			Home About us Contact

Enhancement Patterns (enhancement + pattern)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Clinicopathological review of 46 primary retroperitoneal tumors

INTERNATIONAL JOURNAL OF UROLOGY, Issue 9 2007
Mitsuhiro Tambo
Objectives: To clarify the clinical factors including diagnostic imaging findings that may correlate with the histopathological malignancy in primary retroperitoneal tumors. Methods: The clinical backgrounds and imaging findings of 22 benign and 24 malignant primary retroperitoneal tumors were retrospectively investigated, and the prognosis of patients with malignant retroperitoneal tumors was assessed. Results: There were significant correlations between the presence of symptoms and malignancy (P < 0.01), as well as between the irregularity of tumor margins and malignancy (P < 0.01). On dynamic magnetic resonance imaging (MRI), 90% of malignant tumors showed early enhancement either with quick or slow washout, while 75% of benign tumors showed delayed and no enhancement (P < 0.002). All malignant and benign paraganglioma showed the same early enhancement with quick washout. Malignant lymphoma showed various enhancement patterns. The 2-year and 5-year cause-specific survival rates of the patients with malignant retroperitoneal tumors were 68.0% and 43.2%, respectively. All malignant lymphoma patients were mainly treated with chemotherapy after being diagnosed histologically. Malignant paraganglioma patients who could not meet complete resection needed chemotherapy for promising survival. Conclusion: The symptoms, the irregularity of the margins, and the specific enhancement pattern on the dynamic MRI may be important predictive factors of the primary malignant retroperitoneal tumors. Histological diagnosis was needed for malignant definition of paraganglioma because both benign and malignant paraganglioma showed similar clinical and imaging findings. Preoperative biopsy should be considered for selection of the appropriate treatment particularly in patients that are likely to have malignant lymphoma that could not be diagnosed definitively by the clinical and imaging findings. [source]

Focal nodular hyperplasia: Central scar enhancement pattern using gadoxetate disodium

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2010
Adib R. Karam MD
Abstract Purpose: To illustrate the unusual enhancement pattern of the focal nodular hyperplasia central scar using Gadoxetate Disodium. Materials and Methods: Over a 10-month period, six patients, with a total of seven focal nodular hyperplasia lesions with typical central scar, had MRI of the liver using Gadoxetate Disodium (Eovist, Bayer HealthCare Pharmaceuticals Inc., Wayne, NJ). Four of the six patients had a prior Gadobenate Dimeglumine (Multihance, Bracco Diagnostics Inc., Princeton, NJ) -enhanced MRI of the liver performed within the previous year. The dynamic enhancement pattern of the central scar on the 10 liver MRIs was independently analyzed by two abdominal imaging radiologists who were blinded to the contrast agent used. Results: On the Gadoxetate Disodium-enhanced MRIs and during the arterial phase, 1-min, 2-min, and 3-min delay, none of the central scars demonstrated enhancement. However, all four of the lesions that were previously scanned using Gadobenate Dimeglumine demonstrated typical enhancement after a 3-min delay. Conclusion: On Gadoxetate Disodium-enhanced MRIs of the liver, the central scar of focal nodular hyperplasia lesions does not typically demonstrate delayed enhancement. J. Magn. Reson. Imaging 2010;32:341,344. © 2010 Wiley-Liss, Inc. [source]

BI-RADS MRI Enhancement Characteristics of Ductal Carcinoma In Situ

THE BREAST JOURNAL, Issue 6 2007
Eric L. Rosen MD
Abstract:, To identify the Breast Imaging Reporting and Data System magnetic resonance imaging (MRI) enhancement characteristics of ductal carcinoma in situ (DCIS). A retrospective review of consecutive patients who underwent breast MRI for newly diagnosed breast carcinoma prior to surgery was conducted. This yielded 381 lesions in 361 patients with pathologic confirmation of either DCIS alone, invasive carcinoma alone, or mixed invasive and in-situ disease. Presence or absence of a MRI lesion at the site of the documented carcinoma was recorded, and for all identified MRI lesions the Breast Imaging Reporting and Data System morphology patterns were recorded. MRI features of the different malignancy types were compared utilizing Fisher's exact tests; 64/381 (16.8%) lesions had DCIS, 101/381 (26.5%) had invasive carcinoma, and 216/381 (56.7%) had mixed invasive/in situ carcinoma. A MRI lesion corresponding to the known cancer was identified in 55/64 (85.9%) cases of DCIS, 98/101 (97.0%) cases of invasive carcinoma, and 212/216 (98.1%) cases of mixed invasive and in-situ carcinoma. For pure DCIS lesions, 38/64 (59.4%) exhibited nonmass-like enhancement (NMLE), 9/64 (14.1%) were masses, and 8/64 (12.5%) were a focus. For pure invasive carcinomas 79/101(78.2%) were masses, 16/101 (15.8%) were NMLE, and 3/101 (3.0%) were a focus. For mixed lesions 163/216 (75.5%) were masses, 44/216 (20.4%) demonstrated NMLE, and 5/216 (2.3%) were a focus. The most common NMLE patterns of pure DCIS were segmental distribution and clumped internal enhancement. Although there is overlap in the MRI morphology and enhancement pattern of in situ and invasive breast carcinoma, DCIS more frequently manifests as NMLE than does invasive carcinoma. [source]

Clinicopathological review of 46 primary retroperitoneal tumors

Post-radiotherapy contrast enhancement changes in fast dynamic MRI of cervical carcinoma

