Automated measurement of mean wall thickness in the common carotid artery by MRI: a comparison to intima-media thickness by B-mode ultrasound

PURPOSE: To determine whether the mean wall thickness (MWT) of the common carotid artery (CCA) measured by MRI is comparable to B-mode ultrasound (US) measurement of the intima-media thickness (IMT), an established marker of cardiovascular risk. MATERIALS AND METHODS: As part of the two-year ORION trial, 43 patients with 16-79% stenosis by duplex US underwent high-resolution MRI and B-mode US examinations of their carotid arteries. Twenty-eight carotid arteries were identified as having both sufficient proximal coverage and adequate image quality of the CCA on MRI and a corresponding US. A novel algorithm utilizing statistical shape modeling was developed to automatically detect and measure MWT to within subpixel accuracy. The interrater and interscan reproducibility of the MWT measurement was computed as the root-mean-square (RMS) difference. The MWT and IMT measurements were compared via the Pearson correlation coefficient. RESULTS: The MWT and IMT had a high Pearson correlation coefficient (r = 0.93; P < 0.001). The RMS difference between readers and between scans was 0.01 mm and 0.04 mm, respectively. Our automated algorithm correctly identified the lumen in 28 cases (100%) and the outer-wall boundary in 26 cases (93%). CONCLUSION: Automated measurements of the MWT by MRI are reproducible and have a high correlation with the IMT by B-mode US.     

High predictive value of F-18 FDG PET patterns of the spine for metastases or benign lesions with good agreement between readers

Two nuclear medicine physicians retrospectively evaluated fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) spine abnormalities in patients with cancer with the purpose of identifying straightforward criteria for benign versus malignant spine abnormalities. Four hundred seventy-five consecutive patients with colon, breast, and lung cancer were evaluated with FDG. Thirty-two patients (32) had spine abnormalities, 30 of 32 patients had adequate follow up for a final diagnosis, and 29 of 30 patients' studies were available to both PET readers for this retrospective review. The readers categorized the FDG PET abnormalities as benign, metastatic, or equivocal using a straightforward set of criteria. A final diagnosis was made using magnetic resonance imaging (MRI), computed tomography (CT), plain films, bone scans, previous studies, and clinical follow up. A single spinal focus of increased FDG activity had a relatively high probability of being a spinal metastasis (71%); and the more foci, the higher the probability. Segmental decreased activity of the spine after radiation therapy indicated benignity. The only discrepancies were with 3 abnormalities, each called metastasis by 1 reader and equivocal by the other, with a final diagnosis of metastasis in each case. Equivocal patterns required CT or MR correlation, because these could be either malignant or benign. However, abnormal patterns fulfilling either the benign or metastatic criteria described here resulted in the correct diagnoses of benign spinal changes or spinal metastases, respectively, in 100% of cases with low interobserver variation. No study was interpreted as benign by 1 reader and metastasis by the other. The 2 nuclear medicine readers agreed in their interpretations in 90% of cases.     

Real-Time Sonoelastography Performed in Addition to B-Mode Ultrasound and Mammography: Improved Differentiation of Breast Lesions?

RATIONALE AND OBJECTIVES: The goal of the present study was to compare the sensitivity and specificity of elastography with that of B-mode ultrasound (US) and mammography. MATERIALS AND METHODS: A total of 300 patients with histologically confirmed breast lesions (168 benign, 132 malignant) were included. Evaluation was by means of the three-dimensional finite-element method. The data are color-coded and superimposed on the B-mode US scan. The images were evaluated by two independent readers. The results were compared with mammography, histology, and the data obtained by previous US investigations. Sensitivities and specificities were calculated. RESULTS: Sensitivity and specificity in the differentiation of benign and malignant lesions were 87% and 85%, respectively, for mammography and 94% and 83% for B-mode US. The two examiners were in very good agreement in their evaluation of the elastograms (kappa: 0.86). Elastography had a sensitivity of 82% and a specificity of 87%. Elastography was superior to B-mode US in diagnosing Breast Imaging Reporting and Data System (BI-RADS) 3 lesions (92% vs. 82% specificity) and in lipomatous involution (80% vs. 69% specificity). CONCLUSION: Elastography in breast lesions showed a higher specificity and a lower sensitivity in comparison with B-mode sonography. Elastography may be beneficial in BI-RADS 3 lesions and in lipomatous involution.     

