Frequency-demodulated US: evaluation in the liver. Work in progress

Frequency modulated (FM) imaging is a new ultrasound (US) modality that uses pulse-echo signal instantaneous frequency in addition to the conventional envelope information. Eight features of the FM image in nondiseased livers are described. The technique is evaluated in a study of 34 patients with biopsy-proved diffuse liver disease. Visual grading of FM US image features shows good correlation with levels of biopsy-graded hepatic fibrosis. Patients with diffuse parenchymal liver disease often exhibit evidence of the abnormality when FM liver imaging is used, while such evidence is not as well demonstrated with conventional envelope (AM) imaging.     

Diagnosis of liver cirrhosis by transit-time analysis at contrast-enhanced ultrasonography

Purpose

The aims of this prospective study were to evaluate analysis of sulfur-hexafluoride-filled microbubble contrast agent (Sonovue) transit times as a tool for differentiating liver cirrhosis from the noncirrhotic stage of liver disease and to compare its performance with that of conventional B-mode and Doppler ultrasonography (US).

Materials and methods

Contrast-enhanced hepatic ultrasonography with the US contrast agent Sonovue was performed on 38 patients with diagnoses of hepatic cirrhosis based on unequivocal clinical signs or liver biopsy findings (Child-Pugh classes A in 19, B in 16 and C in three), 31 patients with noncirrhotic diffuse liver disease (biopsy confirmed) and 14 controls without diffuse liver disease. Time curves of hepatic-vein signal intensity were analysed using objective criteria to determine the time of enhancement onset (hepatic-vein arrival time) and peak enhancement (hepatic-vein peak enhancement). Accuracy in diagnosing cirrhosis was compared with that based on B-mode and Doppler data.

Results

Hepatic-vein arrival time in cirrhotic patients was significantly shorter (p<0.01) than in noncirrhotic (chronic liver disease and controls) patients. Peak enhancement times in these three groups were not significantly different. An arrival-time cutoff of 17 s distinguished cirrhotic from noncirrhotic patients with high accuracy (100% sensitivity, 93.3% specificity, positive and negative predictive values 92.6% and 100%, respectively) and excellent reproducibility (kappa coefficients of 1.0 and 0.93 for intraand interobserver agreement). Contrast-enhanced US showed better sensitivity than the B-mode and Doppler data.

Conclusions

Analysis of the time of onset of US contrast enhancement of the hepatic vein appears to be a potentially useful noninvasive supplement to conventional sonography and Doppler in the follow-up of patients with chronic diffuse liver disease.     

Ultrasound evaluation of the fibrosis stage in chronic liver disease by the simultaneous use of low and high frequency probes

A liver biopsy is currently considered the definitive diagnostic modality for establishing the severity of hepatic fibrosis. We analysed the diagnostic sensitivity and accuracy of ultrasound (US) using both low frequency and high frequency probes as a repeatable, inexpensive, and reliable method to determine the fibrosis stage in chronic liver disease and then compared our results with the histological findings. A total of 103 patients with chronic liver disease (60 males and 43 females, average age 51 years old) who had undergone both a liver biopsy and US with 2-5 MHz frequency and 5-12 MHz frequency probes were prospectively evaluated in this study. An US scoring system using both the low frequency and high frequency probes was performed by evaluating the edge, surface and parenchymal texture of the liver. Each score was obtained by evaluating three parameters; the bluntness of the liver edge, the irregularity of the surface and the coarseness of the parenchymal texture were evaluated and then compared with the histological findings. The US scores of the liver edge (rs: 0.6668), liver surface (rs: 0.9007) and liver parenchymal texture (rs: 0.8853) correlated significantly with the fibrosis stage obtained based on the biopsy findings. The accumulated US scores of these three parameters, however, was found to be the most reliable indicator (rs: 0.9524). Patients with an accumulated score of 6.5 or more were all found to have fibrosis stage 4 in which the accuracy of our scoring system for correctly predicting cirrhosis was found to be 100% sensitive. When an accumulated US score of 3 was interpreted to indicate mild fibrosis (a fibrosis score of 0 or 1), all 42 patients with stage 0 or 1 fibrosis were found to have an accumulated US score of 3 or less (a probability of 100%) and 42 of 53 patients with a score of 3 or less were found to have stage 0 or 1 fibrosis (specificity of 79.2%). An ultrasound evaluation of the liver fibrosis stage based on the scoring system using both low and high frequency probes was found to be a reliable and effective alternative to the histological staging in chronic liver diseases.     

