肾上腺腺瘤和非腺瘤动态增强CT表现与血管生成相关性的初步研究

目的探讨肾上腺腺瘤和非腺瘤血管生成[微血管密度（MVD），血管内皮生长因子（VEGF）]特点与动态增强CT表现的相关性，以阐述其动态增强机制。方法经手术病理证实的42例46个肾上腺肿块（腺瘤23个、非腺瘤18个、增生结节5个）均行动态增强CT检查和病理学检查。首先评价肾上腺腺瘤和非腺瘤动态增强CT表现，而后分析肾上腺肿块动态增强CT表现特征[时间-密度（T-D）曲线、廓清率（Wash）]与血管生成之间的相关关系。结果腺瘤与非腺瘤间T—D曲线类型和7min延时点相对廓清率（Washr）和绝对廓清率（Washa）差异均存在统计学意义（P=0．000）。肾上腺肿块T—D曲线廓清迅速组（A、C型）与廓清缓慢组（B、D、E型）间、7min延时点Washr≥34％组与〈34％组间、Washai≥43％组与〈43％组间MVD、VEGF表达水平差异均有统计学意义（P〈0．05）。肿块廓清曲线为A、C型，和（或）Washr≥34HU，和（或）Washai≥43％组均提示为腺瘤，反之提示为非腺瘤。T—D曲线廓清迅速组、7min延时点Washri≥34％组和Washa≥143％组MVD、VEGF表达水平分别高于廓清缓慢组、〈34％组和〈43％组；由此提示动态增强CT表现特征与MVD、VEGF表达存在相关性。另一方面，腺瘤和非腺瘤间MVD和VEGF表达存在显著不同。结论MVD和VEGF可能是导致腺瘤和非腺瘤具有不同的T—D曲线类型和廓清率的主要因素之一。     

动态增强CT检查对肾上腺腺瘤与非腺瘤的鉴别诊断价值

目的探讨动态增强CT检查技术对肾上腺腺瘤与非腺瘤的鉴别诊断价值并优选出有意义的参数，以进一步明确两者的鉴别诊断标准。资料与方法对44例共49个肾上腺肿瘤先平扫再行动态增强CT检查，观察以肿瘤的CT绝对值、绝对开始廓清率及相对开始廓清率作为标准鉴别肾上腺腺瘤与非腺瘤的诊断价值。结果延时3min，以36％的绝对开始廓清率或35％的相对开始廓清率分别与CT绝对值58HU相结合作为标准，对腺瘤有较高的诊断价值，对于腺瘤中的乏脂质性腺瘤与非腺瘤的鉴别诊断也具有同样的价值。结论以肿瘤的廓清率与延时增强后的CT绝对值作为联合标准，能明显提高腺瘤的诊断价值。     

肾上腺腺瘤和非腺瘤动态增强CT曲线与微血管超微结构的相关性研究

目的 探讨肾上腺腺瘤和非腺瘤动态增强CT曲线与微血管超微结构特点的相关关系,以进一步阐明其动态增强机制.资料与方法 经手术病理证实的42例46个肾上腺肿块(腺瘤23个、非腺瘤18个、增生结节5个)均行动态增强CT检查和病理学检查,而后分析肾上腺肿块动态增强CT表现特征[时间-密度(T-D)曲线]与微血管超微结构之间的相关关系.结果 肾上腺腺瘤和非腺瘤间微血管超微结构存在显著不同.肾上腺肿块T-D曲线廓清迅速组(A、C型)与廓清缓慢组(B、D、E型)间的微血管超微结构表现特点亦不同;T-D曲线廓清迅速组微血管超微结构表现为管腔规则,无狭窄;内皮细胞吞饮泡多,窗孔多;细胞间隙增宽;基底膜菲薄,厚薄均匀,有裂口;血管外间隙窄、规则且均匀一致,基质少等,与腺瘤表现一致;由此提示动态增强CT曲线与微血管超微结构存在相关关系.结论 微血管超微结构可能是导致腺瘤和非腺瘤具有不同的T-D曲线类型的主要因素之一.     

