结核病18F-FDG PET图像表现的多样性

目的总结结核病18F-脱氧葡萄糖(FDG) PET显像的影像学特征.方法回顾性分析26例结核病患者的18F-FDG PET图像,其中21例由组织病理学检查结果证实,余5例据临床资料诊断.所有患者在注射18F-FDG 60～90 min后进行衰减校正全身PET显像.其中14例患者同时行早期(40～65 min)和延迟(1.5～2.5 h)双时相检查.图像判读包括目测法和标准摄取值(SUV)半定量分析.双时相显像计算SUV变化率[ΔSUV(%)].结果 26例结核病患者中22例可见18F-FDG摄取,肺结核摄取18F-FDG有4种基本类型肺结节局限性18F-FDG浓聚(9例);肺内病灶同时伴有肺门或纵隔淋巴结浓聚(5例);肺伴有锁骨上和(或)腹腔淋巴结异常浓聚(3例);广泛胸膜异常浓聚(2例).平均SUVmax为3.64±2.58(1.4～7.6 ).延迟相SUV与早期相比较随时间延长而增加[(34.62±7.25)%].3例肺外结核18F-FDG PET显像呈阳性.4例陈旧性肺结核患者在CT所示结节部位未见18F-FDG摄取.结论结核病18F-FDG摄取可作为结核活动性的一个标志,其18F-FDG PET表现呈多样性.阳性18F-FDG摄取在肺部结节良恶性鉴别诊断时应慎重,特别是多发高代谢病灶背景不清晰时.背景不清晰的病灶结合结核菌素试验阳性,应考虑结核可能.     

结核病18F-FDG PET图像表现的多样性

目的总结结核病18F-脱氧葡萄糖(FDG) PET显像的影像学特征.方法回顾性分析26例结核病患者的18F-FDG PET图像,其中21例由组织病理学检查结果证实,余5例据临床资料诊断.所有患者在注射18F-FDG 60～90 min后进行衰减校正全身PET显像.其中14例患者同时行早期(40～65 min)和延迟(1.5～2.5 h)双时相检查.图像判读包括目测法和标准摄取值(SUV)半定量分析.双时相显像计算SUV变化率[ΔSUV(%)].结果 26例结核病患者中22例可见18F-FDG摄取,肺结核摄取18F-FDG有4种基本类型:肺结节局限性18F-FDG浓聚(9例);肺内病灶同时伴有肺门或纵隔淋巴结浓聚(5例);肺伴有锁骨上和(或)腹腔淋巴结异常浓聚(3例);广泛胸膜异常浓聚(2例).平均SUVmax为3.64±2.58(1.4～7.6 ).延迟相SUV与早期相比较随时间延长而增加[(34.62±7.25)%].3例肺外结核18F-FDG PET显像呈阳性.4例陈旧性肺结核患者在CT所示结节部位未见18F-FDG摄取.结论结核病18F-FDG摄取可作为结核活动性的一个标志,其18F-FDG PET表现呈多样性.阳性18F-FDG摄取在肺部结节良恶性鉴别诊断时应慎重,特别是多发高代谢病灶背景不清晰时.背景不清晰的病灶结合结核菌素试验阳性,应考虑结核可能.     

孤立性肺结核球的~(18)F-FDGPET/CT影像学表现

目的：探讨孤立性肺结核球（PTM）的18F-脱氧葡萄糖（FDG）PET/CT影像学表现。方法：回顾性分析23例经病理或临床证实为孤立性PTM患者的18F-FDG PET/CT影像学资料,所有患者均经注射18F-FDG 60min后行螺旋CT平扫和PET显像,分别对PTM进行形态学分析和标准摄取值（SUV）半定量分析。结果：23例病例中,CT平扫显示孤立性PTM直径为1.11~5.10 cm,平均2.48 cm;结节边缘光滑者16例,结节内有空洞者4例、钙化者3例;同时合并纵隔、肺门或腋窝淋巴结增大者6例。本组患者中17例发生18F-FDG摄取,其中11例表现为肺内结节局限性18F-FDG浓聚,6例表现为肺内结节和增大淋巴结18F-FDG浓聚,平均SUVmax为4.01±1.89;12例18F-FDG摄取阳性的患者经抗结核治疗后病灶缩小;6例未发生18F-FDG摄取的患者,经CT随访12个月病灶无明显变化。结论：18F-FDG PET/CT对孤立性PTM的诊断具有重要价值,确诊有赖于穿刺活检或手术病理。     

