MRI Sequences in Head & Neck Radiology – State of the Art

Abstract

ZUSAMMENFASSUNGHintergrund Magnetic resonance imaging (MRI) ist ein essentielles bildgebendes Verfahren für die Beurteilung von Kopf-Hals Erkrankungen. Die diagnostische Aussagekraft der MRI ist jedoch stark von der entsprechenden Auswahl und Interpretation der Protokolle und Sequenzen abhängig. Das Ziel dieses Beitrags ist es, State-of-the-art-Sequenzen für die klinische Routine der Kopf-Hals-MRI zusammenzufassen und die Evidenz zu beschreiben, für welche medizinische Fragestellungen diese Sequenzen nützlich sind.Methode Literaturübersicht von State-of-the-art-Sequences in der Kopf-Hals-MRI.

Diagnosis of demyelinating brain lesion simulating brain tumors on fast imaging employing steady-state acquisition magnetic resonance imaging

“…FIESTA provides a high signal in tissues with high T2/T1 ratios, such as cerebrospinal fluid and fat, enables submillimeter spatial resolution, and has been mainly used to evaluate the cerebellopontine angles and inner ear, allowing the precise differentiation between branches of the cranial nerves. [ 8 ] Recently, this sequence has been reported to be useful in the demonstration of not only intraventricular lesions but also parenchymal lesions. [ 4 5 ] In the present study, FIESTA showed intralesional reticulate or broad-line structures in inflammatory demyelinating lesions in the DGM.…”

“…[ 2 ] A new MRI technique, fast imaging employing steady-state acquisition (FIESTA) MRI, is suitable for depicting the cranial nerves in the cisterns because the sequence has a high spatial resolution and signal-to-noise ratio. [ 1 8 ] FIESTA is also useful for the demonstration and identification of parenchymal solitary cysticercus granuloma, suggesting that FIESTA can demonstrate small structures or lesions in not only the cisterns but also the brain. [ 4 ]…”

Role of computed tomography in the evaluation of neck masses

“…MRI is extremely useful in assessment of neck lesions due to its excellent soft tissue delineation and multiplaner imaging capabilities but is limited by its unsuitability in claustrophobic patients, and individuals with certain devices like pacemakers and cochlear implants. Moreover its availability is not uniform and cost is also prohibitive [8,9,10] .…”

Contribution of dynamic contrast enhancement and diffusion-weighted magnetic resonance imaging to the diagnosis of malignant cervical lymph nodes

“…Diffusion-weighted MRI sequences can identify change in cytoarchitecture and cell density, allowing the use of apparent diffusion coefficient (ADC) values for the characterization of small (4-9 mm) metastatic lymph nodes ( 3 ) , for which the morphology and size criteria would yield false-negative results ( 4 ) . In addition, many studies have demonstrated the importance of post-treatment assessment with diffusion-weighted imaging, suggesting that, by as soon as two weeks after the initiation of treatment, ADC values can indicate whether or not the prescribed pharmacological treatment has been successful ( 5 ) .…”

“…The various techniques of dynamic study after injection of contrast medium allow characterization of vascular permeability and identification of neovascularization, suggestive of metastatic lymph nodes ( 6 ) . Spectroscopy demonstrates a change in the concentration of metabolites, which can guide the diagnosis ( 3 ) .…”