Comparison of ultrasonography and oral cholecystography in lithotripsy. II. Determining retreatment

Both ultrasonography (US) and oral cholecystography (OCG) are being used to evaluate patients after extracorporeal shock wave lithotripsy (ESWL) for gallstones. Criteria for retreatment after the initial ESWL are usually related to the size of the residual fragments. This study examines the efficacy of ultrasound and OCG for determining both the size and number of stone fragments in the gallbladder in an in vitro model and in patients. Ultrasonography and OCG examinations using an in vitro ESWL phantom with ten groups of stones, and on 39 patients, were reviewed independently by three radiologists to determine both the size and number of stone fragments. For the in vitro study, the three readers estimated the correct number of fragments, or the next closest range, in 87% of observations by OCG and in 43% by US. The size of the largest fragment was measured within 1 mm of its actual size in 87% of observations by OCG and 20% by US. Correlation coefficients for the mean measurements of the three readers versus the actual fragment size and number were greater for OCG than for US. For the in vivo study, the three readers agreed in 47% of the OCG versus 32% of US examinations with respect to the number of fragments, and in 65% of OCG compared to 40% of US studies with respect to size of the largest fragment. Multiple statistical analyses demonstrate that these differences are statistically significant. A discrepancy among the readers concerning whether a patient was eligible for retreatment occurred in 15% of OCG as compared to 45% of US studies. Both the in vivo and in vitro studies indicate that there is more interobserver reproducibility for OCG than for US, and that OCG is more reliable in making the decision concerning patient eligibility for retreatment following lithotripsy.     

Degree of cervical carotid artery stenosis and hemispheric stroke: duplex US findings

Duplex ultrasound (US) scans of 110 carotid arteries ipsilateral to hemispheric strokes were compared with scans of 90 asymptomatic vessels in the same patients to determine the relative prevalence of stenotic lesions. In addition, scans of paired carotid arteries in patients with stroke involving only one cerebral hemisphere were compared to determine whether the incriminated side demonstrated a greater degree of stenosis than the asymptomatic side. The duplex US findings demonstrated a positive correlation between stenosis and hemispheric stroke. However, only 20% of carotid arteries ipsilateral to hemispheric stroke showed a reduction in diameter greater than 70%, compared with 5% of asymptomatic vessels. A minimal difference was demonstrated between the symptomatic and asymptomatic groups with respect to lesser degrees of stenosis. In paired carotid arteries, the degree of stenosis of the symptomatic vessel exceeded that of the asymptomatic vessel in only 43% of cases. These results suggest that the prevalence of severe carotid stenosis in stroke patients has been previously overestimated. The findings also emphasize the need for further investigation of other plaque-related risk factors that may enhance stroke prevention through improved selection of surgical or medical therapy. Factors currently under investigation include plaque ulceration, intraplaque hemorrhage, plaque echogenicity, and the effects of sequential stenoses.     

