能谱CT物质分离技术克服肾囊肿伪强化的临床评估

目的 评估能谱CT物质分离技术克服肾囊肿伪强化的价值。方法 80例肾囊肿患者接受能谱GSI模式平扫及双期增强扫描,共入组75个囊肿,按囊肿大小分为3组,A组（n=25）肾囊肿直径0.5~<1.5 cm、B组（n=25）直径1.5~<2.5 cm、C组（n=25）直径2.5~<3.5 cm。采用GSIViewer分析软件生成碘、水基图,记录单能谱70 keV图像上各期肾囊肿的CT值及碘水基值,比较各组肾囊肿平扫和增强双期CT值、碘水基值、CT值和碘水基值差值的差异。结果 3组间实质期与平扫CT值差值总体差异有统计学意义（F=204.128,P<0.001）,且两两比较差异均有统计学意义（P均<0.001）。增强后A、B组实质期CT值增加均超过10HU,出现了伪强化现象,C组CT值增加小于10HU,无伪强化现象。各组肾囊肿平扫、皮质期及实质期间碘基值差异有统计学意义（P均<0.001）。3组平扫和增强双期之间碘基值的差值均在10（100 μg/cm³）内,且差值平均值A组> B组> C组（P均<0.05）。A组肾囊肿皮质期及实质期水基值低于平扫（P均<0.05）,但差值均在10 mg/cm³以内。结论 能谱CT物质分离技术测定肾囊肿各期碘、水基值时同样会发生碘水基值的"漂移",肾囊肿越小其发生"漂移"的程度越大,碘基值发生漂移的程度受肾囊肿大小的影响较水基值更明显。     

酷似肾囊肿的肾盏憩室1例

患者男,34岁.右侧腰背部隐痛3个月余,呈进行性加重.B超提示右肾囊肿.CT平扫:右肾门水平肾实质内一大小约 3.4 cm×3.2 cm×2.8 cm的囊性、卵圆形均匀低密度灶,CT值约2 Hu,边缘锐利.增强检查(图1、2):动脉期、静脉期及延迟3分钟病灶均无变化,CT初步诊断:右肾囊肿.拟行CT引导下肾囊肿穿刺引流并硬化剂治疗,术前CT扫描定位,增强延迟6 h、23 h扫描发现病变内均有高密度造影剂充填,平均CT值分别为145 Hu、66 Hu,随后跟踪扫描48 h后造影剂完全消失.CT最后诊断:右肾盏憩室.     

多层螺旋CT对肝转移瘤介入治疗的应用研究

目的:探讨MSCT对肝转移瘤(HM8)介入治疗的指导意义.方法:23例HMs患者行介入治疗.介入治疗前先行多层螺旋CT(MSCT)平扫,然后行双期增强扫描及血管重建.结果:平扫发现病灶78个:增强扫描于动脉期发现病灶102个、门脉期发现病灶105个.对直径＜1 cm的病灶检出,动态增强扫描明显优于平扫(P＜0.05).CT表现:平扫表现为类圆形低密度灶;增强扫描按强化病灶数目多少分别表现为边缘环形强化、弥漫性强化、不均匀强化、无强化.血管重建显示情况:所有病例通过MSCTA均能显示3级以下肝动脉,与DSA完全相符,显示率达100%;对4级以上肝动脉显示14例,显示率为60.9%.门静脉显示:所有病例通过MSCTA均能显示4级以下门静脉肝内分支;DSA肝动脉造影可间接显示门静脉,但3级以下肝内分支大都显示不清.结论:MSCT动态增强扫描为较常用的影像检查手段,能提高HMs的检出率.动态增强扫描在检出率方面优于平扫,尤其在直径＜1 cm病灶的检出上有显著差异.通过快速的动态增强扫描能重建出高质量的肝动脉及门静脉血管像,且较DSA在诊断方面具有易操作性和非创性的优势,从而为合理制定HMs介入治疗方案提供重要的指导作用.     