肾上腺腺瘤与非腺瘤的CT鉴别诊断

目的 探讨肾上腺腺瘤与非腺瘤的CT鉴别诊断价值.方法 回顾性分析经手术和随访证实的56例(58个病灶)肾上腺肿瘤的CT表现及病理组织学特征,患者均行CT平扫及1 min、5 min增强扫描,对诊断参数进行分析并对照病理组织学表现,对肾上腺肿瘤做出正确的诊断.结果 腺瘤与非腺瘤在CT平扫及增强后1 min、5 min的CT值、相对廓清率和绝对廓清率的差异均有统计学意义(P＜0.05),以平扫时CT≤19 HU,延时5 min时CT≤46 HU,绝对廓清率≥63%,相对廓清率≥31%为阈值相结合作为诊断标准时,诊断腺瘤或乏脂性腺瘤的敏感性分别为96%或86%.结论 以肿瘤平扫及增强后的CT值与肿瘤的廓清率作为联合标准,对腺瘤(包括乏脂性腺瘤)与非腺瘤的鉴别诊断有较高的价值.     

肿瘤廓清率在动态增强MRI检查中对肾上腺肿瘤的鉴别诊断价值

目的　探讨应用动态增强MRI检查技术 ,以肿瘤的廓清率为标准 ,再结合该时间点的信号增加比 ,对肾上腺腺瘤与非腺瘤进行鉴别诊断的临床价值。方法　 3 6例共 41个肾上腺肿瘤均先行常规SE序列T1 WI及T2 WI成像 ,再利用屏气快速多层面破坏性梯度回波序列 (fastmultiplanarspoiledgradient-echo ,FMPSPGR)行轴位扫描 ,先平扫 ,再以同样条件行MRI动态增强检查 ,观察病变的增强程度并分别测量肿瘤实质部分的信号值。分别比较腺瘤与非腺瘤的廓清率及信号增加比 ,明确其鉴别诊断价值。结果　延时 5min并以廓清率 2 2 %为阈值时 ,诊断腺瘤的敏感性 74% ,特异性 73 % ,准确性 73 % ;若将延时 5min时肿瘤的廓清率 (2 2 % )与信号增加比(<0 .48)相结合 ,则诊断腺瘤的敏感性、特异性、准确性明显提高 ,分别为 95 %、91%、93 %。结论　利用动态增强检查技术 ,以肿瘤的廓清率为标准 ,再结合该时间点的信号增加比 ,可在最短的时间内提高肾上腺腺瘤与非腺瘤的鉴别诊断水平     

不典型肾上腺腺瘤的CT 影像误诊分析

目的：通过回顾性分析11例不典型肾上腺腺瘤的C T影像特征及误诊原因,以提高诊断准确率。方法收集近几年经手术病理确诊的不典型肾上腺腺瘤11例,均行C T平扫及三期增强扫描,结合临床资料进行回顾性分析。结果11例肾上腺腺瘤中,高强化腺瘤2例,肿块最大径＞4cm的大腺瘤8例,双侧腺瘤1例。高强化腺瘤在C T增强表现为快进快退;大腺瘤中囊性密度和强化较低的2例,肿瘤内出血的无功能肾上腺瘤1例,CT增强表现为快进快退伴偏心囊变的5例,双侧高强化的肾上腺腺瘤1例。结论详细分析不典型肾上腺腺瘤的CT特征,密切联系临床病史、实验室结果和M RI检查,可提高不典型肾上腺腺瘤的诊断准确率。     

原发醛固酮增多症腺瘤的CT诊断

本文报告47例原发醛固酮增多症腺瘤(Conn’s腺瘤)的CT表现，介绍了这一病变的CT检查方法及注意事项，分析了Conn’s腺瘤的CT表现特征及与其它常见肾上腺肿块鉴别的可能性，从而说明CT的诊断价值。     

