Diagnostic value of gadolinium-enhanced dynamic MR imaging for parotid gland tumors

Objective

This study aimed to evaluate the value of gadolinium-enhanced dynamic MR imaging for differentiating benign and malignant parotid gland tumors, and for characterizing the various histological types.

Patients and methods

Non-enhanced T1-weighted (T1-W), fat-suppressed T2-weighted (T2-W), and gadolinium-enhanced fat-suppressed dynamic T1-weighted images were obtained preoperatively in 27 patients (28 parotid gland tumors), by using a 1.5 or 3 T MR imaging unit (GE, Signa Exite). The tumor margins and the enhancement curve patterns on dynamic MR imaging were analyzed. All patients underwent a parotidectomy with histopathologic analysis.

Results

Pleomorphic adenomas depict a gradual enhancement pattern. Warthin’s tumors depict an early peak of enhancement and a high washout pattern. Malignant tumors depict an early peak of enhancement and a low washout pattern.

Conclusion

Gadolinium-enhanced dynamic MR imaging improved the performance of MR imaging in differentiating benign from malignant parotid gland tumors and characterizing the different histological types of benign tumors.     

Brain MRI Findings of Carbon Disulfide Poisoning

Objective

To evaluate the findings of brain MRI in patients with carbon disulfide poisoning.

Materials and Methods

Ninety-one patients who had suffered carbon disulfide poisoning [male:female=87:4; age, 32-74 (mean 53.3) years] were included in this study. To determine the extent of white matter hyperintensity (Grade 0-V) and lacunar infarction, T2-weighted MR imaging of the brain was performed.

Results

T2-weighted images depicted white matter hyperintensity in 70 patients (76.9%) and lacunar infarcts in 27 (29.7%).

Conclusion

In these patients, the prevalent findings at T2-weighted MR imaging of the brain were white matter hyperintensity and lacunar infarcts. Disturbance of the cardiovascular system by carbon disulfide might account for these results.     

MR imaging findings in two patients with hepatic veno-occlusive disease following bone marrow transplantation

The aim of this study was to describe the MRI features of veno-occlusive disease (VOD) following bone-marrow transplantation in two patients. The MRI features consisted of hepatomegaly, hepatic vein narrowing, periportal cuffing, gallbladder wall thickening, marked hyperintensity of the gallbladder wall on T2-weighted images, ascites, and pleural effusion. In one patient, signs of reduced portal venous flow velocity were also observed. It is concluded that the use of MRI as a complementary technique following non-conclusive US examination enabled a timely diagnosis of this life-threatening disease in both patients. Received: 9 February 1999; Revised: 4 November 1999; Accepted: 28 December 1999     

Comparison of diffuse hepatocellular carcinoma and intrahepatic cholangiocarcinoma using sequentially acquired gadolinium-enhanced and Resovist-enhanced MRI

Purpose

The purpose of this study was to compare MRI findings of diffuse hepatocellular carcinoma (D-HCC) and intrahepatic cholangiocarcinoma (IHC) to identify characteristics of each.

Materials and methods

We retrospectively analyzed MRI that consisted of unenhanced T1- and T2-weighted image, gadolinium (Gd)-enhanced dynamic image, and sequentially acquired Resovist-enhanced image from 29 patients with D-HCCs and 32 patients with IHC.

Results

On T2-weighted imaging, D-HCCs usually appeared as poorly defined, infiltrative mildly hyperintense masses, whereas IHC appeared as well-defined, lobulated mildly hyperintense masses with areas of strong hyperintensity and hypointensity. On dynamic- and Resovist-enhanced T1-weighted MRIs, D-HCCs appeared as hypovascular and homogeneously hypointense or isointense masses with internal reticulation, whereas IHD appeared as centripetal enhancing masses with or without delayed central hyperintensity. Biliary dilatation was predominantly observed in the area adjacent to the IHC and in the intratumoral area of D-HCC. Portal venous tumor thrombus was observed in most of the D-HCC, and portal vein encasement was seen in 17 of the IHC.

Conclusion

D-HCC and IHC exhibited characteristics of each at T1- and T2-weighted imaging, Gd-enhanced dynamic imaging, and sequentially acquired Resovist-enhanced T1-weighted imaging.     

