99Tcm-MIBI半定量显像对甲状腺癌的诊断价值

目的评价半定量99Tcm-甲氧基异丁基异腈(MIBI)显像法对甲状腺癌的诊断价值.方法对269例经病理检查或细胞学证实的甲状腺结节患者的99Tcm-MIBI显像结果进行分析,计算其5和60 min摄取比值(UR),并以甲状腺良性结节组UR值的+s为诊断阈值,分析假阳性和假阴性.结果甲状腺良性结节组5和60 min UR分别为0.806±0.192和0.847±0.189,而甲状腺癌组UR值分别为1.839±0.734和1.675±0.551,同组两时相比较P>0.05,而组间两时相比较P<0.001.以良性结节组+s为诊断阈值,99Tcm-MIBI对甲状腺癌诊断的灵敏度、特异性和准确性分别为89.24%、93.82%和87.36%,假阳性率和假阴性率分别为15.78%和12.09%,阳性预测值和阴性预测值分别为 77.57% 和93.83%.结论 99Tcm-MIBI半定量显像能较好地鉴别甲状腺结节的良恶性,但缺乏特异性,甲状腺腺瘤和结节性甲状腺肿易出现假阳性.     

放射性核素显像在移植肾监护中的应用

肾移植术后所做的放射性核素显像,目的在于鉴别诊断术后所产生的各种并发症及排异反应.~(99m)Tc-DTPA灌注显像可鉴别诊断肾血管病变;~(99m)Tc-MAG_3、~(131)I-邻碘马尿酸钠动态显像可判断肾功能,主要是肾小管功能;~(99m)Tc-硫化锝胶体静态显像鉴别诊断肾排异反应.利用快速通过型肾显像剂所做的动态肾显像,有助于鉴别诊断各种原因所致尿路阻塞.与"B"型超声相比,放射性核素显像法集形态与功能为一体,是一种有价值的诊断方法.     

99Tcm-MIBI甲状腺显像对甲状腺癌诊断价值的再评价

目的 评价99Tcm-甲氧基异丁基异腈(MIBI)甲状腺显像对甲状腺癌的诊断价值.方法 167例甲状腺"冷(凉)"结节患者进行了甲状腺99Tcm-MIBI显像.所有患者均依据病理或穿刺活组织检查诊断.99Tcm-MIBI显像早期相甲状腺结节完全或部分放射性填充视为阳性,轻度或不填充视为阴性;早期相放射性浓聚区与正常组织边界分明者视为分界清楚,否则为模糊;延迟相99Tcm-MIBI从浓聚区清除慢于正常组织者视为清除慢,快于或相同者视为清除快.计算99Tcm-MIBI显像的阳性和阴性预测率,以显像阳性病灶边界模糊和放射性清除慢为标准预测甲状腺癌的发生率.结果 99Tcm-MIBI显像对甲状腺癌的阳性预测率为23.5%(19/81),对甲状腺良性病变的阴性预测率为97.7%(84/86).显像阳性者单独用边界模糊预测甲状腺痛的发生率为36.2%(17/47),单独用清除速度慢预测甲状腺癌的发生率为43.9%(18/41).若放射性浓聚区边界模糊和清除速度慢二者都有时,其预测甲状腺癌的发生率为73.9%(17/23).结论 99Tcm-MIBI甲状腺显像阴性对甲状腺良性结节具有较大的诊断价值;阳性对甲状腺癌的诊断价值不大,但如果同时结合放射性浓聚区边界模糊和清除速度慢,则可提高其诊断价值.     