增强MRI时间-信号增强率曲线对肾上腺肿瘤的鉴别价值

目的 :以肿瘤的时间 信号增强率曲线作为诊断标准 ,进一步证实Gd DTPA动态增强MRI检查技术对肾上腺肿瘤的鉴别诊断价值。方法 :3 6例共 41个肾上腺肿瘤 ,腺瘤 19例共 19个 ,非腺瘤 17例共 2 2个。所有肿瘤均先行常规SE序列T1 W和T2 W成像 ,选定肿瘤中心层面定位后 ,再利用屏气快速多层面破坏性梯度回波序列 (FMPSPGR)行轴位扫描 ,先平扫 ,再以同样条件行MRI动态增强检查 ,即静注Gd DTPA ,自注药后 0 .5min开始扫描 ,之后分别在 60min内共 17个时间点 ,以同等条件延时扫描 ,观察病变的增强程度 ,并分别测量其实质部分的信号值。计算肿瘤的信号比、最大信号增加比、增强率 ,再根据随时间延时肿瘤增强率的变化绘制曲线 ,比较肾上腺肿瘤间的时间 信号增强率曲线有无差异 ,并明确其对肾上腺肿瘤的鉴别诊断价值。结果 :Ⅰ型时间 信号增强率曲线具有高度特异性 ,只有大多数神经源性肿瘤符合此增强特点 ,对区分腺瘤与其它类型的非腺瘤无诊断价值 ;以Ⅲ型或Ⅳ型曲线为标准诊断恶性肿瘤的准确率均不高 ,有 5 0 %的恶性肿瘤无法确诊 ;而以Ⅱ型时间 信号增强率曲线为标准较前 3种曲线更有助于肾上腺肿瘤的鉴别诊断 ,即以早期增强 ,延时 9min内肿瘤增强率下降程度超过肿瘤最大增强率的 5 0 %为诊断腺瘤的标准 ,敏     

螺旋CT三期增强扫描对肝细胞腺瘤的诊断价值（附五例报告）

目的评价螺旋CT三期增强扫描对肝细胞腺瘤的诊断及鉴别诊断的价值,重点探讨动脉期扫描的意义,以进一步提高CT诊断的准确性。方法5例肝腺瘤均行平扫及三期增强扫描,100ml对比剂,3ml/s单相注射,延迟20～30s行动脉期扫描,60～70s行门脉期扫描,3min后行延迟期扫描。测量腺瘤及正常肝组织的强化CT值,观察腺瘤的三期强化特征,并对结果进行统计学分析。结果5例肝腺瘤平扫表现为等密度或略低密度,与正常肝组织无法区分;动脉期均表现为高密度,其平均CT值与正常肝组织相差38HU,定量比较有显著性差异（t=18.94,P<0.01）;在门脉及延迟期,4例腺瘤表现为等密度,1例为略低密度,分别与正常肝组织平均CT值相差(3.7±7.1)HU和(－4.3±3.6)HU,定量比较差异无显著性意义(t=1.10,t=0.75;P值均>0.05);肝腺瘤动脉期平均CT值明显高于门脉及延迟期,定量比较有显著性差异（F=18.39,P<0.01）。结论螺旋CT三期增强扫描对肝腺瘤的诊断与鉴别诊断有重要价值,尤其是动脉期扫描。     

垂体微腺瘤MRI半剂量动态增强扫描影像学分析

目的：分析25例垂体微腺瘤MRI半剂量动态增强扫描的影像学征象及动态增强信号强度一时间曲线图的特点,总结垂体微腺瘤的影像学诊断要点。方法：对25例经过临床综合诊断确诊的病例．行MRI平扫及半剂量（0．05mmol／kg）动态增强扫描,并利用工作站后处理功能．绘制出动态增强信号强度-时间曲线图。结果：平扫垂体信号异常的20例．主要T1wI呈稍低信号T2wI呈稍高或稍低信号。平扫垂体信号无异常的5例;25例均进行半剂量（0．05mmol／kg）动态增强扫描．动脉早期（25～35s）呈低信号的病例8例,动脉中期（35～76s）呈低信号的病例16例·动脉晚期（76～120s）呈高信号的病例1例。结论：半剂量MRI半剂量动态增强扫描在诊断垂体微腺瘤的敏感性、检出率都好于其它检查,有较高的临床价值。     

