Diagnostic utility of an echo-contrast agent in patients with synovitis using power Doppler ultrasound: a preliminary study with comparison to contrast-enhanced MRI

The purpose of this study was to first evaluate Levovist (Schering, Berlin, Germany), an echo-contrast agent, during power Doppler sonography (PDS) in patients with synovitis using asymptomatic joints as controls. Then we evaluated the accuracy of this technique against contrast-enhanced MRI. Forty patients (19 men and 21 women; mean age 40 years) were enrolled on the basis of clinical signs, laboratory tests, and radiographic findings positive for articular inflammatory disease. They were examined with conventional ultrasonography (US) and PDS techniques before and after intravenous contrast medium injection. Fourteen patients then underwent MRI with and without contrast medium 8–14 days after PDS studies. Three expert readers independently evaluated each examination. After contrast medium, synovium in inflammatory arthritis enhanced on PDS compared with normal joints in the same patient. Power Doppler sonography after contrast medium and MRI were concordant in all cases. Power Doppler sonography with contrast medium showed a qualitative increase in signal from synovial vessels, the first sign of synovial changes in inflammatory diseases. Received: 10 February 2000 Revised: 27 July 2000 Accepted: 1 August 2000     

The use of intravenous gadopentetate dimeglumine in magnetic resonance imaging of synovial lesions

Spin echo T1- and T2-weighted images and intravenously administered gadopentetate dimeglumineenhanced T1-weighted images were obtained in 4 normal volunteers and 11 patients (11 joints) with painful, intermittent, or persistent joint swelling of unknown etiology. These studies were retrospectively reviewed to assess the benefits of contrast-enhanced magnetic resonance imaging (MRI) in evaluating the synovium. Normal synovium and joint fluid showed no visually apparent enhancement on images obtained immediately after intravenous injection of gadopentetate dimeglumine. Abnormal synovium enhanced significantly, allowing the precise identification of equivocal or unsuspected synovial disease processes. These results suggest that, in selected cases, enhanced MRI can be a useful adjunct in the evaluation of suspected synovial disease processes.     

Correlation of power Doppler with microvessel density in assessing prostate needle biopsy

AIM: To correlate hypervascular power Doppler ultrasonography with the histological evaluation of microvasculature in the prostate using trans-rectal ultrasound (TRUS)-guided needle biopsy. MATERIALS AND METHODS: Ninety-six patients with a lower urinary tract symptoms (LUTS) and prostate specific antigen (PSA) value more than 4 ng/ml were evaluated using power Doppler ultrasonography before biopsy. The vascularity of the peripheral zone was graded on a scale of PZ0 to PZ2. Core needle biopsies were immunostained with CD31(DAKO) and counting was performed manually on separate high power fields (HPF; x 400) in areas containing the highest number of vessels. RESULTS: There was a significant correlation between the grading system used for power Doppler and the microvessel density (MVD; PZ0 28.61 +/- 8.97,PZ1 36.00 +/- 12.11 & PZ2 64.008 +/- 15.86; p < 0.001). There was also a significant difference in MVD between benign, malignant and tissue cores with atypia and prostatic intra-epithelial neoplasia (PIN; p < 0.001 and p < 0.018 respectively). There was a significant correlation between malignant tissue having a higher Gleason score and increased MVD (p < 0.001) Furthermore, cancer biopsies having a high flow PZ2 are nearly twice as likely (63.2%) to have a Gleason score of 7 or more when compared those having a Gleason score of less than 7 (36.8%). CONCLUSION: The grading system of assessing the power Doppler flow signals appears to be of value as an indicator of MVD. It also correlates with a higher Gleason score and this may reflect the clinical outcome in prostate cancer. It deserves further study and evaluation as a prognostic indicator.     

Assessment of hyperemia in acute appendicitis: Comparison between power Doppler and color Doppler sonography

The purpose of our study was to compare power Doppler sonography (US) and conventional color Doppler US in the diagnosis of acute appendicitis by revealing local signs of hyperemia. One hundred consecutive patients (46 males and 54 females, ages 7–61 years; mean, 24.7 years) with clinically suspected acute appendicitis were prospectively examined with power Doppler US and conventional color Doppler US. Of 38 patients who subsequently underwent surgery, appendicitis was proven in 34. The remaining 62 patients who were not submitted to surgery had no clinical evidence of appendicitis over a 2- to 6-month follow-up. At gray-scale US, the appendix was visualized in 30 (88.2%) of the 34 cases with pathologically proven acute appendicitis. Power Doppler US depicted a moderate to marked hypervascularity of the appendiceal wall and surrounding mesoappendix in 28 (93.3%) of these 30 patients. At conventional color Doppler US, flow signal within the appendiceal wall and surrounding mesoappendix was shown in only 21 (70%) of 30 cases (P<0.05). No false-positive diagnosis was made at either power or color Doppler US among the 62 patients without appendicitis. Power Doppler US is more sensitive than conventional color Doppler imaging for revealing signs of local hyperemia in acute appendicitis.     