Castleman disease of the neck: CT and MR imaging findings

Objective

To characterize the computed tomography (CT) and magnetic resonance imaging (MRI) findings of Castleman disease of the neck.

Methods

The imaging findings of 21 patients with Castleman disease of the neck were reviewed retrospectively. Of the 21 patients, 16 underwent unenhanced and contrast-enhanced CT scans; 5 underwent unenhanced and contrast-enhanced MRI scans.

Results

The unenhanced CT images showed isolated or multiple well-defined homogenous mild hypodensity lesions in fifteen cases, and a heterogeneous nodule with central areas of mild hypodensity in one case. Calcification was not observed in any of the patients. In five patients, MR T1-weighted images revealed well-defined, homogeneous isointense or mild hyperintense lesions to the muscle; T2-weighted images showed these as intermediate hyperintense. Sixteen cases showed intermediate to marked homogeneous enhancement on contrast-enhanced CT or MR T1-weighted images. Of the other five cases that underwent double-phase CT scans, four showed mild or intermediate heterogeneous enhancement at the arterial phase, and homogeneous intermediate or marked enhancement at the venous phase; the remaining case showed mild and intermediate ring-enhancement with a central non-enhanced area at the arterial and venous phases, respectively.

Conclusion

Castleman disease of the neck can be characterized as solitary or multiple well-defined, mild hypodensity or homogeneous intense lesions on plain CT/MR scans, and demonstrates intermediate and marked enhancement on contrast-enhanced CT/MR scans. On double-phase CT scans, Castleman disease often demonstrates mild enhancement at the arterial phase, and gradually uniform enhancement at venous phase. Double-phase enhanced CT or MRI may help to differentiate Castleman disease from other diseases.     

Imaging findings of liver involvement of Wilson's disease

Purpose

The major purpose of this paper is to outline and correlate US, CT and MR imaging findings of liver in patients with Wilson's disease.

Materials and methods

Twenty-eight patients (10 male, 18 female, median age 16) with Wilson's disease were examined with US, CT and MRI. Liver echogenicity, echo pattern, contour irregularity, periportal thickness, perihepatic fat layer thickness, the presence of focal parenchymal lesion, and other associated findings were recorded by US in every patient. CT and MRI were done in 20 and 12 patients, respectively.

Results

Contour irregularity was observed in 24 patients and heterogeneous parenchymal echo pattern was seen in 26 patients with US. The presence of increased perihepatic fat layer was observed in eight patients. Severe parenchymal atrophy was seen in all lobes of the liver including caudate in contrast to post-viral chronic liver disease. Nineteen patients had periportal thickening. US showed multiple hyper and/or hypoechoic nodules smaller than 1 cm in 13 patients. MRI demonstrated small nodular hypointense areas on T2-weighted images in five patients. In only one patient these nodules showed contrast enhancement in CT and MR and pathologically proved to be dysplastic nodule.

Conclusion

Wilson's disease involving the liver has several unique radiological findings in comparison to other types of cirrhosis. These specific features include multiple nodular lesions in the liver, presence of perihepatic fat layer and normal caudate lobe which is contrary to other types cirrhosis. Liver injury in the Wilson's disease can be defined by imaging modalities, especially by US which we think is the most precise imaging modality to detect early parenchymal changes in the progress of the disease.     

3D dynamic pituitary MR imaging with CAIPIRINHA: Initial experience and comparison with 2D dynamic MR imaging

Objectives

To evaluate the validity of 3D dynamic pituitary MR imaging with controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA), with special emphasis on demarcation of pituitary posterior lobe and stalk.

Methods

Participants comprised 32 patients who underwent dynamic pituitary MR imaging due to pituitary or parasellar lesions. 3D dynamic MR with CAIPIRINHA was performed at 3 T with 20-s-interval, precontrast, 1st to 5th dynamic images. Normalized values and enhanced ratios (dynamic postcontrast image values divided by precontrast ones) were compared between 3D and 2D dynamic MR imaging for patients with visual identification of posterior lobe and stalk.

