MRI和螺旋CT增强在肝脏占位性病变诊断中的价值比较

目的:对比分析MRI和螺旋CT增强在肝脏占位性病变诊断中的价值。方法:以2012年7月-2016年5月我院收治的临床考虑为肝脏占位性病变70例患者为研究对象,将70例患者根据入组先后顺序分为两组,35例行增强CT扫描,35例行动态增强MRI扫描,比较两组患者的病理诊断结果、病灶个数及直径、增强CT及MRI的诊断结果和检查过程中的不良反应及耐受性。结果:CT增强组和MRI增强组的肝脏占位性病变的病理诊断、病变类型、分布及病灶个数(71 vs 70)、病灶直径(2.25±2.01 cm vs2.19±1.98 cm)比较差异均无统计学意义(P0.05);以病理诊断结果为金标准,MRI增强组的总诊断符合率为85.71%,CT增强组的总诊断符合率为77.14%,MRI增强组的总诊断符合率高于CT增强组,但差异无统计学意义(P0.05);CT增强组共发生2例不良反应,均为轻度恶心,MRI增强组未出现造影剂不良反应,CT增强组的不良反应发生率(5.71%vs 0.00%)及视觉模拟评分法(VAS)评分(1.25 0.96分vs 0.71 0.56分)均显著高于MRI增强组(P0.05)。结论:CT增强和MRI增强扫描对于肝脏占位性病变的诊断均具有较高的临床价值,其中MRI增强扫描的安全性和耐受性更高,临床医师可根据患者的经济状态、身体状态等因素的综合评估,选择合适的检查手段,必要时可两者联合检查,以提高诊断的准确性。     

CT和MRI鉴定腹膜后间隙脂肪肉瘤与组织病理学特征相关

本研究选取2012年1月至2018年1月在我院治疗的腹膜后间隙脂肪肉瘤患者33例,分析患者术前CT、MRI图像及术后病理结果,旨在探讨不同类型腹膜后间隙脂肪肉瘤病理学及影像学特征。研究结果表明:33例患者中术后病理诊断为高分化脂肪肉瘤19例,去分化脂肪肉瘤7例,黏液性脂肪肉瘤7例;不同病理分型脂肪肉瘤病灶大小比较差异无统计学意义(p>0.05);高分化脂肪肉瘤其CT密度同皮下脂肪,CT值-10～-110 Hu,肿瘤内可见不规则增厚的间隔;去分化脂肪肉瘤部分区域呈脂肪密度(CT值-70～30 Hu),部分区域呈软组织肿块(CT值为30～50 Hu);黏液性脂肪肉瘤CT密度接近水,增强扫描时肿块呈网状、片状、延迟强化,CT值20～40 Hu;高分化脂肪肉瘤MRI信号同皮下脂肪;黏液性脂肪肉瘤MRI呈长T1,长T2信号,与水相似;CT和MRI诊断腹膜后间隙脂肪瘤准确率分别为69.70%和73.33%,差异比较无统计学意义(p>0.05)。本研究得出初步结论,不同病理类型腹膜后间隙脂肪肉瘤的CT、MRI表现有所差异;CT和MRI术前诊断腹膜后间隙脂肪肉瘤准确性相似。     

CT及MRI在直肠癌诊断和分期的应用价值研究

目的:探究在直肠癌的诊断以及分期方面,CT与MRI技术的应用价值。方法:选取我院近年来经过病理检测,确诊为直肠癌的患者160例,随机分为两个实验组,其中一组采取CT成像方法,另一组患者采取MRI成像。并记录在不同的分期中CT及MRI的应用价值。CT诊断包含了常规CT平扫以及CT增强扫描,MRI诊断包括轴位DWI、T2W1冠状位以及矢状位、轴位T1WI、轴位T2WI的图像。结果:在直肠癌的诊断中,CT诊断的T分期与病理性T分期差异不大,其准确率为70.0%。MRI诊断的T分期和病理性T分期差异极小,其准确率为85.0%。CT诊断的N分期与病理性N分期差异不大,准确率为72.5%;MRI诊断的N分期与病理性N分期差异较小,其准确率为87.5%。CT诊断的T分期以及N分期的准确率与MRI诊断的T分期以及N分期的准确率之间差异均存在统计学意义(P0.05)。结论:在直肠癌的术前诊断以及局部分期中,MRI诊断与CT诊断相比,有更高的诊断价值。     

