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Objective: The purpose of this article was to review the current clinical applications of sonographically guided radiofrequency ablation (RFA) techniques., Methods: Publications regarding RFA extracted from a computerized database (MEDLINE) and from references cited in these articles were reviewed to evaluate the clinical effect and patient outcome., Results: Radiofrequency ablation has shown some promising effects in the treatment of tumors in various parts of the body. The recent advances in RFA technology enable larger volumes of treatment and make RFA clinically practical. It is most often used for hepatic and renal tumors, and applications for other organs and structures are increasing and rapidly developing. Sonography provides a convenient way to guide and monitor the procedure in most situations., Conclusions: Effectiveness of RFA in the treatment of tumors in various body parts has been achieved. Radiofrequency ablation should be considered as an alternative or complementary method in the integration of oncologic management to obtain the greatest benefit to patients.

Rationale and Objectives: Accurate measurement of blood volume flow (in ml/min) is an important clinical goal. This project compared in vitro and in vivo volume flow measurements obtained with a novel, real-time three-dimensional (i.e., four-dimensional) ultrasound scanner (Encore PV; Vuesonix Sensors, Wayne, PA) with those from an invasive transit time flowmeter., Materials and Methods: A flow pump was used to generate pulsatile flow rates from 60 to 600 ml/min. The Encore detected absolute blood velocity vectors within a volume. The scanner determined the centerline of the vessel and volume flow was then automatically calculated. Results were compared with those of an invasive technique for volumetric blood flow measurements utilizing a transit-time flowmeter (TS420; Transonic Systems Inc., Ithaca, NY). In vivo, 10 second datasets of the volume flow in the distal aorta of six rabbits were obtained simultaneously with the Encore PV and the flowmeter. Data were compared using linear regression and Bland-Altman analysis (due to the lack of independence)., Results: In vitro, Encore and flowmeter measurements both matched the flow pump (r2 > 0.99; P < .0001) with mean errors of -11.8% and -0.3%, respectively. Marked underestimation of the true flow rates was encountered with the Encore at the lowest pump setting. In vivo mean volume flows between 10.6 and 79.3 ml/min were measured. Mean and maximum volume flows obtained with the two techniques correlated significantly (P < .0001) with r2 values of 0.86 and 0.62, respectively. The corresponding root-mean-square errors were 6.9% for mean flow and 61.2% for maximum volume flow measurements., Conclusion: A new semiautomated four-dimensional Doppler device has been tested in vitro and in vivo. Mean volume flow measurements with this unit are comparable to those of an invasive flowmeter.

Purpose: We determined the feasibility of contrast enhanced ultrasound for radio frequency ablation of the entire prostate as a method of minimally invasive treatment for prostate cancer in a canine model., Materials and Methods: Approval of the Institutional Animal Use and Care committee was obtained. Initially 5 dogs (group 1) were tested using variable power (5 to 30 W), time (4 to 12 minutes), bolus (0.01 to 0.04 ml/kg) and infusion (3 to 11 ml per minute at 0.015 microl/kg) injections of an ultrasound contrast agent with conventional grayscale power Doppler and pulse inversion harmonic imaging to establish optimal parameters. Subsequently 4 dogs (group 2) underwent entire prostate ablation using parameters based on group 1. The size of the thermal lesions and residual viable tissue was measured with ImageJ software (National Institutes of Health, Bethesda, Maryland) on ultrasound and pathological study. Linear regression and Student's t test were used for statistical analysis., Results: A bolus of 0.04 ml/kg, an infusion of 11 ml per minute at 0.015 microl/kg and the contrast enhanced pulse inversion harmonic imaging mode were ranked best for guiding ablation. Thermal lesion volume was proportional to ablation power and time. There was no significant difference in measured thermal lesion size in group 1 between ultrasound and pathological findings (mean +/- SD 1.51 +/- 0.74 and 1.46 +/- 0.74 cm3, p = 0.56) or in residual viable tissue in group 2 (0.43 +/- 0.043 and 0.41 +/- 0.291 cm3, p = 0.21). The average volume of prostate ablation achieved in group 2 was 96.3%., Conclusions: Contrast enhanced pulse inversion harmonic imaging is able to guide, monitor and control radio frequency ablation of the entire prostate.

