Recording event-related activity under hostile magnetic resonance environment: Is multimodal EEG/ERP-MRI recording possible?

Event-related potentials (ERPs) have high temporal resolution, but insufficient spatial resolution; the converse is true for the functional imaging techniques. The purpose of the study was to test the utility of a multimodal EEG/ERP-MRI technique which combines electroencephalography (EEG) and magnetic resonance imaging (MRI) for a simultaneously high temporal and spatial resolution. The sample consisted of 32 healthy young adults of both sexes. Auditory stimuli were delivered according to the active and passive oddball paradigms in the MRI environment (MRI-e) and in the standard conditions of the electrophysiology laboratory environment (Lab-e). Tasks were presented in a fixed order. Participants were exposed to the recording environments in a counterbalanced order. EEG data were preprocessed for MRI-related artifacts. Source localization was made using a current density reconstruction technique. The ERP waveforms for the MRI-e were morphologically similar to those for the Lab-e. The effect of the recording environment, experimental paradigm and electrode location were analyzed using a 2x2x3 analysis of variance for repeated measures. The ERP components in the two environments showed parametric variations and characteristic topographical distributions. The calculated sources were in line with the related literature. The findings indicated effortful cognitive processing in MRI-e. The study provided preliminary data on the feasibility of the multimodal EEG/ERP-MRI technique. It also indicated lines of research that are to be pursued for a decisive testing of this technique and its implementation to clinical practice.

Magnetic resonance imaging of muscular involvement in juvenile dermatomyositis: case report.

A case of 5 year old juvenile patient with dermatomyositis together with conventional and diffusion-weighted MRI images is reported. The reported case was atypical for the pattern of involvement of the accompanying oedema which was affecting distal parts of the extremities and anterior muscle groups. Electromyography was negative. The case confirmed by a pathologist demonstrates the use of diffusion weighted imaging in determining unequivocal oedema and its exact extent.

Estimating femoral nail length in bilateral comminuted fractures using fibular and femoral head referencing.

OBJECTIVE: Femoral nail length can be estimated preoperatively by several methods, but this usually requires an intact contralateral femur. The aim of this study was to determine an alternative method using fibula and femoral head as references. MATERIALS AND METHODS: Digital radiographic views of the lower limbs of 102 healthy volunteers were used to compare femoral medullary length with the sum of fibular length and transverse head diameter. RESULTS: Femoral medullary length and the estimated length were highly correlated (r=0.942, p<0.0001). Paired samples t-testing has produced a high significance (p<0.002). CONCLUSION: The formula provides a simple and accurate estimation of femoral medullary length, and may be used in nailing, particularly of bilateral comminuted femoral fractures.

Use of dynamic contrast-enhanced magnetic resonance imaging for differentiating between aggressive rectal tumours: two cases with small cell carcinoma and malignant melanoma.

Poorly differentiated small cell carcinomas and malignant melanomas are among the rarest of primary colorectal malignancies. Although very aggressive and lethal, small cell carcinomas and the amelanotic variety of malignant melanomas have similar radiological features to adenocarcinomas. We present two different cases with these unusual tumours, with special emphasis on their dynamic contrast-enhanced magnetic resonance imaging features. The dynamic contrast-enhanced magnetic resonance imaging revealed that these tumours have a faster and stronger enhancement pattern than most adenocarcinomas. The technique is thus potentially useful for the preoperative diagnosis of unusual aggressive tumours and for guiding the choice of treatment.

A case of frontal lobe abscess as a complication of frontal sinus ossifying fibroma.

Sinonasal ossifying fibroma is a rare, slow-growing, benign bony tumour, frequently involving the maxilla and mandible in the head and neck region. Although it is known to be the second most frequent fibro-osseous tumour of paranasal sinus, to the best of our knowledge, ossifying fibroma of frontal sinus causing brain abscess has not been presented yet in the relevant literature. We present the clinical, pathological and radiological findings of ossifying fibroma of the frontal sinus associated with brain abscess.