18F-FDG PET/CT在黑色素瘤中的应用价值

目的 探讨18F-脱氧葡萄糖(FDG)PET/CT显像在黑色素瘤诊断、临床分期及监测治疗后肿瘤复发与转移灶中的应用价值.方法 黑色素瘤患者61例,均进行18F-FDG PET/CT全身显像.所有PET、CT及PET/CT融合图像均通过融合软件进行帧对帧对比分析.肿瘤病灶根据病理学检查、多种影像学检查及临床随访结果诊断.结果 18F-FDG PET/CT显像对黑色素瘤病灶检出的灵敏度、特异性和准确性分别为90.9%(40/44)、88.2%(15/17)和90.2%(55/61).其中12例治疗前患者中,18F-FDG PET/CT显像诊断的灵敏度为83.3%(10/12).在黑色素瘤病灶局部切除、尚未进行其他治疗的9例患者中,5例残余病灶18F-FDG PET/CT显像检出3例;4例远处转移灶患者全被检出,提高了临床分期,改变了治疗方案.首先发现转移性黑色素瘤病灶并且手术切除后,寻找原发灶的7例患者中,18F-FDG PET/CT检出原发灶2例,4例其他转移灶全被检出.黑色素瘤患者根治术后监测肿瘤复发或转移患者33例,18F-FDG PET/CT显像灵敏度、特异性和准确性分别为100.0%(19/19)、85.7%(12/14)和93.9%(31/33).与同期临床其他影像学检查比较,18F-FDG PET/CT显像发现更多,33例患者中,16例(48.5%)病灶提高临床分期;7例(21.2%)排除可疑病灶,降低临床分期;10例(30.3%)检出病灶与临床一致.结论 18F-FDG PET/CT显像对于黑色素瘤的诊断,残余病灶、复发病灶及转移灶的检出,临床分期的明确具有重要价值.     

结核病的18F-FDG PET/CT诊断辨析

结核病可以发生于全身多个脏器,且有多种多样的影像学表现,因此结核病与其他全身性疾病（尤其是肿瘤性疾病）的鉴别较为困难。18F-FDG PET/CT在全身性疾病的诊断中有一定优势,但工作中仍需结合患者的临床表现、实验室检查、病灶的CT征象及18F-FDG浓聚程度等信息进行辨析。笔者选取了临床实践中误诊的3个病例,分别为肠结核、肺结核和骨结核,分别从临床特征及18F-FDG PET/CT影像学表现等方面进行鉴别诊断,梳理诊断思路,以期为临床诊断提供帮助。     

肝癌经导管肝动脉化疗栓塞后PET/CT显像的临床价值

目的 探讨18F-脱氧葡萄糖(FDG)PET/CT检查评估肝细胞肝癌(HCC)经导管肝动脉化疗栓塞(TACE)治疗后肿瘤活性及对转移灶的检出能力.方法 22例HCC患者TACE后进行18F-FDG PET/CT检查,以临床随访及部分病理结果为标准进行对照分析.结果 22例患者中,18例复发或转移,其余4例全身未见明显FDG代谢异常增高灶.16例患者肝内有1个或多个18F-FDG放射性增高灶,其中5例碘油沉积区和非碘油沉积区均有FDG浓聚灶,13例并发肝外转移病灶;2例肝内FDG显像阴性但腹膜后淋巴结放射性浓聚.转移灶分布:肺和淋巴结转移各9例,骨转移2例,门静脉瘤栓和膈脚转移各1例.经随访证实2例肝内18F-FDG显像为假阴性,18F-FDG PET/CT检查对肝内肿瘤复发或转移灶的探测灵敏度为88.9%(16/18),特异性为4/4,准确性为90.9%(20/22);全身显像对肿瘤复发或转移检测的灵敏度为94.7%(18/19),特异性为3/3,准确性为95.5%(21/22).结论 18F-FDG PET/CT显像对HCC介入治疗后的残留或复发灶探测有较高的灵敏度,对肝外转移病灶的检出具有独特的优势.     