Purpose: To determine if lymphatic channels and sentinel lymph nodes (SLNs) with and without metastases can be detected with lymphatic ultrasonography (US) after peritumoral injection of a US contrast agent and to determine if lymphatic US can be used to assess SLNs for the presence of metastatic infiltration., Materials and Methods: Six swine with 17 melanomas were evaluated. Conventional gray-scale, color flow, and gray-scale phase-inversion harmonic US examinations were performed. A US contrast agent was administered in four sites around each melanoma (1-mL total dose). Lymphoscintigraphy was followed by injection of a blue dye and then dissection. SLNs identified at lymphatic US were characterized by two readers in consensus as normal or as having metastases; results were compared with histologic findings. Statistical analyses included the sign test and the kappa statistic., Results: Lymphatic US depicted 28 SLNs, while lymphoscintigraphy depicted 27 "hot spots" suspected of representing SLNs (including two false-positive findings). Dissection after blue dye injection helped identify 31 SLNs. There were no false-positive US findings for SLN detection. Five of six nodes not seen with lymphoscintigraphy were detected with lymphatic US. The accuracy of SLN detection was 90% (28 of 31) for lymphatic US and 81% (25 of 31) for lymphoscintigraphy (P =.29). Lymphatic US correctly depicted metastases in 19 of 20 SLNs, and five of the eight normal SLNs were correctly characterized, with an accuracy of 86% (kappa = 0.62)., Conclusion: Detection of SLNs with lymphatic US compared favorably with that at lymphoscintigraphy. Lymphatic US can depict metastases within the SLN, which was not possible with lymphoscintigraphy., (Copyright RSNA, 2004)

Objective: To compare mammography with contrast-enhanced 2- and 3-dimensional power Doppler imaging for the diagnosis of breast cancer., Methods: Fifty-five patients, who underwent breast biopsies with histopathologic assessment, participated in a study of mammography and contrast-enhanced sonography. Levovist (Berlex Laboratories, Montville, NJ) and Optison (Mallinckrodt, St Louis, MO) were administrated to 22 and 33 patients, respectively. Precontrast and postcontrast 2-dimensional power Doppler data of the lesion were obtained with an HDI 3000 system (Philips Medical Systems, Bothell, WA), and 3-dimensional data were acquired with an LIS 6000A system (Life Imaging Systems Inc, London, Ontario, Canada). Two independent and blinded readers assessed diagnosis. Receiver operating characteristic curves were computed individually and in combination for mammography and 2- and 3-dimensional sonography (before and after contrast). Histopathologic and imaging parameters were compared by Mann-Whitney statistics., Results: Mammographic findings were available for 50 patients, biopsy for 54, and 2- and 3-dimensional sonographic images for 53 and 52, respectively. Of the 50 patients who had all 4 measures, 15 (30%) had malignancies. The areas under the receiver operating characteristic curve for the diagnosis of breast cancer were 0.51 for 2-dimensional contrast-enhanced imaging, 0.60 for 3-dimensional power Doppler imaging, and 0.76 for 3-dimensional contrast-enhanced imaging (P < .01). Mammography produced an area of 0.86, which increased when combined with 3-dimensional contrast-enhanced imaging to 0.90 and with all sonographic modalities to 0.96 (P < .001). The histopathologic diagnosis of benign or malignant correlated with the presence or absence of anastomoses and with the degree of vascularity assessed with contrast-enhanced 3-dimensional power Doppler imaging (P = .007 and .02)., Conclusions: Contrast-enhanced 3-dimensional power Doppler imaging increases the ability to diagnose breast cancer relative to conventional 2- and 3-dimensional sonographic imaging.