Sonography of the caudate vein: value in diagnosing Budd-Chiari syndrome

OBJECTIVE: The aim of this study was to evaluate the usefulness of sonography in measuring the caudate vein and lobe when diagnosing Budd-Chiari syndrome. MATERIALS AND METHODS: Our study included a group of 16 patients with Budd-Chiari syndrome. We compared this patient group with a control group of 40 patients with cirrhosis and 66 healthy subjects without liver disease. On sonography, we measured the diameter of the caudate lobe and the presence and diameter of the caudate vein. These measurements were then compared for both groups. RESULTS: In half of the patients with Budd-Chiari syndrome, sonography showed a visible caudate vein (3-21 mm; mean, 7.3 mm; median, 4.6 mm). However, in the control group, spontaneous visualization was seen in only eight (7.5%) of 106 subjects, none of whom had cirrhosis. The caudate lobe was larger in patients with cirrhosis than in healthy subjects. Likewise, in patients with Budd-Chiari syndrome, the caudate lobe was larger than that in patients with cirrhosis. CONCLUSION: When sonography reveals a caudate vein equal to or larger than 3 mm in diameter in the appropriate clinical setting, one should strongly suspect Budd-Chiari syndrome.     

Value of contrast-enhanced sonography for the characterization of focal hepatic lesions in patients with diffuse liver disease: receiver operating characteristic analysis

OBJECTIVE: Our aim was to assess the diagnostic performance of contrast-enhanced agent detection sonographic imaging to characterize focal hepatic lesions in patients with diffuse liver disease in comparison with baseline sonographic images and to determine whether agent detection imaging can reduce the necessity of further diagnostic workup for lesion characterization. MATERIALS AND METHODS: Contrast-enhanced sonography using 4 g of Levovist at a concentration of 300 mg/mL was performed on 75 focal hepatic lesions in 75 patients with diffuse liver disease. Interval reviews for both baseline without and with contrast-enhanced sonography were performed independently by two radiologists. They were requested to determine the malignity of focal hepatic lesions using a 5-point confidence level and to record the specific diagnoses and the necessity for further imaging for lesion characterization. Radiologists' performances for lesion differentiation using baseline and contrast-enhanced sonography were evaluated using receiver operating characteristic (ROC) analysis. Interobserver agreement was also analyzed. RESULTS: When contrast-enhanced sonography was used, ROC analysis revealed a significant improvement for both reviewers (area under the receiver operating characteristic curve [A(z)] = 0.753 and 0.830 and 0.971 and 0.974 at baseline sonography and contrast-enhanced sonography, respectively; p < 0.002) for differentiating malignant and benign focal liver lesions. Contrast-enhanced sonography also improved specificity from 12% to 91% for reviewer 1 and from 26% to 85% for reviewer 2 compared with baseline sonography. Furthermore, excellent interobserver agreement was achieved for contrast-enhanced sonography (weighted kappa = 0.919), whereas only good agreement was achieved for baseline sonography (weighted kappa = 0.656). A better result for specific diagnosis was obtained by contrast-enhanced sonography (79% and 75%) than by baseline sonography (37% and 48%, p < 0.05). Contrast-enhanced sonography (72% and 63%) outperformed baseline sonography (35% and 28%, p < 0.05) as a confirmatory imaging technique. CONCLUSION: Contrast-enhanced agent detection sonography can be used to characterize focal hepatic lesions in patients with diffuse liver disease reliably and with a higher diagnostic confidence than baseline sonography. Furthermore, contrast-enhanced sonography reduced the need for further diagnostic workups for focal hepatic lesion characterization.     