Brucellar breast abscess.

Brucellosis is an endemic disease seen in many countries. It may affect different organ systems. Brucellar breast abscess is a rare entity. We report the radiological findings of breast abscess due to brucella. A 63-year-old female was investigated with mammography, ultrasonography, magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS). A mass measuring 25 x 20 x 15 mm was detected in the left breast on mammography and ultrasonography. The mass was homogenously hyperintense on T1- and T2-weighted MRI images. On contrast-enhanced T1-weighted images, peripheral capsular enhancement was found. MR spectroscopic analysis of the mass revealed elevated lipid and acetate peaks. The diagnosis was provided by fine needle aspiration biopsy and specimen culture. The lesion had diminished in size after 12 months' treatment with combined tetracycline and rifampicine.

Imaging of nail-patella syndrome.

Nail-patella syndrome is a rare disorder, which is inherited as an autosomal dominant trait. This condition is also known as hereditary osteo-onychodysplasia or Fong's syndrome. Posterior iliac horns are commonly found in this syndrome and are considered pathognomonic. In this report, we describe the appearance, location, and structure of iliac horns with respect to radiography and magnetic resonance imaging.

Imaging of granulomatous mastitis: assessment of three cases.

Granulomatous mastitis is a benign, inflammatory breast disease of unknown aetiology, which can mimic breast carcinoma in its clinical manifestations. Imaging features of three cases of granulomatous mastitis mimicking breast carcinoma on both clinical and radiographic examination are presented, with special emphasis on the role of dynamic contrast-enhanced-magnetic resonance mammography in the differential diagnosis.

Ultrasonographic evaluation of age-related changes in bowing of the flexor retinaculum.

The effects of age, gender, and hand dominance on bowing of the flexor retinaculum, used in diagnosing carpal tunnel syndrome, were analyzed. Forty men aged 23-58 years old (39.7 +/- 11.2) and 40 women aged 20-57 years old (39.6 +/- 11.3) were the normal subjects. A total of 160 wrists was examined with a linear array transducer. Bowing of the flexor retinaculum was measured as the distance from a line drawn between the trapezium and the hamate to the palmar apex of the outer surface of the flexor retinaculum. It was 0.5-3.7 mm (2.00 +/- 0.64) for all hands, 0.6-3.7 mm (2.06 +/- 0.62) for men, 0.5-3.4 mm (1.96 +/- 0.67) for women, 0.5-3.4 mm (1.00 +/- 0.64) for dominant, and 0.6-3.7 mm (2.03 +/- 0.65) for nondominant hands. There was no difference between genders or dominant vs non-dominant hands regarding this parameter. However, it was highly correlated with age (r=0.59, p<0.0001). In conclusion, bowing of the flexor retinaculum measurements should be carefully compared with the standardized values when diagnosing carpal tunnel syndrome.

Ultrasonographic assessment of mild and moderate idiopathic carpal tunnel syndrome.

AIM: To investigate the diagnostic value of ultrasonography in mild and moderate idiopathic carpal tunnel syndrome (CTS). MATERIALS AND METHODS: Cross-sectional areas (CSA), flattening ratios at three different levels, swelling ratio, and palmar displacement were analysed in 26 patients (14 with bilateral and 12 with unilateral disease, 40 wrists in total) for the presence and the severity of CTS. Twenty had normal nerve conduction studies (NCS) defined as "mild", and 20 of them had abnormal NCS defined as "moderate". The control group consisted of 20 healthy participants. RESULTS: All parameters were significantly different between patient and control groups. Palmar displacement, swelling ratio, CSA at all levels and distal flattening ratio had the highest significance (p < 0.0001). The criterion with the highest sensitivity was the swelling ratio > or = 1.3 (72.5%), followed by the middle CSA > 9 mm2 and the palmar displacement > 2.5 mm. All of these criteria had a higher sensitivity in diagnosing moderate cases (85-100%) than diagnosing mild cases (30-55%). There was a significant difference between normal and mild CTS groups regarding palmar displacement, distal flattening ratio, middle CSA and swelling ratio (p < 0.0001 for all) and between normal and moderate groups regarding all parameters (p < 0.01 - 0.0001) When combined middle CSA, palmar displacement and swelling ratio had an overall discriminatory accuracy of 83.8%. CONCLUSION: Additional diagnostic confirmation can be provided by ultrasonography and may be preferred as the initial step instead of electrophysiological studies. Detection of at least two of the three criteria (median nerve CSA > 9 mm2 at pisiform level, swelling ratio > or = 1.3, and palmar displacement > 2.5 mm) may be helpful for the verification of the diagnosis.