The Society of Radiologists in Ultrasound convened a multidisciplinary panel of experts in the field of vascular ultrasonography (US) to come to a consensus regarding Doppler US for assistance in the diagnosis of carotid artery stenosis. The panel's consensus statement is believed to represent a reasonable position on the basis of analysis of available literature and panelists' experience. Key elements of the statement include the following: (a) All internal carotid artery (ICA) examinations should be performed with gray-scale, color Doppler, and spectral Doppler US. (b) The degree of stenosis determined at gray-scale and Doppler US should be stratified into the categories of normal (no stenosis), <50% stenosis, 50%-69% stenosis, > or =70% stenosis to near occlusion, near occlusion, and total occlusion. (c) ICA peak systolic velocity (PSV) and presence of plaque on gray-scale and/or color Doppler images are primarily used in diagnosis and grading of ICA stenosis; two additional parameters, ICA-to-common carotid artery PSV ratio and ICA end-diastolic velocity may also be used when clinical or technical factors raise concern that ICA PSV may not be representative of the extent of disease. (d) ICA should be diagnosed as (i) normal when ICA PSV is less than 125 cm/sec and no plaque or intimal thickening is visible; (ii) <50% stenosis when ICA PSV is less than 125 cm/sec and plaque or intimal thickening is visible; (iii) 50%-69% stenosis when ICA PSV is 125-230 cm/sec and plaque is visible; (iv) > or =70% stenosis to near occlusion when ICA PSV is greater than 230 cm/sec and visible plaque and lumen narrowing are seen; (v) near occlusion when there is a markedly narrowed lumen at color Doppler US; and (vi) total occlusion when there is no detectable patent lumen at gray-scale US and no flow at spectral, power, and color Doppler US. (e) The final report should discuss velocity measurements and gray-scale and color Doppler findings. Study limitations should be noted when they exist. The conclusion should state an estimated degree of ICA stenosis as reflected in the above categories. The panel also considered various technical aspects of carotid US and methods for quality assessment and identified several important unanswered questions meriting future research., (Copyright RSNA, 2003)

The wiring of synaptic circuitry during development is remarkably precise, but the molecular interactions that enable such precision remain largely to be defined. Cadherins are cell adhesion molecules hypothesized to play roles in axon growth and synaptic targeting during development. We previously showed that N-cadherin localizes to ventrobasal (VB) thalamocortical synapses in rat somatosensory (barrel) cortex during formation of the whisker-map in layer IV (Huntley and Benson [1999] J. Comp. Neurol. 407:453-471). Such specific association of N-cadherin with one identified afferent pathway raises the prediction that other cadherins are expressed in barrel cortex and that these are, in some combination, also differentially associated with distinct inputs. Here, we first show that N-cadherin and three other classic cadherins (cadherin-6, -8, and -10) are expressed contemporaneously in barrel cortex with relative levels of postnatal expression that are highest during the first 2 weeks, when afferent and intrinsic circuitries are forming and synaptogenesis is maximal. Each displayed distinct, but partly overlapping laminar patterns of expression that changed over time. Cadherin-8 probe hybridization formed a particularly striking pattern of intermittent, columnar patches extending from layer V through layer III, which was first detectable at approximately postnatal day 3. The patches were centered precisely over regions of dysgranular layer IV and, in the whisker barrel field, over barrel septa. This pattern is similar to that formed by the terminal distribution of thalamocortical afferents arising from the posterior nucleus (POm), suggesting cadherin-8 association with the POm thalamocortical synaptic circuit. Consistent with this, cadherin-8 mRNAs were enriched in the POm nucleus, and cadherin-8 immunolabeling in layer IV was enriched in barrel septa and codistributed with labeled POm thalamocortical synaptic-like puncta. The striking molecular parcellation of at least two different cadherins to the two, converging thalamic pathways that terminated in non-overlapping barrel center and septal compartments in layer IV strongly suggested that cadherins provide requisite molecular recognition and targeting that enable precise construction of thalamocortical and other synaptic circuitry., (Copyright 2002 Wiley-Liss, Inc.)