Amplitude coded-colour Doppler sonography in paediatric renal disease

The aim of our study was to assess the ability of amplitude coded-colour Doppler sonography (ACDS) to depict altered perfusion in paediatric renal disease in a prospective study. Colour Doppler sonography (CDS) and ACDS examinations were performed in 180 renal units (90 patients; age range newborn to 16 years) with unilateral or bilateral renal disease (e. g. reflux nephropathy, renal scars, end-stage renal disease, ureteropelvic junction obstruction, urinary tract infection, renal failure, haemolytic uraemic syndrome, nephrotic syndrome, systemic lupus erythematosus (LE), renal biopsy, congenital dysplasia, tumour/infiltration). The ACDS results were compared with scintigraphy or CT as well as to clinical findings. Amplitude colour-coded Doppler sonography accurately demonstrated normal vasculature in 49 of 51 healthy kidneys ( = 96 %); 3 healthy kidneys could not be evaluated due to motion/artefacts. In 39 of 43 kidneys with focally altered perfusion ACDS could be performed and correctly depicted focally impaired vasculature/perfusion in 35 kidneys ( = 89.7 %). Seventy-three of 83 kidneys with diffusely impaired perfusion could be evaluated by ACDS and altered pattern was correctly depicted in 58 kidneys ( = 79.4 %), with an overall percentage of agreement of 87.1 %. Amplitude CDS appears to be useful in infants and children. Compared with CDS it improves visualisation of especially focally impaired vasculature/perfusion and should be considered a valuable adjunct to conventional investigations. Received: 12 June 1999 Revised: 10 December 1999 Accepted: 11 August 2000     

Doppler sonography: a noninvasive method for evaluation of hepatic venocclusive disease

Hepatic venocclusive disease is a serious complication associated with chemotherapy and radiation used in bone marrow transplantation patients. In the past, liver biopsy has been the only reliable means of diagnosing venocclusive disease. Biopsy in such patients may be dangerous or impossible because of severe coagulopathies. The purpose of our study was to evaluate duplex Doppler sonography in diagnosing hepatic venocclusive disease. We measured the blood velocity and flow in the portal vein, hepatic vein, and inferior vena cava of six patients who were histologically proved to have developed hepatic venocclusive disease after bone marrow transplantation. There were three men and three women with a mean age of 32 years (range, 21-44 years). Examination with Doppler sonography suggested the diagnosis a mean of 41 days (range, 11-62 days) after transplantation. In three patients, the diagnosis was suggested by reversed or "to and fro" flow in the portal vein. In the other three patients, the diagnosis was suggested by a decreased flow in the portal vein. One of these patients with decreased flow had subclinical hepatic venocclusive disease. In this patient, it was not the absolute level of flow but the decrease from a baseline established before ablative therapy that suggested the diagnosis. The amplitude of pulsatility in the hepatic veins appeared to decrease with the onset of venocclusive disease. In the hepatic veins and inferior vena cava, flow toward the heart was maintained. Our findings suggest that duplex Doppler sonography may be useful in detection of hepatic venocclusive disease. We speculate that, with wider experience, Doppler sonographic detection of decreased or reversed flow in the portal vein, in the proper clinical setting, may provide a noninvasive means of reliably diagnosing hepatic venocclusive disease in patients too ill to undergo liver biopsy.     