99Tcm-MIBI动态血流灌注显像和双时相核素显像对甲状腺冷结节良恶性的诊断价值研究

目的 探讨99Tcm-MIBI动态血流灌注显像和双时相显像对甲状腺冷结节良恶性的诊断价值.方法 回顾性分析甲状腺冷结节行手术治疗的患者28例,所有患者使用配备低能高分辨准直器的SPECT仪行99Tcm-MIBI动态血流灌注、30 min早期相及120 min延迟相静态平面显像,并用T/NT值等综合分析显像结果.结果 9例甲状腺癌患者在动态血流灌注、30 min早期相和120 min延迟相显像中阳性数分别为5例、6例、7例;19例良性病变患者在动态血流灌注、30 min早期相和120 min延迟相显像中阴性数分别为14例、11例、16例.99Tcm-MIBI动态血流灌注显像诊断甲状腺癌的灵敏度为55.56%,特异度为73.68%,准确率为67.85%;30 min早期相显像诊断甲状腺癌的灵敏度为66.67%,特异度为57.89%,准确率为67.85%;120 min延迟相显像诊断甲状腺癌的灵敏度为77.78%,特异度为84.21%,准确率为82.14%.结论 99Tcm-MIBI的双时相显像对甲状腺冷结节的诊断和鉴别诊断具有一定价值,通过对动态血流灌注和99Tcm-MIBI的双时相显像中T/NT值等综合分析,可以降低假阳性和假阴性的发生.     

99Tcm-DMSA肾皮质显像和肾超声检查在小儿急性肾盂肾炎中的对比研究

目的 比较肾超声检查和99Tcm-二巯基丁二酸（DMSA）肾皮质显像在诊断小儿急性肾盂肾炎（APN）中的作用.方法 对临床拟诊为APN的165例患儿均行肾超声检查及99Tcm-DMSA肾皮质显像.其中男79例,女86例,年龄1.5个月11岁,平均20个月.以肾皮质显像为诊断参考标准,确定肾超声检测APN的灵敏度及特异性.结果 165例患儿330个肾,其中99Tcm-DMSA肾皮质显像发现99个肾存在APN阳性表现,而肾超声仅发现31个肾表现阳性.在余231个99Tcm-DMSA肾皮质显像无异常的肾中,超声检查发现4个肾有异常表现.肾超声探测APN的灵敏度为31.3%（31/99）,特异性为98.3%（227/231）.结论 肾超声对小儿APN的诊断特异性较高,但灵敏度较低.对于肾超声检查阴性的APN,临床仍需采用99Tcm-DMSA肾皮质显像以帮助确诊.     

99Tcm-DMSA肾皮质显像和肾超声检查在小儿急性肾盂肾炎中的对比研究

目的 比较肾超声检查和99Tcm-二巯基丁二酸(DMSA)肾皮质显像在诊断小儿急性肾盂肾炎(APN)中的作用.方法 对临床拟诊为APN的165例患儿均行肾超声检查及99Tcm-DMSA肾皮质显像.其中男79例,女86例,年龄1.5个月11岁,平均20个月.以肾皮质显像为诊断参考标准,确定肾超声检测APN的灵敏度及特异性.结果 165例患儿330个肾,其中99Tcm-DMSA肾皮质显像发现99个肾存在APN阳性表现,而肾超声仅发现31个肾表现阳性.在余231个99Tcm-DMSA肾皮质显像无异常的肾中,超声检查发现4个肾有异常表现.肾超声探测APN的灵敏度为31.3%(31/99),特异性为98.3%(227/231).结论 肾超声对小儿APN的诊断特异性较高,但灵敏度较低.对于肾超声检查阴性的APN,临床仍需采用99Tcm-DMSA肾皮质显像以帮助确诊.     

氯沙坦肾显像对肾血管性高血压的诊断价值

目的　探讨氯沙坦肾显像对肾血管性高血压的诊断价值。方法　 4 6例疑为肾血管性高血压患者 ,基础肾显像后均进行开博通和氯沙坦肾显像 ,并于肾显像后 7d内行肾动脉造影检查。结果　开博通肾显像和氯沙坦肾显像对肾血管性高血压诊断的灵敏度分别为 6 0 .0 %和 84 .0 % ,特异性分别为 95 .5 %和 97.0 % ,准确性分别为 85 .8%和 93.4 % ,阳性预测值分别为 83.3%和 91.3% ,阴性预测值分别为 86 .4 %和 94 .2 % ,两组比较 ,灵敏度和准确性差异有显著性 (P <0 .0 5 ) ,余指标差异无显著性。结论　氯沙坦肾显像对肾血管性高血压诊断的灵敏度和准确性明显高于开博通肾显像     