Classic cadherins are multifunctional adhesion proteins that play roles in tissue histogenesis, neural differentiation, neurite outgrowth and synapse formation. Several lines of evidence suggest that classic cadherins may establish regional or laminar recognition cues by virtue of their differential expression and tight, and principally homophilic, cell adhesion. As a first step toward investigating the role this family plays in generating limbic system connectivity, we used RT-PCR to amplify type I and type II classic cadherins present in rat hippocampus during the principal period of synaptogenesis. We identified nine different cadherins, one of which, cadherin-9, is novel in hippocampus. Using in situ hybridization, we compared the cellular and regional distribution of five of the cadherins (N, 6, 8, 9 and 10) during the first two postnatal weeks in hippocampus, subiculum, entorhinal cortex, cingulate cortex, anterior thalamus, hypothalamus and amygdala. We find that each cadherin is differentially distributed in distinct, but highly overlapping fields that largely correspond to known anatomical boundaries and are often coordinately expressed in interconnected regions. For example, cadherin-6 expression defines CA1 and its principal target, the subiculum; cadherin-10 is differentially expressed in CA1 and CA3 in a manner correlating with the organization of interconnecting Schaffer collateral axons; and cadherin-9 shows a striking concentration in CA3. Some cadherin mRNAs are highly restricted to particular anatomical fields over the entire time course, while others are more broadly expressed and become concentrated within particular domains coincident with the timing of afferent ingrowth. Our data indicate that classic cadherins are sufficiently diverse and differentially distributed to support a role in cell surface recognition and adhesion during the formation of limbic system connectivity.

Although fine-needle aspiration biopsy of salivary gland masses has been reported in the otolaryngology literature, the use of sonography to guide the biopsy of nonpalpable masses and masses seen on other cross-sectional imaging studies has not been described. Our goal was to evaluate sonographically guided biopsy of masses and lymph nodes related to the salivary glands. We analyzed the records of 18 patients who had undergone fine-needle aspiration biopsy of a salivary gland mass or lymph node with a 25-, 22-, or 20-gauge needle. A definitive cytologic diagnosis was made for 13 of the 18 patients (72%); cytology was suggestive but not definitive in three patients (17%) and insufficient in two (11%). Definitive diagnoses were made in three cases of reactive lymph node, in two cases each of lymph node metastasis and Warthin's tumor, and in one case each of pleomorphic adenoma, adenoid-cystic carcinoma, schwannoma-neurofibroma, parotid metastasis, parotid lymphoma, and Sjögren's-related lymphoid-epithelial lesion. Sonographically guided biopsy allows for confident needle placement in masses seen on computed tomography and magnetic resonance imaging. Sonography can usually distinguish a perisalivary lymph node from true intrasalivary masses, and it can help the surgeon avoid the pitfall of a nondiagnostic aspiration of the cystic component of masses. We conclude that sonographically guided biopsy of salivary gland masses can provide a tissue diagnosis that can have a direct impact on clinical decision making.