甲状腺乳头状癌CT及MRI影像征象及其与雌激素受体、孕激素受体、C-myc表达的相关性研究

摘要 目的：探讨甲状腺乳头状癌（PTC）计算机断层扫描（CT）、磁共振成像（MRI）影像征象及其与雌激素受体（ER）、孕激素受体（PR）、C-myc表达的相关性。方法：回顾性分析2019年6月-2020年12月于我院74例诊断为PTC患者的计算机断层扫描CT、MRI影像资料,以手术病理结果作为金标准。分析患者的CT、MRI影像学特征。采用免疫组织化学染色分析ER、PR、C-myc的表达情况。采用Spearman秩相关分析评价CT、MRI影像学特征及其与ER、PR、C-myc表达水平的相关性。结果：PTC患者CT、MRI主要表现为混杂密度/信号,多数病灶形态不规则,病灶突破甲状腺被膜外缘呈咬饼征改变、侵犯周围组织及病灶内见细颗粒状钙化时提示恶性程度较高,患者早期出现颈部淋巴结转移较多。ER、PR、C-myc阳性表达者分别为51例（68.92%）、44例（59.46%）、64例（86.49%）。C-myc阳性表达与PTC肿瘤直径有关,组间差异有统计学意义（P＜0.05）;ER、PR、C-myc阳性表达与PTC形态、咬饼征及淋巴结转移有关,组间差异均有统计学意义（P＜0.0）;ER、C-myc阳性表达与PTC边界有关,组间差异有统计学意义（P＜0.05）;ER阳性表达与PTC增强后病灶范围缩小/模糊有关,组间差异有统计学意义（P＜0.05）;ER、PR、C-myc阳性表达与其余CT、MRI影像学表现特征无关,组间差异均无统计学意义（P＞0.05）。咬饼征与PR、C-myc表达水平呈正相关（P＜0.05）,淋巴结转移状态与ER、PR、C-myc表达水平呈正相关（P＜0.05）,其余影像学表现特征与ER、PR、C-myc表达水平无明显相关性（P＞0.05）。结论：CT、MRI影像征象可在一定程度上评估PTC患者肿瘤细胞的生物学行为,可间接反映肿瘤分化程度、浸润程度等情况,对指导临床综合治疗及评估患者预后可提供客观依据。     

Use of current radiation techniques in the diagnosis and treatment of juvenile angiofibromas of the nasopharynx

In 1992-2001 seventeen patients with juvenile nasopharyngeal angiofibromas (JNAs) were treated at Krasnoyarsk Territorial Clinical Hospital. The patients underwent a comprehensive diagnosis involving computed tomography (CT), magnetic resonance imaging (MRI), and angiography, followed by tumor vascular embolization. Later on JNAs were surgically removed in 14 patients, a course of radiation therapy was performed. In suspected JNA, the authors consider it necessary to concomitantly use CT, MRI, and angiography, which provides the most complete diagnostic picture of a pathological focus. X-ray endovascular occlusion considerably lowers blood loss, facilitates a complete angiofibroma removal, and affects the tolerability of radiation therapy in inoperable cases.     