彩色多普勒超声对移植肾血流动力学的临床研究

目的：应用彩色多普勒血流显像技术,观察移植肾皮质区的血流灌注,并测定其血流动力学参数,寻找诊断肾移植急性排异更敏感的指标。方法：所用仪器为Diasonics Gateway彩色多普勒超声仪,探头频率分别为凸阵／3．5MHz和线阵／10MHz,用CDE模式显示移植肾内各级血管并测定其血流动力学参数;用10MHz探头分别用CDFI及CDE模式测定皮质区血流动力学参数并与血肌酐值作对比分析。结果：移植肾急性排异时,（1）皮质区彩色血流显示减少;（2）皮质区动脉频谱收缩期峰高尖、舒张期无或少血流信号显示,呈单峰显示;（3）移植肾内各级动脉阻力指数明显增高;（4）与血肌酐值相比,皮质区血流动力学的变化诊断肾移植急性排异,具有更敏感、更可靠的价值。结论：移植肾急性异时CDFI上血流动力学的变化早于血肌酐值的变化,评价移植肾急性排异更敏感。彩色多普勒超声对移植肾急性排异的早期诊断及对预后判断有重要价值。     

用ROC曲线法分析99Tcm-HL91肺肿瘤阳性显像的诊断效能

目的探讨半定量分析及接受器工作特性(ROC)曲线法在99Tcm-4,9-二氮-3,3,10,10-四甲基十二烷-2,11-二酮肟(HL91)肿瘤阳性显像鉴别肺部良恶性肿块中的价值.方法经CT检查发现肺部肿块的患者50例,均经活组织检查或手术病理检查证实.根据病理检查结果分为恶性组37例和良性组13例.术前行99Tcm-HL91 2 h、4 h平面显像及4 h断层显像,分别使用视觉判断法、半定量分析及ROC曲线法分析显像结果.结果①视觉判断法99Tcm-HL91显像的灵敏度、特异性和准确性分别为97.3%、69.2%和90.0%.②肿瘤/正常肺组织(T/N)比值半定量分析及ROC曲线法恶性组2 h、4 h平面显像及4 h断层显像T/N比值分别为1.52±0.19、1.73±0.28及2.84±0.97;良性组分别为1.20±0.16、1.24±0.20及1.52±0.40.各个时相的曲线下面积分别为0.909±0.056、0.945±0.039、0.953±0.034.从99Tcm-HL91断层显像ROC曲线的界值点找到1个界点(T/N=1.76),以其作为判断良、恶性的诊断阈值,灵敏度、特异性和准确性分别为100%、84.6%和96.0%.③视觉判断法与半定量分析法比较T/N比值半定量分析及ROC曲线法使诊断的灵敏度、特异性和准确性都有提高,尤其特异性.但两种方法间差异无显著性(P均＞0.05).结论半定量分析及ROC曲线法的诊断阈值可进一步提高99Tcm-HL91肺部肿瘤阳性显像的诊断效能.     

卡托普利介入99mTc-双半胱氨酸肾动态显像对肾血管性高血压患者的价值

目的研究卡托普利介入^99mTc-双半胱氨酸（^99mTc-EC）肾动态显像对高血压患者的肾血管性原因的诊断准确性,并评价其对肾血管性高血压（RVH）患者血管成型术后肾功能改善的预测价值。方法55例临床疑似RVH的患者,口服卡托普利50mg,60min后进行^99mTc-EC肾动态显像,结果异常患者次日再进行基线水平肾动态显像。按照显像结果将RVH的诊断分为高度可能组、不确定组和低度可能组。结果高度可能组的22例患者中20例有肾动脉狭窄（RAS）;不确定组10例中的5例有RAS;低度可能组23例均证实没有RAS。如果将不确定诊断组和低度可能组归为阴性,诊断RAS的灵敏度为80%,特异度为93.3%,阳性预测值为90.9%,阴性预测值为84.8%;如果将高度可能组和不确定诊断组归为阳性,则灵敏度、特异度、阳性预测值和阴性预测值分别为100%、77.7%、78.7%、100%。22例RVH患者进行介入治疗,高度可能组的18例患者中16例治疗有效,不确定组中3例无效、1例有效。结论卡托普利介入^99mTc-EC肾动态显像是诊断RVH的有效手段,同时能预测患者血管成形术治疗效果。     

Renal fibrosis: prediction from acute pyelonephritis focus volume measured at 99mTc dimercaptosuccinic acid SPECT.