The role of magnetic resonance imaging and ultrasound in patients with adnexal masses

AIMS: To evaluate the accuracy of ultrasonography (US) and magnetic resonance imaging (MRI) in characterizing adnexal masses, and to determine which patients may benefit from MRI. METHODS: We prospectively studied 72 women (mean age 53 years, range 19 to 86 years) with clinically suspected adnexal masses. A single experienced sonographer performed transabdominal and transvaginal greyscale spectral and colour Doppler examinations. MRI was carried out on a 1.5T system using T1, T2 and fat-suppressed T1-weighted sequences before and after intravenous injection of gadolinium. The adnexal masses were categorized as benign or malignant without knowledge of clinical details, according to the imaging features which were compared with the surgical and pathological findings. RESULTS: For characterizing lesions as malignant, the sensitivity, specificity and accuracy of MRI were 96.6%, 83.7% and 88.9%, respectively, and of US were 100%, 39.5% and 63.9%, respectively. MRI was more specific (p<0.05) than US. Both MRI and US correctly diagnosed 17 (24%) cases with benign and 28 (39%) cases with malignant masses. MRI correctly diagnosed 19 (26%) cases with benign lesion(s), which on US were thought to be malignant. The age, menopausal status and CA-125 levels in these women made benign disease likely, but US features were suggestive of malignancy (large masses and solid-cystic lesions with nodules). CONCLUSION: MRI is more specific and accurate than US and Doppler assessment for characterizing adnexal masses. Women who clinically have a relatively low risk of malignancy but who have complex sonographic features may benefit from MRI.     

Normal and degenerating articular cartilage: in vitro correlation of MR imaging and histologic findings.

Histologic correlation of the different magnetic resonance (MR) appearances of articular cartilage has not been studied extensively. Therefore, the authors correlated thin (high-resolution) MR sections of articular cartilage with histologic sections. Human cadaver lumbar facet joints were imaged with a 1-mm section thickness and a 4-cm field of view, then sectioned and stained for histologic comparison. MR imaging patterns were identified that correlated with normal cartilage and three histologically different patterns of degeneration.     

Evaluation of Portal Venous Velocity with Doppler Ultrasound in Patients with Nonalcoholic Fatty Liver Disease

Purpose

We examined the relationship between portal venous velocity and hepatic-abdominal fat in patients with nonalcoholic fatty liver disease (NAFLD), using spectral Doppler ultrasonography (US) and magnetic resonance imaging (MRI).

Materials and Methods

In this prospective study, 35 patients with NAFLD and 29 normal healthy adults (control group) underwent portal Doppler US. The severity of hepatic steatosis in patients with NAFLD was assessed by MRI through chemical shift imaging, using a modification of the Dixon method. Abdominal (intra-abdominal and subcutaneous) fat was measured by MRI.

Results

The difference in portal venous velocity between the patients with NAFLD and the control group was significant (p < 0.0001). There was no correlation between the degree of abdominal or hepatic fat and portal venous velocity (p > 0.05). There were strong correlations between the hepatic fat fraction and subcutaneous adiposity (p < 0.0001), intraperitoneal fat accumulation (p = 0.017), and retroperitoneal fat accumulation (p < 0.0001).

Conclusion

Our findings suggest that patients with NAFLD have lower portal venous velocities than normal healthy subjects.     

