Israel Medical Association Journal

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: Aural cholesteatoma is an epidermal cyst of the middle ear or mastoid that can only be eradicated by surgical resection. It is usually managed with radical or modified radical mastoidectomy. Clinical diagnosis of recurrent cholesteatoma in a closed postoperative cavity is difficult. Thus, the accepted protocol in most otologic centers for suspected recurrence consists of second-look procedures performed approximately 1 year after the initial surgery. Brain herniation into a post-mastoidectomy cavity is not rare and can be radiologically confused with cholesteatoma on the high resolution computed tomographic images of temporal bones that are carried out before second-look surgery.

Objectives: To present our experience with meningoceles that were confused with recurrent disease in patients who had undergone primary mastoidectomy for cholesteatoma and to support the use of magnetic resonance imaging as more suitable than CT in postoperative follow-up protocols for cholesteatoma.

Methods: We conducted a retrospective chart review of four patients.

Results: Axial CT sections demonstrated a soft tissue mass in the middle ear and mastoid in all four patients. Coronal reconstructions of CT scans showed a tympanic tegmen defect in two patients. CT failed to exclude cholesteatoma in any patient. Each underwent a second-look mastoidectomy and the only finding at surgery was meningocele in all four patients.

Conclusions: Echo-planar diffusion-weighted MRI can differentiate between brain tissue and cholesteatoma more accurately than CT. We recommend that otolaryngologists avoid unnecessary revision procedures by using the newest imaging modalities for more precise diagnosis of the patients who had undergone mastoidectomy for cholesteatoma in the past.
 

Background: The role of endoscopic ultrasound in evaluating the response of esophageal cancer to neoadjuvant chemotherapy is controversial.

Objectives: To evaluate the accuracy of EUS[1] in restaging patients who underwent NAC[2].

Methods: The disease stage of patients with esophageal cancer was established by means of the TNM classification system. The initial staging was determined by chest and abdominal computed tomography and EUS. Patients who needed NAC underwent a preoperative regimen consisting of cisplatin and fluouracil. Upon completion of the chemotherapy, patients were restaged and then underwent esophagectomy. The results of the EUS staging were compared with the results of the surgical pathology staging. This comparison was done in two groups of patients: the study group (all patients who received NAC) and the control group (all patients who underwent primary esophagectomy without NAC).

Results: NAC was conducted in 20 patients with initial stage IIB and III carcinoma of the esophagus (study group). Post-chemotherapy EUS accurately predicted the surgical pathology stage in 6 patients (30%). Pathological down-staging was noted in 8 patients (40%). However, the EUS was able to observe it in only 2 patients (25%). The accuracy of EUS in determining the T status alone was 80%. The accuracy for N status alone was 35%. In 65% of examinations the EUS either overestimated (35%) or underestimated (30%) the N status. Thirteen patients with initial stage I-IIA underwent primary esophagectomy after the initial staging (control group). EUS accurately predicted the surgical pathology disease stage in 11 patients (85%).

Conclusions: EUS is an accurate modality for initial staging of esophageal carcinoma. However, it is not a reliable tool for restaging esophageal cancer after NAC and it cannot predict response to chemotherapy.

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: Computed tomographic colonography, also known as virtual colonoscopy, is a rapid, non-invasive imaging technique for the detection of colorectal masses and polyps that is becoming increasingly popular.

Objectives: To evaluate the availability, technique, standards of performance and indications for CT colonography in Israel.

Methods: A questionnaire on CT colonography was sent to all radiology departments and private institutions that perform CTC[1] in Israel. We evaluated multiple technical parameters regarding the performance and interpretation of CTC as well as radiologists' training and experience.