PURPOSE: To evaluate whether acute pyelonephritis lesion volume derived from acute technetium 99m ((99m)Tc) dimercaptosuccinic acid (DMSA) renal single photon emission computed tomographic (SPECT) images is predictive of the development of subsequent renal fibrosis. MATERIALS AND METHODS: Children with acute pyelonephritis underwent (99m)Tc DMSA renal SPECT during acute infection and 6-10 months later. At quantitative analysis, the volume of photopenic lesions and the ratio of radioactivity in the photopenic lesion to that in normal renal tissue were calculated. Sensitivity, specificity, and positive and negative predictive values were determined. RESULTS: Sixty-nine acute pyelonephritis foci in 44 children were analyzed. Thirty-seven (54%) of these lesions were normal on follow-up renal scans, while 32 (46%) developed scars. Significant differences in the photopenic lesion volume were found between the two groups (P < .001). When photopenic lesion volume indicated a positive diagnosis (>or=4.6-cm(3) lesion volume), sensitivity, specificity, positive predictive, and negative predictive values were 96.7%, 92.3%, 90.6%, and 97.3%, respectively. CONCLUSION: Quantitative analysis of acute DMSA renal SPECT findings is valuable in predicting renal fibrosis. The volume of an acute pyelonephritis lesion is useful in predicting the development of fibrosis.     

Value of urinary cytology findings in the diagnosis of acute renal graft rejection

BACKGROUND: Acute rejection of allograft is one of the most serious complications of renal transplantation that requires fast and precise diagnostic approach. In this paper our experience in cytologic urinalysis as a diagnostic method of the acute renal allograft rejection was reviewed. METHODS: The study group included 20 of 56 patients with transplanted kidneys who were assumed for the acute allograft rejection according to allograft dysfunction and/or urine cytology findings. Histological findings confirmed allograft rejection in 4 patients. Urine sediment obtained in cytocentrifuge was air-dried and stained with May-Grunwald-Giemsa. Acute allograft rejection was suspected if in 10 fields under high magnification 15 or more lymphocytes with renal tubular cells were found. RESULTS: Acute transplant rejection occurred in 32.1% patients. In 15 patients clinical findings of the acute renal allograft rejection corresponded with cytological and histological findings (in the cases in which it was performed). Three patients with clinical signs of the acute allograft rejection were without cytological confirmation, and in 2 patients cytological findings pointed to the acute rejection, but allograft dysfunction was of different etiology (acute tubular necrosis, cyclosporine nephrotoxicity). In patients with clinical, cytological and histological findings of the acute allograft rejection urine finding consisted of 58% lymphocytes, 34% neutrophilic leucocytes and 8% monocytes/macrophages on the average. The accuracy of cytologic urinalysis related to clinical and histological finding was 75%. CONCLUSION: Urine cytology as the reliable, noninvasive, fast and simple method is appropriate as the a first diagnostic line of renal allograft dysfunction, as well as for monitoring of the graft function.     

Renal scans in pregnant transplant patients

This study demonstrates the normal technetium-99m diethylenetriaminepentaacetic acid ([99mTc]DTPA) renal scan in pregnant patients with transplanted kidneys. Five pregnant renal transplant patients had seven [99mTc]DTPA renal studies to assess allograft perfusion and function. All scans showed the uteroplacental complex. The bladder was always compressed and distorted. The transplanted kidney was frequently rotated to a more vertical position. In all patients allograft flow and function were maintained. There was calyceal retention on all studies and ureteral retention activity in three of five patients. Using the MIRD formalism, the total radiation absorbed dose to the fetus was calculated to be 271 mrad. This radiation exposure is well within NRCP limits for the fetus of radiation workers and an acceptable low risk in the management of these high risk obstetric patients.     