Computed tomography in the evaluation of tumor regression after neoadjuvant therapy: X-ray surgery and X-ray morphological comparisons

An analysis was made of chest computed tomograms of 38 small-cell lung cancer patients subjected to radical surgical treatment after neoadjuvant therapy. CT data were compared with the findings of macro- and microscopic examination of surgical specimens. In 24 (63.2%) patients, computed tomograms made before surgery showed complete tumor response confirmed by gross examination in 22 (96.1%) of them. However, microscopic examination found cancer cells in 8 (33.3%) patients. In 2 (8.3%) patients, small residual tumors could be detected by sight, which was confirmed by pathological examination. In 14 (36.8%) patients with partial response, radiological and gross examination findings fully coincided. Nevertheless, in 2 (14.3%) cases the "residual tumor" appeared to be a segment of fibrocicatrical tissue under pathological examination. On the basis of the CT findings the values of diagnostic sensitivity, accuracy and specificity in tumor response evaluation were calculated which made up 87.5%, 68.4% and 54.5% respectively. With sufficiently high sensitivity, CT specificity is low. CT makes it possible to objectively define the response of small-cell lung cancer to neoadjuvant therapy. However, the conclusion about complete response to the treatment can be made only on the basis of a comprehensive evaluation of the results of all available investigation methods and pathological examination.     

20例葡萄球菌感染所致化脓性脊柱炎的临床特征分析

为探讨葡萄球菌感染所致化脓性脊柱炎(pyogenic vertebral osteomyelitis,PVO)的临床及影像学特征,本研究回顾性分析了2009年1月-12月上海交通大学附属第六人民医院感染病科收治的20例葡萄球菌感染所致PVO患者的临床特征、实验室检查指标、影像学资料及治疗效果。结果显示,20例PVO患者中金黄色葡萄球菌感染较为多见,85%患者病变在腰椎,50%患者白细胞计数升高,13例发热(65%),12例(60%)出现椎旁脓肿,所有患者C反应蛋白、红细胞沉降率、铁蛋白均升高。计算机断层扫描(computed tomography,CT)平扫示感染椎体骨质破坏;磁共振成像(magnetic resonance imaging,MRI)示病变椎体及椎间盘破坏区异常信号灶,增强后可见明显强化;单光子发射计算机断层扫描(emission computed tomography,ECT)示病变椎体不均匀放射性摄取增高。金黄色葡萄球菌对青霉素耐药率达77.8%。12例椎旁脓肿患者经CT引导下穿刺置管引流加敏感抗生素治疗,临床结局良好。结果提示,金黄色葡萄球菌是葡萄球菌感染所致PVO的主要致病菌,其对青霉素普遍耐药,炎症指标和影像学检查可用于疗效评估及随访,内科保守治疗对PVO有效。     

MRI与CT检查对卵巢癌病理分期及复发转移的诊断价值对比研究

摘要 目的：对比磁共振成像（MRI）与计算机断层扫描（CT）检查对卵巢癌病理分期及复发转移的诊断价值。方法：纳入2017年1月～2019年1月于我院接受诊治的卵巢癌患者100例进行研究。所有患者术前均进行MRI与CT检查,并以术后病理组织活检结果为金标准,对比MRI与CT诊断卵巢癌与卵巢癌病理分期的准确率。所有患者均于首次检查6个月后进行复诊,对比MRI与CT诊断卵巢癌复发转移的准确率。结果：MRI诊断卵巢癌的确诊率为94.00%（94/100）,高于CT诊断的81.00%（81/100）;漏诊率为2.00%（2/100）,低于CT诊断的10.00%（10/100）（均P＜0.05）。MRI诊断卵巢癌Ⅰ期、Ⅱ期、Ⅲ期的准确率分别为93.33%（14/15）、95.00%（19/20）、93.33%（28/30）,高于CT诊断的60.00%（9/15）、65.00%（13/20）、73.33%（22/30）（均P＜0.05）。MRI诊断肠管及周围、盆腔淋巴结、腹膜后淋巴结、肝脏等远处侵袭和转移中的准确率分别为100.00%（26/26）、88.89%（24/27）、75.00%（18/24）、95.00%（19/20）,高于CT诊断的76.92%（20/26）、48.15%（13/27）、41.67%（10/24）、45.00%（9/20）（均P＜0.05）。结论：相较于CT检查,MRI检查诊断卵巢癌的准确率更高,漏诊率更低,且在卵巢癌病理分期以及复发转移的诊断准确率更高,具有较好的临床应用价值。     