胰岛细胞瘤的多排螺旋CT诊断

目的 评价多排螺旋CT(MSCT)双期增强扫描对胰岛细胞瘤的诊断价值.方法 回顾性分析14例经手术病理证实的胰岛细胞瘤的临床和MSCT影像资料.患者均于术前行MSCT平扫及动脉期、门静脉期双期增强扫描,造影剂注射剂量1.5 ml/kg,速率3.0 ml/s,延迟时间分别为30秒、70秒.结果 14例胰岛细胞瘤均被检出,其中功能性胰岛细胞瘤5例,直径均≤2 cm,平扫呈等密度或稍高密度,于动脉期呈明显均匀强化.无功能性胰岛细胞瘤9例,平扫表现为较大肿瘤,直径3～12 cm,平均8.6 cm;其中7例可见囊变坏死,内可见分隔及壁结节,增强扫描壁结节及囊壁呈中度至明显强化.结论 多层螺旋CT双期增强扫描对胰岛细胞瘤的诊断有重要价值,可在术前提供重要信息.     

MSCT对肾脏嗜酸细胞腺瘤和透明细胞癌的鉴别诊断价值

目的:探讨多层螺旋CT(Multi-slice spiral computed tomography,MSCT)四期扫描对肾脏嗜酸细胞腺瘤(Renal oncocytoma,RO)和透明细胞癌(Clear-cell renal cell carcinomas,ccRCC)的鉴别诊断价值。方法:搜集因肾脏占位行肾脏CT平扫和三期增强扫描患者79例共80枚瘤灶,经术后病理证实RO 29例,ccRCC 50例,并回顾性分析两组病例的影像表现,采用SPSS 19.0软件对肿瘤CT值、校正CT值、皮质期与实质期CT差值及增强廓清率进行独立样本t检验分析。采用Fisher确切概率法对肿瘤部位、形态、平扫特点、强化程度、强化方式、皮质期与实质期强化CT值差异、节段增强反转等征象进行统计分析。结果:RO和ccRCC皮质期CT值、皮质期校正CT值、皮质期与实质期CT差值和增强廓清率差异有统计学意义(P<0.05),平扫、实质期、排泄期CT值校正CT值差异均无统计学意义(P>0.05)。中央星状低密度影、强化程度、强化均匀度、轮辐状强化、皮质期与实质期强化CT值差异及节段增强反转等征象差异有统计学意义(P<0.05),部位、形态、钙化,病灶周边絮状和条索状影等征象差异无统计学意义(P>0.05)。结论:在MSCT多期扫描表现中,皮质期CT值、皮质期校正CT值、皮质期与实质期CT差值和增强廓清率、中央星状低密度影、强化程度、强化均匀度、轮辐状强化、皮质期与实质期强化CT值差异及节段增强反转等征象对于RO、ccRCC二者的鉴别具有重要价值。     

多层螺旋CT在腮腺良性肿瘤中的诊断价值(附84例分析)

目的回顾分析84例经病理证实的腮腺良性肿瘤MSCT扫描影像特征,探讨MSCT在腮腺良性肿瘤中的诊断价值。方法搜集84例经手术病理证实的腮腺良性肿瘤的MSCT检查资料,所有病例术前均进行CT平扫和双期增强扫描。影像评价:病灶数目、位置,密度、双期增强程度和方式;静脉期与动脉期相比,增强动态变化程度:增高、无变化、减低和混合型,双期增强方式:均匀、不均匀,是否存在不强化的囊变坏死区。结果单发混合瘤40例;腺淋巴瘤29例(6例多发,2例为双侧多发病灶);基底细胞瘤10例(1例为单侧两个病灶);肌上皮瘤5例。肿瘤平扫都表现为大小约1~5cm的边界清楚的软组织密度肿块,部分病例有囊变。增强方式显著不同:腮腺混合瘤动脉期无强化或轻度强化,静脉期呈轻度强化,较动脉期略明显,CT值约升高20Hu;腮腺腺淋巴瘤绝大多数病灶位于浅叶后下极,动脉期显著强化,静脉期呈轻度强化,较动脉期明显减低;腮腺基底细胞瘤动脉期和静脉期均有较显著强化,两者无显著差别,CT值约升高40Hu;腮腺肌上皮瘤动脉期和静脉期均有轻度强化,两者无显著差别,CT值约升高20Hu。结论不同类型的腮腺良性肿瘤的CT平扫和增强表现具有一定的特征性,CT增强检查对于肿瘤的定性诊断有更大帮助。     