兔急性肾功能衰竭CT灌注成像与核素显像对照的实验研究

目的探讨兔急性肾功能衰竭(ARF)早期的CT灌注情况及其与核素扫描结果的关系。方法兔后腿肌注50%甘油10ml/kg,建立急性肾小管坏死性ARF动物模型,分别于注射前、注射后6h行CT灌注扫描和核素扫描。运用GE公司Perfusion2软件,测量右肾皮质的CT灌注血流量(BF),并与核素显像ERPF结果进行相关性分析。结果两种检查方法,注药前后结果差异均具有显著性意义(P<0.01),且注药前后CT灌注扫描与核素扫描有较好的相关性。结论急性肾小管坏死性ARF时,CT灌注成像能较准确地评价早期血流动力学的改变。     

Renal cortical scintigraphy in the diagnosis of acute pyelonephritis

Comparative clinical studies have shown renal cortical scintigraphy, using technetium-99m (99mTc)-labeled glucoheptonate or dimercaptosuccinic acid (DMSA), to be significantly more sensitive than either intravenous pyelography or renal sonography in the diagnosis of acute pyelonephritis. However, due to uncertainties about the diagnostic accuracy of the clinical and laboratory parameters used in these studies, true sensitivity of renal cortical scintigraphy was unknown. Therefore, we evaluated the accuracy of [99mTc]DMSA scintigraphy in the diagnosis of experimentally induced acute pyelonephritis in piglets using strict histopathologic criteria as the standard of reference. The sensitivity and specificity of the DMSA scan for the diagnosis of acute pyelonephritis were 91% and 99%, respectively, with an overall 97% agreement between the scintigraphic and histopathologic findings. Based on the results of this experimental study, we used the [99mTc]DMSA scan as the standard of reference for the diagnosis of acute pyelonephritis, and conducted a prospective clinical study of 94 children hospitalized with the diagnosis of acute febrile urinary tract infection (UTI). The aims of this study were (1) to determine the relationship among vesicoureteral reflux, P-fimbriated Escherichia coli, acute pyelonephritis, and renal scarring, and (2) to evaluate the diagnostic reliability of the clinical and laboratory parameters commonly used in the diagnosis of acute pyelonephritis. We documented acute pyelonephritis in 62 (66%) of 94 patients. Vesicoureteral reflux was demonstrated in 29 (31%) of the total group and in only 23 (37%) of 62 patients with acute pyelonephritis. The prevalence of P-fimbriae in the E coli isolates was 64% in the patients with acute pyelonephritis and 78% in those with a normal DMSA scan. Even in patients without reflux, P-fimbriae were found in 71% of isolates from the patients with acute pyelonephritis and in 75% of those with a normal renal scan. Follow-up DMSA scans were obtained in 33 patients with acute pyelonephritis in 38 kidneys. We found complete resolution of the acute inflammatory changes in 58% of the involved kidneys and renal scarring in the remaining 42%, including 40% of the kidneys associated with reflux and 43% of those without reflux.(ABSTRACT TRUNCATED AT 400 WORDS)     

Tc-99m sulfur colloid and Tc-99m tagged red blood cell methods are comparable for detecting lower gastrointestinal bleeding in clinical practice

PURPOSE: The objective of this study was to determine whether the Tc-99m red blood cells (Tc-99m RBC) method has a true advantage over the Tc-99m sulfur colloid (Tc-99m SC) technique in a busy clinical practice for detecting and localizing lower gastrointestinal bleeding sites. METHODS: Three hundred fifty-nine consecutive gastrointestinal bleeding studies performed during the past 4 years were reviewed retrospectively. One hundred ninety-three scans were obtained with Tc-99m SC (scan duration, 30 minutes) and 138 studies were performed after the administration of Tc-99m RBC (scan duration, 1 hour). In addition, 28 examinations with Tc-99m SC were followed immediately by Tc-99m RBC scans for a duration of several hours. The results of the two methods were analyzed and the performance of the two techniques was compared. RESULTS: Among 193 scans performed using the Tc-99m SC method, 47 (24.4%) successfully identified the location of the bleeding site, whereas in 138 scans performed using Tc-99m RBC, 38 (27.5%) were successful for this purpose. In the remaining 28 scans in which the Tc-99m SC scan was followed by the Tc-99m RBC study, only 4 (14.3%) positive bleeding sites were identified after a prolonged imaging period. DISCUSSION: The theoretical advantages of the Tc-99m RBC technique compared with the Tc-99m SC method cannot be substantiated by this study. Our findings suggest that the efficacy of these two methods is nearly equal at a practical level. CONCLUSION: The simpler and cost-effective Tc-99m SC method is as efficient as the Tc-99m RBC method when the scanning time is limited to 1 hour and optimal imaging and interpretation schemes are used.     