良、恶性乏脂质性肾上腺肿瘤的动态MRI检查

目的：探讨MRI动态增强检查技术对乏脂质性肾上腺肿瘤良、恶性的鉴别诊断价值。方法：经手术和临床证实的29例共33个乏脂质性肾上腺肿瘤行MRI平扫并于注药后1min、2min、3min、5min、7min和9min时间点行动态增强检查,分别观察病变的增强程度并获取乏脂质性肾上腺肿瘤的廓清率（Wash）和时间-信号强度曲线（T-S curve）,以评估良、恶性肿瘤间是否存在统计学差异。结果：T-S曲线分Ⅰ~Ⅴ五种类型。良性乏脂质性肿瘤的特征曲线为Ⅰ、Ⅱ型和Ⅳ型;恶性乏脂质性肿瘤的特征曲线为Ⅲ型和Ⅴ型（P=0.000）,肾上腺良性乏脂质性肿瘤的廓清率高于恶性肿瘤,两者之间差异有统计学意义（P=0.006）,在5min延迟点诊断价值较大,Wash≥23%提示为良性肿瘤。结论：MRI动态增强检查技术对乏脂质性肾上腺肿瘤良、恶性的鉴别诊断具有较高价值。     

Adrenal masses: characterization with combined unenhanced and delayed enhanced CT

PURPOSE: To assess the accuracy of a dedicated adrenal computed tomographic (CT) protocol. MATERIALS AND METHODS: One hundred sixty-six adrenal masses were evaluated with a protocol consisting of unenhanced CT, and, for those with attenuation values greater than 10 HU, contrast material-enhanced and delayed enhanced CT. Attenuation values and enhancement washout calculations were obtained. An adenoma was diagnosed if a mass had an attenuation value of 10 HU or less at unenhanced CT or a percentage enhancement washout value of 60% or higher. RESULTS: The final diagnosis was adenoma in 127 masses and non-adenoma in 39. Masses measuring more than 10 HU on unenhanced CT scans were confirmed at biopsy (n = 28) or were examined for stability or change in size at follow-up CT performed at a minimum interval of 6 months (n = 33). Thirty-six (92%) of 39 non-adenomas and 124 (98%) of 127 adenomas were correctly characterized. The sensitivity and specificity of this protocol were 98% and 92%, respectively. This protocol correctly characterized 160 (96%) of 166 masses. CONCLUSION: With a combination of unenhanced and delayed enhanced CT, nearly all adrenal masses can be correctly categorized as adenomas or non-adenomas.     

Computed tomographic histogram analysis in the diagnosis of lipid-poor adenomas: comparison to adrenal washout computed tomography

OBJECTIVE: To evaluate the ability of computed tomographic histogram analysis to diagnose lipid poor adenoma in comparison with adrenal washout computed tomography (CT). MATERIALS AND METHODS: Adrenal CT washout examinations performed during a period from January 2000 to July 2005 were reviewed. Computed tomographic histogram analysis was performed on the unenhanced component of the study, and sensitivity was assessed at thresholds of more than 5% and 10% negative pixels. Liver and spleen were used to represent the control/nonadenoma group. Computed tomographic noise was measured recording standard deviation (SD) of mean CT attenuation in adrenal, liver, and spleen. RESULTS: Twenty-four lipid-poor adenomas included exhibited more than 60% absolute enhancement washout (range, 60%-79%, mean, 69%) and remained stable for a period greater than 6 months. At threshold of more than 5% or 10% negative pixels CT histogram analysis yielded sensitivities of 91.6% and 70.8%, respectively, with 100% specificity. The mean SDs of adrenal, liver, and spleen were 18.2, 16.4 and 15, respectively. These differences in the mean SD were much smaller compared with the differences in the percentage of negative pixels in adrenal, liver, and spleen of 12.75%, 0.75%, and 0.25%, respectively. CONCLUSIONS: Computed tomographic histogram analysis has good potential in the diagnosis of lipid-poor adenoma and can reduce the need to perform adrenal washout CT.     

Are the washout values currently accepted for lesion characterization in dedicated adrenal CT adequate for diagnosis?