Objective: We evaluated the ability of power Doppler sonography to show increased soft-tissue blood flow in patients with reflex sympathetic dystrophy of the lower extremity., Subjects and Methods: Power Doppler sonography was performed in 30 patients with reflex sympathetic dystrophy of the lower extremity and in 26 asymptomatic control subjects. The bilateral power Doppler sonograms that were obtained of the soft tissues of the dorsum of the foot of each subject were grouped in pairs, and three sonologists who were unaware of clinical information independently reviewed the images. Images were evaluated for the amount of power Doppler signal shown on the following scale: 1 = no flow or minimal flow; 2 = mild flow; 3 = moderate flow; and 4 = marked flow., Results: More power Doppler flow was seen in the patients with reflex sympathetic dystrophy than in the control subjects (p < .005). In addition, side-to-side asymmetry of flow was seen in patients, but this trend was not statistically significant (p < .20). Receiver operating characteristic (ROC) analysis showed that combined flow and asymmetry were more related to reflex sympathetic dystrophy than either parameter alone (area under the ROC curve: for flow, 0.748; for asymmetry, 0.566; for both, 0.799). We found that when the sum of power Doppler flow in both feet was greater than or equal to five, and asymmetry of flow was greater than or equal to one, the sensitivity of power Doppler sonography for reflex sympathetic dystrophy was 73% and the specificity was 92%., Conclusion: Patients with reflex sympathetic dystrophy of the lower extremity have increased power Doppler flow compared with asymptomatic control subjects. Patients may also exhibit more side-to-side asymmetry of flow than control subjects.

Objective: Fetal growth rates determined on the basis of findings at two separate sonographic examinations can be used to detect growth abnormalities. This article determines the relationship between the length of the interval between examinations and the associated variability in measured fetal growth rates., Materials and Methods: We analyzed 1479 fetal measurements of the biparietal diameter, average abdominal diameter, and femur length from 539 normal pregnancies. Mean growth rates were computed as functions of gestational age. The standard deviation of the growth rate was computed as a function of the interval between examinations., Results: The standard deviation of fetal growth rates is relatively constant when the interval between examinations is 8-10 weeks or more, but increases substantially when the interval is fewer than 6 weeks., Conclusion: From a purely statistical point of view, the optimal interval for assessment of fetal growth rates is 8-10 weeks or more. Shorter intervals, however, usually are mandated by the clinical situation. Correction factors can be used to determine the standard deviations and associated confidence intervals for fetal growth measured over a period of fewer than 10 weeks.

Objective: Nontumorous perfusion defects occur during CT arterial portography (CTAP) as normal variants or in cirrhosis, focal fatty infiltration, and portal vein obstruction. The purpose of this study was to determine whether delayed CT 4-6 hr after CTAP improves sensitivity to hepatic tumors and differentiates them from other hepatic perfusion defects., Subjects and Methods: CTAP was done at 1-cm increments on 26 patients for evaluation of hepatic tumors. Delayed CT scans were obtained 4-6 hr later in all patients. Two observers retrospectively reviewed the CT scans obtained during CTAP and recorded size, shape, and location of suspected hepatic tumors. Confidence levels were assigned for each tumor. The delayed CT scan was then interpreted in conjunction with the CT scans obtained during CTAP, and confidence levels were reassigned. Surgical correlation was obtained for all patients. In the 26 patients, 86 masses were found at surgery. The sensitivity and number of false-positives for both CTAP alone and CTAP combined with delayed CT were compared with a two-tailed Student t-test. Receiver-operating-characteristic analysis also was performed., Results: CTAP detected 73 (85%) of the 86 hepatic masses. Delayed CT had no effect on the sensitivity of CTAP. However, adding delayed CT decreased the total number of false-positives by 11, a statistically significant difference (p < .05). Receiver-operating-characteristic analysis revealed a significantly greater (p < .05) area under the curve (Az index) of 0.927 +/- 0.025 for CTAP combined with delayed CT compared with 0.886 +/- 0.032 for CTAP alone. Delayed CT was most useful for larger (> 1 cm) wedge-shaped perfusion defects and least useful for smaller (< 1 cm) round defects., Conclusion: Delayed CT has no effect in detecting tumors but may be useful for differentiating tumors from other hepatic perfusion defects seen on CTAP. The greatest benefit of delayed CT is in evaluating regions obscured by large wedge-shaped perfusion defects on CT scans obtained during CTAP.