老年急性心肌梗死并心源性休克冠状动脉介入治疗的临床效果分析

目的:对比分析介入治疗和保守治疗对急性心梗合并心源性休克的老年患者的治疗效果。方法:回顾性分析急性心肌梗死并心源性休克患者,共入选230例,按照医生评估进行分组治疗,分为介入治疗组和非介入治疗组,介入组患者120例,接受冠脉介入治疗;非介入组患者110例,接受非介入治疗。对比分析危险因素以及治疗效果。结果:介入组中心肌梗死病史及心衰病史患者明显高于非介入组(24.2%vs 20%P<0.05;25%vs 17.3%,P<0.05),经皮冠状动脉介入治疗与非介入治疗相比能显著降低急性心梗合并心源性休克的老年患者住院病死率(40.8%vs 71.8%,P<0.05),非介入治疗组心律失常发生率高于介入治疗组(26.7%vs 21.8%,P<0.05),同时非介入治疗组肺部感染及肾衰的发病率较高(11.8%vs 5.8%P<0.05;8.2%vs 2.0%,P<0.05)。结论:针对急性心梗合并心源性休克的老年患者制定治疗方案时,虽然介入治疗存在更多的并发症,但是可以显著改善患者预后。     

特发性腹膜后纤维化一例并文献复习

目的：分析腹膜后纤维化（RPF）的诊断以及治疗情况,以提高对RPF的认识。方法：回顾性分析我科18F-FDGPET/CT诊断的1例RPF患者的临床资料,并对相关文献进行复习。结果：本例患者以腹胀及右下腹部隐痛不适就诊,腹部CT表现为腹主动脉周围肿块,18F-FDGPET/CT显示腹膜后间隙中线大血管周围糖代谢增高肿块,经CT引导下穿刺及手术病理确诊为特发性腹膜后纤维化。结论：腹膜后纤维化属罕见病,CT、MRI在诊断中有较重要作用,PET/CT在IRPF的诊断及治疗随访中有比较重要的价值,在治疗方面,糖皮质激素治疗效果较好,晚期常需要手术治疗。     

肾嗜酸细胞腺瘤的诊疗分析（附47 例报告）

目的:分析肾嗜酸细胞腺瘤的临床特征,指导并提升诊疗水平。方法:回顾性分析47例肾嗜酸细胞腺瘤的临床资料,包括临床特点、影像表现、病理特征、治疗方法及预后等方面。结果:47例患者中43例因查体偶然发现,仅4例表现为患侧腰痛症状。术前影像诊断中1例考虑嗜酸细胞腺瘤,1例考虑腺瘤,2例CT与MRI报告不一致(CT与MRI各有1例诊断良性,具体类型不确定),其余43例均诊断为肾细胞癌(1例囊性肾癌)。27例行肾癌根治性切除术,16例行肾部分切除术,4例行微波或射频消融术。所有患者术后病理均诊断为肾嗜酸细胞腺瘤,随访4～179月,均无转移或复发。结论:肾嗜酸细胞腺瘤作为一种与肾细胞癌难相鉴别的良性肿瘤,因缺乏特异性表现,极易误诊为肾细胞癌,因此对肾肿瘤患者应尽可能选择保肾治疗方案。     

