Israel Medical Association Journal

There are major dilemmas regarding the optimal modalities for breast cancer screening. This is of particular relevance to Israel because of its high-risk population. It was suggested that an avenue for further research would be to incorporate advances in signal processing through the fast Padé transform (FPT) to magnetic resonance spectroscopy (MRS). We have now applied the FPT[1] to time signals that were generated according to in vitro MRS[2] data as encoded from extracted breast specimens from normal, non-infiltrated breast tissue, fibroadenoma and cancerous breast tissue. The FPT is shown to resolve and precisely quantify the physical resonances as encountered in normal versus benign versus malignant breast. The FPT unambiguously delineated and quantified diagnostically important metabolites such as lactate, as well as phosphocholine, which very closely overlaps with glycerophosphocholine and phosphoethanolamine, and may represent a magnetic resonance-visible molecular marker of breast cancer. These advantages of the FPT could clearly be of benefit for breast cancer diagnostics via MRS. This line of investigation should continue with encoded data from benign and malignant breast tissue, in vitro and in vivo. We anticipate that Padé-optimized MRS will reduce the false positive rates of MR-based modalities and further improve their sensitivity. Once this is achieved, and given that MR entails no exposure to ionizing radiation, new possibilities for screening and early detection emerge, especially for risk groups. For example, Padé-optimized MRS together with MR imaging could be used with greater surveillance frequency among younger women with high risk of breast cancer.

Background: Assessment of small intestinal disease remains a challenge for both clinicians and radiologists. Modern magnetic resonance enterography (MRE) is a non-radiation modality that can demonstrate both intestinal wall pathologies and extraluminal lesions.

Objectives: To analyze the results of 213 MRE scans performed since 2005.

Methods: Consecutive MRE[1] scans performed in our academic medical center between December 2005 and November 2009 were reviewed for patients' demographic data, indications for the examination, and main imaging findings. The imaging findings recorded were mural changes and intraluminal filling defects; there were also mesenteric findings and extraintestinal inflammatory findings.

Results: During the study period 213 MRE scans were performed; 70% of them for proven or suspected Crohn's disease (CD) of the small bowel. Another indication was small bowel neoplasm (6% of the scans). Bowel wall thickening and enhancement were seen in 60% and 53% of MRE scans, respectively. Mesenteric involvement was found in 52% of the patients. Incidental extraintestinal findings were detected in 17% of the scans. In 22% of the scans there was no pathological finding.

Conclusions: Our 4-year clinical experience with MRE shows that this non-invasive and non-radiating modality is a powerful technique for evaluation and long-term follow-up of small bowel pathologies. The most common clinical indication was the evaluation of Crohn’s disease. With physicians’ increased awareness, the future use of MRE in the evaluation of other small bowel pathologies such as neoplasm and celiac disease will increase.

Background: Magnetic resonance imaging of the breast has emerged as a valuable imaging tool in addition to conventional imaging modalities. It has high sensitivity for malignant lesions, and can detect mammographically, sonographically and clinically occult cancers. “MR only” lesions are best biopsied under MR guidance; however, this may be a challenging task.

Objectives:  To evaluate our initial clinical experience with MR-guided core needle breast biopsy and MR-guided needle localization.

Methods: We retrospectively evaluated 81 women with 97 lesions, who were scheduled for guided core needle biopsy or MR-guided needle localization followed by surgery. Lesions were categorized as malignant, high risk, or benign according to the BI- RADS MR classification system. MR findings were compared with final histopathology or with follow-up imaging findings.

Results: Fifteen (16%) lesions were malignant (9 invasive ductal carcinoma, 2 invasive lobular carcinoma, 4 ductal carcinoma in situ); 7 (7%) lesions were high risk (4 atypical ductal hyperplasia, 3 radial scars); 75 (77%) lesions were benign, mainly fibrocystic changes. Other benign findings were sclerosing adenosis, pseudoangiomatous stromal hyperplasia, fat necrosis, intraductal papilloma, fibroadenoma, capillary hemangioma, and florid ductal hyperplasia. No major complications were encountered.
Conclusions: MR-guided interventional procedures of the breast are accurate, safe and feasible methods for sampling breast lesions detected only by MR and have become a significant tool in the management of certain patients.

Background: Stem cell-based therapy is a promising approach for the treatment of neurodegenerative disease. In our laboratory, a novel protocol has been developed to induce bone marrow-derived mesenchymal stem cells into neurotrophic factor-secreting cells. These cells produce and secrete factors such as BDNF (brain-derived neurotrophic factor) and GDNF (glial-derived neurotrophic factor).