Multicontrast-weighted magnetic resonance imaging of atherosclerotic plaques at 3.0 and 1.5 Tesla: ex-vivo comparison with histopathologic correlation

The purpose was to analyze magnetic resonance (MR) plaque imaging at 3.0 Tesla and 1.5 Tesla in correlation with histopathology. MR imaging (MRI) of the abdominal aorta and femoral artery was performed on seven corpses using T1-weighted, T2-weighted, and PD-weighted sequences at 3.0 and 1.5 Tesla. Cross-sectional images at the branching of the inferior mesenteric artery and the profunda femoris were rated with respect to image quality. Corresponding cross sections of the imaged vessels were obtained at autopsy. The atherosclerotic plaques in the histological slides and MR images were classified according to the American Heart Association (AHA) and analyzed for differences. MRI at 3.0 Tesla offered superior depiction of arterial wall composition in all contrast weightings, rated best for T2-weighted images. Comparing for field strength, the highest differences were observed in T1-weighted and T2-weighted techniques (both P< or =0.001), with still significant differences in PD-weighted sequence (P< or =0.005). The majority of plaques were histologically classified as calcified plaques. In up to 21% of the cases, MRI at both field strengths detected signal loss characteristic of calcification although calcified plaque was absent in histology. MRI at 3.0 Tesla offers superior plaque imaging quality compared with 1.5 Tesla, but further work is necessary to determine whether this translates in superior diagnostic accuracy.     

Evolution of VX2 carcinoma in rabbit tibia: magnetic resonance imaging with pathologic correlation

OBJECTIVE: To evaluate the evolution of a metastatic bone tumor model with MRI-pathology correlation. MATERIALS AND METHODS: VX2 carcinoma was implanted into the tibiae of 20 rabbits. The rabbits were divided into four groups of five (Groups I-IV). MRI was repeated at 1-week interval up to the fourth week, including sagittal T1-weighted image (T1WI), T2-weighted image (T2WI), gadolinium-enhanced fat-suppressed T1WI (GdT1WI), and diffusion-weighted image (DWI). Each group was sacrificed after the imaging, then histological examination for the tibiae with an implanted tumor was performed and MRI-pathologic correlation was done. RESULTS: On MRI-pathology correlation, the corresponding findings were as follows; low SI on T1WI, T2WI-tumor cells, fibrosis (1 week); central low SI on T1WI, T2WI, GdT1WI -tumor cells with fibrosis and necrosis; peripheral high SI on T2WI, DWI, GdT1WI-edema, fibrosis (2 weeks); heterogeneous SI with central low SI on T2WI, DWI-tumor cell nests with extensive necrosis, fibrosis; high SI on T2WI along periosteum-periosteal reaction; high SI around low SI and in bone marrow on T2WI, DWI, GdT1WI-edema, fibrosis; low SI on T1WI in surrounding bone marrow-tumor extension (3-4 weeks). CONCLUSION: The evolution of VX2 carcinoma model was well depicted on MR imaging. Necrosis and extent of tumor were best depicted on enhanced, fat-suppressed T1-weighted images. Heterogeneity of the tumor, peripheral edema, and fibrosis were represented well on T2-weighted images. Diffusion-weighted imaging could have a role in depicting necrosis in the evaluation of bone tumor.     

US correlation for MRI-detected breast lesions in women with familial risk of breast cancer

AIM: To examine the value of US correlation for MRI-detected breast lesions in women with familial risk of breast cancer. METHODS: From an initial dataset of 245 women with positive family history who had breast cancer surveillance involving mammography or MRI between November 1994 and February 2001, 179 subjects with follow-up data were selected. A total of 43 women with 48 MRI-detected lesions underwent further assessment with US. Histopathological correlation was available from 38 breast biopsies performed for 33 women. RESULTS: Sonographic correlates were identified in 32 (66.7%) of the 48 MRI-detected lesions, with cancer present in 11 (34.4%) of these. This compares with 1 (6.3%) cancer found in the 16 lesions without sonographic correlates. Of the 12 malignant lesions, 11 (91.7%) had sonographic correlates whereas 21 (58.3%) of the 36 benign lesions had sonographic correlates. In all 74% of breast biopsies were performed under US guidance compared with 8% under MRI guidance. The proportion of MRI- and US-correlated benign and malignant lesions undergoing US-guided biopsy were 85.7% and 90.9%, respectively. CONCLUSION: The probability of cancer was significantly higher in MRI-detected breast lesions with sonographic correlates compared with those without such correlation. The advantage of convenient biopsy under US guidance as opposed to MRI guidance highlights the value of sonographic assessment of MRI-detected breast lesions.     