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 4 2001
Erik A. Boss MD
Abstract This pilot study determines fast dynamic gadolinium enhanced MRI contrast enhancement parameters (onset of enhancement and time to peak enhancement) before and after radiotherapy in 10 cervical carcinoma patients. Before radiotherapy, onset of enhancement and time to peak enhancement were early, with a median of 4.5 and 5.2 seconds, respectively. High-grade tumors showed early enhancement, compared with low-grade. After radiotherapy, contrast enhancement patterns differed. In survivors, onset of enhancement after radiotherapy was later than before radiotherapy. In non-survivors, onset of enhancement after radiotherapy was still early. The median difference in onset of enhancement before and after radiotherapy in survivors and non-survivors was an increase of 3.2 and a decrease of 1.1 seconds, respectively. Early onset of enhancement after radiotherapy was a better predictor for survival than a high-signal intensity zone on post radiotherapy unenhanced T1/T2-weighted MRI. It is concluded that enhancement parameters from fast dynamic Gd-enhanced MR images can provide additional functional information with regard to tumor vascularization, and may have prognostic significance. It complements clinical examination and unenhanced MRI in determining the effectiveness of radiotherapy treatment in cervical carcinoma. Future studies will focus on the clinical utility and improvements of the estimation of contrast-enhanced parameters with this new technique. J. Magn. Reson. Imaging 2001;13:600,606. © 2001 Wiley-Liss, Inc. [source]

Recent advances in breast MRI and MRS

NMR IN BIOMEDICINE, Issue 1 2009
S. Sinha
Abstract Breast MRI is an area of intense research and is fast becoming an important tool for the diagnosis of breast cancer. This review covers recent advances in breast MRI, MRS, and image post-processing and analysis. Several studies have explored a multi-parametric approach to breast imaging that combines analysis of traditional contrast enhancement patterns and lesion architecture with novel methods such as diffusion, perfusion, and spectroscopy to increase the specificity of breast MRI studies. Diffusion-weighted MRI shows some potential for increasing the specificity of breast lesion diagnosis and is even more promise for monitoring early response to therapy. MRS also has great potential for increasing specificity and for therapeutic monitoring. A limited number of studies have evaluated perfusion imaging based on first-pass contrast bolus tracking, and these clearly identify that vascular indices have great potential to increase specificity. The review also covers the relatively new acquisition technique of MR elastography for breast lesion characterization. A brief survey of image processing algorithms tailored for breast MR, including registration of serial dynamic images, segmentation and extraction of morphological features of breast lesions, and contrast uptake modeling, is also included. Recent advances in MRI, MRS, and automated image analysis have increased the utility of breast MR in diagnosis, screening, management, and therapy monitoring of breast cancer. Copyright © 2008 John Wiley & Sons, Ltd. [source]

MRI and 1H MRS of The Breast: Presence of a Choline Peak as Malignancy Marker is Related to k21 Value of the Tumor in Patients with Invasive Ductal Carcinoma

THE BREAST JOURNAL, Issue 6 2008
Patricia R. Geraghty MD
Abstract:, To assess which specific morphologic features, enhancement patterns, or pharmacokinetic parameters on breast Magnetic Resonance Imaging (MRI) could predict a false-negative outcome of Proton MR Spectroscopy (1H MRS) exam in patients with invasive breast cancer. Sixteen patients with invasive ductal carcinoma of the breast were prospectively included and underwent both, contrast-enhanced breast MRI and 1H MRS examination of the breast. The MR images were reviewed and the lesions morphologic features, enhancement patterns and pharmacokinetic parameters (k21-value) were scored according to the ACR BI-RADS-MRI lexicon criteria. For the in vivo MRS studies, each spectrum was evaluated for the presence of choline based on consensus reading. Breast MRI and 1H MRS data were compared to histopathologic findings. In vivo 1H MRS detected a choline peak in 14/16 (88%) cancers. A false-negative 1H MRS study occurred in 2/16 (14%) cancer patients. K21 values differed between both groups: the 14 choline positive cancers had k21 values ranging from 0.01 to 0.20/second (mean 0.083/second), whereas the two choline-negative cancers showed k21 values of 0.03 and 0.05/second, respectively (mean 0.040/second). Also enhancement kinetics did differ between both groups; typically both cancers that were choline-negative showed a late phase plateau (100%), whereas this was only shown in 5/14 (36%) of the choline positive cases. There was no difference between both groups with regard to morphologic features on MRI. This study showed that false-negative 1H MRS examinations do occur in breast cancer patients, and that the presence of a choline peak on 1H MRS as malignancy marker is related to the k21 value of the invasive tumor being imaged. [source]

Magnetic Resonance Imaging of Benign Phyllodes Tumors of the Breast

THE BREAST JOURNAL, Issue 3 2004
Takayuki Kinoshita MD
Abstract: Magnetic resonance imaging (MRI) has the potential to become a useful adjunct in breast imaging. Contrast-enhanced breast MRI has demonstrated a high sensitivity in the detection of benign and malignant breast disease. Our study aimed to correlate the dynamic contrast-enhanced MRI appearance of benign phyllodes tumor of the breast with histopathologic findings. We retrospectively reviewed the MRI findings in eight patients with benign phyllodes tumor of the breast to describe the image characteristics of this disease. The architectural features and enhancement patterns of this tumor were assessed and compared with other breast diseases. MRIs demonstrated some characteristics for large benign phyllodes tumors (more than 3 cm in size). On T2 -weighted images, they were imaged as spotted tumors in high to iso signal intensity with cystic components or septations inside. In the time-signal intensity curve for the eight patients in our study who underwent dynamic MRI, we demonstrated two patterns of their curve: rapidly and gradually enhanced. In conclusion, MRI findings in benign phyllodes tumor include dynamic curves of gradually and rapidly enhancing types, and a low and inhomogeneous signal intensity on T2 -weighted images compared with fibroadenoma. These findings appear to be useful for diagnosis., [source]