Israel Medical Association Journal

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.

Background: Testicular torsion associated with undescended testis is uncommon but requires immediate treatment. Ultrasound Doppler is recognized as the preferred imaging modality for testicular torsion due to its high specificity, sensitivity and availability.

Objectives: To determine the accuracy of ultrasound Doppler in diagnosis of torsion of undescended testis.

Methods: We describe three patients with known undescended testis who were admitted with groin pain and had preoperative ultrasound Doppler. The discrepancy between these and the intraoperative findings is discussed.

Results: In two patients incarcerated inguinal hernia was diagnosed with ultrasound Doppler; however, surgery revealed torsion of an undescended testis. In the third patient ultrasound Doppler diagnosed torsion of undescended testis, but at surgery incarcerated inguinal hernia was found, without evidence of testicular torsion.

Conclusions: Torsion of undescended testis should be a clinical rather than radiologic diagnosis.
 

Background: The current methods for pre‑ and post‑chemotherapy examination of the extent of disease in the breast and lymph nodes do not provide sufficiently accurate information and, not infrequently, the surgeon has to re‑operate.

Objectives: To correlate the findings between three methods of examination (physical examination, ultrasonography, mammography), all performed by the same oncologic and radiologic team, in patients with locally advanced breast cancer or a tumor/breast tissue ratio that precludes breast-conserving surgery.

Methods: Forty patients (median age 48 years, range 24–73) with locally advanced breast cancer or with a tumor/breast ratio that precluded breast‑conserving surgery were evaluated by the same medical team and received neoadjuvant chemotherapy. Surgery was performed in all, and the pathologic specimen was correlated with the results of the other examinations.

Results: In the pre‑chemotherapy evaluation, the imaging findings of the breast correlated with the physical findings in 78% of the patients and with the axilla examination in 66.7%. In the post‑chemotherapy analysis, imaging agreed with the physical findings of the breast in 62.2% and in 76.3% of the axilla. Sonography best detected occult breast disease and axillary lymph nodes but correlated with pathology in only 58% of the patients in diagnosing breast tumor and in 65.8% in diagnosing axillary lymph nodes. Mammography correlated with breast and lymph node pathology in half the patients.

Conclusions: None of the classical methods of post‑neoadjuvant chemotherapy evaluations could adequately delineate the actual extent of the disease in the breast and axillary lymph nodes. More exacting techniques of imaging combined with the classical methods are required.