Vaddi Anusha, Parasher Pranav, Khurana Sonam
Department of Oral Diagnostic Sciences, School of Dentistry, Virginia Commonwealth University, 520 N 12th Street, Richmond, VA 23298, USA.
Section of Oral and Maxillofacial Radiology, Division of Oral and Maxillofacial Diagnostic Sciences, UConn School of Dental Medicine, UConn Health, 263 Farmington Avenue, Farmington, CT 06030, USA.
Diagnostics (Basel). 2025 May 1;15(9):1153. doi: 10.3390/diagnostics15091153.
Diagnostic imaging is fundamental in dentistry for disease detection, treatment planning, and outcome assessment. Traditional radiographic methods, such as periapical and panoramic radiographs, along with cone beam computed tomography (CBCT), utilize ionizing radiation and primarily focus on visualizing bony structures. Magnetic resonance imaging (MRI) is emerging as a non-ionizing alternative that offers superior soft tissue contrast. However, standard MRI sequences face challenges visualizing mineralized tissues due to their short transverse relaxation times (T2), which results in rapid signal decay. Recent advancements exploring short T2 sequences, including Ultrashort Echo Time (UTE), Zero Echo Time (ZTE), and Sweep Imaging with Fourier Transformation (SWIFT), allow direct visualization of dental hard tissues. UTE captures signals from short T2 tissues using rapid pulse sequences, while ZTE employs encoding gradients before radiofrequency pulses to reduce signal loss. SWIFT enables near-simultaneous excitation and acquisition, improving ultrashort T2 detection. Additionally, customized intraoral and extraoral surface coils enhance the image resolution and signal-to-noise ratio (SNR), increasing MRI's relevance in dentistry. Research highlights the potential of these short T2 sequences for early caries detection, pulp vitality assessment, and diagnosing jaw osseous pathology. While high-field MRI (3 T-7 T) improves resolution and increases susceptibility artifacts, low-field systems with specialized coils and short sequences offer promising alternatives. Despite obstacles such as cost and hardware constraints, ongoing studies refine protocols to enhance clinical applicability. Incorporating MRI in dentistry promises a safer, more comprehensive imaging methodology, potentially transforming diagnostics. This review emphasizes three types of short T2 sequences that have potential applications in the maxillofacial region.
诊断成像在牙科领域对于疾病检测、治疗计划制定和治疗效果评估至关重要。传统的放射成像方法,如根尖片和全景片,以及锥形束计算机断层扫描(CBCT),都利用电离辐射,主要侧重于显示骨结构。磁共振成像(MRI)作为一种非电离的替代方法正在兴起,它能提供出色的软组织对比度。然而,标准的MRI序列在显示矿化组织方面面临挑战,因为矿化组织的横向弛豫时间(T2)很短,这会导致信号快速衰减。最近在探索短T2序列方面取得的进展,包括超短回波时间(UTE)、零回波时间(ZTE)和傅里叶变换扫描成像(SWIFT),使得能够直接观察到牙齿硬组织。UTE使用快速脉冲序列捕获来自短T2组织的信号,而ZTE在射频脉冲之前采用编码梯度来减少信号损失。SWIFT实现了近乎同时的激发和采集,提高了对超短T2的检测能力。此外,定制的口腔内和口腔外表面线圈提高了图像分辨率和信噪比(SNR),增强了MRI在牙科领域的实用性。研究突出了这些短T2序列在早期龋齿检测、牙髓活力评估和颌骨骨质病理学诊断方面的潜力。虽然高场MRI(3T - 7T)提高了分辨率并增加了磁化率伪影,但配备专门线圈和短序列的低场系统也提供了有前景的替代方案。尽管存在成本和硬件限制等障碍,但正在进行的研究不断完善方案以提高临床适用性。将MRI纳入牙科有望提供一种更安全、更全面的成像方法,可能会改变诊断方式。本综述重点介绍了在颌面区域具有潜在应用的三种短T2序列。