Results: Fourteen institutions – 7 hospitals and 7 private clinics – participated in the study. Most of the small radiology departments and nearly all of the more peripheral radiology departments do not perform CTC studies. Since 2000 and until March 2007, a total of 15,165 CTC studies were performed but only 14% (2123 examinations) were performed at public hospitals and 86% (13,042 exams) at private clinics. CTC was performed after an incomplete colonoscopy or for various contraindications to endoscopic colonoscopy in up to a third of cases. In the various institutions patients were self-referred in 20–60% of cases, more commonly in private clinics. All CTC examinations were performed on 16–64 slice CT scanners and only a small minority was performed on 4-slice scanners in 2001. All but one center used low radiation protocols. Nearly all facilities used a 2 day bowel-cleansing protocol. All except one facility did not use stool tagging or computer-aided diagnosis. All facilities inflated the colon with room air manually. All institutions used state-of-the-art workstations, 3D and endoluminal navigation, and coronal multi-planar reconstructions routinely. There are 18 radiologists in the country who perform and interpret CTC studies; half of them trained abroad. Ten of the radiologists (56%) have read more than 500 CTC studies.

Conclusions: In Israel, CTC examinations are performed by well-trained and highly experienced radiologists using the latest CT scanners and workstations and adhering to acceptable CTC guidelines.  

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.
 

Background: Catheter ablation is assuming a larger role in the management of patients with cardiac arrhythmias. Conventional fluoroscopic catheter mapping has limited spatial resolution and involves prolonged fluoroscopy. The non-fluoroscopic electroanatomic mapping technique (CARTO) has been developed to overcome these drawbacks.

Objectives: To report the early and late outcome in patients with different arrhythmias treated with radiofrequency ablation combined with the CARTO mapping and navigation system.

Methods: The study cohort comprised 125 consecutive patients with different cardiac arrhythmia referred to our center from January 1999 to July 2005 for mapping and/or ablation procedures using the CARTO system. Forty patients (32%) had previous failed conventional ablation or mapping procedures and were referred by other centers. The arrhythmia included atrial fibrillation (n=13), atrial flutter (n=38), atrial tachycardia (n=25), ventricular tachycardia (n=24), arrhythmogenic right ventricular dysplasia (n=9), and supraventricular tachycardia (n=16).

Results: During the study period, a total of 125 patients (mean age 49 ± 19 years, 59% males) underwent electrophysiological study and electroanatomic mapping of the heart chambers. Supraventricular arrhythmias were identified in 92 patients (73 %) and ventricular arrhythmias in 33 (27%). Acute and late success rates, defined as termination of the arrhythmia without anti-arrhythmic drugs, were 87% and 76% respectively. One patient (0.8%) developed a clinically significant complication.

Conclusions: The CARTO system advances our understanding of arrhythmias, and increases the safety, efficacy and efficiency of radiofrequency ablation.

Background: Echocardiographic assessment of left ventricular function includes calculation of ejection fraction and regional wall motion analysis. Recently, speckle imaging was introduced for quantification of left ventricular function.

Objectives: To assess LVEF[1] by speckle imaging and compare it with Simpson’s method, and to assess the regional LV strain obtained by speckle imaging in relation to conventional echocardiographic scores.

Methods: Thirty consecutive patients, 28 with regional LV dysfunction, underwent standard echocardiographic evaluation. LV end-diastolic volume, LV end-systolic volume and EF were calculated independently by speckle imaging and Simpson’s rule. The regional peak systolic strain presented by speckle imaging as a bull's-eye map was compared with the conventional visual estimate of echo score.

Results: Average EDV[2] obtained by speckle imaging and by Simpson’s method were 85.1 vs. 92.7 ml (P = 0.38), average ESV[3] was 49.4 vs. 48.8 ml (P = 0.94), calculated EF was 43.9 vs. 50.5% (P = 0.08). The correlation rate with Simpson’s rule was high: 0.92 for EDV, 0.96 for ESV, and 0.89 for EF. The peak systolic strain in two patients without wall motion abnormality was 17.3 ± 4.7; in normal segments of patients with regional dysfunction, peak systolic strain (13.4 ± 4.9) was significantly higher than in hypokinetic segments  (10.5 ± 4.5) (P < 0.000001). The strain in hypokinetic segments was significantly higher than in akinetic segments (6.2 ± 3.6) (P < 0.000001).

Conclusions: Speckle imaging can be successfully used for the assessment of LV volumes and EF. Bull's-eye strain map, created by speckle imaging, can achieve an accurate real-time segmental wall motion analysis.