肝癌经导管肝动脉化疗栓塞后PET/CT显像的临床价值

目的 探讨18F-脱氧葡萄糖(FDG)PET/CT检查评估肝细胞肝癌(HCC)经导管肝动脉化疗栓塞(TACE)治疗后肿瘤活性及对转移灶的检出能力.方法 22例HCC患者TACE后进行18F-FDG PET/CT检查,以临床随访及部分病理结果为标准进行对照分析.结果 22例患者中,18例复发或转移,其余4例全身未见明显FDG代谢异常增高灶.16例患者肝内有1个或多个18F-FDG放射性增高灶,其中5例碘油沉积区和非碘油沉积区均有FDG浓聚灶,13例并发肝外转移病灶;2例肝内FDG显像阴性但腹膜后淋巴结放射性浓聚.转移灶分布:肺和淋巴结转移各9例,骨转移2例,门静脉瘤栓和膈脚转移各1例.经随访证实2例肝内18F-FDG显像为假阴性,18F-FDG PET/CT检查对肝内肿瘤复发或转移灶的探测灵敏度为88.9%(16/18),特异性为4/4,准确性为90.9%(20/22);全身显像对肿瘤复发或转移检测的灵敏度为94.7%(18/19),特异性为3/3,准确性为95.5%(21/22).结论 18F-FDG PET/CT显像对HCC介入治疗后的残留或复发灶探测有较高的灵敏度,对肝外转移病灶的检出具有独特的优势.     

肝癌经导管肝动脉化疗栓塞后PET/CT显像的临床价值

目的 探讨18F-脱氧葡萄糖(FDG)PET/CT检查评估肝细胞肝癌(HCC)经导管肝动脉化疗栓塞(TACE)治疗后肿瘤活性及对转移灶的检出能力.方法 22例HCC患者TACE后进行18F-FDG PET/CT检查,以临床随访及部分病理结果为标准进行对照分析.结果 22例患者中,18例复发或转移,其余4例全身未见明显FDG代谢异常增高灶.16例患者肝内有1个或多个18F-FDG放射性增高灶,其中5例碘油沉积区和非碘油沉积区均有FDG浓聚灶,13例并发肝外转移病灶;2例肝内FDG显像阴性但腹膜后淋巴结放射性浓聚.转移灶分布:肺和淋巴结转移各9例,骨转移2例,门静脉瘤栓和膈脚转移各1例.经随访证实2例肝内18F-FDG显像为假阴性,18F-FDG PET/CT检查对肝内肿瘤复发或转移灶的探测灵敏度为88.9%(16/18),特异性为4/4,准确性为90.9%(20/22);全身显像对肿瘤复发或转移检测的灵敏度为94.7%(18/19),特异性为3/3,准确性为95.5%(21/22).结论 18F-FDG PET/CT显像对HCC介入治疗后的残留或复发灶探测有较高的灵敏度,对肝外转移病灶的检出具有独特的优势.     

肝癌经导管肝动脉化疗栓塞后PET/CT显像的临床价值

目的 探讨18F-脱氧葡萄糖(FDG)PET/CT检查评估肝细胞肝癌(HCC)经导管肝动脉化疗栓塞(TACE)治疗后肿瘤活性及对转移灶的检出能力.方法 22例HCC患者TACE后进行18F-FDG PET/CT检查,以临床随访及部分病理结果为标准进行对照分析.结果 22例患者中,18例复发或转移,其余4例全身未见明显FDG代谢异常增高灶.16例患者肝内有1个或多个18F-FDG放射性增高灶,其中5例碘油沉积区和非碘油沉积区均有FDG浓聚灶,13例并发肝外转移病灶;2例肝内FDG显像阴性但腹膜后淋巴结放射性浓聚.转移灶分布:肺和淋巴结转移各9例,骨转移2例,门静脉瘤栓和膈脚转移各1例.经随访证实2例肝内18F-FDG显像为假阴性,18F-FDG PET/CT检查对肝内肿瘤复发或转移灶的探测灵敏度为88.9%(16/18),特异性为4/4,准确性为90.9%(20/22);全身显像对肿瘤复发或转移检测的灵敏度为94.7%(18/19),特异性为3/3,准确性为95.5%(21/22).结论 18F-FDG PET/CT显像对HCC介入治疗后的残留或复发灶探测有较高的灵敏度,对肝外转移病灶的检出具有独特的优势.     

肝癌经导管肝动脉化疗栓塞后PET/CT显像的临床价值

目的 探讨18F-脱氧葡萄糖(FDG)PET/CT检查评估肝细胞肝癌(HCC)经导管肝动脉化疗栓塞(TACE)治疗后肿瘤活性及对转移灶的检出能力.方法 22例HCC患者TACE后进行18F-FDG PET/CT检查,以临床随访及部分病理结果为标准进行对照分析.结果 22例患者中,18例复发或转移,其余4例全身未见明显FDG代谢异常增高灶.16例患者肝内有1个或多个18F-FDG放射性增高灶,其中5例碘油沉积区和非碘油沉积区均有FDG浓聚灶,13例并发肝外转移病灶;2例肝内FDG显像阴性但腹膜后淋巴结放射性浓聚.转移灶分布:肺和淋巴结转移各9例,骨转移2例,门静脉瘤栓和膈脚转移各1例.经随访证实2例肝内18F-FDG显像为假阴性,18F-FDG PET/CT检查对肝内肿瘤复发或转移灶的探测灵敏度为88.9%(16/18),特异性为4/4,准确性为90.9%(20/22);全身显像对肿瘤复发或转移检测的灵敏度为94.7%(18/19),特异性为3/3,准确性为95.5%(21/22).结论 18F-FDG PET/CT显像对HCC介入治疗后的残留或复发灶探测有较高的灵敏度,对肝外转移病灶的检出具有独特的优势.     

