The benefits of comparing conventional sonography, real-time spatial compound sonography, tissue harmonic sonography, and tissue harmonic compound sonography of hepatic lesions

This study aimed to compare conventional sonography, tissue harmonic imaging (THI), spatial compound sonography (SONOCT), and SONOCT+THI for overall image quality, lesion conspicuity, and elimination of artifacts of hepatic lesions. Forty-five patients were randomly selected, and 51 different hepatic lesions were scanned using each of the four techniques. The combined images of SONOCT+THI exhibited the best image quality for solid and cystic lesions, while conventional images were the worst for most hepatic lesions (P<.001). SONOCT was the best for fatty liver.     

Comparison of fundamental sonography, tissue-harmonic sonography, fundamental compound sonography, and tissue-harmonic compound sonography for focal hepatic lesions

Image qualities of fundamental, tissue-harmonic, fundamental compound, and tissue-harmonic compound sonography for evaluating focal hepatic lesions were compared. Two radiologists, blinded to the type of techniques and to the final diagnosis, independently evaluated 384 images of 96 hepatic lesions: hemangiomas (n=35), hepatic cystic lesions (n=28), cirrhosis-related nodules (n=22), focal nodular hyperplasia (n=1), and metastases (n=10). All images were graded in terms of lesion conspicuity, margin sharpness, and overall image quality using a 4- or 5-point scale. In the cases of cystic lesions, posterior acoustic enhancement and internal artifacts were also analyzed. A Friedman test was used for multiple statistical comparisons of the four techniques for all parameters. Compound imaging was significantly superior to fundamental imaging regarding lesion conspicuity, margin sharpness, and overall quality (P<0.05). For posterior enhancement and internal artifacts within the cyst, harmonic ultrasonography (US) was significantly better than fundamental US (P<0.05). For evaluating focal hepatic lesions on US, compound imaging provided better lesion conspicuity, better margin sharpness, and better overall image quality than fundamental imaging did. Tissue harmonic imaging also provided better posterior enhancement and fewer internal artifacts of the cyst than fundamental imaging.     

Diagnostic accuracy of phase-inversion tissue harmonic imaging versus fundamental B-mode sonography in the evaluation of focal lesions of the kidney

OBJECTIVE: We compared phase-inversion tissue harmonic imaging with fundamental B-mode sonography in the evaluation of focal lesions of the kidney. SUBJECTS AND METHODS: For our prospective study, 114 patients underwent sonography of the kidneys in both modes, fundamental B-mode sonography and phase-inversion tissue harmonic imaging, in a randomly chosen scanning order. Imaging parameters were standardized. Sonographic diagnoses were made under real-time conditions by the examining radiologist. All sonographic diagnoses were compared with a diagnostic reference modality: contrast-enhanced CT, contrast-enhanced MR imaging, or histopathology. Three radiologists different from the examiners evaluated overall image quality, lesion conspicuity, and fluid-solid differentiation for both modalities using hard-copy images. RESULTS: In 70 patients, fundamental B-mode sonography as the first technique depicted 73 of 111 lesions 10 mm or larger and enabled 71 lesions to be correctly characterized (sensitivity, 65.8%; accuracy, 64.0%). As the first mode, phase-inversion tissue harmonic imaging depicted 57 of 65 focal lesions and enabled 54 lesions to be accurately classified in 44 patients (sensitivity, 87.7%; accuracy, 83.1%). The differences in sensitivity and accuracy were statistically significant (95% confidence interval). For overall image quality, lesion conspicuity, and fluid-solid differentiation phase-inversion harmonic imaging was superior to fundamental B-mode sonography (p < 0.0001). CONCLUSION: Phase-inversion tissue harmonic imaging is superior to fundamental B-mode sonography in the sonography of focal kidney lesions because phase-inversion tissue harmonic imaging has better overall image quality, lesion conspicuity, and fluid-solid differentiation. In six cases, phase-inversion tissue harmonic imaging added crucial diagnostic information that changed patient management.     