Objective: We studied the findings on conventional arteriography in patients who had suspected graft ischemia after orthotopic liver transplantation to determine the value of a single Doppler signal in predicting these lesions., Materials and Methods: We retrospectively reviewed selective visceral arteriograms with abnormal findings from 20 adults who had suspected graft ischemia after orthotopic liver transplantation and a single Doppler signal from the hepatic artery at the porta hepatis on sonograms obtained before arteriography. Arteriographic abnormalities were categorized according to morphology and location as follows: stenosis of recipient's hepatic artery, occlusion or stenosis of the transplanted extrahepatic artery, and occlusion or stenosis of the transplanted intrahepatic artery., Results: Twenty-three arteriographic abnormalities were detected: four recipient celiac axis stenoses, seven extrahepatic occlusions, nine extrahepatic stenoses, and two occlusions and one stenosis of the transplanted intrahepatic artery. Six of the extrahepatic occlusions, two of the extrahepatic stenoses, and none of the recipient artery stenoses or the intrahepatic occlusions or stenoses were correctly diagnosed on the basis of Doppler findings. One patient with both an extrahepatic stenosis and an extrahepatic occlusion was thought to have an intrahepatic occlusion, and two patients with mild (< 50%) extrahepatic stenoses and one with an intrahepatic occlusion were thought to have an extrahepatic occlusion., Conclusion: A wide spectrum of abnormalities in the recipient's celiac axis or the transplanted arteries that may be associated with graft ischemia after orthotopic liver transplantation are often not detected or findings are misinterpreted on routine Doppler examination. In patients with suspected graft ischemia, visceral arteriography should be performed promptly to confirm the diagnosis and to allow early intervention.

Objective: Right common carotid artery (RCCA) ligation after extracorporeal membrane oxygenation by venoarterial bypass may contribute to lateralized cerebral injury. Reconstruction of this artery after extracorporeal membrane oxygenation has proved feasible but has not been evaluated for neurologic outcome in any substantial series of infants., Methods: We evaluated RCCA reconstruction in 47 infants treated with ECMO and compared their cerebrovascular and neuroanatomic imaging findings, electroencephalograms, and developmental outcomes with those of 93 infants who had no reconstruction. SUMMARY RESULTS: Color Doppler blood flow imaging revealed that carotid artery patency was usually obtained after RCCA reconstruction. Right internal carotid and bilateral anterior and middle cerebral arterial blood flow velocities were generally higher, and were more symmetrically distributed in infants with reconstructed RCCA. Electroencephalography did not disclose an increased risk of deterioration or marked abnormalities in infants after reconstruction, nor were neuroimaging findings consistent with an increased number of either focal or generalized abnormalities. Neurodevelopmental follow-up revealed no differences in the incidence of delays between those with a reconstructed RCCA and those with a ligated RCCA during the first year of life., Conclusions: Reconstruction of the RCCA after extracorporeal membrane oxygenation may facilitate normal distribution of cerebral blood flow through the circle of Willis, and may augment both left and right middle cerebral artery blood flow immediately after decannulation. The long-term consequences of either ligation or reconstruction of the RCCA will require careful scrutiny, however, before either course is recommended routinely.

Iatrogenic injuries of the groin are becoming more common after increasingly sophisticated vascular intervention. These injuries are accurately detected by duplex and color Doppler ultrasonography. Recent treatment of these lesions by ultrasound-guided compression repair (UGCR) has been described. During a 1-year period we identified 18 femoral artery injuries, including 17 pseudoaneurysms and one arteriovenous fistula. Three of the pseudoaneurysms thrombosed spontaneously before attempted treatment. The remaining 15 lesions underwent a trial of UGCR. Successful closure was accomplished in 10 patients (56%). Seven of these lesions were successfully treated during the initial session, and thrombosis was accomplished after repeat compression in three additional lesions. Three patients who were given anticoagulants had a failed UGCR, but their pseudoaneurysms thrombosed after administration of anticoagulants was discontinued. Two patients had failed UGCR and required operation. Seven (88%) of eight patients who were not given anticoagulants were successfully treated. In contrast only two (29%) of seven patients given therapeutic doses of anticoagulant medication were successfully treated by the technique. There was no statistical difference between mean pseudoaneurysm diameter, mean width and length of pseudoaneurysm neck, or depth of pseudoaneurysm neck from skin surface in patients in whom successful initial closure was achieved when compared with those patients in whom the initial attempt failed. UGCR is a safe, simple, noninvasive technique that can be used to treat many femoral artery injuries that traditionally were treated with surgery. The technique can be applied by any laboratory that has the necessary ultrasonography equipment and is currently the method of choice for treating uncomplicated iatrogenic femoral artery injuries at our institution.