Diagnostic efficacy of technetium-99m pentavalent-dimercapto succinic acid versus gallium-67 citrate, imaging in patients with highly suspected acute bone and joint infections

The purpose of this study was to evaluate and compare the diagnostic efficacy of (99m)Tc(V) dimercaptosuccinic acid ((99m)Tc(V)DMSA) with the (67)Ga-citrare ((67)Ga-C) scintigraphy in patients with suspected bone and joint infection. Thirty one patients, 19 men and 12 women, aged 18-78 y with median age 56 y, with suspected acute bone infection, were enrolled in this study. Besides (67)Ga-C and (99m)Tc(V)DMSA scintigraphy, all patients underwent X-ray radiography and technetium-99m methylene disphosphonate ((99m)Tc-MDP) bone scan for supporting the initial diagnosis. The (99m)Tc-MDP bone scan was considered positive for acute bone and joint infection when all its four scintigraphic phases were positive. Final diagnosis was based on needle aspiration and/or biopsy findings. Sensitivity, specificity, accuracy, positive and negative predictive values (PPV and NPV) were calculated. Our results have shown the following: Seventeen patients (17/31) had histologically confirmed acute bone and joint infections, while the remaining patients had no infection. (99m)Tc(V)DMSA diagnosed bone and joint infections in all positive (17/31) patients while (67)Ga-C in 16/31 patients. Discordant scintigraphic results were observed by (67)Ga-C in 2/31 cases: in one positive case of femur postoperative infection (false negative for (67)Ga-C) and in one case of clinicaly suspected infection in the femur while the patient had a preexisting fracture (false positive with (67)Ga-C). No false negative results were observed with (99m)Tc(V)DMSA. Sensitivity, specificity, PPV, NPV and accuracy were maximum for (99m)Tc(V)DMSA, while for (67)Ga-C were: 94.1%, 93%, 94.1%, 93%, and 93.5% respectively. It is concluded that considering the high sensitivity and specificity of (99m)Tc(V)DMSA in the detection of acute bone and joint infections, the lower radiation dose, the cost and the shorter time spent for the imaging procedure, as compared to (67)Ga-C, (99m)Tc(V)DMSA should be preferred to (67)Ga-C as a bone scan agent for the detection of acute bone and joint infections.     

Renal allograft rejection: US evaluation

Real-time ultrasonography (US) was performed on the allografts of 100 consecutive renal transplant recipients at the time of allograft biopsy. Evaluation of the sonograms included the grading of parameters previously demonstrated to be indicative of allograft rejection. The appearance of the renal sinus fat, allograft size, corticomedullary ratio, sharpness of the corticomedullary junction, medullary conspicuity, presence of focal parenchymal abnormalities, and thickening of the pelvic or infundibular wall were individually evaluated. The authors correlated the US and the histopathologic findings. While the accuracy of a positive prediction of rejection was relatively high (83%-90%), this result is influenced by the relatively high prevalence of rejection in the biopsy group (83%). Accuracy of a negative prediction was uniformly low (17%-30%). Mild rejection was difficult to differentiate ultrasonographically from no rejection, although severe rejection could usually be differentiated from mild or no rejection, particularly in patients with the interstitial type of rejection.     