Combination of tissue harmonic sonography, real-time spatial compound sonography and adaptive image processing technique for the detection of carotid plaques and intima-medial thickness

Background and purpose

Conventional sonography (CS) had many unwanted artifacts, which obscured the carotid artery lesions. We try to explore whether the combination of tissue harmonic imaging (THI), real-time spatial compound sonography (SCS), and adaptive image processing (AIP) techniques (CTX) could be a better way to reduce the artifacts in the carotid artery and enhance the visualization of its plaques and intima-medial thickness (IMT) than CS.

Methods

Eighty-three patients who harbored IMT (73) and carotid plaques (19) with variable degrees of stenosis underwent scanning for which five different ultrasound techniques were performed for overall image quality, lesion conspicuity, and elimination of artifacts. Two observers, who were blinded to the imaging techniques, graded the different images. A Friedman test was used for multiple statistical comparisons between the five techniques. To make paired comparisons between different imaging modes, Wilcoxon's signed-rank test was used.

Results

The mean Kappa score for the two independent observers was 0.812 (standard error, 0.021), and reflected moderate-to-high interobserver agreement. Combining SCS + THI + AIP (CTX) provided the best for overall image quality, lesion conspicuity, and elimination of undesired artifacts of carotid plaques whereas CS produced the worst quality (p < 0.001). There were significant differences among the five techniques (p < 0.001); however, there were no differences between SCS and THI on either image quality (p = 0.417), lesion conspicuity (p = 0.594), or elimination of artifact (p = 0.064).

Conclusions

The combined technique of SCS, THI, and AIP may represent the optimal ultrasonic technique for the evaluation of the IMT and carotid plaque echomorphology.     

Tissue harmonic imaging sonography of breast lesions: Improved margin analysis, conspicuity, and image quality compared to conventional ultrasound

The purpose of this preference study is to determine if tissue harmonic imaging (THI) is preferred over conventional sonography for imaging breast masses. A prospective evaluation of 73 identical image pairs (one obtained with conventional sonography, one with THI sonography) was performed, examining 25 cysts, 36 solid masses, and 12 indeterminate lesions. Each image was evaluated for lesion contrast, margins, and overall image quality using a graduated score. Statistical analysis was performed using a modified t test. For cystic and solid lesions, THI was preferred for lesion conspicuity, margin, and overall quality (P<.001). For indeterminate lesions, THI was significantly preferred for lesion conspicuity and overall quality (P<.05), but the preference for margins was not significant. Overall, THI of breast lesions was significantly preferred for lesion contrast and margin evaluation compared to conventional sonography. This modality deserves further evaluation and may improve detection and evaluation of breast lesions.     

Compound spatial sonography of the thyroid gland: evaluation of freedom from artifacts and of nodule conspicuity

OBJECTIVE: The purpose of this study was to compare compound spatial sonography with conventional sonography of the thyroid gland with respect to freedom from sonographic artifacts and conspicuity of thyroid nodules. SUBJECTS AND METHODS: A prospective study was performed on 50 thyroid nodules (in 43 patients). Each nodule was examined using compound spatial sonography and conventional sonography. The sonographic techniques were then compared with respect to freedom from sonographic artifacts and thyroid nodule conspicuity. RESULTS: For freedom from artifacts, compound spatial sonography was superior in 45 cases (90%), and conventional sonography was superior in five cases (10%). Statistical analysis showed that compound spatial sonography was superior to conventional sonography for freedom from artifacts (p < 0.001). For thyroid nodule conspicuity, compound spatial sonography was superior in 37 cases (74%), and conventional sonography was superior in 13 cases (26%). Statistical analysis showed that compound spatial sonography was superior to conventional sonography for thyroid nodule conspicuity (p < 0.001). CONCLUSION: Compound spatial sonography of the thyroid displays greater freedom from artifacts and better nodule conspicuity than does conventional sonography.     

Hepatic sonography: comparison of tissue harmonic and standard sonography techniques.