Prostate cancer: three-dimensional sonoelastography for in vitro detection

PURPOSE: To prospectively evaluate the accuracy of three-dimensional (3D) sonoelastographic imaging, relative to that of gray-scale ultrasonography (US), in the in vitro detection of prostate cancer. MATERIALS AND METHODS: The study was approved by the institutional review board and was HIPAA compliant. Informed consent was obtained from all patients. Nineteen prostatectomy specimens from patients aged 46-70 years with biopsy-proved prostate cancer were scanned in three dimensions by using conventional B-mode US and sonoelastography with vibrations of more than 100 Hz. Step-sectioned whole-mount histologic specimens were used to create a 3D volume of the prostate and the tumors within it. B-mode US scans and regions of low vibration on the sonoelastographic images (hard regions) were formatted in three dimensions. The lesions in the 19 cases were classified into two groups, as follows: G1 lesions were pathologically confirmed tumors with a volume of at least 1.0 cm3, and G2 lesions were pathologically confirmed tumors smaller than 1.0 cm3. G1 lesions were evaluated with B-mode US and sonoelastography and classified as true-positive, false-positive, true-negative, or false-negative; G2 lesions were evaluated only with sonoelastography. Findings at histologic examination were used as the reference standard. True-positive findings necessitated 3D lesion correlation between pathologic and imaging data. Conventional definitions of accuracy and sensitivity were used for statistical analysis. RESULTS: For G1 lesions (seven lesions with a volume of at least 1.0 cm3), sonoelastography had an accuracy of 55% and a sensitivity of 71% and B-mode US had an accuracy of 17% and a sensitivity of 29%. The mean tumor volume was 3.1 cm3 +/- 2.1 (standard deviation). For G2 lesions (22 lesions with a volume of less than 1.0 cm3), the mean tumor volume was 0.32 cm3 +/- 0.21. Sonoelastography had an accuracy of 34% and a sensitivity of 41%; there were six false-positive findings. CONCLUSION: Sonoelastography performed considerably better than did gray-scale US in the depiction of prostate cancer for tumors with volumes of more than 1 cm3.     

Efficacy and sensitivity of axial scans and different reconstruction methods in the study of the ulcerated carotid plaque using multidetector-row CT angiography: comparison with surgical results

BACKGROUND AND PURPOSE: Carotid plaque ulceration is an important risk factor for stroke, and its diagnosis may be very important to plan a correct therapeutic approach. We hypothesized that axial scans and various reconstruction methods could have different specificity and sensitivity in the study of plaque ulceration. The object of this study was to evaluate their role and diagnostic efficacy in patients with carotid plaque complicated by ulceration through the comparison with surgical results. Materials and METHODS: From January 2004 to November 2005, 109 patients who underwent a carotid endarterectomy were analyzed using CT angiography for a total of 218 carotid arteries. We assessed every carotid for the presence of ulcerations. For each patient axial image, maximum intensity projection (MIP), multiplanar reconstruction (MPR), shaded surface display (SSD), and volume rendering (VR) reconstructions were obtained. RESULTS: Multidetector row CT angiography (MDCT) found 32 ulcerations; surgical confirmation underlined an overall 93.9% sensitivity (95% confidence interval [CI] 0.858-1.021), and a 98.7% specificity (95% CI, 0.961-1.012). Axial scans and volume rendering images demonstrated the highest sensitivity (90.9% and 87.9%, respectively); SSD, on the contrary, showed the lowest sensitivity: 39.4% (95% CI sensitivity, 0.227-0.561). CONCLUSION: Axial scans plus VR reconstruction techniques offer superior depiction of carotid plaque ulceration compared with MIP, MPR, and SSD.     

Acute appendicitis in children: evaluation with US

During a 4-month period, high-resolution ultrasonography (US) was used to prospectively evaluate 70 children with clinically suspected acute appendicitis. Thirty-five US scans showed a noncompressible appendix with maximal outer diameters greater than 6 mm. This finding was considered positive for the diagnosis of acute appendicitis. Thirty-one of these 35 patients had acute appendicitis documented by surgical and pathologic findings. The remaining four patients were observed, and their symptoms resolved. Thirty-five patients had US scans considered negative for appendicitis. Seventeen of these patients had US findings positive for other conditions including mesenteric adenitis, ileitis, intussusception, Crohn disease, and Burkitt lymphoma. In this series US enabled diagnosis of acute appendicitis with a sensitivity of 94%, a specificity of 89%, and a predictive accuracy of 91%. Diagnosis of acute appendicitis can be made with US with the same accuracy in children as has been previously reported in series of adult patients. The use of US in clinically ambiguous cases may allow earlier diagnosis, prevention of perforation, and decreased complications in the pediatric patient with acute appendicitis.     