Endorectal color doppler sonography and endorectal MR imaging features of nonpalpable prostate cancer: correlation with radical prostatectomy findings

OBJECTIVE. The purpose of this study was to describe endorectal sonography and color Doppler sonography features of nonpalpable prostate cancer and to assess the value of endorectal MR imaging for the preoperative local staging of these tumors. MATERIALS AND METHODS. Ninety-four patients with nonsuspicious findings on digital rectal examination and a mean prostate-specific antigen level of 16.3 +/-10 ng/mL (median, 13 ng/mL) underwent endorectal sonography, color Doppler sonography, sextant endorectal sonographically guided biopsy, and endorectal MR imaging before radical prostatectomy. RESULTS. Tumors were visible in 48 cases and not visible in 46. The mean Gleason biopsy score, the frequency of tumors involving three sextants or more of the prostate gland at biopsies, and the frequency of stage pT3 tumors were significantly higher in patients with visible tumors (5.9+/-0.9, 42%, and 37.5%) than in those with invisible tumors (5.4+/-1.1, 17%, and 17%). The 42 hypervascular tumors were hypoechoic in every case and had a higher rate of Gleason tumor grades 4 and 5 at biopsy than did the 52 hypovascular tumors (33% versus 11.5%). Six hypovascular tumors (6/52, 11.5%, two visible) had an insignificant tumor volume. Established extraprostatic tumor spread was detected on MR imaging in six of 18 cases (sensitivity, 33%; specificity, 100%0, all of which had the following four features: hypervascularity, prostate-specific antigen level greater than 20 ng/mL, three or more sextants of the gland having positive findings at biopsy, and seminal vesicle invasion. CONCLUSION. Endorectal sonography and color Doppler sonography are useful to differentiate low-risk invisible and hypovascular tumors from high-risk visible and hypervascular tumors. However, MR imaging has a poor sensitivity for the detection of extraprostatic spread and is accurate only in a minority of highly selected high-risk hypervascular tumors.     

The diagnosis of small hepatocellular carcinomas: efficacy of various imaging procedures in 100 patients.

The efficacy of various imaging procedures used for the diagnosis of small hepatocellular carcinomas (HCCs) (lesions no larger than 3 cm in diameter) was evaluated in a retrospective study of 100 patients. Seven patients with hepatic adenomatous hyperplastic nodules containing HCC foci were also assessed. In 89 patients, the lesion was initially detected during follow-up of chronic liver disease. In 21 patients, it was first diagnosed on the basis of elevated serum alpha-fetoprotein; in the remaining 79 it was diagnosed incidentally with imaging procedures. The overall sensitivities of sonography (84%), CT (84%), and angiography (81%) were compared with those of arterial angiographic CT (82%), portal angiographic CT (91%), lipiodol CT (93%), and intraoperative sonography (96%). The differences in sensitivity between angiography and lipiodol CT (p less than .05) and between intraoperative sonography and the other studies (p less than .01) were statistically significant. In 22 lesions smaller than 1 cm, the sensitivities of lipiodol CT and intraoperative sonography were high (83% and 86%, respectively). Adenomatous hyperplasias containing HCC foci were frequently detected by arterial angiographic CT and intraoperative sonography. These results show that sonography or CT and alpha-fetoprotein are useful in detecting small HCCs in screening programs of patients with chronic liver disease. Lipiodol CT and intraoperative sonography are necessary in patients who are candidates for surgery.     

Importance of evaluating all vascular phases on contrast-enhanced sonography in the differentiation of benign from malignant focal liver lesions

OBJECTIVE: Our objective was to evaluate the accuracy of a blood-pool sonographic contrast agent in the late phase compared with the three vascular phases for differentiation between benign and malignant focal liver lesions. SUBJECTS AND METHODS: In 152 patients (105 with chronic liver disease), 152 solid focal liver lesions characterized either by fine-needle biopsy or by dynamic CT or MRI were studied. The final diagnoses were metastasis for 24, hepatocellular carcinoma for 75, focal nodular hyperplasia for 13, regenerating or dysplastic nodule for 14, hemangioma for 22, cholangiocarcinoma for two, and another focal liver lesion for two. Real-time sonography was performed after a bolus injection of 2.4 mL of SonoVue, using a low mechanical index (< 0.2). All lesions were evaluated in the arterial, portal, and late phases; classified as benign or malignant; and correlated with final diagnoses. RESULTS: For discrimination between malignant and benign focal liver lesions, evaluation of all vascular phases improved the sensitivity from 78.4% to 98% and the accuracy from 80.9% to 92.7%, compared with evaluation of the late phase alone. The increase in accuracy was higher in patients with chronic liver disease (16.3%) than in those without (2.1%). CONCLUSION: Evaluation of SonoVue enhancement in all three vascular phases is superior to evaluation of SonoVue enhancement in the late phase alone, especially in patients with chronic liver disease.     