PURPOSEWe aimed to investigate the accuracy of density characteristics and washout values of lesions detected on computed tomography (CT) at the cutoff values obtained from the literature by taking the pathological results of adrenalectomy specimens as reference and to determine the cutoff values of parameters evaluated on CT for the differentiation of adenoma and nonadenoma lesions in the study group.METHODSHospital records and standard CT imaging data (noncontrast early phase [65 s] and late phase [15 min] ) of 84 patients with 87 lesions who underwent adrenalectomy between January 2012 and December 2018 were retrospectively reevaluated by two radiologists in consensus. The patients were categorized as having adenoma and nonadenoma lesions according to the pathology results. The sensitivity, specificity and diagnostic accuracy of CT parameters (density values and washout percentages) were evaluated. Differences in the CT parameters (size, noncontrast and early-late enhancement density and absolute and relative washout values) were investigated. The optimal cutoff values of CT parameters were determined by ROC analysis.RESULTSNoncontrast CT had a specificity of 87.75% and 95.9%, sensitivity of 60% and 48.6%, diagnostic accuracy of 77.7% and 89.47% for adenomas, at the cutoff values of ≤10 HU and ≤0 HU, respectively. For absolute washout value ≥ 60%, the sensitivity, specificity and accuracy were 64.7%, 52.38% and 56.75%, respectively; while these rates were 76.47%, 56.52% and 62.16%, respectively, for relative washout value ≥40%. Adenomas and nonadenomas showed significant difference in terms of size (p < 0.0001), unenhanced attenuation (p < 0.0001), relative washout (p = 0.020) and delay enhancement (p < 0.001). But there were no differences in terms of absolute washout (p = 0.230) and early enhancement (p = 0.264). The cutoff values for the differentiation of adenomas and nonadenomas were as follows: size ≤44 mm, noncontrast density <20 HU, early-phase density ≥45 HU, delayed-phase density ≤44 HU, absolute washout 74.83% and relative washout 57.76%.CONCLUSIONThe current washout criteria used in the differentiation of adenoma and nonadenoma lesions in dynamic CT imaging can give false negative and positive results. According to the existing criteria, the most reliable parameter in adenoma–nonadenoma differentiation is ≤ 0 HU noncontrast CT density value.

According to the autopsy studies, adrenal masses are among the most common tumors detected in humans (1). In autopsy series, this prevalence has been reported as 1% to 9.8% (1). With the advances in imaging techniques and their increasing use, there has also been a recent increase in radiologically reported adrenal masses (2–5), varying between 0.35% and 5% for CT examinations (6). Adenomas are the most common adrenal lesions in patients without primary malignancy (1, 7, 8). Although adrenal gland is a common site for distant metastases in patients with known malignancies, adenomas are more common than metastases in these patients. Since the majority of adrenal adenomas are benign and nonfunctional lesions, a clinical and radiological follow-up is sufficient. In nonadenoma lesions, a biopsy or direct surgical resection can be recommended according to the characteristics of the patient. Therefore, determination of whether a detected adrenal mass is an adenoma or nonadenoma is critically important in patient management and changes the form of treatment (9).Computed tomography (CT) is the radiological method of choice in the characterization of adrenal mass lesions (8, 10). Adenomas have low density values in noncontrast CT scans due to their intracytoplasmic fat content (3, 6, 10, 11). However, as much as 30% of adrenal adenomas are poor in fat, thus making it impossible to distinguish them from other masses based on noncontrast CT density (8, 10). In this case, most authors reported that the washout character determined by dynamic contrast-enhanced CT examination differentiates adrenal adenomas from other lesions (10–13). Due to their rich capillary network, adenomas are stained early with the contrast agent, causing them to exhibit a high level of washout (8). However, some nonadenoma lesions, particularly pheochromocytoma, have been reported to show a similar washout pattern (4, 14–18). In the literature, there are many studies that investigated noncontrast and contrast-enhanced CT density and the washout criterion for the differentiation of adenoma and nonadenoma lesions (4, 6, 10–18). However, the scan parameters used in these studies, the characteristics of the devices, the time of wash-in and washout, contrast agent dose, and iodine concentration are not standard and show differences (e.g., 2.5–10 mm collimation; 3–5 mm reconstruction intervals; 80–140 kVp; 150–370 mA; 0.75–3:1 pitch; nonhelical, helical, or multi-slice device; 35–120 s wash-in time; 3–45 min washout time; 100–150 mL contrast agent dose; 300–370 mg/L iodine concentration). In a study using different minutes as washout criteria in the same lesions, different specificity and sensitivity values were found according to the washout time (19). In studies evaluating the effectiveness of adrenal CT in the literature, the reference method also differs. For these reasons, the available literature data is far from being standard. Nonadenoma lesions, which are evaluated as adenoma based on the available data, may cause serious problems in patient management.In the current study, we aimed to investigate the accuracy of density characteristics and washout values of lesions detected on CT at the cutoff values obtained from the literature by taking the pathological results of adrenalectomy specimens as reference to determine the cutoff values of parameters evaluated on CT for the differentiation of adenoma and nonadenoma lesions in the study group.     