OBJECTIVE: This study was performed to compare tissue harmonic sonography of the liver with conventional sonography of the liver. SUBJECTS AND METHODS: Forty-eight patients underwent tissue harmonic and conventional sonography of the liver, using a randomized imaging sequence. Imaging parameters were standardized, but gain varied. Techniques were compared using predetermined impact analysis categories. If a finding was revealed by only one sonographic technique, additional confirmation was obtained by another imaging technique or by surgery. In a separate image quality analysis, masked images were reviewed by two experienced radiologists to evaluate fluid-solid differentiation, near-field, far-field, and overall image quality. Rankings were correlated with field of view of images and body habitus of patients as determined by body mass index. RESULTS: Tissue harmonic sonography provided the same information as conventional sonography in 34 patients (71%) and added information in 14 patients (29%). The findings from tissue harmonic sonography resulted in altered treatment in five patients (10%). Eight patients (17%) had lesions revealed by tissue harmonic sonography only. Four patients (8%) had inadequate far-field visualization by both techniques. Both observers ranked tissue harmonic sonography the same as or better than standard sonography in 46 patients (96%) for fluid-solid differentiation, in 46 patients (96%) for near-field image quality, and in 45 patients (94%) for overall image quality. For far-field image quality, one observer ranked tissue harmonic sonography the same as or better than conventional sonography in 40 patients (83%), and the second observer, in 41 patients (85%). Image quality ratings showed no correlation with body habitus of the patients or field of view of images. CONCLUSION: Tissue harmonic sonography of the liver provides more information and better image quality than does conventional sonography of the liver.     

Advantages of real-time spatial compound sonography of the musculoskeletal system versus conventional sonography

OBJECTIVE: Spatial compound sonography is a method that obtains sonographic information from several different angles of insonation and combines them to produce a single image. By reducing speckle and improving definition of tissue planes, this method can potentially improve image quality in musculoskeletal sonography. The purpose of our study was to compare real-time spatial compound sonography with conventional high-resolution musculoskeletal sonography. MATERIALS AND METHODS: Thirty-four patients underwent sonography of the musculoskeletal system for a variety of indications. All patients were evaluated using conventional high-resolution sonography and real-time spatial compound sonography performed with a 12-5-MHz multifrequency linear array transducer. Conventional images and compound images depicting the same musculoskeletal structure were obtained in pairs. A total of 118 images (59 image pairs) were randomly assorted and reviewed on a computer monitor by three experienced sonologists working independently. The reviewers were unaware of the type of images they were evaluating. Image quality was rated using a 5-point scale. The image parameters evaluated were definition of tissue planes, speckle, other noise, and image detail. RESULTS: Analysis of variance revealed that real-time spatial compound sonography significantly improved definition of soft-tissue planes, reduced speckle and other noise, and improved image detail when compared with conventional high-resolution sonography (p < 0.0001 for all evaluated parameters). CONCLUSION: Real-time spatial compound sonography significantly improved sonographic image quality in the musculoskeletal system when compared with conventional high-resolution sonography. Because musculoskeletal sonography is highly dependent on image quality and tissue-plane definition, spatial compound sonography represents an important development.     

Sonographic Evaluation of Breast Nodules: Comparison of Conventional, Real-Time Compound, and Pulse-Inversion Harmonic Images

Objective

To compare the use of conventional, real-time compound, and pulse-inversion harmonic imaging in the evaluation of breast nodules.

Materials and Methods

Fifty-two breast nodules were included in this study, conducted between May and December 2000, in which conventional, real-time compound, and pulse-inversion harmonic images were obtained in the same plane. Three radiologists, each blinded to the interpretations of the other two, evaluated the findings, characterizing the lesions and ranking the three techniques from grade 1, the worst, to grade 3, the best. Lesion conspicuity was assessed, and lesions were also characterized in terms of their margin, clarity of internal echotexture, and clarity of posterior echo pattern. The three techniques were compared using Friedman''s test, and interobserver agreement in image interpretation was assessed by means of the intraclass correlation coefficient.

Results

With regard to lesion conspicuity, margin, and internal echotexture of the nodules, real-time compound imaging was the best technique (p < 0.05); in terms of posterior echo pattern, the best was pulse-inversion harmonic imaging (p < 0.05). Real-time compound and pulse inversion harmonic imaging were better than conventional sonography in all evaluative aspects. Interobserver agreement was greater than moderate.

