New intravascular contrast agent applied to dynamic contrast enhanced MR imaging of human breast cancer.

PURPOSE: To evaluate the feasibility of using dynamic contrast-enhanced MR imaging with a new intravascular contrast agent in grading human breast cancer. MATERIAL AND METHODS: 23 patients with 27 breast tumors (21 carcinomas and 6 fibroadenomas) were examined with dynamic MR imaging after administration of Clariscan, an iron oxide nanoparticle with large T1 relaxivity and a long plasma half life. A 3D T1-weighted gradient echo sequence with an acquisition time of 60 s was repeated at regular intervals of 3-5 min before and up to 1 h after injection of 2 mg/kg b.w. of Clariscan. The endothelial transfer constant, Kps, which reflects overall vascular permeability, and the fractional plasma volume, fPV, were estimated from time-intensity curves acquired from three separate regions of interest (ROIs): whole tumor, a permeability hot spot, and a blood volume hot spot. Kps and fPV were compared to the results of histologic tumor grading (Scarff-Bloom-Richardson, SBR) and microvascular density, MVD. RESULTS: A statistically significant correlation between the MR-derived Kps parameters and the SBR score was obtained for the whole tumor ROI (R = 0.70), and for the permeability hot spot ROIs (R = 0.67). A correlation between fPV and SBR was detected for the blood volume hot spot ROIs (R = 0.48). There was no statistically significant correlation between Kps or fPV with MVD. CONCLUSION: The results support the hypothesis that dynamic MR with the intravascular contrast agent Clariscan may be used for non-invasive tumor grading.

Magnetic resonance imaging in diplegic form of cerebral palsy.

Eighteen children with diplegic form of cerebral palsy (CP) underwent magnetic resonance imaging (MRI) because of the enlarged occipital horns of both lateral ventricles found on previous computerized tomography (CT). In 16 of them squint was present. MRI in flow attenuated inversion recovery (FLAIR) and turbo spin echo (TSE) modes (T2 weighted images) best showed white matter lesions in occipital areas in all patients with squint, while no white matter changes could be detected in CT (in retrospect), thus proving the superiority of MRI in examining CP children. The authors postulate that the hemispheric occipital lesion causing impairment of visual co-ordination may result in squint.

Axillary lymph node metastases in breast cancer: preoperative detection with dynamic contrast-enhanced MRI.

Metastatic involvement of axillary lymph nodes is one of the most important prognostic variables in breast cancer. The aim of our work was to study the value of dynamic contrast-enhanced MR imaging in revealing axillary lymph node metastases from breast cancer. A total of 65 patients with invasive breast cancer treated with axillary lymph node dissection were preoperatively evaluated by MRI. T1-weighted dynamic contrast-enhanced 3D images were acquired using a coil covering the breast and the axilla. The dynamic contrast enhancement, size, and morphology of the axillary lymph nodes were registered. Histopathological examination revealed axillary lymph node metastases in 24 patients. When using a signal intensity increase in the lymph nodes of >100% during the first postcontrast image as a threshold for malignancy, 57 of 65 patients were correctly classified (sensitivity 83%, specificity 90%, accuracy 88%). These results were not improved when lymph node size and morphology were used as additional criteria. Axillary lymph nodes can be evaluated as a part of an MR-mammography study without substantial increase in examination time, and provide the surgeon with knowledge about the localization of possible metastatic lymph nodes.

Breast lesions: evaluation with dynamic contrast-enhanced T1-weighted MR imaging and with T2*-weighted first-pass perfusion MR imaging.

PURPOSE: To evaluate the diagnostic value of an imaging protocol that combines dynamic contrast-enhanced T1-weighted magnetic resonance (MR) imaging and T2*-weighted first-pass perfusion imaging in patients with breast tumors and to determine if T2*-weighted imaging can provide additional diagnostic information to that obtained with T1-weighted imaging. MATERIALS AND METHODS: One hundred thirty patients with breast tumors underwent MR imaging with dynamic contrast-enhanced T1-weighted imaging of the entire breast, which was followed immediately with single-section, T2*-weighted imaging of the tumor. RESULTS: With T2*-weighted perfusion imaging, 57 of 72 carcinomas but only four of 58 benign lesions had a signal intensity loss of 20% or more during the first pass, for a sensitivity of 79% and a specificity of 93%. With dynamic contrast-enhanced T1-weighted imaging, 64 carcinomas and 19 benign lesions showed a signal intensity increase of 90% or more in the first image obtained after the administration of contrast material, for a sensitivity of 89% and a specificity of 67%. CONCLUSION: T2*-weighted first-pass perfusion imaging can help differentiate between benign and malignant breast lesions with a high level of specificity. The combination of T1-weighted and T2*-weighted imaging is feasible in a single patient examination and may improve breast MR imaging.

[Intranasal meningeal cysts]. / Intrasakrale meningeale cyster.

Intrasacral meningeal cysts are relatively uncommon. They are usually asymptomatic, but because of their expansive character, radicular symptoms or functional disturbances in the urinary bladder or rectum can occur. It is of importance to recognize these cysts in order to give the patient the correct treatment and to avoid unnecessary examinations and operations. The diagnosis can be made by myelography, computer tomography or magnetic resonance imaging.

[Anterior sacral meningocele]. / Fremre sakralt meningocele.

Anterior sacral meningocele is an uncommon and often occult disorder of clinical importance. The pelvic mass induces symptoms mainly because of its pressure on surrounding organs. Obstipation and urinary symptoms are common. In females, complications due to prolonged or obstructed labour and infections are serious and can be fatal. The radiological manifestation is quite typical. It is important to be aware of anterior sacral meningocele in order to reach the right diagnosis, and to suspect it when typical symptoms are present.