Pseudocontinuous Arterial Spin Labeling: Clinical Applications and Usefulness in Head and Neck Entities

Abstract

As functional magnetic resonance imaging, arterial spin labeling (ASL) techniques have been developed to provide quantitative tissue blood flow measurements, which can improve the performance of lesion diagnosis. ASL does not require contrast agents, thus, it can be applied to a variety of patients regardless of renal impairments and contrast agent allergic reactions. The clinical implementation of head and neck lesions is limited, although, in recent years, ASL has been increasingly utilized in brain lesions. Here, we review the development of the ASL techniques, including pseudocontinuous ASL (pCASL). We compare readout methods between three-dimensional (3D) turbo spin-echo and 2D echo planar pCASL for the clinical applications of pCASL to head and neck lesions. We demonstrate the clinical usefulness of 3D pCASL for diagnosing various entities, including inflammatory lesions, hypervascular lesions, and neoplasms; for evaluating squamous cell carcinoma (SCC) treatment responses, and for predicting SCC prognosis.

Modern possibilities of MRI-based diagnosis of multiple sclerosis. Literature review

“…Однако идентификация выявленных на МРТ изменений как клинически значимых при РС до сих пор представляет собой известные трудности в связи с тем, что данные традиционной МРТ (общее количество и объем очагов) слабо коррелируют со степенью неврологического дефицита. Данный феномен, получивший название «клинико-магнитно-резонансный парадокс», привел к необходимости изучения патологических процессов, развивающихся в ЦНС наряду с демиелинизацией, и разработки новых методов оценки ультраструктурных, биохимических и функциональных изменений ЦНС [24].…”

Imaging in translational cancer research

“…Most applications of ASL are in translational or preclinical research; however, some institutes use ASL measurements to assess perfusion in pediatric tumors without a need for contrast agent administration 139 . Owing to difficulties in finding adequate labeling planes, ASL is typically used in brain, head and neck, and renal tumors [140][141][142][143] , but has also been investigated in other organs, such as the liver 144 , heart 145 , and prostate 146 . The low resolution of ASL images with respect to that of conventional MR sequences limits its use in oncological screening; however, the benefit of avoiding contrast agent administration is expected to result in increased use of this technique in pediatric imaging, in oncological patients with many follow-up exams, and in oncological wards aiming to replace contrastagent-based perfusion MRI with less expensive imaging.…”

A Combination of Amide Proton Transfer, Tumor Blood Flow, and Apparent Diffusion Coefficient Histogram Analysis Is Useful for Differentiating Malignant from Benign Intracranial Tumors in Young Patients: A Preliminary Study

“…Multiparametric MRI with different types of scan sequences provides quantitative information about various tumor characteristics, which could contribute to differential diagnoses [ 11 , 12 , 13 , 14 ]. These quantifiable imaging data are compatible with objective analysis methods, such as histogram analysis, which are considered reproducible and repeatable when compared to subjective analysis methods, including visual evaluation [ 11 , 12 , 13 , 14 ]. Thus, these analyzed data can improve the diagnostic performance, even for brain tumors defined by the 2021 WHO classification.…”