Adrenal masses falsely diagnosed as adenomas on unenhanced and delayed contrast-enhanced computed tomography: Pathological correlation

Objectives To assess the accuracy of CT for the diagnosis of histologically confirmed adrenal adenoma and nonadenoma using CT numbers. Materials and methods Our study included 91 adrenal masses in 83 patients; histopathological diagnoses were 45 adenomas, 31 pheochromocytomas, 6 hyperplasias, 4 metastasis, and 5 miscellaneous lesions. Unenhanced CT in 46 patients and unenhanced and delayed contrast-enhanced (DCE) CT in 37 patients were retrospectively reviewed to examine the correlation between CT findings and those on pathological examination and to obtain diagnostic accuracy. Results Sensitivity, specificity, and accuracy for adenoma were 40% (18/45), 91% (42/46), and 66% (60/91) with unenhanced CT, and 96% (24/25), 61% (11/18), and 81% (35/43) with DCE CT. Adrenal masses falsely diagnosed as adenoma on unenhanced CT included three hyperplasias and one endothelial cyst, and those falsely diagnosed as adenoma on DCE CT were five pheochromocytomas, one oncocytic coritical tumor, and one primary pigmented nodular adrenocortical dysplasia. Twenty-five lipid-poor adenomas were falsely diagnosed as nonadenomas on unenhanced CT and one degenerated adenoma both on unenhanced CT and on DCE CT. Conclusion Diagnosing adenoma merely on CT numbers can lead to misdiagnosis. The lower specificity than expected is due to pheochromocytomas presenting as false positives. An erratum to this article can be found at     

MR化学位移成像诊断肾上腺腺瘤的研究

目的：研究MRI对肾上腺肿瘤的定性诊断价值。方法：对23个肾上腺腺瘤和35个其他肾上腺占位性病变的患者行SE序列T1WI、快速自旋回波（TSE）序列T2WI和化学位移成像（CSI）序列扫描。肿物直径8-92mm。计算并比较肿物与肝脏、脾脏和水模在反相位和同相位上的信号比值变化。结果：腺瘤组有20/23的病例肿物-脾脏信号比（ASR）＜0.59,而基人他占位性病变ASR均大于0.73。MR CSI序列诊断肾上腺腺瘤的敏感性为87%,特异性为100%。结论：MR化学位移成像对肾上腺腺瘤的定性诊断具有重要价值。     

Adrenal mass evaluation in patients with lung carcinoma: a cost-effectiveness analysis

OBJECTIVE: This study evaluates the cost-effectiveness of various imaging and biopsy strategies for characterizing adrenal masses in patients with newly diagnosed non-small cell carcinoma of the lung. MATERIALS AND METHODS: A decision-analysis model was used to compare the cost-effectiveness of nine strategies. Initial imaging included unenhanced CT using an adenoma or nonadenoma threshold of 0 or 10 H or in- and opposed-phase MR imaging. When initial imaging did not confirm an adenoma, CT-guided biopsy or subsequent imaging was performed. Medicare reimbursement was used as a surrogate of cost. Net costs were calculated as the difference in costs between two limbs of the decision tree. Net benefits were calculated as the difference between strategies and were calculated for life expectancy in years. MR imaging, CT, and biopsy accuracy, average life expectancy, and surgical mortality rates were based on the literature. RESULTS: The base case analysis determined that the most cost-effective strategy was CT with an adenoma or nonadenoma threshold of 10 H followed by MR imaging, if necessary. CT with a threshold of 0 H followed by biopsy, if necessary, was the least costly. The incremental cost-effectiveness ratio between these two strategies was $16,370 per year of life gained. CONCLUSION: Unenhanced CT using a 10 H threshold followed by MR imaging, if needed, was the most cost-effective strategy for evaluating an adrenal mass in a patient with newly diagnosed non-small cell lung cancer.