Ferumoxide-enhanced MR imaging of hepatocellular carcinoma: correlation with histologic tumor grade and tumor vascularity

PURPOSE: To evaluate ferumoxide-enhanced MR imaging findings of hepatocellular carcinomas (HCCs) in correlation with the histologic tumor grades and the tumor vascularity evaluated by CT hepatic arteriography (CTHA) and CT during arterial portography (CTAP) combined. MATERIALS AND METHODS: By searching the radiologic, surgical, and pathologic reports of our institution between January 1999 and February 2001, we identified 43 patients with 51 pathologically confirmed HCCs who underwent ferumoxide-enhanced MR imaging and combination CTHA and CTAP within two weeks. The HCCs consisted of 17 well-differentiated, 28 moderately differentiated, and six poorly differentiated tumors. The MR and CT were retrospectively reviewed by two radiologists in consensus for signal intensity on MR images and vascularity on CT. The Spearman's rank correlation coefficient was calculated to correlate the frequency of tumors with ferumoxide uptake with the histologic tumor grades and the tumor vascularity on CTHA and CTAP. RESULTS: A total of 45 tumors (88%) did not take up ferumoxide, and thus showed distinct, homogeneous hyperintensity. Six tumors (12%) ranging 5-16 mm in size (mean, 11 mm) took up ferumoxide, and thus showed isointensity, mixed intensity, or hypointensity, including five of 17 (29%) well-differentiated tumors and one of 28 (4%) moderately differentiated tumors. Five of the six tumors (83%) showed hyper- or hypovascularity on CTHA or hypovascularity on CTAP. The frequency of tumors with ferumoxide uptake showed weak correlation with tumor grades (coefficient = 0.26, P < 0.01) and vascularity on CTHA (-0.35, P < 0.05) and CTAP (0.39, P < 0.01). CONCLUSION: Although a small number of well-differentiated HCC take up ferumoxide and show iso-, mixed, or hypointensity, most such tumors show increased hepatic arterial or decreased portal venous perfusion. The present results suggest the limitation of reticuloendothelial contrast imaging, particularly in the diagnosis of small, well-differentiated HCC.     

Magnetic resonance imaging of the hip with a pelvic phased-array surface coil: a technical note

Objective. The aim of this study was to assess the capability of high-resolution images obtained with a commercially available pelvic phased-array surface coil to demonstrate normal hip anatomy. Design. We retrospectively analyzed the oblique coronal magnetic resonance (MR) images of hips of 36 consecutive patients acquired on a 1.5-T clinical imager using a pelvic phased-array coil as a receiver, a 16–20 cm field of view, and 5 mm slice thickness. Patients. Thirty-six patients were studied, age 15–81 years. There were 20 males and 16 females. Results and conclusions. The articular cartilage, cortex, superior labrum, and iliofemoral ligament were well visualized on proton density weighted fat saturation (PDF) images. The femoral and obturator vessels, obturator nerve, and various muscles were easily seen on T1-weighted images. High-resolution imaging of the hip is achievable in a reasonable amount of time using newer phased-array surface coils and may play an increasing role in the future evaluation of hip disorders.     

Differentiation of hepatocellular adenoma and focal nodular hyperplasia of the liver: comparison of power Doppler imaging and conventional color Doppler sonography

The aim of our study was to compare the diagnostic efficacy of power Doppler imaging and conventional color Doppler sonography for differentiating between hepatocellular adenoma (HCA) and focal nodular hyperplasia (FNH) of the liver. Thirty-one focal liver lesions (in 29 patients) with histologic proof of HCA (n = 9) or FNH (n = 22) were studied with power and color Doppler sonography according to a standardized examination protocol. The size of the lesions ranged between 1.5 and 14.5 cm (HCA, 3.5–14.5 cm, mean ± SD 7.3 ± 3.3 cm; FNH, 1.5–9.1 cm, mean ± SD 5.1 ± 2.1 cm). Intratumoral vessels with a venous Doppler spectrum, associated with either pulsatile or continuous peripheral flow, were detected in HCA (eight of nine lesions by power Doppler imaging and six of nine by color Doppler imaging) but not in FNH. In contrast, color signals with an arterial Doppler spectrum, radiating from the center to the periphery of the lesion, were depicted in FNH (20 of 22 cases by power Doppler imaging and 15 of 22 by color Doppler sonography) but not in HCA. Differentiation of HCA and FNH was achieved in 28 of 31 cases (90 %) by power Doppler imaging and in 21 of 31 (68 %) by color Doppler sonography (p < 0.01). Power Doppler imaging is superior to conventional color Doppler sonography in the depiction of the intratumoral flow characteristics of HCA and FNH, and enables a more accurate differential diagnosis than color Doppler sonography. Received 13 January 1997; Revision received 24 February 1997; Accepted 28 March 1997     

Contrast-enhanced,ultrafast 3d pulmonary MR angiography in a single breath-hold: Initial assessment of imaging performance

