Nuclear medical imaging devices, such as those enabling photon emission imaging (gamma camera, single photon emission computed tomography, or positron emission imaging), that are typically used in today’s clinics are optimized for assessing large portions of the human body, and are classified as whole-body imaging systems. These systems have known limitations for organ imaging, therefore application-specific devices have been designed, constructed and evaluated. These devices, given their compact nature and superior technical characteristics, such as their higher detection sensitivity and spatial resolution for organ imaging compared to whole-body imaging systems, have shown promise for niche applications. Several of these devices have further been integrated with complementary anatomical imaging devices. The objectives of this review article are to (1) provide an overview of such application-specific nuclear imaging devices that were developed over the past two decades (in the twenty-first century), with emphasis on brain, cardiac, breast, and prostate imaging; and (2) discuss the rationale, advantages and challenges associated with the translation of these devices for routine clinical imaging. Finally, a perspective on the future prospects for application-specific devices is provided, which is that sustained effort is required both to overcome design limitations which impact their utility (where these exist) and to collect the data required to define their clinical value.

核医学成像设备，例如那些支持光子发射成像（伽马相机、单光子发射计算机断层扫描或正电子发射成像）的设备，通常用于当今的诊所，经过优化以评估人体的大部分，并被归类为全身成像系统。这些系统在器官成像方面具有已知的局限性，因此已经设计、构建和评估了特定应用的设备。这些设备由于其紧凑的性质和卓越的技术特性，例如与全身成像系统相比，具有更高的器官成像检测灵敏度和空间分辨率，已显示出在利基应用中的前景。这些设备中的一些已进一步与互补的解剖成像设备集成在一起。这篇评论文章的目的是 (1) 概述过去二十年（二十一世纪）开发的此类专用核成像设备，重点是脑、心脏、乳房和前列腺成像；(2) 讨论将这些设备用于常规临床成像的基本原理、优势和挑战。最后，提供了对特定应用设备的未来前景的看法，即需要持续的努力来克服影响其效用（如果存在）的设计限制，并收集定义其临床价值所需的数据。重点是脑、心脏、乳房和前列腺成像；(2) 讨论将这些设备用于常规临床成像的基本原理、优势和挑战。最后，提供了对特定应用设备的未来前景的看法，即需要持续的努力来克服影响其效用（如果存在）的设计限制，并收集定义其临床价值所需的数据。重点是脑、心脏、乳房和前列腺成像；(2) 讨论将这些设备用于常规临床成像的基本原理、优势和挑战。最后，提供了对特定应用设备的未来前景的看法，即需要持续的努力来克服影响其效用（如果存在）的设计限制，并收集定义其临床价值所需的数据。