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Background Surgical resection of prolactinomas resistant to dopamine agonists is frequently incomplete due to fibrotic changes of the tumour under pharmacological therapy. In order to identify a subgroup of patients who may benefit from early surgery, we thought to investigate possible predictive factors of pharmacological resistance of prolactinomas to dopamine agonists. Methods We retrospectively analyzed a database of a Belgian tertiary reference center for patients with pituitary tumours from 2014 to 2016. The groups of interest were patients with dopamine agonist responsive and resistant prolactinomas. The possible predictive factors, including MRI findings, endocrinological parameters, response of tumour and patient factors for dopamine agonist resistance were investigated. Results We included 69 patients of whom 52 were women (75,4%) and 17 were men (24,6%). Rate of dopamine agonist resistance was 15.9%. We identified four significant predictors of dopamine agonist resistance: male gender, a large tumour volume, prolonged time to prolactin normalization and presence of a cystic, hemorrhagic and/or necrotic component. In addition, symptoms due to mass effect, high baseline prolactin level and a high contrast capture on MRI are factors that can be taken into consideration. Conclusion We identified predictive factors for pharmacological resistance and developed a scoring system for patient specific prediction of resistance to dopamine agonists. This scoring system may have impact on the timing and decision of surgery in prolactinoma patients after further prospective evaluation.

Objectives: Recently, T1-weighted DCE-MRI was proposed as an alternative to T2*-weighted DSC-MRI for the quantification of perfusion and permeability in brain tumors. The aim of the present feasibility study was to explore the clinical potential of the technique in different tumor types using a case-based review of initial results. Patients and methods: The method for data analysis was adapted from cerebral perfusion CT and applied in this study to a small group of patients with grade IV glioma and other brain tumors. The possible use of the proposed methodology was also explored for characterizing, following-up and planning the therapy of brain tumors. Results: Parametric maps clearly differentiated tumor from the surrounding brain tissue, and also distinguished areas within the tumor presenting with different characteristics, thereby allowing identification of significant target areas for biopsy and/or treatment. Differences in cerebral blood flow (CBF) and lower extraction fractions (E) were observed in various tumors. Progression from a grade II to grade IV glioma over the course of a year was characterized by an increase in CBF and a decrease in E. Conclusion: DCE-MRI-based quantitative perfusion and permeability may be helpful for tumor-grade characterization, biopsy guidance, radiotherapy planning, radiotherapy monitoring and clinical follow-up, thereby improving the non-invasive characterization of brain tumors. (C) 2011 Elsevier Masson SAS. All rights reserved.

Transcranial magnetic stimulation (TMS) is currently used as a non-invasive treatment for depression. In most clinical trials, the left dorsolateral prefrontal cortex (DLPFC) has been selected as the target site for TMS treatment and this region is commonly determined by a "standard procedure", using a fixed position with respect to the motor cortex. In this study, to evaluate the relevance of using individual anatomical data during coil positioning, we used a more individualized localization method, based on three-dimensional magnetic resonance imaging of the head (3D-MRI). We wanted to examine the intra-individual variability of the localization of the stimulation area using a method taking into account individual brain anatomy by 3D-MRI, by comparing this method to the "standard procedure". As expected, even in a gender-controlled sample, our results demonstrate that the difference between the anatomical localization and the standard procedure of a well-defined part of the prefrontal cortex varies within subjects. Therefore, our results confirm the need for a TMS-coil positioning method which incorporates individual anatomical information.

The recent reports confirm the idea that the selection of cerebral stroke patients for thrombolysis should be performed by MRI. These studies suggested that DWI/PWI/MRA may be able to identify patients who are most likely to benefit from thrombolytics, and that the PWI>DWI pattern in particular is associated with an improved outcome from thrombolytic therapy. However, many questions remain unanswered and a lot of work is necessary before MRI guided thrombolysis in acute cerebral stroke becomes a part of the standard care.

Calcifications are uncommon in metastases. Adenocarcinoma, osteopenic, osteosarcoma, lung and breast carcinoma can be the origin. A rare case of calcified cystic brain metastasis deriving from papillary cystadenocarcinoma is reported.