Recent reports have indicated that identification of the yolk sac should precede the detection of the embryo in a normal first-trimester sonographic examination and that failure to visualize a yolk sac strongly suggests an abnormal intrauterine pregnancy. A first-trimester prospective study was performed in 163 normal and 49 abnormal consecutive singleton gestations. All women were examined both abdominally and transvaginally, with pregnancy outcome determined by delivery of a normal infant or a spontaneous abortion. The yolk sac was analyzed in all patients in whom an embryo was not identified (n = 76). When the yolk sac was identified, the following was found: by the abdominal approach with the mean sac diameter (MSD) less than 27 mm (n = 15), nine gestations were normal and six were abnormal, and by the transvaginal approach with the MSD less than 18 mm (n = 13), seven gestations were normal and six were abnormal. The presence of a yolk sac was not consistently predictive of a normal early pregnancy. When the yolk sac was also not identified, the following was found: abdominally with the MSD less than 27 mm (n = 41), 19 gestations were normal and 22 were abnormal, and transvaginally with the MSD less than 18 mm (n = 11), six gestations were normal and five were abnormal. Absence of the yolk sac was not consistently predictive of a spontaneous abortion. When using the MSD range (20-27 mm abdominally and 7-16 mm transvaginally), over which the yolk sac but not the embryo should be identified sonographically, the yolk sac was again not consistently visualized. On abdominal sonograms, the yolk sac was present and absent in three and 10 patients, respectively, for both normal and abnormal pregnancies. On transvaginal sonograms, the yolk sac was present and absent in seven and five normal gestations and in six and four abnormal gestations, respectively. The results of this study suggest that detection of the yolk sac in the first trimester is not an early predictor of pregnancy outcome.

A prospective study was performed to determine whether thoracic CT yielded useful information regarding the status of axillary lymph nodes (LNs) in patients with breast cancer. Thirty-five consecutive patients with clinically suspected stage II or III breast carcinomas were scanned preoperatively from the supraclavicular regions to the lung bases. Axillary LNs measuring greater than or equal to 1 cm were considered abnormal. The lymph nodes were classified according to their relationship to the pectoralis muscle. Extracapsular lymph node extension was diagnosed when there was irregularity and spiculation of the lymph node margin with surrounding fatty infiltration. Correlation with axillary dissection was obtained in 20 patients, giving a positive predictive value for axillary metastases of 89% with 50% sensitivity, 75% specificity, and 20% negative predictive value. CT was also able to detect the level of axillary involvement accurately when the lymph nodes were enlarged and to evaluate extracapsular LN extension. Although superior to physical examination, CT was not an accurate predictor of axillary LN involvement, primarily because of its low negative predictive value.

The space between the left lobe of the liver and the lesser curvature of the stomach normally contains intraperitoneal structures. These include the gastrohepatic recess of the greater peritoneal cavity, the medial recess of the lesser sac and the interposed gastrohepatic ligament. An anterior protrusion of retroperitoneum can project into this space, dorsal to the posterior reflection of the medial compartment of the lesser sac. Tumors that extend into this fossa are anterior and medial to the fundic and upper body region of the stomach. These tumors may cause confusion regarding their origin if the radiologist is not aware of the existence of this retroperitoneal protrusion. Between 1982, and 1986, 183 patients with pancreatic cancer were hospitalized at our institution, 63 of whom had computed tomography (CT) scans of the abdomen. Four of these patients (6.3%) demonstrated direct tumor extension anterior to the stomach. During this same period, four large benign retroperitoneal tumors also exhibited this finding. Masses in the gastrohepatic interval between the liver and stomach can be extensions of retroperitoneal processes and should not be assumed to represent intraperitoneal involvement.