Stress MR imaging for evaluation of popliteal artery entrapment

The popliteal artery entrapment (PAE) syndrome has been recognized as a cause of arterial occlusion in young people. It is the result of an anomaly of the relationship between the popliteal artery and the gastrocnemius muscle. Eight young healthy volunteers (16 legs) and six patients (10 legs) with suspected PAE underwent magnetic resonance (MR) imaging. Gradient-echo images were obtained in axial planes with the leg at rest and during active plantar flexion against resistance. Imaging at rest allowed identification of PAE signs in only one leg, which had an anomalous medial course of the popliteal artery. In the other cases, only the stress technique was able to show signal loss in the popliteal artery due to muscular compression (two legs) or the presence of accessory muscle slip around the vessel (two legs), as confirmed at surgery. MR imaging is therefore a useful technique for the diagnosis of PAE because of its capability of combining information obtainable with other modalities.     

MR imaging of muscle and tender points in fibromyalgia

Fibromyalgia is a syndrome manifested by chronic, diffuse muscu-loskeletal aching and soreness, palpable muscle tender points, and other symptoms. Standardized clinical diagnostic criteria have recently been developed. Skeletal muscle has been postulated as the end organ in this disease. Biochemical, histologic, electromyographic, and conventional radiographic studies have demonstrated no definitive abnormality. This study sought to establish whether magnetic resonance (MR) imaging could demonstrate any abnormality in these patients. Eighteen patients were entered in the study, 14 of whom were able to complete their examinations. T1 -weighted, T2-weighted, gradient-echo, and STIR (short-tau inversion-recovery) sequences were performed in all patients, with selected patients examined with T1weighted, gadopentetate dimeglu-mine-enhanced sequences. The trapezius and suboccipital regions were imaged in patients who, clinically, had active fibro-myalgia. No abnormalities could be detected. The authors conclude that the conventional MR imaging used in this study was unable to depict any primary skeletal muscle abnormality in fibromyalgia.     

Uterine contractions: Possible diagnostic pitfall at MR imaging

A total of 206 nongravid patients with various gynecologic problems underwent pelvic magnetic resonance (MR) examinations that included both sagittal T2-weighted and contrast agent–enhanced T1-weighted images. MR images were retrospectively reviewed to identify changes in endometrial configuration on serial images obtained during the same MR examination. In 20 MR examinations (all in women of reproductive age), endometrial distortion due to myometrial bulging was noted on T2-weighted or contrast-enhanced T1-weighted images. It was absent on other MR images obtained at different times. Myometrial bulging exhibited low signal intensity in 18 examinations. The finding resembled adenomyosis or leiomyoma on T2-weighted or contrast-enhanced T1-weighted images. These results evidence the presence of transient myometrial bulging and transient low-intensity myometrium in the nongravid uterus. This phenomenon is thought to represent uterine contraction. Clinicians should be aware of the potential presence of transient low-signal-intensity myometrial bulging that could present diagnostic problems in the normal uterus.     

Controversies in cervical spine imaging in trauma patients

No area of emergency radiology has generated as much discussion in recent years as the subject of cervical spine imaging for trauma patients. This review will be in three parts. The first will examine the indications for cervical imaging and will focus on those factors that make patients at high risk or low risk for cervical injury. The second part will discuss the merits of radiography and computed tomography as the main screening diagnostic examination. In addition to the roles of each modality in the evaluation process, such factors as efficacy of diagnosis, time (duration) of study, and cost will be discussed. Finally, the third part will explore the methods currently employed to clear the cervical spine in comatose patients.Presented at the Annual Meeting of the American Society of Emergency Radiology, Las Vegas, Nevada, 22–25 October, 2003     

Brodie Abscess: MR imaging appearance in 10 patients

The magnetic resonance (MR) imaging features of Brodie abscess have not yet been fully evaluated. Ten patients with Brodie abscess, eight of long bone and two of vertebra, were studied with MR imaging. Long bone abscess had a characteristic “target” appearance with four layers: (a) a center with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR (short-inversion-time inversion recovery) images, (b) an inner ring isointense to muscle on T1-weighted images and with high signal intensity on T2-weighted and STIR images, (c) an outer ring hypoin-tense on all images, and (d) a peripheral halo hypointense on T1-weighted images. In six of eight cases, a soft-tissue mass was found. The two vertebral abscesses had a less specific appearance, with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR images. Only the peripheral halo was clearly identified in both cases.     