Late-phase pulse-inversion sonography using the contrast agent levovist: differentiation between benign and malignant focal lesions of the liver

OBJECTIVE: We assessed the ability of contrast-enhanced sonography to reveal differences between benign and malignant focal hepatic lesions. SUBJECTS AND METHODS: We examined 67 patients with focal hepatic lesions in a prospective study. The causes of the lesions were confirmed by histology, CT, MR imaging, or scintigraphy. The liver was screened for focal lesions using sonography. Thereafter, 2 g of Levovist (300 mg/mL; 1 mL/sec) was injected IV as a bolus. After a delay of at least 2.5 min without scanning, the liver was examined via three different scans using pulse-inversion sonography. RESULTS: For the discrimination of malignant versus benign liver lesions, contrast-enhanced sonography improved sensitivity from 85% to 100% and specificity from 30% to 63%, as compared with baseline sonography. Receiver operating characteristic analysis revealed a significant improvement in this discrimination (A(z) = 0.692 +/- 0.065 at baseline sonography, A(z) = 0.947 +/- 0.037 with contrast-enhanced sonography, p < 0.001). Furthermore, a lower interobserver variability was found for contrast-enhanced sonography (weighted kappa = 0.947), as compared with baseline sonography (weighted kappa = 0.469). All lesions that had homogeneous enhancement in the late phase of Levovist enhancement were benign. In distinction, 90% of lesions without contrast enhancement in the late phase were malignant. All lesions were malignant that were isoechoic (invisible) on baseline sonography but visible because of lack of enhancement after injection. CONCLUSION: Contrast-enhanced sonography has greater specificity and sensitivity than baseline sonography for the differentiation of benign and malignant liver lesions.     

Evaluation of children for liver transplantation: value of MR imaging and sonography

Diagnostic imaging plays a major role in the diagnosis and treatment of chronic liver disease in children. Decisions regarding the need for sclerotherapy, palliative shunts, and anatomic suitability for hepatic transplantation are based on the upper abdominal anatomy. Thirty-six children with various forms of chronic liver disease were referred for diagnostic imaging, including MR and sonography. Each study was evaluated independently without knowledge of the other examination. The first six patients were evaluated retrospectively and the last 30 patients prospectively. The size of the portal vein and inferior vena cava varied in this population, with excellent agreement between sonography and MR. A 2-mm portal vein was shown only on MR imaging in two patients, but MR missed a 3-mm portal vein. Portosystemic collateral vessels also were evaluated and noted to be detected more readily with MR imaging (64%) than with sonography (22%). In particular, paraumbilical veins were detected more often with MR (28% vs 6% by sonography). Associated or coexisting anomalies were relatively common in children with chronic liver disease (14%). These included polysplenia (two cases), preduodenal portal vein (one), unilateral dysplastic kidneys (two), ureteropelvic junction obstruction (one), and splenic (one) and renal (one) cysts. MR imaging was more sensitive than sonography for detection of abnormal anatomy in this group of patients and should be considered the pretransplantation imaging technique of choice in children with end-stage liver disease.     

Diagnosis and staging of hepatocellular carcinoma: comparison of CT and sonography in 36 liver transplantation patients.