Dynamic MRI in indirect estimation of microvessel density, histologic grade, and prognosis in colorectal adenocarcinomas.

The relations of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters to microvessel density (MVD), histologic grade, and presence of metastasis were evaluated to establish new prognostic indicators in colorectal cancer (CRC). Fast-low angle shot DCE-MRI parameters (time-intensity curves, TICs; maximal relative enhancement within the first minute, E(max/1); maximal relative enhancement of the entire study, Emax; steepest slope of the contrast enhancement curve; and time to peak enhancement) of 21 CRCs (seven Duke stage B, 12 Duke stage C, and two Duke stage D) were retrospectively evaluated and correlated with corresponding postoperative MVD measurements, histologic grades, and presence of metastasis at 2 years. TICs were classified as type A in nine (43%), type B in seven (33%), and type C in five cases (24%). There was a significant difference between TIC types with regard to MVD (p < 0.05-0.001). Time to peak enhancement, steepest slope of TIC, and E(max/1) were strongly correlated with MVD (r = -0.765, p < 0.01; r = 0.681, p < 0.01; r = 0.634, p < 0.01; respectively). MVD, steepest slope of the enhancement curve, E(max/1), and Emax strongly correlated with histologic grade (r = 0.475, p < 0.05; r = 0.683, p < 0.01; r = 0.687, p < 0.01; r = 0.791, p < 0.01; respectively). There was a significant difference between groups of patients with and without metastasis with regard to histologic grade (p < 0.05) and two of the DCE-MRI parameters (p < 0.005 for E(max/1) and p < 0.05 for time to peak enhancement). Discriminant analysis correctly predicted the metastatic occurrence at 2 years in 90.5% of cases using E(max/1) (p < 0.001). Histologic grade resulted in lower rates of discrimination (66.7%; p < 0.05). DCE-MRI parameters may help in the prediction of MVD and histologic grade in CRC and may be used to predict therapeutic outcome.

Asymptomatic choroid plexus cysts in the lateral ventricles: an incidental finding on diffusion-weighted MRI.

We assessed the role of diffusion-weighted imaging (DWI) in the detection of choroid plexus cysts. We reviewed more than 1000 patients who had undergone MRI in a 1-year period. We reviewed echo-planar DWI with b=1000 s/mm(2), acquired at 1.0 tesla, for any difference in signal intensity which might indicate choroid plexus cysts. On conventional images, all cystic lesions were isointense with cerebrospinal fluid, and 72 cysts could not be identified. On DWI, 90 rounded high-signal foci were detected in 58 patients; 64 cysts were bilateral. Focal ventricular expansion due to large cysts was observed in nine cases. DWI were found to show choroid plexus cysts undetected within the cerebrospinal fluid on conventional images.

Primary angiosarcoma of the spleen: in vivo and in vitro MRI findings.

Primary splenic angiosarcomas are extremely rare tumors with very poor prognosis. These tumors, highly aggressive and lethal, present with widespread metastatic disease or splenic ruptures. The possibility to lengthen the survival by splenectomy before the development of splenic rupture makes an early radiological diagnosis a necessity. Multimodality imaging findings of a patient with splenic angiosarcoma is presented. In vivo and in vitro magnetic resonance imaging (MRI) features of the spleen are compared to macro- and micropathological findings.