Objectives: To evaluate the migratory capacity and efficacy of NTF-SC[1] in animal models of Parkinson's disease and Huntington's disease.

Methods: MSCs[2] underwent two-phase medium-based induction. An efficacy study was conducted on the 6-hydroxydopamine-induced lesion, a rat model for Parkinson's disease. Cells were transplanted on the day of 6-OHDA[3] administration, and amphetamine-induced rotations were measured as a primary behavioral index. In a second experiment, migratory behavior was examined by transplanting cells a distance from a quinolinic acid-induced striatal lesion, a rat model for Huntington's disease. Migration, in vivo, was monitored using longitudinal magnetic resonance imaging scans followed by histology.

Results: NTF-SCs attenuated amphetamine-induced rotations by 45%. HPLC analysis demonstrated a marked decrease in dopamine depletion, post-cellular treatment. Moreover, histological assessments revealed that the engrafted cells migrated and acted to regenerate the damaged striatal dopaminergic nerve terminal network. In a preliminary work on an animal model for Huntington's disease, we demonstrated by high resolution MR images and correlating histology that induced cells migrated along the internal capsule towards the QA[4]-induced lesion.

Conclusions: The induced MSCs are a potential therapy for neurodegenerative diseases, due both to their NTF secretion and their ability to migrate towards the diseased tissue.

Background: Manganism is a central nervous system disorder caused by toxic exposure to manganese. Manganism has been related to occupational exposures, liver diseases, prolonged parenteral nutrition, and abuse of illicit drugs. Initially manifested by a reversible neuropsychiatric syndrome (locura manganica), the main symptoms and signs of manganism are emotional lability, compulsive behavior and visual hallucinations. Locura manganica is followed by an irreversible extrapyramidal syndrome, the onset of which occurs years after chronic exposure.

Objectives: To characterize the regional distribution of Mn[1] in the rat brain after subchronic exposure to Mn. This animal model holds special clinical relevance, reflecting the earlier clinical stages of manganism before chronic exposure to Mn exerts its irreversible effects.

Methods: Sprague-Dawley rats were intravenously injected with MnCl₂ weekly, for a total of 14 weeks – approximately 1/10 of the lifetime of the rat. T1-weighted magnetic resonance imaging was used to detect the distribution of Mn deposition in brain tissues, as evidenced by areas of T1-weighted hyperintense signals.

Results: A consistent region-specific pattern of T1-weighted hyperintensities was observed in the brains of Mn-treated rats. Cortical hyperintensities were prominent in the hippocampus and dentate gyrus. Hyperintensities were also observed in the olfactory bulbs, pituitary gland, optic nerves and chiasma, pons, midbrain tegmentum, habenula, lentiform and caudate nuclei, thalamus, chorioid plexus and cerebellar hemispheres.

Conclusions: Prominent Mn depositions, evidenced by T1-weighted hyperintensities in the hippocampus after subacute exposure to Mn, are compatible with the clinical picture of manganism during its early stages; and may explain its pathophysiology.  

Background: Occult breast cancer without clinically or mammographically detectable breast tumor is an uncommon presentation.

Objectives: To assess the role of breast MRI in women with metastatic carcinoma and an occult primary, and to define the MRI characteristics of the primary breast tumor.

Methods: This retrospective study evaluated 20 women with metastatic carcinoma of unknown origin who underwent breast MRI between 2000 and 2006. Four women were excluded, leaving 16 in the study group. Probability of malignancy was assessed according to BIRADS classification. MRI performance in detecting lesions and evaluating disease extent was assessed, with the gold standard being surgical or biopsy pathology.

Results: MRI detected suspicious lesions in 15 patients. Lesion size ranged from 0.4 to 7 cm (median 1.5 cm). MRI detected a single lesion in 6 patients (40%), multifocal disease in 3 (20%), multicentric disease in 4 (27%), and bilateral breast lesions in 2 (13%). In 13 patients MRI depicted the primary breast cancer. Initial treatment was surgical in nine; MRI correctly estimated disease extent in 6 (67%), underestimated disease extent in 1 (11%), and overestimated it in 2 (22%). Four patients had biopsy followed by chemotherapy; one had multicentric disease and one had multifocal disease. MR findings were false positive in two patients and false negative in one.

Conclusions: MRI is sensitive in detecting the primary tumor and beneficial in assessing tumor extent. Small size and multiple foci are common features. We suggest that bilateral breast MRI be part of the evaluation of women with metastatic carcinoma and an occult primary.