Combination of low and high resolution sequences in two orientations for dynamic contrast-enhanced MRI of the breast: more than a compromise.

The purpose was to combine T1-weighted 3D gradient echo sequences at low and high spatial resolution (and short and longer acquisition time, respectively) in two orientations without compromising signal/time curve analysis and to evaluate the incremental value of assessing architectural features in high resolution images in dynamic contrast-enhanced MR mammography. T1-weighted 3D-FLASH sequences in a 1.5-T scanner (512 x 256 pixel matrix at high resolution; 256 x 128 pixels at low resolution sequences, 72 slices, 1.7-mm slice thickness, TR 8.8 ms, TE 4.5 ms, flip angle 25 degrees) were acquired in a special order during a single investigation. Three observers evaluated architectural features of 36 histopathologically proven lesions using high or low resolution images independently. Architectural features of each lesion were assessed by rating on two three-point scales. Kappa statistics verified the decrease of inter-observer variability. All observers improved assessment of architectural features regarding high resolution images in transversal and coronal orientation (observer A: eight positive, three negative corrections; B: 12/5; C: 16/4). Most positive corrections resulted from improved detection of morphologic criteria of malignancy. Mean inter-observer agreement significantly (P<0.05) increased from "slight" to "moderate" (mean weighted kappa increased from 0.185 to 0.422). This protocol at the charge of slightly enlarged time for measurement offers an elegant way to improve analysis of architectural features in MRM.

Sympathetic vasomotor response of the radial artery in patients with diabetic foot syndrome.

OBJECTIVE: Neurophysiological assessment of the peripheral autonomic system is characterized by various limitations. An alternative approach to laser Doppler and venous plethymography is the assessment of the sympathetic vasomotor response of the radial artery obtained by continuous wave Doppler sonography. Nomogram data have been established and demonstrate the temporary disappearance of diastolic flow after coughing or deep inspiration. RESEARCH DESIGN AND METHODS: We assessed the sympathetic vasomotor response in 25 patients (mean age 64 years, range 43-76) with diabetic foot syndrome. The Doppler data were correlated with nerve conduction studies of the median and peroneal nerve, the extent of radiologically diagnosed media sclerosis, and compared with nomogram values (n = 41). RESULTS: Although similar mean flow velocities were found under baseline conditions, the flow pattern was characterized by higher pulsatility in the diabetic group (resistance index [RI] 1.1 vs. 0.7). No significant difference in RI was observed after coughing. The latency of onset of the response was prolonged (2.1 vs. 1.5 s), while the duration of the response did not differ (18 vs. 15 s). Only the nerve conduction velocity of the peroneal nerve correlated inversely with the RI. The extent of radiologically proven calcification tended to correlate with the pulsatility of the baseline signal and the response latencies. CONCLUSIONS: The data obtained by this study suggest the concurrent existence of reduced vessel elasticity due to media sclerosis and dysfunction of the autonomic vasomotor system.

Outcome analysis and rational management of enhancing lesions incidentally detected on contrast-enhanced MRI of the breast.

OBJECTIVE: The purpose of our study was to assess the prevalence, characteristics, and clinical consequence of incidentally detected enhancing lesions on MRI of the breast. SUBJECTS AND METHODS. MRI of the breast (1.0-T scanner, dynamic gadolinium-enhanced T1-weighted three-dimensional gradient-echo sequence, double breast coil) was performed on 1273 women for different indications. Enhancing incidental lesions were defined as enhancing lesions on MRIs that were not expected from findings on the previous conventional imaging. They were classified in five assessment categories using a scoring system based on morphologic and kinetic enhancement characteristics. Detection of enhancing incidental lesions resulted in a review of mammograms and sonograms with the aim of also localizing these lesions on conventional imaging. The lesions were either biopsied or followed up. RESULTS: Twenty-five percent (274/1086) of all enhancing lesions detected in the study population were enhancing incidental lesions. Enhancing incidental lesions were found in 16% (210/1273) of all study patients. Forty-one percent (113/274) of the enhancing incidental lesions were histologically confirmed. Forty-eight percent (54/113) of the biopsied and 20% (54/274) of all enhancing incidental lesions were malignant. Eleven percent (54/508) of all malignant lesions occurring in the 1273 women were detected solely through additional MRI. Fifty-seven percent (31/54) of these MRI-detected malignant lesions could be identified on a reevaluation of sonograms and mammograms. CONCLUSION: Detection of enhancing incidental lesions should lead to a thorough reevaluation of mammograms and sonograms. If not reidentified, suspicious enhancing incidental lesions should be biopsied, and enhancing incidental lesions that are probably benign should be carefully followed up. Indeterminate enhancing incidental lesions should be histologically examined by minimally invasive techniques or, if they are small, followed up by another MRI 6 months later.