The role of the mamillary body in the propagation of the ictal activity.

To determine the importance of fornix and mamillary body atrophy in the secondary generalization of the complex partial seizures fornix and mamillary bodies of 11 hippocampal sclerosis patients with secondary generalization (SG) and 3 without secondary generalization (WSG) were retrospectively evaluated using MRI images. Small fornix and/or mamillary body was not found in WSG group. In SG group the frequencies of small fornix and mamillary body were 64% and 45%, respectively, all being ipsilateral to sclerotic side. The frequency of small fornix in the SG group was statistically higher than WSG group (p<0.01). All small mamillary bodies were accompanied by ipsilateral small fornices. Considering the spatially decreasing frequency and the ipsilaterality of the hippocampal sclerosis, forniceal atrophy and mamillary body atrophy, a temporo-spatial relationship of the above-stated structures that may link focal seizures to secondary generalization was postulated.

Staphylococcal pyomyositis in a patient with non-Hodgkin's lymphoma.

Pyomyositis is a rare disease, encountered mainly in tropical climates. The diagnosis of this entity is difficult, if not misdiagnosed, because of its rarity and its subacute presentation. We report of a 42-year-old man, in whom pyomyositis developed while he was receiving the standard chemotherapy for T-cell non-Hodgkin's lymphoma (NHL). Three months following splenectomy, multiple abscesses occurred in the muscles of both thighs while the patient was receiving the third course of the CHOP regimen. A purulent exudate was aspirated from the abscesses under computed tomographic guidance. Coagulase-positive Staphylococcus aureus was cultured in the aspirate. Pyomyositis was completely resolved following the surgical drainage and the antistaphylococcal antibiotic treatment. This patient has shown that immunosuppression due to splenectomy, NHL, and chemotherapy, especially when using steroids, could be risk factors for pyomyositis in nontropical or semitropical countries.

Limbic P300s in temporal lobe epilepsy with and without Ammon's horn sclerosis.

Limbic P300 potentials can be recorded within the mesial temporal lobes of patients with temporal lobe epilepsy (TLE). To delineate possible mechanisms of their generation and pathological alteration, we analysed limbic P300s in 55 TLE patients with and 29 without Ammon's horn sclerosis (AHS) and correlated their amplitudes with neuronal cell counts in 30 histopathological specimens. Limbic P300 amplitudes were reduced on the side of the epileptogenic focus only in patients with AHS. Moreover, in AHS patients, limbic P300 latencies were prolonged bilaterally; and in patients with left-sided AHS, amplitudes were reduced bilaterally. Both findings suggest bilateral functional deficits in TLE with unilateral AHS. Limbic P300 areas correlated significantly with neuronal densities of dentate gyrus granule cells but not hippocampal pyramidal cells in the CA1-4 (cornu ammonis) subfields. This finding points to a potential mechanism for the bilateral effects of unilateral AHS as both dentate gyri exhibit strong reciprocal contralateral connectivity.

Retrobulbar hydatid cyst: assessment of two cases.

A 54-year-old man with a unilocular hydatid cyst within the infero-posterior angle of the orbit and a 6-year-old male child with a unilocular hydatid cyst within the supero-medial angle of the orbit are presented. The retrobulbar cysts were diagnosed with computed tomography and ultrasonography and were treated after serologic confirmation.

Intrathoracic extramedullary haemopoiesis.

Intrathoracic extramedullary haemopoiesis is a rare condition accompanying chronic haematologic diseases. A 25 year old male beta-thalassaemia intermedia patient with bilateral posterior mediastinal masses is reported. Computed tomography and magnetic resonance imaging provide detailed information for evaluation of thalassaemia and similar haemolytic diseases. In geographic areas where thalassaemia is prevalent, to avoid unnecessary surgical interventions, extramedullary haemopoiesis should be considered in differential diagnosis of patients who have chronic anaemia with asymptomatic intrathoracic tumours.