were found in the other 21 fetuses. Karyotype analysis revealed trisomy 21 in 14 (2%) of the remaining 877 fetuses who did not exhibit intracardiac echogenic foci. The sensitivity, specificity, positive predictive values, and negative predictive values for intracardiac echogenic foci in predicting trisomy 21 were 18%, 98%, 13%, and 98%, respectively. The association of intracardiac echogenic foci and trisomy 21 was significant (p < .009) by the two-tailed Fisher's exact test. CONCLUSION: In a high-risk obstetric population, the association between fetal intracardiac echogenic foci and trisomy 21 was statistically significant. Therefore, women carrying fetuses with intracardiac echogenic foci should be informed of the statistical association with trisomy 21.

Planning and cost analysis of digital radiography services for a network of hospitals (the Veterans Integrated Service Network).

This study analysed the design and cost of a picture archiving and communications system (PACS), computerized radiography (CR) and a wide-area network for teleradiology. The Desert Pacific Healthcare Network comprises 10 facilities, including four tertiary medical centres and one small hospital. Data were collected on radiologists' workloads, and patient and image flow within and between these medical centres. These were used to estimate the size and cash flows associated with a system-wide implementation of PACS, CR and teleradiology services. A cost analysis model was used to estimate the potential cost savings in a filmless radiology environment. ATM technology was selected as the communications medium between the medical centres. A strategic plan and business plan were successfully developed. The cost model predicted the cost-effectiveness of the proposed PACS/CR configuration within four to six years, if the base costs were kept low. The experience gained in design and cost analysis of a PACS/teleradiology network will serve as a model for similar projects.

Ability of a phase shift US contrast agent to improve imaging of the main renal arteries.

PURPOSE: To evaluate the ability of a phase shift contrast agent to improve Doppler sonographic imaging of the main renal arteries in cases of suspected renal artery stenosis. MATERIALS AND METHODS: In 25 patients in whom renal artery stenosis was suspected, baseline Doppler sonography was performed followed by two studies performed after blinded administration of contrast material or placebo (saline). Each kidney (n = 45) was evaluated for (a) visualization of the main renal artery on a scale of 0-4, (b) presence of accessory renal arteries, and (c) direct Doppler sonographic findings suggestive of renal artery stenosis. Correlative magnetic resonance angiography was performed in 24 patients, and angiograms were obtained in eight kidneys with stenosis at one or both imaging studies. RESULTS: Contrast enhancement was observed in 23 patients. Enhancement was 8-20 minutes. Renal artery visualization scores improved from a mean of 2.56 and 2.71 on baseline and noncontrast scans, respectively, to 3.69 after administration of contrast material. Contrast-enhanced images depicted seven kidneys with accessory renal arteries not seen at other studies. Two of eight cases of stenosis were seen only with contrast-enhanced sonography. CONCLUSION: Use of the phase shift contrast agent appears to enable a reduction in the number of equivocal findings of renal artery stenosis.

Transcranial color Doppler imaging of brain arteriovenous malformations in adults.

This study was performed to investigate the utility of transcranial color Doppler sonography in evaluating adult cerebral arteriovenous malformations. Twelve patients with such malformations underwent sonography. Spectral Doppler sonographic assessment included peak systolic velocity, end diastolic velocity, and resistive index within the intracranial and extracranial vessels. Color Doppler sonography was used to visualize the site of shunting. Paired and unpaired Student's t-tests were used to determine significance of spectral findings. The nidus was seen in eight of 10 pial malformations. The nidi in two patients were located in the parietal region and not visualized. When compared with the corresponding contralateral artery, feeding arteries (identified in all 10 of the pial lesions) demonstrated diminished resistive indices (P = 0.09). Similarly, the end diastolic velocity was increased in all feeding arteries (P = 0.03). When compared with published normal values, the peak systolic and end diastolic velocities were significantly elevated and the resistive indices were low (P < 0.0003). Transcranial color Doppler sonography depicted the nidi of pial arteriovenous malformations in 80% of cases. Feeding arteries demonstrated abnormal peak systolic velocity, end diastolic velocity, and resistive index in all cases when compared with published values. Transcranial color Doppler sonography is not a good screening tool due to limited acoustical window, but it may be useful for noninvasive study of the physiology of arteriovenous malformations as they are treated.

Clinical experience with sonographic contrast agents.

Early generations of sonographic contrast agents are beginning to reach the attention of the clinician. Research and development of ultrasound contrast agents is progressing at a rapid pace with several new agents approaching US Food and Drug Administration approval. Cardiac imaging has been affected by even the limited availability of contrast agents on the market today both with regard to diagnosis of shunts and chamber opacification, and most recently actual enhancement of the myocardium. Later generations of contrast are capable of providing consistent opacification of both peripheral veins and arteries, and should prove useful in a variety clinical applications. Thus far, it appears that longer vessel segments may be seen with contrast rather than without contrast, and that flow may be demonstrated in vessels which were not seen or thought to be occluded with conventional color imaging. Improved detection of arterial and venous collaterals and enhanced identification of run-off vessels is demonstrated with sonographic contrast agents. An improved ability to evaluate renal artery stenosis and subtotal occlusion of the carotid artery are specific advantages of using contrast as well. Several compounds are currently being tested that may allow routine parenchymal opacification. Ultrasound is the most commonly performed diagnostic imaging procedure; therefore, contrast agents have the potential to dramatically alter the practice of clinical medicine. This article reviews the current status of ultrasound contrast agents and speculates regarding the future applications of these agents.

Nurse evaluation of a pain medication protocol in a selective postoperative population.

Postoperative pain in 33 patients who underwent radical prostatectomy was managed by an intramuscular nonsteroidal antiinflammatory drug protocol rather than by administration of narcotics. Patients rated their perception of pain with a visual analog scale on the first postoperative day both before and after receiving ketorolac tromethamine. The medication was effective in relieving pain after this major operation. Costs were approximately one half that of the traditional narcotic protocol used before this study.

Ultrafast networks (ATM): first clinical experiences.

Ultrafast networks using asynchronous transfer mode (ATM) technology can provide the bandwidth and throughput that may be sufficient to satisfy the medical imaging community. Several trials are underway to assess the effect of ATM network capabilities on the clinical practice of radiology, by providing immediate interactive radiology consultations between subspecialists and general radiologists at affiliated academic institutions. The hardware to build such networks is now commercially available and its cost is decreasing steadily, but the monthly charges for ATM bandwidth use are still high. Nevertheless, given the tremendous increase in communication capability and data transfer rates possible with ATM networks, cost alone should not be the determining factor for selecting this technology. The ATM concept in general is first reviewed, followed by a description of early clinical ATM network installation in four medical environments worldwide. These medical clusters include: the UCLA affiliated hospitals (UCLA Medical Center, West LA VAMC and Olive-View UCLA Medical Center), the UCSF affiliated hospitals, Duke University Hospitals and a cluster of medical centers in Berlin which have all been connected via ATM networks. The use of ATM technology in these realistic clinical environments is discussed and evaluated for its potential impact on patient care and clinical teaching within radiology departments. From this preliminary study it is concluded that image communications over a regional PACS using an ATM network can allow interactive consultations between different subspecialist and general radiologists or other specialized radiologists spread over different medical centers.

Diverticular disease. Surgical options, patient management.

Diverticular disease is a common and occasionally complicated disease in our western society. Although the exact etiology is unknown, diet is thought to be a contributing factor to the formation of diverticula. Diverticular disease most often is managed medically. When surgery is indicated, perioperative nursing care is based on knowledge of the disease process and attention to the physical and emotional needs of the patient.