Preoperative assessment of breast cancer: sonography versus MR imaging.

OBJECTIVE: The purposes of our study were to compare the diagnostic value of whole-breast sonography and MR imaging as adjunctive techniques to mammography and to determine whether MR imaging should be used routinely in the preoperative assessment of patients with suspected breast cancer. SUBJECTS AND METHODS: . One hundred four women (age range, 34-84 years; mean age, 60 years) with findings highly suggestive of malignancy in the breast were examined with mammography, sonography, and dynamic MR imaging before undergoing surgery. All visualized suspicious lesions were correlated histologically. The diagnostic relevance of sonographic and MR imaging findings was compared with the diagnostic value of the findings of clinical examination and mammography alone. RESULTS: . Twenty-seven tumors showed multifocal or multicentric invasive growth at pathology. Of these 27, 48% were correctly diagnosed via mammography alone; 63%, via the combination of mammography and sonography; and 81%, via MR imaging. Nine of the index tumors were invisible on mammography but were detected on sonography. Use of sonography benefited 13 patients and produced two studies with false-positive findings. Use of MR imaging benefited seven patients and produced eight studies with false-positive findings. In summary, 93% of all patients gained no advantage from MR imaging. Relevant additional findings were significantly more frequent in patients with dense breasts. CONCLUSION: Although MR imaging is most sensitive for the detection of small tumors, routine preoperative MR imaging appears to be unnecessary for most patients if a combination of mammography and whole-breast sonography is used. Additional MR imaging can be restricted to problematic cases in women with dense breast parenchyma.

Undetected malignancies of the breast: dynamic contrast-enhanced MR imaging at 1.0 T.

PURPOSE: To assess the prevalence and characteristics of malignant breast lesions not identified with magnetic resonance (MR) imaging. MATERIALS AND METHODS: Breast tissue specimens were obtained in 464 of 967 patients who had undergone dynamic gadolinium-enhanced T1-weighted fast low-angle shot three-dimensional MR imaging of both breasts. A comparison of sensitivity, specificity, and predictive values of the prospectively recorded findings of mammography, ultrasonography (US), and MR imaging with the histopathologic results was performed with receiver operating characteristic (ROC) curve analysis. MR imaging examination findings that caused a false-negative diagnosis were reviewed to identify possible sources of error. RESULTS: Histopathologic analysis revealed 244 benign and 354 malignant lesions. The sensitivity values for mammography, mammography combined with US, MR imaging alone, and the combination of all three modalities were 73.7%, 88.1%, 88.4%, and 95.5%, and the areas under the ROC curves were 0.744, 0.829, 0.850, and 0.876, respectively. Twenty-eight (8.4%) of 334 invasive and 13 (65%) of 20 intraductal carcinomas were missed with MR imaging. In eight cases, motion artifacts (n = 1), tumor location near or beyond the outer boundary of the field of view (n = 3), inadequate infusion of the contrast material (n = 1), and masking of the tumors by intensively enhanced surrounding glandular tissue (n = 3) were identified as adequate explanations for the false-negative results. The remaining missed breast cancers (n = 33) exhibited very diffuse growth patterns or were 5 mm or smaller. CONCLUSION: MR imaging did not depict 41 of 354 malignant tumors for several reasons.