Results

In 3D, stalk was identified in 29 patients and unidentified in 3, and posterior lobe was identified in 28 and unidentified in 4. In 2D, stalk was identified in 26 patients and unidentified in 6 patients, and posterior lobe was identified in 15 and unidentified in 17. Normalized values of pituitary posterior lobe and stalk were higher in 3D than 2D (P < 0.001). No significant difference in enhancement ratio was seen between 3D and 2D.

Conclusions

3D dynamic pituitary MR provided better identification and higher normalized values of pituitary posterior lobe and stalk than 2D.     

CT and MR images of pleomorphic adenoma in major and minor salivary glands

Purpose

To investigate the CT and MR imaging features of pleomorphic adenoma in the head and neck area.

Materials and methods

Our materials of this study consisted of 50 pleomorphic adenomas from 50 patients which were all histopathologically diagnosed. The CT and MR images were retrospectively evaluated. The following features were evaluated: the detectability of the lesion, the tumor margin, the border of the lesion, the aspect of the lesion, the contrast between the lesion and surrounding tissue, the signal intensity of the lesion, the enhancement of contrast medium, the aspect of the lesion after the injection of contrast medium, the detectability of the capsule, and the detectability of bone resorption of the lesion.

Results

The tumor detectabilities were 77% on axial plain CT images and 90% on axial CE CT images, respectively. On CT images, pleomorphic adenoma tended to show a well-defined margin, a smooth border, an inhomogeneous aspect, a low or high contrast, and intermediate or high signal intensity. After contrast medium administration, pleomorphic adenoma tended to show a slightly high enhancement and either an inhomogeneous or a periphery enhancement on the CE CT images. The capsule could be hardly detected on CT images. The tumor detectabilities were 86% on axial T1-weighted MR images, 88% on axial T2-weighted MR images, and 85% on axial CE T1-weighted MR images, respectively. On MR images, pleomorphic adenomas tended to show well-defined margin, a lobulate border, an inhomogeneous aspect, a high contrast, and intermediate or high signal intensity. After contrast medium administration, pleomorphic adenoma tended to show a high enhancement and either an inhomogeneous or a periphery enhancement on MR images. The capsule could be detected in many cases on MR images.

Conclusions

It was possible to detect the capsule in pleomorphic adenoma using MR images. The pleomorphic adenomas in head and neck area should be evaluated with MR images.     

Diagnostic accuracy of MR sialography in sialolithiasis and salivary ductal stenosis

Objectives

The purpose of this study is to determine the diagnostic accuracy of MR sialography in the examination of patients with salivary duct disease.

Patients and methods

Twenty-eight patients (twenty males and eight females, average age, 47 years), with symptoms related to the salivary glands, underwent both conventional sialography and MR sialography. The latter was performed using heavily T2-weighted, two dimensional, fast spin-echo techniques and a neck coil. Contiguous 3-mm axial images with frequency-selective fat suppression were acquired through the symptomatic gland. The MR sialography findings were compared with the final diagnoses determined by conventional sialography, and with surgery in the case of those who underwent surgical intervention. Ultrasound examination was performed using 7.5 MHz transducer. Conventional sialography was performed with the use of 0.012–0.021 inch sialographic catheter and an injection of 0.3–1.5 ml Ultravist 300 mg/ml.

Results

Final diagnosis included sialolithiasis in eleven cases, sialolithiasis and stenosis in four cases, stenosis without lithiasis in ten cases and normal salivary glands in three cases. (The normal cases were excluded from the study).

Conclusion

It is concluded that MR sialography with a heavily T2-weighted sequence is highly successful in the noninvasive visualization of the ductal system of major salivary glands in cases that could not be examined by conventional sialogram. It is useful for diagnosing sialolithiasis and ductal stenosis. However, normal MR sialographic findings do not allow the exclusion of small calculi. Thus in patients with strong clinical suspicion of calculi and normal MR sialographic findings, conventional sialography should still be performed.     

MR grading system of osteochondritis dissecans lesions: Comparison with arthroscopy

Objective

To assess the diagnostic performance of combined three-dimensional (3D) gradient-echo (GRE) T1-weighted and routine MR imaging protocol for the evaluation of osteochondritis dissecans (OCD).