Echography of pyloric stenosis

In order to assess the accuracy of ultrasonographic (US) criteria for the diagnosis of pyloric stenosis (PS), the record of 78 infants admitted to H?pital Sainte-Justine with the clinical diagnosis of PS during the past year was reviewed. Fifty-eight patients had PS at laparatomy. Thirty-four of these had US with 30 true positives and four "doubtful" findings. Twenty-two had normal US. Two of these had PS, nine gastroesophageal reflux and five normal barium studies of the upper gastrointestinal tract (the last six were followed clinically and remained well). The following were criteria for US diagnosis of PS: pyloric anteroposterior diameter greater than or equal to 1.5 cm, length greater than or equal to 2 cm or a muscle thickness greater than or equal to 4 mm. This series contains no false positive US studies and two false negatives, for a positive predictive accuracy of 94% and a negative predictive accuracy of 100% when we measure the length greater than or equal to 2 cm or combine a length of less than or equal to 2 cm with a muscle thickness greater than or equal to 4 mm.     

Local tumefaction of the gallbladder wall due to pancreatic heterotopia

A 38-year-old woman was examined because of vague abdominal symptoms. Cholecystography and US studies demonstrated a lobulated tumor, 14 mm in length, with a homogeneous structure, sharp limits, adjacent to the posterior wall of the gallbladder and producing no acoustic shadow. Pathological examination demonstrated subserosal pancreatic heteropia. More than 22 different kinds of focal lesions affecting the gallbladder wall have been described. Unfortunately, no clinical or US criteria allow a definite diagnosis. Only the size makes a difference: more than 94% of the adenomas measuring less than 10 mm are benign whereas 88% of the malignant lesions are over 10 mm. Considering the absence of specific criteria, surgical removal is therefore indicated for lesions over 10 mm.     

Articular cartilage defects: in vitro evaluation of accuracy and interobserver reliability for detection and grading with US

PURPOSE: To determine the accuracy and reliability of detecting and grading articular cartilage defects in porcine and human knees by using ultrasonography (US). MATERIALS AND METHODS: US was used to evaluate 175 porcine and 16 human knee surfaces with a linear 5-12-MHz transducer. Porcine defects of varying diameter and depth were surgically created. Each porcine surface was independently assessed in blinded fashion by two radiologists for the presence and severity of defects. Accuracy of detection, interobserver reliability, and concordance between US and surgical grades were determined. Human specimens were retrieved from knees of patients who underwent joint arthroplasty. Defects in human knees detected with US were correlated with defects seen at direct surface visualization. RESULTS: Sensitivities for detection of porcine defects were 94% and 93% for readers 1 and 2, respectively; specificities were 90% and 77%, respectively; positive predictive values were 98% and 95%, respectively; and negative predictive values were 78% and 73%, respectively. Interobserver agreement was high (weighted kappa = 0.80), and concordance between US and surgical grades for both readers was high (weighted kappa = 0.90 and 0.78). In human cartilage, the distribution of cartilage denudation determined at US was the same as that determined at direct visualization. CONCLUSION: High-frequency US was accurate and reliable for detection and grading of knee articular cartilage defects.     

Morton Neuroma: Evaluated with Ultrasonography and MR Imaging

Objective

The purpose of this study was to compare the diagnostic accuracy of both ultrasonography (US) and magnetic resonance imaging (MRI) for the assessment of Morton neuroma.

Materials and Methods

Our study group was comprised of 20 neuromas from 17 patients, and the neuromas were confirmed on surgery following evaluation with US, MRI, or both US and MRI. The diagnostic criterion for Morton neuroma, as examined by US, was the presence of a round or ovoid, well-defined, hypoechoic mass. The diagnostic criterion, based on MR imaging, was a well defined mass with intermediate to low signal intensity on both the T1- and T2-weighted images. The retrospective comparison between the sonographic and MR images was done by two experienced radiologists working in consensus with the surgical and pathologic correlations.

Results

The detection rate of Morton neuroma was 79% for 14 neuromas from 11 patients who had undergone US followed by an operation. The detection rate was 76% for 17 neuromas from 15 patients who had undergone MRI and a subsequent operation. The mean size of the examined neuromas was 4.9 mm on the US images and it was 5.1 mm on the MRI studies. Ten neuromas (71%) were 5 mm or less as measured by US, and three neuromas were not detected, whereas on the MRI analysis, 10 neuromas (59%) were 5 mm or less and four neuromas were not visualized. Among the patients examined during postoperative follow-up, symptoms were completely relieved in 85% and the symptoms were partially relieved in 15%.