CT和MRI在宫颈癌分期诊断中的临床对比分析

目的：比较CT和MRI在宫颈癌分期诊断中的临床应用价值。方法：回顾性分析宫颈癌患者96例,上述患者均有完整临床资料及术前CT和MRI检查结果,根据术后病理检查结果,比较两种检查方法影像学诊断、侵犯宫颈旁组织、侵犯子宫体、侵犯阴道、淋巴结转移的术前检查结果与病理诊断的符合率。结果：两种检查方法在宫颈癌Ⅰb期、Ⅱa期和Ⅱb期诊断符合率比较差异具有高度统计学意义（P〈0．01）;宫颈癌Ⅲa期和Ⅲb期符合率比较,差异具有统计学意义（P〈0．05）;宫颈癌Ⅳ期符合率比较,差异无统计学意义（P〉O．05）;检查提示侵犯宫颈旁组织、侵犯子宫体与侵犯阴道与术后病理诊断符合率比较,差异具有统计学意义（P〈0．05）。结论：对于宫颈癌患者,术前应积极采取MRI检查方式,可提高诊断符合率,有利于对患者术后治疗的开展和预后的判断。     

A practical methodology to improve the dosimetric accuracy of MR-based radiotherapy simulation for brain tumors

PurposeTo investigate the dosimetric accuracy of synthetic computed tomography (sCT) images generated by a clinically-ready voxel-based MRI simulation package, and to develop a simple and feasible method to improve the accuracy.Methods20 patients with brain tumor were selected to undergo CT and MRI simulation. sCT images were generated by a clinical MRI simulation package. The discrepancy between planning CT and sCT in CT number and body contour were evaluated. To resolve the discrepancies, an sCT specific CT-relative electron density (RED) calibration curve was used, and a layer of pseudo-skin was created on the sCT. The dosimetric impact of these discrepancies, and the improvement brought about by the modifications, were evaluated by a planning study. Volumetric modulated arc therapy (VMAT) treatment plans for each patient were created and optimized on the planning CT, which were then transferred to the original sCT and the modified-sCT for dose re-calculation. Dosimetric comparisons and gamma analysis between the calculated doses in different images were performed.ResultsThe average gamma passing rate with 1%/1 mm criteria was only 70.8% for the comparison of dose distribution between planning CT and original sCT. The mean dose difference between the planning CT and the original sCT were −1.2% for PTV D₉₅ and −1.7% for PTV D_max, while the mean dose difference was within 0.7 Gy for all relevant OARs. After applying the modifications on the sCT, the average gamma passing rate was increased to 92.2%. Mean dose difference in PTV D₉₅ and D_max were reduced to −0.1% and −0.3% respectively. The mean dose difference was within 0.2 Gy for all OAR structures and no statistically significant difference were found.ConclusionsThe modified-sCT demonstrated improved dosimetric agreement with the planning CT. These results indicated the overall dosimetric accuracy and practicality of this improved MR-based treatment planning method.     

Imaging Non-Specific Wrist Pain: Interobserver Agreement and Diagnostic Accuracy of SPECT/CT,MRI, CT,Bone Scan and Plain Radiographs

Purpose

Chronic hand and wrist pain is a common clinical issue for orthopaedic surgeons and rheumatologists. The purpose of this study was 1. To analyze the interobserver agreement of SPECT/CT, MRI, CT, bone scan and plain radiographs in patients with non-specific pain of the hand and wrist, and 2. to assess the diagnostic accuracy of these imaging methods in this selected patient population.

Materials and Methods

Thirty-two consecutive patients with non-specific pain of the hand or wrist were evaluated retrospectively. All patients had been imaged by plain radiographs, planar early-phase imaging (bone scan), late-phase imaging (SPECT/CT including bone scan and CT), and MRI. Two experienced and two inexperienced readers analyzed the images with a standardized read-out protocol. Reading criteria were lesion detection and localisation, type and etiology of the underlying pathology. Diagnostic accuracy and interobserver agreement were determined for all readers and imaging modalities.

Results

The most accurate modality for experienced readers was SPECT/CT (accuracy 77%), followed by MRI (56%). The best performing, though little accurate modality for inexperienced readers was also SPECT/CT (44%), followed by MRI and bone scan (38% each). The interobserver agreement of experienced readers was generally high in SPECT/CT concerning lesion detection (kappa 0.93, MRI 0.72), localisation (kappa 0.91, MRI 0.75) and etiology (kappa 0.85, MRI 0.74), while MRI yielded better results on typification of lesions (kappa 0.75, SPECT/CT 0.69). There was poor agreement between experienced and inexperienced readers in SPECT/CT and MRI.