Purpose: To prospectively evaluate whether dose reduction and the application of a prebolus technique can effectively alleviate signal saturation effects in T1 dynamic contrast enhanced (T1-DCE) magnetic resonance imaging (MRI) data in breast tumors and lead to increased diagnostic efficacy of the regional tumor blood flow (TBF) values obtained with deconvolution of T1-DCE MRI data. Materials and Methods: After obtaining informed consent, 23 women (32–80 years) with histologically proven breast tumors underwent MR mammography that included a whole-breast T1 DCE sequence. In the slice where the tumor enhanced maximally, a prebolus protocol was applied. One mL of Gd-DTPA solution at 2 mL/s was injected at the beginning of a dynamic axial single slice inversion-prepared turbo field echo acquisition. At the 400th dynamic, a high dose of either 20 mL (15 patients) or 10 mL (8 patients) of contrast agent was injected at 2 mL/s and a further 400 dynamics were acquired. From the aortic prebolus curve an arterial input function (AIF) was reconstructed by time-shifting and adding the prebolus data. The relative enhancement time course from the tumor region of interest was deconvolved with the reconstructed AIF to generate the impulse response function, the maximum of which yielded the TBF. The institutional ethical committee approved the study. Results: Reducing the contrast dose by a factor of 2 led to an increase in diagnostic contrast for the TBF values of malignant and benign tumors by a factor of slightly more than 2. Addition of the prebolus technique improved this further by 45%. receiver operating characteristic analysis showed a significant increase of diagnostic yield related to the combined use of a prebolus and minimal dose. Conclusion: Using a prebolus approach provides an estimate of the unsaturated AIF, while reduction of the high-dose bolus minimizes possible saturation effects in the tumor time course. J. Magn. Reson. Imaging 2010;31:556–561. ©2010 Wiley-Liss, Inc.

Purpose To determine the association between renal cortical perfusion parameters from T1-DCE magnetic resonance imaging (MRI) and age in human kidney. Materials and Methods Thirty-five patients (mean age: 53 years, SD = 15 years) were imaged using inversion recovery (IR)-prepared FLASH (pulse repitition time [TR] = 4.4 msec, echo time [TE] 2.2 msec, inversion time [TI] = 180 msec, FA 50°, matrix 128 × 256, 0.3 sec/slice) during the injection of Gadolinium-DTPA. Tissue concentration–time courses were deconvolved. Renal blood flow (RBF), volume of distribution (RVD), and mean transit time (MTT) were derived from the resulting impulse response function. Results Mean RBF, RVD, and MTT were 127 mL/min/100 mL (SD = 81 mL/min/100 mL), 40 mL/100 mL (SD 23 mL/100 mL), and 22 sec (SD = 9 sec). A significant moderately negative correlation was found between RBF and age (R = −0.447, P = 0.007), RVD and age (R = −0.420, P = 0.012). MTT and age did not show a significant correlation (R = 0.017, P = 0.924). Repeating this analysis for each gender revealed a moderate age dependence of RBF (R = −0.600 with P = 0.009) and RVD (R = −0.540 with P = 0.021) in the male group only. Conclusion T1-DCE quantitative perfusion MRI was sufficiently sensitive to demonstrate a significant negative correlation of RBF and RVD with patient age. This was due to a moderate age dependence of these quantities in males that seems to be absent in females. J. Magn. Reson. Imaging 2009;29:398–403. © 2009 Wiley-Liss, Inc.

Postmastectomy edema is a current complication after axillary lymph node dissection in cases of breast cancer treatment. Staging is important in order to select those patients who can benefit from complex physical therapy (CPT). Different imaging techniques can be used to evaluate the edema. Ultrasonography (US) is a harmless, cheap, and easily applicable technique to visualize the dermal and subcutaneous tissue, but interpretation of the obtained images is not always evident. The aim of this study was to compare ultrasound images of irreversible edema with tissue histology, magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). Ultrasonographic images of the edematous dermis show an homogeneous hypoechogenic dermal layer that appears on tissue histology to be less compact, due to the excess of fluid in the interstitium separating the collagen fibres and making it more transparent on light microscopy. MRI of the dermis gives a hyperintense signal, indicating the presence of fluid. In the subcutis, increase of the adipose tissue could be observed on US, MRI, and tissue histology. In the case of lymphedema, the area and perimeter of fat cells is significantly (p < 0.05) increased. Hypoechogenic areas near the muscle fascia are registered on US corresponding with epifascial fluid on MRI, and hyperechogenic branches are embedded within the adipose tissue, on tissue histology seen as large fibrotic septa enclosing adipose cells. MRI has a honeycomb picture corresponding with fluid bound to fibrosis.