Radiologic studies are important in the detection of hepatocellular carcinoma and the selection of patients for partial liver resection, liver transplantation, or palliation. We retrospectively studied 36 patients with hepatocellular carcinoma who were examined with both CT and sonography before undergoing hepatic transplantation. Pathologic findings of the entire resected liver were correlated with results of imaging studies before transplantation. Parenchymal lesions were shown by sonography in 29 cases (81%) and by CT in 34 cases (94%). Although CT was more sensitive than sonography was, both CT and sonography frequently failed to depict reliably the size of tumor or the exact number of tumor nodules as determined pathologically. Pathologic findings showed vascular invasion in 19 cases (53%), whereas CT showed invasion in 11 cases (31%) and sonography showed it in only six (17%). Nodal metastasis to the porta hepatis was found in four patients; CT correctly showed two cases (three false-positive) and sonography correctly showed one case. Intrahepatic ductal dilatation was seen in eight patients on CT but was not identified on sonography. We conclude that CT is more accurate for identifying and staging hepatocellular carcinoma, but both CT and sonography frequently fail to depict the extent (size and number of lesions) of disease, especially when underlying cirrhosis is present.     

Sonographic detection and sonographically guided biopsy of breast microcalcifications

OBJECTIVE: The purpose of this study was to evaluate the ability of sonography to depict and guide biopsies of mammographically suspicious microcalcifications and to reveal the mammographic features and histologic outcomes of lesions amenable to sonographically guided biopsy. SUBJECTS AND METHODS:. Suspicious clusters of microcalcifications without other mammographic abnormalities were evaluated on sonography before biopsy and divided into two groups: those with and those without microcalcifications seen on sonography. Sonographically detected lesions underwent sonographically guided biopsy; lesions not seen on sonography underwent mammographically guided biopsy. Imaging features and histologies were correlated, and the positive predictive value of sonography was determined. RESULTS: Of 111 lesions (105 patients), 26 lesions (23%) were identified and underwent sonographically guided biopsy; 85 lesions (77%) were not identified sonographically. The diameters of microcalcification clusters in the sonographically identified group were significantly larger (p = 0.0005) and contained larger numbers of microcalcification particles (p = 0.038) compared with clusters not identified sonographically. Sonographically identified lesions were seen as masses (77%) or dilated ducts (23%) with echogenic foci. Sonographically identified lesions were more likely to be malignant than those not seen on sonography (69% vs 21%, respectively; p < 0.00002). Of 38 malignant lesions, those visible on sonography were more likely to be invasive than those not seen on sonography (72% vs 28%, respectively; p = 0.018). In malignant lesions undergoing core biopsy and surgical excision, the extent of disease was underestimated less with sonographically guided biopsy (7%, 1/15) than with stereotactic biopsy (33%, 5/15). CONCLUSION: Suspicious microcalcifications are seen infrequently on sonography (23%) but, when detected, can be successfully biopsied with sonographic guidance and more frequently are malignant and represent invasive cancer than those seen on mammography alone.     