Conclusion

Real-time compound and pulse-inversion harmonic imaging procedures are superior to conventional sonography in terms of both lesion conspicuity and the further characterization of breast nodules. Real-time compound imaging is the best technique for evaluation of the margin and internal echotexture of nodules, while pulse-inversion harmonic imaging is very effective for the evaluation of the posterior echo patterns.     

Phase-inversion tissue harmonic imaging compared with conventional B-mode ultrasound in the evaluation of pancreatic lesions

The aim of this study was to compare the diagnostic sensitivity, specificity, and image quality of conventional B-mode US (BM) and phase-inversion tissue harmonic imaging (PTHI) regarding pancreatic pathology. In a prospective study, 107 patients, aged between 28 and 85 years, underwent US examinations of the pancreas with both BM and PTHI in a randomly chosen order. As diagnostic reference, either contrast-enhanced CT or MRI examinations of the upper abdomen were obtained in all patients. Sensitivity and specificity were evaluated using the Students t test. Differences in overall image quality, lesion conspicuity, fluid–solid differentiation, and delineation of the pancreatic tail were analyzed using Wilcoxons signed ranks test and Bowkers symmetry test. Sixteen of 107 examined patients (15%) were non-diagnostic and excluded due to technical limitations such as abdominal gas. A total of 60 pancreatic lesions (cysts, acute pancreatitis, dilatation of the pancreatic duct, calcifications, and solid tumors) were diagnosed by CT or MRI. Phase-inversion tissue harmonic imaging had a higher sensitivity of 70% (14 of 20) than BM (60%; 24 of 40) for the detection of pancreatic lesions; however, the difference was not statistically significant (p=0.46). In the assessment of lesions <1 cm of size, PTHI had a sensitivity of 70% and BM 46.7%, whereby the difference again was not statistically significant. Phase-inversion tissue harmonic imaging proved to be superior to BM regarding overall image quality (p<0.0001), lesion conspicuity (p=0.0045), and fluid–solid differentiation (p=0.0002), as well as the delineation of the pancreatic tail (p<0.0001). These differences were statistically significant. The statistically significant improvement of image quality with regards to lesion conspicuity, fluid–solid differentiation, and delineation of the pancreatic tail favors the use of PTHI when evaluating the pancreas with US. Sensitivity for pancreatic lesions is increased with PTHI in comparison with conventional sonography (BM), especially in lesions <1 cm in diameter, although the difference was not statistically significant.     

Four-dimensional volume contrast ultrasound imaging of the gallbladder compared with tissue harmonic imaging: preliminary experience

Comparison of volume contrast US imaging with tissue harmonic imaging for the evaluation of gallbladder lesions and determination of the adequate slice thickness in volume contrast US imaging were performed. Forty-one patients who had gallbladder lesions (polyps in 26, stones in 12, and sludge in 3) were enrolled in our study. A Voluson 730 Expert US scanner was used throughout. Volume contrast US imaging with slice thicknesses of 3, 5, 10 and 15 mm and tissue harmonic imaging of the gallbladder were obtained. Two abdominal radiologists reviewed the masked images and graded by consensus these images using a five-point scale [from grade 1, (best), to grade 5, (worst)], based on the sharpness of the anterior gallbladder wall, internal artifact, lesion conspicuity and acoustic shadowing from stone. Volume contrast US imaging with thin slice thicknesses (3 or 5 mm) was judged superior to both tissue harmonic imaging and with thick slice thicknesses (10 or 15 mm), with respect to the sharpness of the anterior wall and lesion conspicuity (P<0.001). In terms of internal artifact, volume contrast imaging with thin slice thicknesses was significantly superior to both tissue harmonic imaging and volume contrast imaging with a 15 mm thickness (P<0.001) and was judged to be marginally better than with a 10 mm thickness (p>0.01). With regard to acoustic shadowing, volume contrast imaging with thin slice thicknesses was also significantly better than with thick slice thicknesses (P<0.01), and it was also marginally better than tissue harmonic imaging (P>0.01). Volume contrast US imaging with thin slice thicknesses provides a better image quality with fewer artifacts than three other types of images for the evaluation of gallbladder diseases.     