The increasing use and availability of renal transplantation has resulted in a demand for noninvasive methods to study possible complications. One of the most serious adverse reactions is acute rejection, a possibly reversible cause of transplant failure if treated promptly. Differentiation from other causes of acute renal failure frequently is difficult, and the lack of specificity in many imaging studies has been troublesome. Eighty-one patients with renal transplants, including 41 with acute rejection, were examined. Duplex Doppler examination of the intrarenal arteries and a simplified formula, the resistive index ([peak systolic frequency shift--lowest diastolic frequency shift]/[peak systolic frequency shift]), were used to diagnose rejection. With a resistive index greater than 0.90, a 100% positive predictive value was obtained for the diagnosis of acute rejection. A value less than 0.70 was unlikely to be rejection (negative predictive value, 94%). This approach uses a simple analysis of the waveform. Use of a duplex Doppler examination and the formula described here appears to be an accurate method for the detection of acute rejection and for the differentiation of acute rejection from the various other causes of acute renal failure.

Sonograms of 110 patients were compared to recently performed liver biopsies for evaluation of the accuracy of sonography in predicting the type (pattern) of pathology and its grade of severity (mild, moderate, or severe) in a wide variety of diffuse liver processes. There are two distinct, abnormal sonographic patterns: the fatty-fibrotic pattern seen primarily with cirrhosis, chronic hepatitis, and/or fatty infiltration, and the centrilobular pattern seen primarily with acute hepatitis. Sonography was 88% accurate in assigning the correct pattern to the corresponding pathology (sensitivity 89%, specificity 86%, p less than 0.001). The degree of accuracy was dependent on the grade of pathologic severity, with mild disease offering the greatest difficulty; moderate and severe diseases were accurately detected and placed in the correct pattern in all cases. Sonographic grading of the severity of disease was far less precise (63% overall). This study showed that sonography can distinguish between two abnormal sonographic patterns of diffuse benign liver disease as well as between normal and abnormal patterns.

Color Doppler imaging (CDI) can demonstrate the relative direction and velocity of blood flow in color, superimposed on a conventional gray-scale ultrasound image that depicts stationary tissue. Twenty-five infants were studied with portable CDI in the coronal, sagittal, and axial planes. Bilateral antegrade flow was noted in the anterior, middle, and posterior cerebral arteries in all patients. Multiplanar CDI can image flow in the circle of Willis and its tributaries and branches.

A case is reported in which the fetal acid-base status was assessed by means of cordocentesis in a fetus without end-diastolic umbilical artery blood flow. The absence of end-diastolic flow was not associated with acidosis or hypoxia. However, the fetal condition deteriorated 3 days later, which suggests that even with a normal fetal acid-base status, an extended margin of safety cannot be assumed with the absence of end-diastolic umbilical flow.

Hand-held sonomammography was used intraoperatively to localize 52 masses in 45 women in an out patient operating suite. All but five women had a positive X-ray mammogram. The ultrasound mammogram was able to identify all lesions. In 42 women studied by a preoperative ultrasound examination before the operating room procedure, all the masses were successfully identified. Precise localization was successfully performed in the operating room before sterile preparation in less than 10 minutes. Relocalization after incision in the sterile operating field was necessary in two cases. This technique requires no ionizing radiation and expedites outpatient surgical removal of the lesion. Of the 52 masses, there were 32 fibroadenomas, three carcinomas, three cysts, six cases of focal fibrous mastitis, and eight patients with focal fibrocystic disease. In patients with positive sonograms for nonpalpable masses, ultrasound localization is a fast, accurate alternative to X-ray needle placement.