Conclusion

US and MR imaging are comparable modalities with high detection rate for the evaluation of Morton neuroma.     

Hepatobiliary manifestations of cystic fibrosis in children: correlation of CT and US findings.

MATERIAL AND METHODS: Abdominal US and CT scans of 50 pediatric cystic fibrosis (CF) patients were evaluated to search for specific data that can be attributed to the involvement of the hepatobiliary system. The liver findings of the two patients who were HBs antigen carriers were excluded from the study. RESULTS: 30 out of 48 patients had at least one abnormal finding of liver on CT and/or US. Although increased echogenicity of the liver was detected in 24 of 48 patients (50%), only six of these (12%) were regarded as steatosis according to CT criteria of low attenuation values. CT and US scans both showed unique multilobular fatty pattern, described as "pseudomasses" in three patients. Increased periportal echogenicity was seen in 18 (37%) patients on US, while CT could not demonstrate any sign of increased periportal thickness. Findings of cirrhosis were present in five patients with either modalities. Lymph nodes of less than 10-15 mm in diameter were detected at the hepatico-duodenal ligament in 18 (37%) patients. Anomalies of the gallbladder (absence or microgallbladder or stone) were detected in 12 cases (24%). CONCLUSION: Although US is the most widely used modality in CF patients, CT and US correlation will help to better delineate the abnormalities between steatosis and periportal fibrosis and increase the sensitivity of the imaging methods to achieve the most accurate diagnosis.     

Normal and acutely torn posterior cruciate ligament of the knee at US evaluation: preliminary experience

PURPOSE: To determine the ultrasonographic (US) findings of normal and acutely torn posterior cruciate ligament (PCL) of the knee and evaluate the usefulness of US in the injured PCL. MATERIALS AND METHODS: US images were obtained in 30 knees in 15 asymptomatic volunteers as a control group and in 35 patients clinically suspected of having an acute PCL injury. Only the distal half of the PCL was evaluated. Of the 35 patients, 28 had their PCL status confirmed: 13 had a normal PCL at magnetic resonance (MR) imaging plus clinical examination, and 15 had a torn PCL at either MR imaging and surgery or MR imaging and clinical follow-up. RESULTS: Normal PCLs were homogeneously hypoechoic, with a well-defined posterior border. Torn PCLs were heterogeneously hypoechoic (12 [80%] of 15 patients), with an indistinct posterior margin (11 [73%] of 15 patients). Torn PCLs were significantly thicker (range, 12.0-20.0 mm; mean, 15.6 mm +/- 2.5 [SD]; P <.01), as compared with normal PCLs in 13 patients (range, 3.8-5.8 mm; mean, 4.6 mm +/- 1.0; P <.01) and in the volunteers (range, 3.7-6.2 mm; mean, 4.5 mm +/- 1.2; P <.01). CONCLUSION: An acutely torn PCL thickens (>10 mm), loses its sharply defined posterior border, and has a heterogeneously hypoechoic appearance. US may be useful as a screening examination for patients suspected of having PCL injury and for deciding whether to perform more expensive MR imaging or surgical intervention.     

Percutaneous radiofrequency (RF) thermal ablation of rabbit tumors embedded in fat: a model for RF ablation of breast tumors

