Magnetic resonance imaging of breast lesions - A pathologic correlation
Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Ngan Shing Street, Shatin, NT, Hong Kong. Breast Cancer Research and Treatment
(Impact Factor: 3.94).
06/2007; 103(1):1-10. DOI: 10.1007/s10549-006-9352-3
Magnetic resonance imaging of the breast is useful in assessing breast lesions. An understanding of the pathologic characteristics of the tumors may help to understand these magnetic resonance imaging observations.
Large lesional size (>10 mm), ill-defined margin, and irregular outlines are associated with malignancy. These correlate with the pathological features of breast tumor, characterized by rapid growth rate, large size, and infiltrative growth pattern, invasion into stroma resulting in desmoplasia, and hence irregular outline and margin. The detection and estimation of tumor extent of invasive lobular carcinoma is problematic, even with magnetic resonance imaging, which is considered the most sensitivity. This inaccuracy likely derives from the characteristic linear, single cells infiltration growth pattern of the tumor, which is also often underestimated by clinical examination. Estimation of tumor extent after neoadjuvant chemotherapy is also essential but problematic by imaging, as the shrunken tumor becomes fibrotic, with stromal hyalinization, diminished microvasculature and tumor break up causing size underestimation. Non-enhancement of breast tumors occurs in about 8% of cases correlates with diffuse growth pattern, particularly of infiltrative lobular carcinoma. The observation of disproportionately high non-enhancing ductal carcinoma in situ remains an enigma. Finally, early rim enhancement correlates with small cancer nests, low ratio of peripheral to central fibrosis and high ratio of peripheral to central microvessel density. These may be related to increased vascular endothelial growth factor mediated increased microvessel density as well as increased permeability, which manifest as increased rapid contrast uptake and dissipation.
Available from: Marc Lobbes
- "For nonmass-like enhancement, features that have the highest positive predicitive value are clumped linear, segmental or regional enhancement. Lesions larger than 10 mm have a higher positive predictive value for being malignant than lesions < 10 mm (Tse et al., 2007). "
[Show abstract] [Hide abstract]
ABSTRACT: The system described in this paper is an outgrowth of one described in  and is a combination of deterministic and probabilistic speech recognition strategies. It is intended for telephone quality speech and possible single chip implementation with memory requirements of 256 bytes for processing (RAM) and 8k bytes for template storage and programs (ROM). Two major modifications for effecting reduction in memory requirements are described. The first is the use of a one-pass analysis algorithm for processing an utterance. The second is an approach for generation of uniform segment prototypes. Modification of the original system for telephone quality speech included obvious changes in filter bank analysis and parameterization of each phonetically classified segment with more emphasis on the voiced portions of utterances. The system was evaluated on a ten digit vocabulary (21 talkers, over 1000 tokens) and showed an accuracy of 94.4% with a 3.1% error rate and 2.5% rejection rate.
Available from: ajronline.org
[Show abstract] [Hide abstract]
ABSTRACT: The purpose of our study was to evaluate the effectiveness of gadolinium-enhanced MR imaging in imaging arterial, venous, and ureteric anatomy in a group of potential laparoscopic renal donors and to compare our findings with those established at surgery.
Sixty-four consecutive patients underwent successful laparoscopic donor nephrectomy. Imaging of the kidneys was performed before surgery with MR imaging and breath-hold three-dimensional gadolinium-enhanced MR angiography. All studies were reviewed prospectively by one of two attending radiologists. Results were compared with findings at the time of laparoscopic nephrectomy.
Of the 64 patients, MR imaging and MR angiography identified 30 patients with normal arterial, venous, and ureteric anatomy, and concordance was found at surgery in 29 of these patients. Vascular anomalies were depicted on MR imaging in 34 patients, with complete concordance at surgery in 29 patients. The use of MR angiography for revealing arterial anomalies had a sensitivity of 89.4%, specificity of 94.1%, and accuracy of 90.6%. For venous anomalies, there was a sensitivity of 98.3%, specificity of 100%, and accuracy of 98.4%. No important utereric anomalies were identified at surgery or on MR imaging.
Renal MR imaging and gadolinium-enhanced MR angiography provide a safe, accurate, and minimally invasive means of comprehensive assessment of the potential living renal donor.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.