Materials and methods

This prospective study was approved by our institutional review board and all patients gave informed consent. Three-dimensional GRE MR sequence was added to the routine protocol performed on 40 consecutive patients (35 men, 5 women; age range, 12–57 years; mean age, 20 years) with 17 juvenile and 24 adult OCD lesions (27 in knees; 14 in elbows) which were confirmed by arthroscopy. Two independent musculoskeletal radiologists reviewed all MR images. The OCD lesions were classified into five stages by assessing the signal intensity of fragment–bone interface and the integrity of articular cartilage on MR images. Stage-IV and -V lesions were considered as unstable. The sensitivity, specificity, accuracy, and interobserver agreement (κ statistics) were calculated.

Results

The sensitivity, specificity, and accuracy for detection of OCD instability were 100% (11 of 11), 100% (6 of 6), and 100% (17 of 17) in juvenile lesions; and 93% (14 of 15), 100% (9 of 9), and 96% (23 of 24) in adult lesions. The overall accuracy of MR findings in determining the staging was 90% (37 of 41) for reader 1 and 83% (34 of 41) for reader 2. Agreement between readers was substantial with a κ value of 0.75 for MR staging of OCD lesions.

Conclusions

Three-dimensional GRE T1-weighted MR imaging combined with the routine sequences demonstrates excellent diagnostic capabilities in detecting unstable OCD lesions.     

Relationship between levels of serum creatinine and perirenal hyperintensity on heavily T2-weighted MR images

Objective

To determine the frequency of perirenal hyperintensity on heavily T2-weighted images and to evaluate its relationship with serum creatinine levels.

Subjects and methods

Axial and coronal single-shot fast spin-echo images which have been originally obtained for MR cholangiopancreatography in 150 subjects were examined by two observers individually for the presence of perirenal hyperintensity. The morphologic properties of perirenal hyperintensity (peripheral rim-like, discontinuous, polar) were recorded. Chi square test was used to test whether the frequencies of bilateral perirenal hyperintensity differ significantly in subjects with high serum creatinine levels and those with normal creatinine levels. This test was also used to compare the frequencies of perirenal hyperintensity in patients with and without renal cysts and in patients with and without corticomedullary differentiation. A p value of less than 0.05 was considered to be statistically significant.

Results

The perirenal hyperintensity was identified in 40 of 150 cases (26.6%) on heavily T2-weighted image. Serum creatinine levels were high in 18 of 150 cases (12%). The perirenal hyperintensity was present in 11 of 18 subjects (61%) with high serum creatinine levels and 26 of 132 subjects (19.7%) with normal creatinine levels. The difference of rates in two groups was statistically significant. Odds ratio was 6407 (95% confidence interval 2264-18,129). The frequency of perirenal hyperintensity was also significantly higher in subjects with renal cyst or cysts in whom serum creatinine levels were normal (p < 0.05) (37.5% vs. 11.8%).

Conclusion

Perirenal hyperintensities are more frequent in patients with high serum creatinine levels. They are also more common in patients with simple renal cysts.     

Role of proton MR spectroscopy in the high field magnet (3T) in diagnosis of indeterminate breast masses (BIRDS 3 & 4)

Background

Since 80% of abnormalities found in the breast are benign upon biopsy, New techniques must provide more precise evaluation of these indeterminate lesions .MR spectroscopy is one of the available new techniques on MRI, it refers to the measurement of biochemical compounds in the tissue using specialized sequences.

Purpose

To evaluate the role of MR spectroscopy using the state of the art high field magnet (3 Tesla) as a diagnostic method in indeterminate breast lesions (BIRADS 3 and 4 lesions) aiming at decreasing the un-necessary breast intervention.

Material & method

In this study 240 female patients classified as BIRADS 3 & 4 by sono-mammography (Sono-MX) were examined by MRI using the multiphase dynamic sequence and proton MR spectroscopy using a high field magnet (3 Tesla). Single voxel technique after adequate shimming was used.

Results

Eighty eight cases (35%) were malignant (based on the presence of high choline peak in the spectrum) and 152 cases (65%) were benign (no choline peak). MR-spectroscopy has increased the sensitivity & specificity of Dynamic MR-Mammography for diagnosis of probable lesion from 93.6% (88/94) and 77.9% (152/195) to 96.7% (88/91) and 95.5% (152/159), False positive results were found in 4 cases and False negative results were found in 7 cases.