✓ A case of solitary dorsal intramedullary schwannoma diagnosed by magnetic resonance imaging and treated surgically is reported. The authors review the previously published cases. The possible etiology of the tumor as well as some difficulties encountered in the diagnostic procedure and treatment are discussed.

Background: Myxopapillary ependymoma commonly affects the filum terminale. They are usually well-circumscribed lesions; making complete removal is possible in most cases. Subarachnoidal seeding has been reported months or years after partial or subtotal resection, and more rarely infratentorial metastases. We report an exceptional case presenting with diffuse metastases along the spinal and intracranial subarachnoidal space from the sacral level up to the lateral sulci. Methods: This 25-year-old Caucasian male presented with a 2.5-month history of severe back pain when lying and dysesthesia in both legs. Neurological examination showed only some fasciculations in both quadriceps muscles and was further normal. MR imaging revealed numerous enhancing nodular lesions, varying from 1 to 3 cm in size, scattered throughout the whole spinal cord, around the brainstem and in the Sylvian sulci.We performed a dorsal laminectomy at D4 level because of severe spinal cord compression. Pathological examination demonstrated a myxopapillary ependymoma. Oral chemotherapy was started to avoid radiotherapy regarding the important tumour extent. Despite stable MR imaging, the patient complained of increased back pain and bilateral leg dysesthesia after 2 cycles of Temozolamide and was subsequently treated by radiation therapy. Discussion: Myxopillary ependymoma is considered to be a benign tumour (WHO grade I) arising from the medullar conus and filum terminale involving the whole CNS. The tumour tends to grow slowly, without infiltration of the surrounding neural tissue with seldom metastasis. Intracranial seeding has been reported several months or years after subtotal or partial removal, but spontaneously intracranial seeding at diagnosis is extremely rare.

Open skull surgery of deeply located intracerebral lesions requires precise determination of the treatment area in 3-dimensional (3-D) space. 3-D MRI can give important additional information in presurgical determination of the surgical approach to the target, taking into account highly functional brain areas and important vascular structures. The day before surgery, a grid composed of 9 tubings intersecting at 90 degrees at 1 cm intervals and filled with a CuSO4 solution is firmly attached to the skin of the patient's head in the presumed region of the craniotomy. A 3-D turbo-FLASH sequence is then performed in the sagittal plane after intravenous Gd-DOTA injection on a 1T Magneton. 3-D surface reconstruction of the cortical gyri and sulci is performed. Once the gyri are identified, the 3-D program is then implemented in order to perform a color display of the cortical veins and of the tumor boundaries. The surgical access is then chosen by the surgeon, taking into account highly functional areas. Finally, the boundaries of the tumor are projected on the cortex reconstruction and on the external reference placed on the skin. The entry place for surgery as well as the size of craniotomy are drawn on the skin and the tubed grid is removed. The accuracy of this method tested in 9 patients with deeply located brain tumors or arteriovenous malformations was very satisfactory.(ABSTRACT TRUNCATED AT 250 WORDS)

Purpose: To prospectively determine whether breast carcinomas possess characteristic values of tumor blood flow (TBF) that correlate with pathologic and molecular prognostic markers. Materials and Methods: The institutional ethics committee approved this study. After informed consent was obtained, 57 women (age range, 31-80 years) with histologically proved breast cancer underwent routine magnetic resonance (MR) mammography, which included a whole-breast dynamic contrast material-enhanced (DCE) sequence. A second contrast material bolus was injected during dynamic single-section turbo field-echo imaging of the section where the lesion was maximally enhanced. The relative signal intensity changes were deconvolved in a pixelwise fashion to yield the TBF. Formalin-fixed paraffin-embedded tumor specimens on slides were evaluated for histologic size and grade, as well as for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) protein. In patients with a HER2 protein score of 2+ or 3+, HER2 gene status was assessed. For all prognostic parameters, the Mann-Whitney U test was used to compare median TBF in the HER2-positive group with that in the HER2-negative group. Results: Significantly higher TBF was observed in tumors larger than 2 cm in diameter and in PR-negative and HER2 gene-amplified tumors (P