An ultrafast three-dimensional (3D) sequence was developed, enabling the acquisition of 44 contiguous 2.0-to 2.2-mm thin sections, during intravenous application of paramagnetic contrast, in a single breath-hold. To estimate the potential clinical usefulness, images were assessed qualitatively and quantitatively with regard to visibility of main, lobar, segmental, and subsegmental pulmonary arteries. Five volunteers were examined using a 192 × 192 matrix with an imaging time of 23 seconds and five other volunteers with a 160 × 160 matrix (18 seconds). Each volunteer was imaged in apnea and during shallow respiration. The breath-held 23-second scans revealed excellent image quality and near complete visualization of central and segmental, as well as 81% of subsegmental, pulmonary arteries. Imaging time can be shortened to 18 seconds with only marginal loss in visualization performance (P < .05). Respiratory motion was found to cause significant worsening of image quality and vessel detectability. To maintain relevance in a clinical setting, imaging time can be minimized at the cost of a reduction in spatial resolution.     

A case of scapulothoracic dissociation with brachial plexus injury: magnetic resonance imaging findings

Scapulothoracic dissociation is defined as violent lateral or rotational displacement of the shoulder girdle from its thoracic attachments with severe neurovascular injury. We describe the radiographic and associated magnetic resonance (MR) imaging findings of a case of scapulothoracic dissociation with brachial plexus injury in a 17-year-old man, and include a review of the relevant literature.     

Chondromalacia of the knee: Evaluation with a fat-suppression three-dimensional SPGR imaging after intravenous contrast injection

Twenty-one MRI studies with a fat-suppression three-dimensional spoiled gradient-recalled echo in a steady state (3D SPGR) pulse sequence after intravenous contrast injection were evaluated to assess the accuracy in depicting chondromalacia of the knee. On the basis of MR images, chondromalacia and its grade were determined in each of five articular cartilage regions (total, 105 regions) and then the results were compared to arthroscopic findings. The sensitivity, specificity, and accuracy of MRI were 70%, 99%, and 93%, respectively. MR images depicted 7 of 11 lesions of arthroscopic grade 1 or 2 chondromalacia, and seven of nine lesions of arthroscopic grade 3 or 4 chondromalacia. The cartilage abnormalities in all cases appeared as focal lesions with high signal intensity. Intravenous contrast-injection, fat-suppression 3D SPGR imaging showed high specificity in excluding cartilage abnormalities and may be considered as an alternative to intra-articular MR arthrography when chondromalacia is suspected.     

Evaluation of supraspinatus muscle tears by ultrasonography and magnetic resonance imaging in comparison with surgical findings

Objective

To evaluate the sensitivity, specificity and diagnostic accuracy of ultrasonography (US) and magnetic resonance imaging (MRI) in evaluating suspected supraspinatus muscle injury compared with surgery.

Subjects and methods

One hundred patients underwent both US and MRI for their shoulders due to shoulder pain. Forty patients with non-improved symptoms underwent surgical exploration. We compared the sensitivity, specificity and accuracy of US and MRI for detection of supraspinatus pathology, using surgical findings as ‘gold standard’.

Results

Study included 40 patients (27 men and 13 women, age range from 20 to 68 years). US had sensitivity, specificity and accuracy of 92.3%, 92.6% and 92.5%, respectively in diagnosing partial thickness tears (PTT); 92.6%, 94% and 95%, respectively in diagnosing full thickness tears (FTT). MRI had sensitivity, specificity and accuracy of 84.6%, 92.6% and 90%, respectively in diagnosing partial thickness tears (PTT); 100%, 88.2% and 95%, respectively in diagnosing full thickness tears (FTT). There was no statistically significant difference between the two techniques on one hand and surgery on the other hand in detecting both PTT and FTT.

Conclusion

US and MRI yield high sensitivity, diagnostic accuracy in detecting FTT. Regarding PTT rotator cuff tears both tests were less sensitive.     

Myxoid solitary fibrous tumor of the retroperitoneum: MRI findings with the pathologic correlation.

We report here on a case of solitary fibrous tumor of the retroperitoneum, and the tumor displayed a predominantly myxoid histology. A 56-year-old man presented with an incidentally detected retroperitoneal mass. On the MR images, the mass was observed as having iso-signal intensity on the T1-weighted images and high signal intensity on the fat-saturated T2-weighted images. The mass showed intense enhancement on the Gd-DTPA enhanced T1-weighted images. At surgery, a well-defined solid mass was found in the left retroperitoneum. The histological diagnosis was made as solitary fibrous tumor with a predominantly myxoid histology.