Conclusions

SPECT/CT proved to be the most helpful imaging modality in patients with non-specific wrist pain. The method was found reliable, providing high interobserver agreement, being outperformed by MRI only concerning the typification of lesions. We believe it is beneficial to integrate SPECT/CT into the diagnostic imaging algorithm of chronic wrist pain.     

Comprehensive Comparison of Multiple-Detector Computed Tomography and Dynamic Magnetic Resonance Imaging in the Diagnosis of Hepatocellular Carcinoma with Varying Degrees of Fibrosis

Methods841 patients with liver tumor who had liver CT or dynamic MRI examinations followed by surgical resection were included in the study. We defined typical HCC imaging characteristics as early enhancement in the artery phase and early washout in the venous phase. The tumor size was recorded based on pathological examination after surgery. The pathologic fibrosis score was verified by the METAVIR scoring classification.ResultsAmong the 841 patients, 756 underwent liver CT and 204 underwent dynamic liver MRI before surgery. The etiologies of chronic liver disease included hepatitis B virus, hepatitis C virus, hepatitis B and C virus, and non-hepatitis B or C virus. The sensitivity and accuracy of liver CT or MRI for HCC diagnosis was approximately 80%~90%. Liver CT had a diagnostic accuracy for HCC similar to that of dynamic MRI, and liver fibrosis stage did not influence their diagnostic efficacies.ConclusionsThe application of 4-phase dynamic CT and MRI exhibit similar diagnostic accuracy for hepatocellular carcinoma, in tumors of sizes 1 to 2 cm and >2 cm. Liver fibrosis status did not affect the diagnostic accuracy of liver CT or MRI for HCC. The AASLD and EASL restrictions of dynamic imaging studies for HCC diagnosis to cirrhotic patients alone are unnecessary.     

3.0 T高分辨磁共振在直肠癌术前T N分期、环周切缘有无累及淋巴结转移的评估价值

摘要 目的：研究3.0 T高分辨磁共振（MRI）在直肠癌术前T N分期、环周切缘有无累及淋巴结转移的评估价值。方法：将我院从2018年1月～2019年12月收治的直肠癌患者120例纳入研究。所有患者均接受3.0 T高分辨MRI检查,以术后病理结果为金标准,分析其对术前T N分期、环周切缘有无累及淋巴结转移的评估价值。结果：直肠癌术前3.0 T高分辨MRI T分期与病理结果一致性较高,检验结果显示Kappa值=0.543,P值=0.000。直肠癌术前3.0 T高分辨MRI N分期与病理结果一致性较高,检验结果显示Kappa值=0.519,P值=0.000。以术后病理结果为金标准,直肠癌术前3.0 T高分辨MRI诊断环周切缘累及的灵敏度、特异度、准确度、阴性预测值、阳性预测值分别为92.50%（37/40）、93.75%（75/80）、93.33%（112/120）、96.15%（75/78）、88.10%（37/42）。直肠癌淋巴结转移者MRI边缘模糊、肠周围脂肪信号不均匀占比较无淋巴结转移者更高,且短径较无淋巴结转移者更长（均P＜0.05）。结论：3.0 T高分辨MRI在直肠癌术前T N分期、环周切缘有无累及淋巴结转移的评估价值较高,具有一定的临床应用价值。     