Conclusion

MR Proton spectroscopy in the high field magnet (3T) offered additional information that increased the sensitivity and specificity of the conventional dynamic MRI in evaluating probable breast lesions and hence reduced the need for unnecessary intervention.     

CT and MR features of xanthogranulomatous cholecystitis: An analysis of consecutive 49 cases

Objective

To study the CT and MR features of xanthogranulomatous cholecystitis (XGC).

Materials and methods

49 patients had pathologically confirmed XGC. All patients underwent contrast enhanced CT, and 10 patients had additional plain MRI. The CT and MRI results were retrospectively analyzed.

Results

On CT, all patients had thickening of gallbladder wall, with 87.8% cases showed diffuse thickening. 85.7% cases had intramural hypo-attenuated nodules in the thickened wall. Continuous mucosal line and luminal surface enhancement were noted in 79.6% and 85.7% cases, respectively. Gallbladder stones were seen in 69.4% patients. The coexistence of the above 5 CT features was seen in 40% cases, and 80% cases had the coexistence of ≥4 features. Diffused gallbladder wall thickening in XGC is more likely to have disrupted mucosal line, and XGC with disrupted mucosal line is more likely to be associated with liver infiltration. In 60% patients the inflammatory process extended beyond gallbladder, with the interface between gallbladder and liver and/or the surrounding fat blurred. 40% cases had an early enhancement of liver parenchyma. Infiltration to other surrounding tissues included bowel (n = 3), stomach (n = 2), and abdominal wall (n = 1). On MR images, 7 of 9 intramural nodules in 7 subjects with T1-weighted dual echo MR images showed higher signal intensity on in-phase images than out-of-phase images.

Conclusion

Coexisting of diffuse gallbladder wall thickening, hypo-attenuated intramural nodules, continuous mucosal line, luminal surface enhancement, and gallbladder stone highly suggest XGC. XGC frequently infiltrate liver and surrounding fat. Chemical-shift MRI helps classifying intramural nodules in the gallbladder wall.     

MR imaging of medullary carcinoma of the breast

Purpose

To examine the magnetic resonance imaging (MRI) findings of medullary carcinoma of the breast and to correlate them with histopathologic features.

Materials and methods

Eight patients were retrospectively evaluated with pathologically confirmed medullary carcinoma of the breast. T1-weighted fat-saturated, T2-weighted fast spine echo, and gadolinium-enhanced fat-saturated fast spoiled gradient-echo images were obtained. Interpretation of the MRI findings was based on evaluation of the configuration, internal signal intensity, contrast enhancement, and type of the time–intensity curve.

Results

Medullary carcinoma showed a lobular shape and a smooth margin, either homogenous or heterogeneous enhancement and delayed peripheral enhancement in the late phase on contrast-enhanced MRI, and either a plateau or washout type with rapid initial rise on the time–intensity curve of the dynamic study.

Conclusion

Although the MRI findings showed a close relationship with histopathologic features of medullary carcinoma, it was difficult to differentiate medullary carcinoma from other histologic types of invasive breast carcinomas.     

The role of multi-parametric MR imaging in the detection of early inflammatory sacroiliitis according to ASAS criteria

Purpose

To retrospectively evaluate the accuracy of multi-parametric magnetic resonance (MR) imaging including fat saturated (FS) T2-weighted, short-tau inversion recovery (STIR), diffusion-weighted (DW-MR), and dynamic-contrast-enhanced MR (DCE-MR) imaging techniques in the diagnosis of early inflammatory sacroiliitis and determine the additional value of DW-MR and DCE-MR images according to recently defined ‘Assessment in SpondyloArthritis international Society’ criteria.

Materials and methods

The study included 45 patients with back pain. Two radiologists estimated the likelihood of osteitis in 4 independent viewing sessions including FS T2-weighted, STIR, DW-MR and DCE-MR images. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic (ROC) curve (AUC) were calculated.