Renal transplant rejection. Limited value of duplex Doppler sonography

Over a two-year period, 275 duplex Doppler ultrasound (US) examinations were performed on 75 renal allograft recipients. Retrospective visual analysis of the Doppler tracings was compared to concurrent clinical findings and to biopsy results. One hundred eight of the 176 Doppler examinations (61%) that showed acute rejection clinically or histologically were interpreted as rejection, while 80 of 99 examinations (81%) in clinically normal patients were interpreted as normal. Two hundred thirty-four examinations had resistive index (RI) calculations. Seventy-two of 141 examinations (51%) with RI less than 0.70 had clinical or biopsy evidence of rejection. Studies compared with only concurrent biopsies revealed that 35 of 39 US examinations interpreted as rejection were confirmed histologically, but only one of 32 examinations that appeared normal sonographically was histologically normal. The low sensitivity of Doppler US, whether by waveform analysis or RI calculation, makes it a poor screening test for acute rejection. The findings support the conclusion that Doppler sonography cannot replace biopsy in the evaluation of renal transplant dysfunction, particularly when the waveform analysis is normal and the RI less than 0.70.     

First evaluation of a 99mTc-tricarbonyl complex, 99mTc(CO)3(LAN), as a new renal radiopharmaceutical in humans.

(99m)Tc-Mercaptoacetyltriglycine ((99m)Tc-MAG3), (99m)Tc-dd- and ll-ethylene-dicysteine ((99m)Tc-EC), and (99m)Tc-mercaptoacetamide-ethylene-cysteine ((99m)Tc-MAEC) contain N(3)S or N(2)S(2) ligands designed to accommodate the 4 ligating sites of the ((99m)TcO)(3+) core; they are all excellent renal imaging agents but have renal clearances lower than that of (131)I-orthoiodohippurate ((131)I-OIH). To explore the potential of the newly accessible but less polar [(99m)Tc(CO)(3)](+) core with 3 ligating sites, we decided to build on the success of (99m)Tc-EC, with its N(2)S(2) ligand and 2 dangling carboxylate groups; we chose an N(2)S ligand that also has 2 dangling carboxylate groups, lanthionine, to form (99m)Tc(CO)(3)(LAN), a new renal radiopharmaceutical. METHODS: Biodistribution studies were performed on Sprague-Dawley rats with (99m)Tc(CO)(3)(LAN) isomers, meso-LAN and dd,ll-LAN (an enantiomeric mixture), coinjected with (131)I-OIH. Human studies also were performed by coinjecting each (99m)Tc-labeled product ( approximately 74 MBq [ approximately 2 mCi]) and (131)I-OIH ( approximately 7.4 MBq [ approximately 0.2 mCi]) into 3 healthy volunteers and then performing dual-isotope imaging by use of a camera system fitted with a high-energy collimator. Blood samples were obtained from 3 to 90 min after injection, and urine samples were obtained at 30, 90, and 180 min. RESULTS: Biodistribution studies in rats revealed rapid blood clearance as well as rapid renal extraction for both preparations, with the dose in urine at 60 min averaging 88% that of (131)I-OIH. In humans, both agents provided excellent renal images, with the plasma clearance averaging 228 mL/min for (99m)Tc(CO)(3)(meso-LAN) and 176 mL/min for (99m)Tc(CO)(3)(dd,ll-LAN). At 3 h, both (99m)Tc(CO)(3)(meso-LAN) and (99m)Tc(CO)(3)(dd,ll-LAN) showed good renal excretion, averaging 85% and 77% that of (131)I-OIH, respectively. Plasma protein binding was minimal (10% and 2%, respectively), and erythrocyte uptake was similar (24% and 21%, respectively) for (99m)Tc(CO)(3)(meso-LAN) and (99m)Tc(CO)(3)(dd,ll-LAN). CONCLUSION: Although the plasma clearance and the rate of renal excretion of the (99m)Tc(CO)(3)(LAN) complexes were still lower than those of (131)I-OIH, the results of this first application of a (99m)Tc-tricarbonyl complex as a renal radiopharmaceutical in humans demonstrate that (99m)Tc(CO)(3)(LAN) complexes are excellent renal imaging agents and support continued renal radiopharmaceutical development based on the (99m)Tc-tricarbonyl core.