Dynamic contrast-enhanced MR imaging assessment of vascularized free fibular grafts

Magnetic resonance (MR) imaging may be a noninvasive method for assessing perfusion of vascularized bone grafts placed for treatment of avascular necrosis. One proximal femur of seven beagles was devascularized, with insertion of a vascularized fibular graft. MR imaging at 1 week (seven dogs) and 6 weeks (five dogs) after surgery included pre- and postcontrast spin-echo sequences, unenhanced twodimensional time-of-flight (TOF) vascular imaging, and dynamic gradient-echo imaging during infusion of gadolinium. Relative signal intensity values of selected regions obtained from the dynamic gradientecho images were plotted as percent enhancement versus time. In the operated hip, MR imaging did not show enhancement in six of seven femoral heads and greater trochanters at 1 week after surgery, with similar results after 6 weeks. MR imaging of fibular grafts 6 weeks after surgery showed an initial rapid increase in enhancement and a subsequent slower increase in five of five dogs, although no enhancement was seen in six of seven dogs at 1 week. These findings contrasted with a rapid initial increase in enhancement followed by slow decline in non-operated hips. Two-dimensional TOP imaging did not show the vascular pedicle of the graft in any dog. Findings of radionuclide bone scanning performed 1 week after surgery were consistent with devascularization of the operated femur and fibular graft. However, tetracycline distribution and histologic findings confirmed the viability of five of five grafts within the devascularized femurs 6 weeks after surgery. Thus, dynamic contrast-enhanced MR imaging at 6 weeks after surgery is valuable for assessing vascular bone graft perfusion, while similar imaging at 1 week may suggest otherwise.     

Right-side aortic arch with aneurysm of aberrant left subclavian artery: MR imaging appearance.

Reports of aneurysms of the subclavian artery in both normal and anomalous aortic arches have been rare. The authors describe a patient with a right-side aortic arch and an aneurysm of the aberrant left subclavian artery, which, to the authors' knowledge, is a previously unreported association. At presentation, the aneurysm appeared as a calcified left superior mediastinal mass. Magnetic resonance imaging enabled preoperative diagnosis and guided surgical planning.     

Adrenal tissue characterization with 0.5-T MR imaging: Value of T2*-weighted images

The authors investigated the value of magnetic resonance (MR) imaging at 0.5 T for distinguishing adrenal adenomas from adrenal metastases. The series included 23 adrenal adenomas (18 nonhyperfunctioning, five hyperfunctioning) and 23 adrenal metastases from various organs. Adrenal tumor–liver signal intensity ratios on T1-, T2-, and T2*-weighted images were calculated for adrenal tissue characterization. Adrenal adenomas were more precisely distinguished from adrenal metastases on T2*-weighted images (21 of 23, 91%) than on T2-weighted images (15 of 23, 65%). T1-weighted images were not useful for this distinction. In conclusion, T2*-weighted images were better than routine T2-weighted images for distinguishing adrenal adenomas from adrenal metastases. It can be postulated that the total signal intensity of adrenal adenomas, which contain some fat components, decreased on T2*-weighted images because of an out-of-phase effect.     

MR angiography of congenital heart disease: Value of segmented two-dimensional inflow technique and maximum-intensity-projection display

Magnetic resonance (MR) angiography of the cardiovascular system was evaluated in 41 patients with congenital heart disease by using a two-dimensional (2D) inflow technique based on a magnetization-prepared gradient-echo pulse sequence with segmented k-space data acquisition and electrocardiographic gating at 0.5 T. Inversion and saturation prepulses were used to suppress stationary tissue and enhance intravascular signal. Presaturation slabs were applied where certain vascular structures had to be suppressed. Sequence parameters were optimized by evaluating signal intensity and contrast characteristics for various flip angles and inversion and saturation delay times. The heart and intrathoracic vasculature were encompassed with 40–50 overlapping sections. Both 2D angiograms and maximum-intensity-projection images were evaluated. Combining data sets acquired in the sagittal and transverse orientations provided the most satisfactory information about the pulmonary arteries. The highest signal-to-noise ratios were obtained with a flip angle of 65° and short prepulse delay times. Two-dimensional MR angiography can provide useful diagnostic information but requires a thorough understanding of in-plane and hemodynamically induced signal intensity changes.