64层螺旋CT增强扫描评价肾功能

目的 探讨利用64层螺旋CT增强扫描评价肾功能的可行性.方法 回顾性分析接受泌尿系统螺旋CT增强扫描的150例患者,将其分为女性≤50岁组、女性＞50岁组、男性≤50岁组、男性＞50岁组4组,测量动脉期双侧肾门水平肾脏外侧肾皮质CT值并求和(以下简称CT值),将所得结果与同期实验室方法测定的肌酐值进行相关性分析,同时分析肌酐正常者与升高者间CT值是否存在差异.结果 4组CT值与肌酐均呈负相关.女性≤50岁组:r=-0.43(P＜0.05),女性＞50岁组:r=-0.57(P＜0.05),女性肌酐正常者平均CT值为(339.5±72.6) HU,升高者平均CT值为(235.1±66.5) HU(P＜0.05).男性≤50岁组:r=-0.53(P＜0.05),男性＞50岁组:r=-0.43(P＜0.05),男性肌酐正常者平均CT值为(314.5±59.9)HU,升高者平均CT值为(255.1±63.7) HU(P＜0.05).结论 通过测量肾皮质动脉期CT值对肾功能进行评价是可行的;肾功能受损者肾皮质动脉期强化CT值降低.     

肺内孤立结节的CT诊断

[目的]探讨CT增强扫描及多层螺旋CT(MSCT)对肺内孤立性结节(SPN)的鉴别诊断价值.[方法]对85例经针吸活检、手术病理证实的良、恶性SPN患者CT影像,增强扫描CT影像及MSCT进行分析,分别测定注射造影剂前及造影剂后同一层面的CT值, 对其进行统计学比较.[结果]①恶性SPN的CT强化值平均升高39.46±9.19,良性SPN的CT强化值平均升高11.65±2.05,表明两组病理性质不同的SPN在增强扫描时病灶中心层面的CT强化值有显著的差异(P＜0.05);②肺癌、炎性结节和结核球三种病变增强后的时间一密度曲线形态和强化形式不同;③肺癌、肺结核血管集束征阳性率较高,炎症以Ⅰ型血管集束征为主,肺癌以Ⅲ型为主.[结论]动态增强CT扫描及MSCT对肺内孤立性小结节鉴别诊断有一定意义.     

泌尿系统炎性肌纤维母细胞瘤CT表现

目的:探讨泌尿系统炎性肌纤维母细胞瘤(IMT)的CT影像学表现特征,提高诊断水平。材料与方法:经手术病理证实的IMT 8例。女6例,男2例。平均年龄35(13～62)岁。临床主要表现为血尿、尿痛等。病变位于膀胱5例,输尿管2例,尿道1例。行CT平扫8例,行多期增强扫描5例,观察影像学表现特征。结果:CT平扫膀胱病变呈菜花样或类圆形软组织肿物5例,密度均匀或不均匀或伴有坏死,CT值11.5～36.0 Hu,可伴有邻近膀胱壁增厚及周围脂肪间隙模糊;2例输尿管病变均呈边缘光滑的实性肿物,密度均匀并与肌肉等密度,CT值约40.3 Hu;1例尿道病变呈境界较清的肿物伴有钙化,密度稍低不均匀,CT值17.5～22.6 Hu。增强扫描肿瘤动脉期呈均匀或不均匀轻到中度强化,延迟期持续性明显强化,CT值102.7～118.6 Hu。结论:CT影像学特征特别是延迟期强化明显而持久能为泌尿系统IMT的诊断及其鉴别提供重要的信息。     

MSCT多期扫描在早期肾癌诊断中的应用价值

目的:评价多层螺旋CT(MSCT)多期扫描在早期肾细胞癌(RCC)诊断中的价值。方法:回顾性分析20例经病理证实的早期肾癌平扫及多期增强扫描的MSCT表现。结果:①MSCT平扫中10例病灶呈稍低密度,5例等密度,2例稍高密度,3例为囊实性肿块;增强扫描皮质期除1例轻度强化外,其余肿瘤强化均较明显,强化为均匀或不均匀,实质期及肾盂期强化迅速减退。②本组早期肾癌检出率100%,定性诊断率95%,分期准确度为95%。结论:①皮质期与实质期“快进快退”的强化特点对早期肾癌具定性诊断意义。②MSCT双期(皮质期与实质期)增强扫描是早期肾癌可靠的检查方法,必要时结合肾盂期扫描,可了解肾盂、肾盏受侵情况。③MSCT多期扫描提高了早期肾癌诊断的敏感性、特异性与准确度。     