Results

Of the 45 patients, 31 had inflammatory back pain. Of 31, 28 (90.3%) patients had inflammatory sacroiliitis diagnosed by clinical and laboratory analysis. FS T2-weighted MR images had the highest sensitivity (42.8% for both radiologists) for detecting osteitis in patients with inflammaory sacroiliitis when compared to other imaging sequences. For specificity, PPV, NPV, accuracy, and AUC levels there were no statistically significant difference between image viewing settings. However, adding STIR, DW-MR and DCE-MR images to the FS T2-weighted MR images did not improve the above stated indices.

Conclusion

FS T2-weighted MR imaging had the highest sensitivity when compared to other imaging sequences. The addition of DW-MR and DCE-MR images did not significantly improve the diagnostic value of MR imaging in the diagnosis of osteitis for both experienced and less experienced radiologists.     

Conventional magnetic resonance imaging versus MR arthrography (MRA) of the wrist in the evaluation of triangular fibrocartilage lesions

Objective

The aim of this study is to assess the diagnostic value of direct MR arthrography compared to conventional MR imaging in the diagnosis of different pathologic entities affecting the triangular fibrocartilage.

Subjects and methods

This study included 51 patients complaining of chronic wrist pain. Conventional MRI and MR arthrography (MRA) was done for all cases.

Results

A comparison of the sensitivity of conventional MRI versus MRA was done by correlating the final diagnosis of each modality with the results of arthroscopy. MRI revealed a sensitivity (SEN) of 88.5%, specificity (SPE) of 100%, positive predictive value (PPV) of 100%, and a negative predictive value (NPV) of 69.2%, with an overall accuracy (ACC) of 90.9%, while MRA revealed a SEN of 94.2%, SPE of 100%, PPV of 100%, NPV of 81.8%, and ACC of 95.5%.

Conclusion

MR arthrography is a potent additional tool facilitating the diagnosis of different pathologic entities affecting the triangular fibrocartilage requiring surgical intervention and help to reduce arthroscopic interventions.     

Imaging study of ossifying fibroma with associated aneurysmal bone cyst in the paranasal sinus

Objective

To determine the CT and MR imaging features of ossifying fibroma with aneurysmal bone cyst of the paranasal sinus.

Materials and methods

We retrospectively reviewed 15 patients with histopathology-proven ossifying fibromas with aneurysmal bone cysts in the paranasal sinus. All 15 patients underwent CT and MR imaging. The following imaging features were reviewed: location, shape, margin, CT findings, and MR imaging appearances and time-intensity curve of dynamic contrast-enhanced MR imaging.

Results

Ossifying fibromas occurred in the maxillary sinus in one patient, sphenoid sinus in 2, frontal sinus in 3, frontoethmoid sinuses in 3, and ethmoid sinus in 6 patients. Ossifying fibromas showed an elliptic-shape and aneurysmal bone cysts revealed a multicystic appearance, with well-demarcated margins. On unenhanced CT, ossifying fibromas appeared isodense to gray matter with scattered calcifications in nine, ground-glass appearance in 6 patients and aneurysmal bone cysts showed mixed density. Ossifying fibromas appeared isointense to gray matter in 12 and slightly hypointense in three patients on T1-weighted images, and isointense in 4 and hypointense in eleven patients on T2-weighted images, with moderate or marked enhancement after administration of contrast material. The time-intensity curves of eight ossifying fibromas exhibited a rapidly enhancing and rapid washout pattern. The intracystic components of aneurysmal bone cysts showed heterogeneous signal intensity on MR images, with fluid–fluid levels identified clearly by T2-weighted images, without enhancement. The periphery and septa of aneurysmal bone cysts appeared isointense on MR images, with marked enhancement.

Conclusions

Fluid–fluid levels within an elliptic-shape mass with scattered calcifications or ground-glass appearance is highly suggestive of this complicated entity in the paranasal sinus.     

Imaging features of small hepatocellular carcinomas with microvascular invasion on gadoxetic acid-enhanced MR imaging

Objectives

Detection of hepatocellular carcinomas (HCCs) before microvascular invasion (MVI) occurs is important due to the poor outcomes associated with MVI. We retrospectively investigated the imaging features of small HCCs with MVI on gadoxetic acid-enhanced MR imaging.

Methods

Fifty patients (40 men and 10 women; mean age, 54 years) with 58 surgically proven small (2 cm or less) HCCs were evaluated by gadoxetic acid-enhanced MRI. Signal intensities on imaging sequences and the presence of the typical dynamic enhancement pattern (arterial enhancement and washout) were assessed. Fisher's exact tests were performed to evaluate the relationships between the presence of MVI, tumor size, and imaging findings.