Real-time compound sonography of the rotator-cuff: evaluation of artefact reduction and image definition

PURPOSE: The aim of this study was to compare real time compound sonography with conventional sonography in the evaluation of rotator cuff tears. MATERIALS AND METHODS: A prospective study was performed on 50 supraspinatus tendons in 101 patients treated by surgical acromioplasty. The surgeon described 33 (66%) full-thickness tears and 17 (34%) partial-thickness tears. All tendons were examined by conventional sonography and real time compound sonography on the day before surgery. The techniques were compared by evaluating the images for freedom from artefacts, contrast resolution and overall image definition. RESULTS: Real time compound sonography proved to be superior to conventional sonography as regards freedom from artefacts in 50 cases out of 50 (100%). It was superior to conventional sonography in evaluating the image contrast resolution in 45 cases out of 50 (90%), and superior to conventional sonography in overall image definition in 45 out of 50 cases (90%). CONCLUSIONS: Real-time compound sonography reduces the intrinsic artefacts of conventional sonography and allows better overall image definition. In particular, the digital technique allowed us to study the rotator cuff with better contrast resolution and sharper and more detailed images than did conventional sonography.     

Phase-inversion tissue harmonic imaging compared to fundamental B-mode ultrasound in the evaluation of the pathology of large and small bowel

Our purpose was to compare phase-inversion harmonic imaging (PIHI) with conventional B-mode ultrasound (US) regarding image quality in the evaluation of bowel pathology. Forty-one patients prospectively underwent intestinal ultrasound scans with US and PIHI in randomly chosen order. Crucial technical parameters were standardized. Bowel morphology as well as perienteric pathology and complications were documented. In 24 cases, the ultrasound results were compared to those of other imaging modalities. Three radiologists evaluated (1) overall image quality, (2) lesion conspicuity and diagnostic confidence, and (3) detection of free fluid on hardcopy films. The ratings for image quality were compared using the two-sample paired t test for means and Bowkers test for symmetry (p=0.05). Compared to US, PIHI provided significantly better overall image quality, lesion conspicuity and diagnostic confidence, as well as better detection of free fluid (p< 0.05). Bowel wall pathology, detected by both modalities, showed good correlation to additional imaging modalities. In 12 patients (29.3%), a gain of crucial diagnostic information was observed with PIHI when compared to US. PIHI significantly enhances sonography of the intestine by offering better overall image quality, better visualization of bowel pathology and associated changes. Additionally, PIHI adds crucial diagnostic information in several patients.     

Percutaneous ablation therapy guided by contrast-enhanced sonography for patients with hepatocellular carcinoma

OBJECTIVE: The newly developed contrast-enhanced harmonic gray-scale sonography technique enables us to improve the real-time detectability of viable tumor tissue in hepatocellular carcinoma lesions. We evaluated the usefulness of real-time percutaneous ablation therapy under guidance with this method for patients with hepatocellular carcinoma that is not depicted on conventional sonography. SUBJECTS AND METHODS: We examined 30 patients with 56 hepatocellular carcinomas using real-time contrast-enhanced harmonic gray-scale sonography after injection of a galactose-palmitic acid contrast agent and compared the results with the findings of contrast-enhanced helical CT. We performed percutaneous ablation therapy guided by this modality for treatment of viable hepatocellular carcinoma lesions that could not be detected using conventional sonography. RESULTS: High detection rates of viable hepatocellular carcinoma lesions were obtained using real-time contrast-enhanced harmonic gray-scale sonography (52/56 lesions, 93%); these rates were comparable to those of helical CT (54/56 lesions, 96%). Nine (90%) of the 10 lesions that were not detected on conventional sonography but were depicted on real-time contrast-enhanced harmonic gray-scale sonography (incomplete local treatment, n = 4; small new lesion, n = 6) were successfully treated with percutaneous ablation therapy guided by this method. CONCLUSION: Real-time contrast-enhanced harmonic gray-scale sonography improved the sensitivity for the detection of viable hepatocellular carcinoma lesions. Percutaneous ablation therapy guided by this modality may be useful in patients with hypervascular hepatocellular carcinoma lesions that cannot be detected using conventional sonography.     