RATIONALE AND OBJECTIVES: To develop an experimental tumor model for RF ablation of breast tumors surrounded by fat and to investigate the minimally invasive treatment of such tumors by saline-enhanced RF ablation monitored by ultrasound (US). METHODS: Twenty-eight VX2 tumors were implanted into the retroperitoneum of 14 rabbits and monitored by B-mode US at regular intervals of 2 to 3 days. Saline-enhanced RF ablation (25-mm tip length) was performed 16 days after tumor implantation (10-minute treatment time, 28 W, 15 mL/h infusion of 0.9% NaCl, which was increased to 30 mL/h in cases of an impedance increase). Thermal lesion growth was monitored by B-mode US. Treatment was considered complete if no relapse was detectable histopathologically after a follow-up period of up to 3 weeks. RESULTS: All tumor implantations were successful, reaching sizes from 5 to 38 mm 16 days after implantation. Tumors >20 mm showed central necrosis on US. Smaller tumors without signs of necrosis required greater needle perfusion to maintain constant needle-to-tissue impedance. Local relapses occurred in 14 of 27 tumors (51.8%), all with tumors >20 mm. In 12 cases, they were already detected sonographically. In 2 cases, "islands" of vital tumor were detected only during histopathological assessment. CONCLUSIONS: VX2 tumors are implantable into hypovascular adipose tissue with a high success rate and may be used as a model for RF ablation of breast tumors. B-mode US is not suitable for guiding RF ablation of tumors embedded in fat. The method appears to be more successful with smaller tumors.     

CT findings of surgically resected large cell neuroendocrine carcinoma of the lung in 38 patients

OBJECTIVE: We sought to assess the CT features of surgically resected large cell neuroendocrine carcinoma of the lung. MATERIALS AND METHODS: The cases of all patients who underwent surgical resection for primary lung cancer in a single institution from 1993 to 2000 and who received an initial diagnosis of poorly differentiated non-small cell lung carcinoma, small cell carcinoma, carcinoid tumor, and large cell neuroendocrine carcinoma were histologically reviewed. The findings for 43 patients were histologically reclassified and confirmed as large cell neuroendocrine carcinoma. The CT scans available for 38 patients were evaluated by two observers. RESULTS: In the 38 patients, six central tumors and 32 peripheral tumors, with diameters ranging from 12 to 92 mm (mean +/- SD, 32 +/- 19 mm), were identified. None of the tumors had air bronchograms or calcification in the mass or nodule. Of the 19 patients with thin-section CT scans, 14 (74%) showed the tumor-lung interface as well defined and five (26%) showed the interface to be ill defined. Lobulation was identified on 15 scans (79%) and spiculation was evident on six scans (32%). On contrast-enhanced CT scans, inhomogeneously enhanced tumors appeared to be larger (51 +/- 18 mm) than homogeneously enhanced tumors (25 +/- 10 mm; p < 0.001). At histopathologic examination, gross necrosis was noted in 20 of 28 patients who had undergone contrast-enhanced CT, and the cause of inhomogeneous enhancement on CT scans was determined to be intratumoral necrosis. Multiple microscopic necroses were present in all 28 patients. CONCLUSION: Large cell neuroendocrine carcinoma usually appears as a well-defined and lobulated tumor with no air bronchograms or calcification. The inhomogeneous enhancement (caused by necrosis) seen in large cell neuroendocrine carcinomas with large diameters is not necessarily apparent in small-diameter (< 33 mm) large cell neuroendocrine carcinomas, even if the tumor contains necrosis.     

Power Doppler ultrasound of gallbladder wall vascularization in inflammation: clinical implications

We investigated the role of Power Doppler US in the diagnosis and follow-up of cholecystitis. We reviewed the examinations of 21 surgical patients aged 27–48 years with US findings of cholecystitis. We performed B-mode and then Power Doppler US. Wall thickness and US structure, the presence/absence of stones, and US Murphy's sign were assessed at B-mode US, whereas only the presence/absence of wall vascularization was studied with Power Doppler. B-mode and Power Doppler changes post treatment were also investigated. Ultrasound showed wall thickening in all patients. In addition, positive Murphy's sign and/or gallbladder stones were seen in 6 patients each at B-mode US and wall vascularization in 7 patients with Power Doppler. Acute cholecystitis was diagnosed in these patients. The other 14 patients presenting wall thickening but no vascularization and negative US Murphy's sign were diagnosed as having chronic cholecystitis; 10 of them had gallbladder stones. Two of seven acute cholecystitis patients were operated on in the acute stage for the onset of complications and histologic findings confirmed the US diagnosis. As for the remaining patients, histology diagnosed chronic cholecystitis in 17, whereas wall thickening was not inflammatory in 2 cases. All the cases with early wall vascularization were eventually diagnosed as cholecystitis. Power Doppler US permits confirmation of the diagnosis of acute cholecystitis and distinguishing of chronic disease, which helps in planning of surgery. Received: 30 April 1999; Revised: 26 November 1999; Accepted: 27 January 2000     