Results

None of the 12 small HCCs with diameters of 1 cm or less had MVI, while 15 (33%) of the 46 small HCCs with diameters of 1.1–2.0 cm had MVI (p = 0.025, Fisher's exact test). Among the small HCCs with diameters of 1.1–2.0 cm, all HCCs with MVI showed the typical dynamic pattern and hyperintensity on T2- and diffusion-weighted images. Most HCCs (54 lesions, 93%) were hypointense on hepatobiliary phase images regardless of the presence of MVI.

Conclusions

All small HCCs with MVI showed typical dynamic pattern and hyperintensity on T2-weighted and diffusion-weighted images, while atypical dynamic pattern and size of less than 1 cm in diameter may suggest absence of MVI.     

Malignant spiculated breast masses: dynamic contrast enhanced MR (DCE-MR) imaging enhancement characteristics and histopathological correlation

Aim

Spiculation of breast masses is usually the result of significant desmoplastic reaction. Diminished neovascularization is expected due to sparsely dispersed tumor cells within the lesion. This feature can cause differences in enhancement patterns which can cause pitfalls while evaluating MR images as well. Aim of this study is to explore the enhancement characteristics of malignant spiculated masses and to correlate these findings with histopathological features.

Materials and methods

Eighteen spiculated and seventeen non-spiculated masses depicted with mammography were included in the study. MR imaging was performed with 1.5 T magnet with breast coil. In MR imaging, T2-weighted turbo spin echo (TSE) with fat suppression sequence followed by pre- and post-contrast T1-weighted 3D-fast low angle shot (FLASH) sequences were used. Lesions were evaluated according to enhancement characteristics: early phase enhancement (first 2 min; less than 50%, 50–100% and more than 100%), late phase enhancement (2–6 min; persistent, plateau and washout) and inner enhancement pattern (homogenous, heterogenous and rim). Desmoplasia and lymphocyte infiltration was classified as mild, moderate and severe. MR images and histopathological findings (desmoplasia, lymphocyte infiltration and grade) of both groups were compared.

Results

Mean ages of patients in spiculated and non-spiculated-mass groups were 55.07 (41–71) and 47.35 (31–62), respectively. Mean diameter of lesions was 17.3 mm (10–31 mm) for spiculated masses while non spiculated masses were 15.8 mm (6–40 mm). There were statistically significant differences between late phase enhancement, persistent enhancement, plateau and washout (p < 0.05). Intergroup comparison of desmoplasia revealed significant difference between severe versus and mild, moderate (p < 0.05).

Conclusion

Spiculated malignant lesions are supposed to contain intense desmoplastic reaction. On DCE-MR images they can show persistent enhancement pattern more often than non-spiculated lesions.     

Evaluation of tumor extent in breast cancer patients using real-time MR navigated ultrasound: Preliminary study

Objectives

To evaluate the accuracy of real-time MR navigated ultrasound (MRnav US) for tumor extent measurements in breast cancer and to investigate variables influencing the accuracy of MRnav US in comparison with US alone.

Methods

Fifty-three patients with 60 malignancies underwent preoperative breast MRI and US with or without MRI navigation. Maximum lesion sizes based on MRnav US and US alone were measured, and their relationship with the pathology was analyzed considering the differences in the clinicopathologic variables of the patients.

Results

Among 60 breast cancers, mean lesion size at initial breast US without MRI navigation and at MRI-navigated US was 19 mm and 24 mm, respectively, compared with 28 mm on the histopathology. Overall, the tumor size estimated with MRnav US was more strongly correlated with the histologic tumor size than with US alone. Accurate measurements by MRnav US were significantly more frequent in the lesions that were presented as a mass type on MRI. In addition, the accurate measurement of mass extent was improved with MRnav US in patients who had non-mass type lesions on MRI and who had undergone neoadjuvant systemic chemotherapy when compared with US alone.

Conclusion

MRnav US was more accurate for tumor extent estimation than US alone, and specific clinicopathologic variables can affect the accuracy of MRnav US.