正常小肠的MSCT表现

目的 总结口服及灌肠双重肠道准备后小肠MSCT各种正常表现.方法 对44名健康志愿者,经结肠、小肠双充盈法准备后,对小肠进行测量,包括肠壁厚度、肠管充盈直径、肠壁分层、肠壁CT值、空肠黏膜皱襞数、肠系膜脂肪密度、肠系膜血管影以及肠系膜淋巴结和后腹膜淋巴结MSCT显示率等.结果 小肠总的肠壁厚度平均值为(1.72±0.20)mm;整个小肠平均充盈肠管直径(21.24±3.05)mm;小肠各组段肠壁平扫、增强动脉期和门静脉期平均CT值分别为(28.13±0.38)HU、(55.42±0.88)HU和(67.86±0.94)HU;正常小肠每厘米肠段内可见的空肠黏膜皱襞数为2.29个,肠系膜血管影为2.59个;平均肠系膜脂肪密度-98.57 HU;肠壁改变以单层为主.结论 对正常小肠MSCT的各种表现和测量指标的正确认识有助于小肠病变的诊断.     

Struma ovarii: CT findings

Background  The purpose of this study was to evaluate computed tomographic findings of struma ovarii. Methods  Computed tomography (CT) scans of 13 pathologically proven struma ovarii were retrospectively reviewed by two radiologists in consensus. Scans were evaluated for the laterality, size, mass configuration, margins, internal architecture, presence of intracystic high attenuation lesions on precontrast scans, and cyst wall enhancement. Results  The mean size of the tumors was 11.4 cm (range 4.7–21.0 cm). Mainly cystic (n = 8, 61.5%) or cystic (n = 5, 38.5%) appearance was common to all the tumors. All tumors were unilateral and had smooth margins. The most common internal architecture in the tumors was multicystic architecture (n = 11, 84.6%). Eleven tumors (84.6%) showed a high attenuation lesion in the cyst portion of the mass on precontrast scans and the attenuation ranged from 92.2 to 120.5 Hounsfield units (HU) (mean, 106.8 ± 8.8 HU). The cyst wall showed no (n = 7, 53.8%), moderate (n = 5, 38.5%), or marked (n = 1, 7.7%) enhancement after administration of contrast medium. Conclusions  On CT scans, struma ovarii appeared most often as a smooth marginated multicystic mass with a high attenuation lesion on precontrast scans and no or moderate cyst wall enhancement.     

胰腺癌瘤体强化程度与其恶性度的对照分析

目的探讨胰腺癌瘤体CT强化程度与其恶性度的关系。方法42例胰腺癌患者术前均行螺旋CT增强扫描,扫描延迟时间分别定为30s(胰腺实质期)、70s(门脉期)和180s(延迟期),以2.5～3.0ml/s速度团注对比剂100ml,观察胰腺癌胰实质期瘤体强化的程度和形式,结合胰腺癌病理组织学分级,对胰腺癌胰腺实质期的CT强化情况和病理级别作对照分析。结果胰腺高分化腺癌14例,平均胰腺-瘤体CT值差为(9.64±2.84)Hu,中分化腺癌16例,平均胰腺-瘤体CT值差(31.44±5.98)Hu,低分化腺癌12例,平均胰腺-瘤体CT值差(44.08±5.33)Hu,胰腺实质期病灶基本呈等密度强化13例,稍低密度强化15例,低密度强化伴小囊样改变9例,低密度强化伴大片坏死5例。胰腺癌实质期强化程度和形式与其病理分级有显著相关性,其秩相关检验结果为r=0.664(P<0.001)。结论胰腺癌实质期可以得到肿瘤的最大胰腺-瘤体密度差值,其瘤体强化程度和形式与其病理分级有显著相关性,即胰腺癌恶性度与其瘤体强化程度成反比。     

Evaluation of Split Renal Function for Children with Kidney Diseases by Renal and Vascular Color Ultrasonography

