杨宁介入医学网

与成功消融治疗有关的MR和CT的影像学发现已经为经典。成功的消融后，大部分的消融区，包括被治疗的肿瘤称为非增强组织。打算消融区的范围是要大于原肿瘤的边界5~10mm，被称为安全边界。影像学通常表现围绕消融区周围有一个很薄的增和炎症相关强圈。这种炎症边缘的存在影像学检查如CT增强，对比增强磁共振成像，甚至FDG-PET（图11）的结果，而且很难解释；然而，炎症的边缘薄和其均匀性通常可以区别来自于一个残余癌灶较粗大或结节状增强模式【127】。

 

与消融后的基线影像比较随着时间的推移，消融区逐渐减小。炎症的迹象通常是消退【128，129】。复发或残留肿瘤一般表现为增强结节。然而，在有些情况下，结节状增强可能是炎症而不是肿瘤残留【130】，有报道称，在某些情况下，非增强区域的消融区可能仍有存活的癌细胞【131】。这些发现强调了需要继续研究以改进的方法确定残留或复发性疾病。

 Clear cell type RCC with no evidence of residual or recurrent RCC seen after RF ablation

Nephrographic phase CT scan shows a solid mass in the right kidney. RF ablation was performed	Excretory phase CT scan obtained 5 months after ablation shows a round mass with soft-tissue attenuation representing the ablated tumor. A curvilinear hyperattenuating area, or “halo” (arrowheads), is seen in the perinephric fat adjacent to the tumor	On an excretory phase CT scan obtained 9 months after ablation, the mass is unenhanced, with fat replacement at the interface between the ablated tumor and the normal kidney (arrow) due to shrinkage of the tumor. Arrowheads indicate the curvilinear hyperattenuating area (cf b). Analysis of attenuation on both unenhanced CT scans and arterial phase and excretory phase CT scans showed no evidence of tumoral contrast enhancement.

Exophytic mass in the left kidney. The mass was solid at CT and US; however, biopsy performed at the time of RF ablation was nondiagnostic. No evidence of residual or recurrent tumor was seen after RF ablation.

Unenhanced CT scan obtained immediately prior to ablation shows an exophytic left renal mass (arrow). RF ablation of the mass was performed under CT guidance with the patient prone.	CT scan obtained during ablation shows minimal perinephric hemorrhage (arrows) and adjacent soft-tissue stranding. (c–e) Contrast-enhanced excretory phase CT scans obtained 1 month	12 months

49 months

after RF ablation show evolution of the ablated lesion with a persistent soft-tissue-attenuation component (arrows in e). A linear circumferential area of high attenuation (arrowheads in e) is seen surrounding the lesion. Analysis of the attenuation of this soft-tissue-attenuation component on both unenhanced CT scans and arterial phase and excretory phase CT scans showed no evidence of tumoral contrast enhancement.

Recurrence of clear cell type RCC after RF ablation.

Contrast-enhanced excretory phase CT scan shows a 2.2 × 1.6-cm enhancing mass (arrow) in the right kidney. RF ablation was performed	Contrast-enhanced excretory phase CT scan obtained 4 months after ablation shows a partially exophytic hypoattenuating lesion with peripheral linear circumferential hyperattenuation in the perirenal fat (arrowheads)	On a contrast-enhanced corticomedullary phase CT scan obtained 8 months after ablation, the lesion has a stable appearance.

Contrast-enhanced corticomedullary phase CT scan obtained 20 months after ablation shows a nodular enhancing component (arrow) in the medial portion of the ablation zone	Contrast-enhanced CT scan obtained 31 months after ablation shows an interval increase in the size of the mass, a finding that represents recurrent RCC. A region of interest (circled) was placed to measure CT attenuation

Postprocedural therapy assessment. PET/CT images in 64-year-old patient with inoperable non–small cell lung cancer

Stage 1a non–small cell lung cancer	Early (4.5-month) postablation image with expected apparent enlargement of the tumor bed at CT but without increased focal FDG activity. A low-level ring of FDG activity larger than the original tumor is interpreted as inflammatory. New baseline-CT size at the early follow-up date is established from which future size change is judged	Forty-month image shows reduction in FDG activity and size of the treated tumor.