Tissue Doppler and strain imaging for evaluating tissue elasticity of breast lesions

RATIONALE AND OBJECTIVES: Sonoelastography depicts the intrinsic elastic properties of a tissue which are characterized by the strain applied to achieve tissue deformation and the velocity at which tissue deformation occurs. The present study served to investigate whether the specificity of B-mode ultrasound (US) can be improved by combining B-mode imaging with tissue Doppler imaging (TDI) and offline analysis of tissue strain imaging (TSI). MATERIALS AND METHODS: Fifty women, 25 with malignant and 25 with benign focal breast lesions, were examined by US with a linear transducer (9 MHz, Aplio, Toshiba, Otawara, Japan). B-mode US views of the lesions were overlaid with color-coded TDI information and area quotients (AQ = area B-mode view/area TDI) were calculated. TSI views were reconstructed offline from the source data. This was done by placing a region of interest (ROI) in the target lesion and color-encoded display of the information. In addition, tissue elasticity was evaluated using a scale of 1-5 corresponding to the BI-RADS categories. Maximum strain (strain factor, SF) was determined in the ROI. All patients also underwent mammography. Sensitivities and specificities were calculated and statistical analysis was performed using Wilcoxon's test. RESULTS: Sensitivity/specificity was 96%/68% for B-mode US, 100%/40% for combined B-mode US and mammography, and 96%/80% for TSI. The AQ of benign and malignant lesions was significantly different (p = .00008) as was the difference in SF (p = .0004). The readers considered TSI a feasible technique. CONCLUSION: Evaluation of elasticity based on the quantification of strain factors improves characterization of focal breast lesions, especially the differentiation of BI-RADS 3 and 4 lesions. Surprisingly, significant results in characterizing breast lesions were obtained with the simple technique of TDI, showing a lower tissue displacement in malignant cases.     

PTC对梗阻性黄疸诊断价值之探讨（附114例分析）

目的本文旨在探讨PTC对梗阻性黄疸的诊断价值。方法本组共114例梗阻性黄疸，均经手术病理证实，术前均行PTC检查及B超检查，其中56例做了CT检查。结果114例梗阻性黄疸的PTC检查，诊断正确者103例，符合率90.3%；B超诊断明确者86例，符合率75.4%；56例CT检查，诊断正确者46例，符合率82%。结论PTC对梗阻性黄疸具有相当重要的诊断价值，尤其是基层医院术前行此项检查非常必要。     

MRI appearances of the sphenoid sinus at the late follow-up of trans-sphenoidal surgery for pituitary macroadenoma

We aimed to demonstrate the appearances of the sphenoid sinus on MRI performed later than 2 years post- transsphenoidal surgery (TSS). We retrospectively reviewed 47 patients in whom follow-up MRI scans had been performed at least 2 years post-TSS. We specifically reviewed the clinical and imaging of those patients in whom the sphenoid sinus was filled with signal abnormality or masses were present arising from the sinus roof and classified them as tumour or indeterminate abnormalities on imaging criteria. We documented other clinicoradiological details. Twelve of 47 patients demonstrated sphenoid sinus filling or sinus roof masses and in six of 12 patients it was possible to classify them as tumourous using imaging and clinical criteria. The indeterminate and non-tumourous sphenoid sinus abnormalities most frequently had a T1-weighted signal similar to subsellar tumour and displayed rim enhancement and thus could not be reliably distinguished from tumourous abnormality on the basis of signal or enhancement characteristics. The presence of a well-defined surgical defect in the sella floor was associated with resolution of abnormality on MRI follow-up. We concluded MRI findings of sphenoid sinus filling or sinus roof masses are present in approximately 26% of scans performed longer than 2 years post-TSS. Half of these are of indeterminate origin and follow-up is required to discriminate tumour from non- tumour with certainty. A well-defined surgical defect in the sella floor is, however, suggestive of a non-tumourous abnormality.