Hilar biliary obstruction: preliminary results with Levovist-enhanced sonography

OBJECTIVE: The aim of this study was to investigate the value of using Levovist in the postvascular phase of sonography performed to assess hepatic hilar biliary obstruction. SUBJECTS AND METHODS: In our prospective study, 50 patients underwent routine sonography followed by postvascular Levovist-enhanced pulse inversion imaging of the liver. Thirty-six patients had malignant disease (28 invasive parenchymal tumors and eight intraductal tumors), and 14 had benign disease. The 36 malignancies included 29 cholangiocarcinomas, six invasive gallbladder carcinomas, and one colon metastasis. Fourteen patients had benign disease: benign strictures (n = 5), primary sclerosing cholangitis (n = 5), chronic Mirizzi's syndrome (n = 1), varicosities of the parabiliary venous plexus (n = 1), and inflammatory liver lesions (n = 2). Sonographic findings in all 50 patients were correlated with findings from other imaging modalities (n = 50) as well as surgical specimens (n = 20), core biopsies (n = 3), and both clinical and imaging follow-ups (n = 24). RESULTS: Seventeen (61%) of the 28 invasive intraparenchymal malignancies were visualized on routine sonograms, whereas all 28 (100%) were visualized on enhanced sonograms (p < 0.01). In 15 (88%) of 17 patients in whom tumor was seen on routine sonograms, contrast-enhanced sonography showed further mass extent, increased conspicuity, or satellite nodules not visualized on the baseline image. All eight noninvasive intraductal malignancies were correctly identified and staged on the routine sonography. In one of these patients, hepatic invasion was prospectively overcalled on the enhanced image. Of the 14 benign lesions, three had inflammatory periductal abnormalities seen exclusively or to advantage on the enhanced study. Correct prediction of resectability in the 16 patients with malignant disease who underwent surgery improved from 11 (69%) of 16 on unenhanced sonography to 15 (94%) of 16 on enhanced sonography (p = 0.13). CONCLUSION: Detection and staging of malignant hilar obstructions are improved by the use of Levovist in the postvascular phase of sonography compared with routine sonography.     

Sonography of lymphangioleiomyoma in lymphangioleiomyomatosis: demonstration of diurnal variation in lesion size

OBJECTIVE: Our aims were to define the sonographic features of abdominal and pelvic lymphangioleiomyomas in lymphangioleiomyomatosis (LAM) and to evaluate the utility of sonography in visualizing diurnal change in the size of the masses. MATERIALS AND METHODS: Forty-four patients with LAM and abdominal and pelvic lymphangioleiomyomas found on screening CT underwent sonography. Twenty-two patients had two studies on the same day, one in the morning and the other late in the afternoon. RESULTS: Forty-nine masses were scanned in the 44 patients. The anatomic distribution of the masses was the following: retroperitoneal (29/44 patients, 66%), pelvic (10/44, 23%), and both retroperitoneal and pelvic (5/44, 11%). Of the 49 masses, 12 (24%) were cystic, 16 (33%) were solid, and 21 (43%) were complex. Twenty-two patients underwent sonography in the morning and afternoon. The masses increased in size between the two studies in all 21 patients in whom the masses were visualized in both studies. In three of 21 patients, the echotexture of the masses changed between the morning and afternoon studies: In two the echotexture changed from solid to complex, and in the other, it changed from hyperechoic to isoechoic relative to the liver. CONCLUSION: The sonographic characteristics of lymphangioleiomyomas are similar to some neoplasms such as lymphoma and ovarian cancer (a similarity that sometimes prompts biopsy). After a mass is shown in a patient with LAM, repeat sonography in the morning and afternoon is useful to depict diurnal variation in size and echotexture and to confirm the diagnosis of lymphangioleiomyoma and avoid biopsy.     

Value of sonographic screening for gallstones in patients with chest pain and normal coronary arteries

The prevalence of sonographically detectable gallstones in patients with chest pain and normal coronary arteries was compared with the prevalence of gallstones in patients referred to sonography for nonbiliary disease. Among 545 patients with chest pain and normal coronary arteriograms, 101 (18.5%) were referred for sonographic examination of the gallbladder. This test group was compared to a matched control group (n = 101) undergoing abdominal sonography for nonbiliary disease. Six patients (5.9%) in the test group and eight patients (7.9%) in the control group were found to have gallstones by accepted sonographic criteria. Studies based on oral cholecystogram screening of healthy populations have claimed a prevalence of cholelithiasis of 2.3%-6.2% for males and 2.3%-12% for females. The authors were unable to demonstrate a higher prevalence of sonographically identified gallstones in patients with chest pain and normal coronary arteries than in patients examined for nonbiliary disease. The frequency of gallstones in this test group is comparable to that reported for a screened population of healthy men and women.     

