Neurovascular study of the trigeminal nerve at 3 t MRI.

This study aimed to show a novel visualization method to investigate neurovascular compression of the trigeminal nerve (TN) using a volume-rendering fusion imaging technique of 3D fast imaging employing steady-state acquisition (3D FIESTA) and coregistered 3D time of flight MR angiography (3D TOF MRA) sequences, which we called "neurovascular study of the trigeminal nerve". We prospectively studied 30 patients with unilateral trigeminal neuralgia (TN) and 50 subjects without symptoms of TN (control group), on a 3 Tesla scanner. All patients were assessed using 3D FIESTA and 3D TOF MRA sequences centered on the pons, as well as a standard brain protocol including axial T1, T2, FLAIR and GRE sequences to exclude other pathologies that could cause TN. Post-contrast T1-weighted sequences were also performed. All cases showing arterial imprinting on the trigeminal nerve (n = 11) were identified on the ipsilateral side of the pain. No significant relationship was found between the presence of an artery in contact with the trigeminal nerve and TN. Eight cases were found showing arterial contact on the ipsilateral side of the pain and five cases of arterial contact on the contralateral side. The fusion imaging technique of 3D FIESTA and 3D TOF MRA sequences, combining the high anatomical detail provided by the 3D FIESTA sequence with the 3D TOF MRA sequence and its capacity to depict arterial structures, results in a tool that enables quick and efficient visualization and assessment of the relationship between the trigeminal nerve and the neighboring vascular structures.

Susceptibility-weighted angiography of intracranial blood products and calcifications compared to gradient echo sequence.

This study evaluated the sensitivity of susceptibility-weighted angiography (SWAN) compared with gradient echo (GRE) sequence in the depiction of haemorrhagic and calcium lesions by virtue of correlation analysis between the number, area and contrast index. The study included 21 patients (15 women, 6 men; age range 18 to 80 years) in whom intracranial haemorrhage or calcifications were previously diagnosed with CT and/or MR. GRE and SWAN sequences were performed as part of a conventional Brain MR study using a 3T scanner. Pathologic findings were: cavernoma (n=8), chronic intraparenchymal haemorrhage (n=5), petechial bleeding (n=3), parenchymal calcifications (n=2), sequelae of haemorrhagic contusion focus (n=1), post-surgical glioma (n=1) and venous angioma (n=1). In eight patients, more lesions were found in the SWAN sequence than in GRE. In the measurement of the largest area, in all cases the measured area was larger in the SWAN sequence than in GRE. The SWAN sequence was reported to have shown higher contrast between the lesion and the healthy white matter than in GRE. The SWAN sequence is more sensitive than GRE in the identification of cerebral haemorrhage and calcifications. The SWAN sequence also obtained significantly larger images than with GRE, and a higher contrast difference between the lesion and the healthy parenchyma.

Yerba mate (Ilex paraguariensis) como contraste oral negativo para colangiopancreatoresonanacia / Yerba mate (Ilex paraguariensis) as a negative oral contrast colangiopancreatoresonancia

Objetivo: valorar el uso de yerba mate como contraste oral negativo para anular la señal del estómago e intestino durante el estudio colangiopancreatoresonancia. Materiales y métodos: En la primera fase del estudio utilizamos fantomas con distintos tipos de contraste oral de señal de cada uno, siendo la yerba mate hipointensa en secuencias T2. En la siguiente fase, 30 pacientes (10 voluntarios asintomáticos y 20 con síntomas dispépticos inespecíficos) fueron estudiados con secuencias singles-shot turbo spinecho 2D antes y después de ingerir el contraste oral. Las imágenes obtenidas de los conductos, hepático común, cístico, colédoco y pancreático fueron examinadas y calificadas por dos médicos radiólogos. Resultados: El contraste fue bien tolerado por todos los pacientes. En todos ellos, la alta señal del estómago, el marco duodenal y parte de yeyuno fue suprimida por completo. La discriminación de la mayoría de las estructuras anatómicas evaluadas mejoró significativamente tras la administración de contraste oral negativo. Conclusiones: La infusión de yerba mate es un medio de contraste inocuo para el paciente y efectivo en cuanto a la eliminación de la señal del tracto gastrointestinal, mejorando de esta manera la visualización de las estructuras anatómicas de la vía biliar.