Comparison of conventional fast spin echo, single-shot two-dimensional and three-dimensional half-fourier RARE for T2-weighted female pelvic imaging

PURPOSE: To evaluate the usefulness of the three-dimensional half-Fourier RARE sequence in comparison with single-shot two-dimensional half-Fourier RARE and conventional fast spin echo (FSE) for female pelvic imaging. MATERIALS AND METHODS: Imaging with all sequences was performed in 146 patients with 166 focal lesions on a 1.5-T system. The images were compared on the basis of quality, lesion conspicuity, and lesion to the uterus contrast-to-noise ratio (CNR). RESULTS: The sharpness of intrapelvic organs on the three-dimensional half-Fourier RARE sequence was better than that on two-dimensional half-Fourier RARE and worse than that on FSE. Motion-related artifacts for three-dimensional half-Fourier RARE were more frequent than those for two-dimensional half-Fourier RARE. There was no statistical difference between the three-dimensional half-Fourier RARE sequence and FSE in regard to lesion conspicuity and overall image quality. The CNR of leiomyoma to myometrium and cervical cancer to cervical stroma was the highest with three-dimensional half-Fourier RARE (P< 0.05). CONCLUSION: The three-dimensional half-Fourier RARE sequence generates images with higher contrast and better image resolution than two-dimensional-RARE. The three-dimensional data set provided images that can be observed in any orientation without acquiring an additional scan by using the multiplanar reconstruction (MPR) method.     

CT versus sonography for monitoring radiofrequency ablation in a porcine liver

OBJECTIVE: The objective of this study was to compare CT and sonography for monitoring radiofrequency (RF) lesions in porcine livers. SUBJECTS AND METHODS: RF lesions (n = 12) were created in three pig livers by applying 13 min of current to a multielectrode RF probe with a target temperature of 95 degrees C. Helical unenhanced CT and corresponding axial sonography were performed before ablation, at 2 min, 8 min, and immediately after ablation. Contrast-enhanced CT was performed after ablation. CT scans and sonograms were evaluated by blinded observers for conspicuity of the RF lesion, edge detection (visibility of liver-lesion interface), and artifacts. Hounsfield units were recorded at every time interval, and radiologic-pathologic correlation for lesion size and configuration was performed. RESULTS: Mean size of RF lesions was 3. 03 +/- 0.9 cm. On CT, RF lesions had consistently lower attenuation values than surrounding liver (22.2 H lower than liver at 8 min, p < 0.0001). Echogenicity was variable with sonography (hypoechoic = 59%, hyperechoic = 25%, isoechoic = 16%). Unenhanced CT significantly improved conspicuity, edge detection of RF lesions, and decreased artifacts compared with sonography (p < 0.05). Contrast-enhanced CT improved RF lesion detection, border discrimination, and artifacts compared with sonography (p < 0.05). Unenhanced CT had the best correlation to pathologic size (r = 0.74), followed by contrast-enhanced CT (r = 0.72) and sonography (r = 0.56). Contrast-enhanced CT best correlated with lesion shape, but slightly overestimated size because of areas of ischemia peripheral to the RF lesion. CONCLUSION: In this animal model, unenhanced CT was an effective way to monitor RF ablation compared with sonography because of increased lesion discrimination, reproducible decreased attenuation during ablation, and improved correlation to pathologic size.     

Depiction of renal perfusion defects with contrast-enhanced harmonic sonography in a porcine model.