CT- or sonography-guided biopsy of the liver in the presence of ascites: frequency of complications

The presence of ascites has been considered a contraindication to percutaneous biopsy of the liver. To determine the validity of this assumption, we performed percutaneous biopsies of the liver under CT or sonographic guidance in 28 patients who had ascites and in 28 patients who did not have ascites and compared the complication rates in the two groups. Twenty-two patients (79%) in the group with ascites and 19 patients (68%) in the group without ascites had biopsies to determine the cause or extent of chronic liver disease. The remainder were oncologic patients who had biopsies to determine the cause of a focal hepatic mass. The complication rate in the patients who had ascites (32%) was less than that in the patients who did not have ascites (43%) (the difference did not reach statistical significance, p less than .30). In the ascites group, complications included transient hypotension (five patients), a mild-to-moderate fall in hematocrit (three patients), and a small leak of ascites from the biopsy site (one patient). In the control group, minor complications included transient hypotension (three patients), a mild-to-moderate fall in hematocrit (seven patients), and a small subcapsular hematoma (one patient). One major complication occurred in the control group: a patient required a blood transfusion because of the fall in his hematocrit. We conclude that the complication rate in liver biopsies guided by CT or sonography in the presence of ascites is not higher than similar biopsies done in the absence of ascites. Ascites should not be considered a contraindication for performing such biopsies.     

Exercise and cognitive performance in chronic fatigue syndrome

PURPOSE: To determine the effect of submaximal steady-state exercise on cognitive performance in patients with chronic fatigue syndrome (CFS) alone, CFS with comorbid fibromyalgia FM (CFS + FM), and sedentary healthy controls (CON). METHODS: Twenty CFS-only patients, 19 CFS + FM, and 26 CON completed a battery of cognitive tests designed to assess speed of information processing, variability, and efficiency. Tests were performed at baseline, immediately before, and twice following 25 min of either cycle ergometry set at 40% of peak oxygen capacity or quiet rest. RESULTS: There were no group differences in average percentage of peak oxygen consumption during exercise (CFS = 45%; CFS + FM = 47%; Control = 43%: P = 0.2). There were no significant effects of acute exercise on cognitive performance for any group. At baseline, one-way ANOVA indicated that CFS patients displayed deficits in speed of processing, performance variability, and task efficiency during several cognitive tests compared with healthy controls. However, the CFS + FM patients were not different than controls. Repeated measures ANOVA indicated that across all tests (pre- and postexercise) CFS, but not CFS + FM, were significantly less consistent (F2,59 = 3.7, P = 0.03) and less efficient (F2,59 = 4.6, P = 0.01) than controls. CONCLUSION: CFS patients without comorbid FM exhibit subtle cognitive deficits in terms of speed, consistency, and efficiency that are not improved or exacerbated by light exercise. Importantly, our data suggest that CFS + FM patients do not exhibit cognitive deficits either pre- or postexercise. These results highlight the importance of disease heterogeneity in studies determining acute exercise and cognitive function in CFS.     

Transjugular liver biopsy: a review of 461 biopsies

Transjugular liver biopsy was performed in a large series of patients for whom routine percutaneous biopsy was contraindicated; most of the patients had severe liver disease associated with coagulopathies or massive ascites. Of the 461 biopsies performed over a 7-year period, adequate specimens for histologic diagnosis were obtained in 425; in 14 (3.3%), the biopsy provided a false-negative result. Minor complications such as neck pain, hematoma at the puncture site, or pyrexia occurred in 79 patients (17.1%). Serious complications were encountered in six patients (1.3%) (two with cardiac arrhythmias; four with intraperitoneal hemorrhage following capsular perforation), with an overall mortality rate for the series of 0.22%. Modification of the technique--taking the biopsy with the catheter positioned centrally rather than wedged peripherally--has reduced the occurrence of capsular perforation without affecting the success rate. Transjugular liver biopsy is a valuable technique that provides diagnostic information in a high proportion of cases in which conventional percutaneous biopsy is contraindicated.