Renal dynamic imaging and radionuclide renography use radioactivity to evaluate split renal function. We aimed to investigate the use of renal vascular color Doppler ultrasonography for evaluation of split renal function in children. Thirty-five children with unilateral kidney diseases were enrolled. For patients with unilateral renal tumor, peak systolic velocity (V_max?=?113.04 ± 13.59 cm/s) and resistance index (RI?=?0.73 ± 0.02) were higher on abnormal compared with normal sides (V_max?=?86.03 ± 6.49 cm/s, RI = 0.62 ± 0.01), and blood perfusion was good, indicating compensatory enhancement in split renal function. For unilateral renal cyst, V_max (58.20 ± 7.38 cm/s) was lower on the abnormal compared with the normal (87.71 ± 14.83 cm/s) size, and perfusion was poor. For unilateral hydronephrosis and renal atrophy, the parameters were similar to those of renal cyst, suggesting a weakening of renal function. For unilateral renal agenesis, V_max (106.07 ± 13.07 cm/s) and RI (0.71 ± 0.05) were higher, and perfusion was good. Renal vascular color Doppler ultrasonography was superior in the evaluation of split renal function in children, without being invasive or radioactive.     

肾脏原发恶性孤立性纤维瘤的CT特点

目的 探讨肾脏原发恶性孤立性纤维瘤(MSFT)CT特点。方法 回顾性分析本院经手术病理证实的5例肾脏MSFT患者的临床和CT表现。结果 肿瘤位于右肾4例,左肾1例;4例来源于肾被膜,1例起自肾实质;均呈类圆形,边界清楚,见包膜,长径5.1~18.3 cm。CT平扫均呈低密度,2例见点状钙化灶,1例病灶多发且位于一侧肾脏。5例增强扫描均为皮髓期轻度强化,实质期及排泄期持续性不均匀强化,且内部见囊变坏死区。结论 当肾脏CT检查发现类圆形、边界清楚、有包膜、体积较大的肿块,瘤体内出现坏死、囊变、钙化或多发病灶,且平扫及增强扫描肿瘤密度低于周围正常肾实质密度,出现渐进性"地图"样强化时,应考虑肾脏MSFT的可能。     

IVU后CT扫描对小儿先天输尿管畸形的诊断价值

目的探讨IVU/CT诊断小儿先天输尿管畸形的价值.方法 49例疑诊输尿管畸形患儿,行头低位腹部无加压静脉尿路造影,造影后20 min行CT扫描,观察IVU和IVU/CT显示肾脏、尿路及输尿管病变,并与手术结果对照.结果①16侧肾脏IVU不显影,IVU/CT示重度肾积水,其中UPJ 8侧,UVJ 4侧,发育不良重肾2侧,膀胱输尿管返流2侧;②IVU/CT 39侧积水肾实质密度(130.5±29.8) Hu,正常肾实质密度(82.4±19.0) Hu,二者存在显著差异 (P<0.05);③IVU、IVU/CT对39例UPJ、15例UVJ和15例重复肾输尿管畸形的诊断符合率分别为78.8%和 97.0% (P>0.05)、53.3%和100%(P<0.05)、40.0%和93.3% (P<0.001).结论 IVU/CT相当于肾脏CT增强延迟扫描,可不依赖肾功能丧失程度显示输尿管畸形;IVU/CT对输尿管末端梗阻和重复肾输尿管畸形的诊断具有重要价值.     

Quantitative multiparametric MR analysis of small renal lesions: correlation with surgical pathology

Purpose

The purpose of the study is to evaluate the utility of apparent diffusion coefficient (ADC), chemical shift signal intensity index (SII), and contrast enhancement in distinguishing between benign lesions and renal cell carcinoma (RCC) and between subtypes of renal lesions.

Methods

This retrospective study included 98 renal lesions (≤ 3 cm) on MRI with correlative surgical pathology. Scanner field strength, lesion location, and size were recorded. Two readers blinded to surgical pathology independently measured ADC ratio (ADC lesion/ADC non-lesion kidney), SII, and absolute/relative enhancement in the corticomedullary and nephrographic phases of contrast.

