Gwyther S J
Department of Radiology, East Surrey Hospital, Redhill, U.K.
Ann Oncol. 1994;5 Suppl 4:3-7. doi: 10.1093/annonc/5.suppl_4.s3.
Radiological imaging has existed for about 100 years and there have been significant advances in computer technology during the last 25 years. The ideal investigation should be non-invasive, repeatable, and have a sensitivity (detection of the lesion) and specificity (ability to predict the absence of disease) of 100%.
Recent advances in ultrasonography, computed tomography (CT) scanning and magnetic resonance imaging (MRI) have enabled a more accurate demonstration of anatomical structures and better spatial resolution. This has led to the detection of smaller lesions and faster scan times, and thus new or recurrent disease is demonstrated at an earlier stage and motion artefacts are reduced. Advances in imaging techniques have also enabled percutaneous manoeuvres, ranging from diagnostic biopsy of suspicious lesions to therapeutic stenting of malignant strictures, to be performed. Magnetic resonance spectroscopy (MRS) and positron emission tomography (PET) represent a different concept. They assess in vivo tissue metabolism and provide a physiological approach which allows comparison of normal and abnormal tissue, such as tumour. The measurement of certain metabolites or isotope tracers correlates with tumour metabolism, and the response to treatment can be predicted by quantitative changes. Thus, PET scanning and MRS will probably be valuable in assessing new chemotherapeutic agents in animals and patients in vivo. Patients likely to respond to a certain drug can be selected and further studies may help determine ideal dosing regimens. Lack of fine anatomical detail on PET images can be overcome by 'fusing' the 'slice' with the corresponding CT or MRI slice, allowing accurate anatomical and physiological information to be displayed.
As more specific indicators of disease and the response to therapy become available, the combination of anatomical and functional imaging modalities will enable treatment to be undertaken at an earlier stage with the potential for increased survival.
放射成像技术已经存在了大约100年，在过去25年中计算机技术取得了重大进展。理想的检查应该是非侵入性的、可重复的，并且灵敏度（病变检测）和特异性（预测无疾病的能力）均为100%。
超声检查、计算机断层扫描（CT）和磁共振成像（MRI）的最新进展使得能够更准确地显示解剖结构并提高空间分辨率。这导致能够检测到更小的病变，缩短扫描时间，从而在更早阶段发现新的或复发性疾病，并减少运动伪影。成像技术的进步还使得能够进行经皮操作，范围从对可疑病变进行诊断性活检到对恶性狭窄进行治疗性支架置入。磁共振波谱（MRS）和正电子发射断层扫描（PET）代表了不同的概念。它们评估体内组织代谢，并提供一种生理学方法，可对正常和异常组织（如肿瘤）进行比较。某些代谢物或同位素示踪剂的测量与肿瘤代谢相关，并且可以通过定量变化预测对治疗的反应。因此，PET扫描和MRS在评估动物和患者体内新的化疗药物方面可能具有重要价值。可以选择可能对某种药物有反应的患者，进一步研究可能有助于确定理想的给药方案。PET图像上缺乏精细的解剖细节可以通过将“切片”与相应的CT或MRI切片“融合”来克服，从而能够显示准确的解剖和生理信息。
随着更多疾病和治疗反应的特异性指标出现，解剖学和功能成像方式的结合将使治疗能够在更早阶段进行，有可能提高生存率。