OBJECTIVE: Our purpose was to test the feasibility and optimization of contrast-enhanced gray-scale harmonic sonography for the evaluation of focal renal perfusion defects in an animal model. SUBJECTS AND METHODS: We performed arteriography and contrast-enhanced harmonic sonography on six anesthetized piglets after embolization of each kidney with an autologous clot through the main renal artery. Harmonic images were obtained with continuous (30 Hz) and ECG-triggered acquisition. The two harmonic sonography strategies were compared with respect to the number and conspicuity of devascularized areas, and correlation was made with arteriographic findings. RESULTS: Contrast-enhanced harmonic sonography showed focal areas of absent or diminished vascularity that corresponded closely with perfusion defects seen on angiography. Enhancement ratios to perfused cortex were significantly higher than to devascularized cortex in both continuous (mean +/- SD, 469 +/- 5% versus 102 +/- 8%, p < .0005 by t test) and triggered (673 +/- 7% versus 198 +/- 7%, p < .0001) modes. Triggered acquisition increased the conspicuity of perfusion defects over that obtained with continuous imaging (p < .002 by t test). CONCLUSION: Contrast-enhanced harmonic sonography is an effective method of depicting focal renal perfusion defects. Triggered acquisition further improves lesion conspicuity.     

Comparison of tissue harmonic imaging with conventional US in abdominal disease.

Harmonic waves are generated from nonlinear distortion of an acoustic signal as an ultrasound wave insonates tissues in the body. These beams are integer multiples of a fundamental transmitted frequency. Potential advantages of harmonic imaging include improved axial resolution due to higher frequencies and better lateral resolution due to narrower beams. Decreased noise from side lobes improves signal-to-noise ratios and reduces artifacts. Deleterious effects of the body wall are also reduced. The authors prospectively studied ultrasonographic (US) findings in 100 adult patients with 202 abdominal lesions by comparing harmonic US images with conventional US images. The results were subjected to statistical analysis. Harmonic imaging was superior to conventional US in regard to lesion visibility and diagnostic confidence. Harmonic imaging was particularly useful for depicting cystic lesions and those containing echogenic tissues such as fat, calcium, or air. In patients with a body mass index of 30 or more, harmonic imaging was clearly better for lesion visibility and confidence of diagnosis. The authors recommend routine use of harmonic imaging for abdominal US studies in all adult patients.     

常规SE序列和动态增强MRI诊断肝局灶性病变的比较

目的比较常规SE序列与动态Gd-U．----x增强扫描对肝局灶病变的诊断价值。方法对34例肝局灶病变做了常规SE平扫和动态Gd-U．---A增强及延迟万WI增强扫描；就各序列对肝局灶病变的检出率、病变的信噪比（C／N）值和图像质展进行定员和定性分析。结果36例共142个病灶，动态Gd-lyl？l？A检出率（138／142，958％）明st高于IFZWI和延迟TW［增强（128／14，叨％；119／142，838％）（P＜005）：动态Gd-IJ：1713A增强的C／N值高于TZWI和TIWI延迟增强（P＜0．05）；动态增强的伪影较L们少（P＜0．01），而病灶清晰度各序列之间无明显差别（P＞0．历）。结论动态u-ly：1717A增强扫描在病灶检出率、图像质显反C／N值方面均优于IWI，对肝局灶病变的诊断是一种有价值的方法，     

MR imaging of focal lung lesions: elimination of flow and motion artifact by breath-hold ECG-gated and black-blood techniques on T2-weighted turbo SE and STIR sequences.

Respiratory and cardiac motion correction may result in better turbo spin-echo (SE) imaging of the lung. To compare breath-hold cardiac-gated black-blood T2-weighted turbo SE and turbo short-inversion-time inversion-recovery (STIR) magnetic resonance (MR) imaging pulse sequences with conventional breath-hold turbo SE and half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences for lesion conspicuity of focal lung lesions, 42 patients with focal lung lesions were prospectively studied with MR imaging at 1.5 T. Helical computed tomography was used as a reference. In comparison with the conventional breath-hold turbo SE sequence, all black-blood sequences had fewer image artifacts arising from the heart and blood flow. The overall image quality for the black-blood turbo SE and turbo STIR sequences was superior to that for the breath-hold turbo SE and HASTE sequence (P < 0.01). Not only focal lung lesions but also surrounding inflammatory changes were clearly visualized with these two sequences. With the HASTE sequence, although several slices could be obtained in one breath-hold, both the tumor and vessels appeared blurred. We conclude that T2-weighted turbo SE and turbo STIR imaging of the lung with effective suppression of flow and motion artifacts provide high-quality images in patients with focal lung lesions.