Results

There were 76 malignant and 22 benign lesions. 42 RCC were clear cell (ccRCC), 19 papillary (pRCC), 5 chromophobe (cbRCC). Benign lesions included both solid and cystic lesions. Interreader agreement for all variables was good–excellent (ICC 0.70–0.91). There was no difference in ADC or SII between benign and malignant lesions. There was greater absolute corticomedullary enhancement of benign versus malignant lesions (150.0 ± 111.5 vs. 81.1 ± 74.8, p = 0.0115), which did not persist when excluding pRCC. For lesion subtype differentiation, ADC_ratio for pRCC was lower than benign lesions (0.74 ± 0.35 vs. 1.03 ± 0.46, p = 0.0246). ccRCC demonstrated greater SII than other RCC (0.09 ± 0.22 vs. 0.001 ± 0.26, p = 0.0412). Oncocytomas and angiomyolipoma (AML) showed greater absolute corticomedullary enhancement than ccRCC and pRCC (145.6 ± 65.2 vs. 107.2 ± 85.3, p = 0.043 and 186.2 ± 93.9 vs. 37.6 ± 35.3, p = 0.0108), respectively.

Conclusions

While corticomedullary-phase enhancement was a differentiating feature, quantitative metrics from diffusion and chemical shift imaging cannot reliably differentiate benign from malignant lesions. Quantitative assessment may be useful in differentiating some benign and malignant lesion subtypes.

     

肺内支气管囊肿的CT表现

目的 探讨肺内支气管囊肿的CT表现特点。方法 回顾性分析57例经手术病理证实的支气管囊肿的CT表现。结果 57例肺内支气管囊肿,48例发生于单叶肺,3例累及一侧多叶肺,6例累及双肺多叶。21例CT表现为球灶型,19例呈空腔型,8例呈肿块样型,9例呈蜂窝型。13例含有曲菌球,5例囊壁发生钙化。15例见囊肿周围透亮度增高影,24例见周围条状实变影,4例见邻近肺组织节段性压缩不张,9例见近端引流支气管扩张积液。结论 大部分肺内支气管囊肿的CT表现具有特征性,有助于术前诊断。     

Analysis of Dosimetric Impacts of Cone Beam Computed Tomography–Based Volumetric Modulated Arc Therapy Planning

ObjectiveTo quantify the Hounsfield unit (HU) variations between computed tomography (CT) and cone beam CT (CBCT) and study its impact on volumetric modulated arc therapy (VMAT) plans.MethodsHU number variations in CT and CBCT images were evaluated using the Catphan-504 phantom, and changes in seven different materials within the phantom (air, polymethylpentene, low-density polyethylene, polystyrene, acrylic, Delrin, and Teflon) were studied. The HU variations in half-fan and full-fan modes of CBCT were evaluated. The effect of variations in the shape of the body cross sections was assessed by reducing the body of the Catphan by 0.5 cm and 1.0 cm. CBCT-based VMAT plans in 27 patients (10 prostate, 10 brain, and 7 head and neck (HN)) were compared with corresponding CT-based plans. The dosimetric variations were assessed referring to different points on the dose volume histogram (D_5%, D_50%, and D_95% for PTVs and D_1%, D_max, and D_mean for organs at risk). The relative percentage of difference (ΔD (%)) between CT- and CBCT-based VMAT plans were examined on these points. To evaluate the dosimetric accuracy, dose distributions were compared using Omnipro-I'mRT software. The VMAT plans were evaluated based on 3 mm-3%, 2 mm-2%, and 1 mm-1% gamma criteria.ResultsThe HU difference in CT and CBCT was highest for air, Delrin, and Teflon, whereas the difference was less than 20 HU for the other materials. The dose volume histograms of both CT- and CBCT-based plans were in excellent agreement in both phantom and patients, except in HN cases where the difference was 7%. The average 3 mm-3% gamma pass points in brain, prostate, and HN patients were 97 ± 0.2%, 96 ± 0.06%, and 93.3 ± 1.1%, respectively. The gamma pass rates reduced to 88.8 ± 0.06%, 91 ± 0.04%, and 79 ± 6% in 2 mm-2%, and further declined to 76.6 ± 0.09%, 75.2 ± 0.5%, and 60 ± 6% using the stringent 1 mm-1% gamma criteria for brain, prostate, and HN cases, respectively.ConclusionBased on the results of this study, it is our belief that CBCT images can be used as a tool for evaluating the dosimetric variation in patient VMAT plans.