磁共振成像应用于检测胎盘植入介入治疗

为了探讨磁共振成像(magnetic resonance imaging, MRI)在胎盘植入介入治疗中的诊断作用和为临床治疗提供依据,本研究选取30例于2012年6月至2015年12月间在我院进行介入治疗的胎盘植入患者作为研究对象,根据病理诊断标准,分析患者胎盘植入介入治疗前后的MRI检查结果。结果显示,粘连性胎盘的敏感性和特异性分别为77.5%和90.2%,植入性胎盘的敏感性和特异性分别为75.5%和87.7%,穿透性胎盘的敏感性和特异性分别为85%和100%。最好的预测胎盘植入的MRI特征是在T2W磁共振成像(T2W-MRI)序列上存在暗色的胎盘内条带。介入治疗1年后复查时,发现患者子宫恢复为正常大小,宫腔内的胎盘组织基本消失,宫壁与植入胎盘融合、宫腔内膜线和子宫结合带的信号完整。综上结果,说明MRI可作为检测胎盘植入可靠性和可重复性的工具,并且能够显示胎盘植入部位及子宫肌层受侵程度,可用于评价胎盘植入介入治疗的疗效。     

Early-stage Hodgkin's disease: current approaches to treatment.

Most patients with early-stage Hodgkin''s disease can now be cured by one of several therapeutic approaches. This review highlights the developments in the diagnosis and treatment of the disease that have led to long-term survival rates greater than 90%. Past and present radio-therapy (RT) planning and treatment practices are discussed in the context of both clinical and pathological staging. The role of initial bimodal therapy (RT and chemotherapy [CT]) and the use of CT in patients who suffer relapse after initial treatment with RT alone are reviewed. On the basis of prognostic factors, subgroups of patients for whom bimodal therapy is recommended, including those with a bulky mediastinal mass, have now been identified. Although treatment is highly successful, debilitating consequences of RT and CT, such as infertility, infection and second malignant diseases, remain. Newer treatment regimens may reduce morbidity and have similar or better long-term results with respect to survival and quality of life.     

18F-2-deoxy-2-fluoro-D-glucose positron emission tomography, computed tomography, and magnetic resonance imaging for the detection of experimental colorectal liver metastases

During the treatment of colorectal liver metastases, evaluation of treatment efficacy is of the utmost importance for decision making. The aim of the present study was to explore the ability of preclinical imaging modalities to detect experimental liver metastases. Nine male Wag/Rij rats underwent a laparotomy with intraportal injection of CC531 tumor cells. On days 7, 10, and 14 after tumor induction, sequential positron emission tomography (PET), computed tomography (CT), and magnetic resonance imaging (MRI) scans were acquired of each rat. At each time point, three rats were euthanized and the metastases in the liver were documented histologically. Topographically, the liver was divided into eight segments and the image findings were compared on a segment-by-segment basis with the histopathologic findings. Sixty-four liver segments were analyzed, 20 of which contained tumor deposits. The overall sensitivity of PET, CT, and MRI was 30%, 25%, and 20%, respectively. For the detection of tumors with a histologic diameter exceeding 1 mm (n = 8), the sensitivity of PET, CT, and MRI was 63%, 38%, and 38%, respectively. The overall specificity of PET, CT, and MRI was 98%, 100%, and 93%, respectively. This study showed encouraging detectability and sensitivity for preclinical imaging of small liver tumors and provides valuable information on the imaging techniques for designing future protocols.     

Magnetic resonance tomography in the diagnosis of lung metastases in the mediastinum and thorax

The results of MRI in 81 patients with morphologically verified lung cancer, mainly Stages IIIA and IIIB, were analyzed. They were compared with CT data in 37 cases and surgical findings in 28. MRI was performed by using Magnaview 0.04 T and Vectra 0.5 T apparatus in the T1- and T2-weighted SE and PC sequences as well in the fat-suppression mode. Thoracic metastases were evaluated from the direct signs tumor spread into the adjacent tissue and vessels. The criteria for the involvement of lymph nodes were their over 1-cm enlargement and characteristic changes in the intensity of signals from them. CT was found to yield less information on pleural, pericardial, and vascular invasion (66-75% sensitivity). MRI detected this type of cancer spread (88-94% sensitivity). Both techniques have nearly equal sensitivities in revealing intrathoracic lymphadenopathy. The interpretation of MRI data did not depend on the voltage of a magnetic field. It is recommended that MRI should be made after CT when there is a need for assessing large vessels or for making clear the data that remain open to question following CT.