Subcutaneous whole-body radionuclide venography using Tc-99m in vivo tagged red blood cells

PURPOSE: The accurate diagnosis of deep vein thrombosis (DVT) is essential to prevent its complications and to initiate appropriate treatment. Doppler ultrasound (DUS), contrast venography, and intravenous radionuclide venography have been used for many years to detect DVT. However, obtaining venous access in the foot for injection of contrast agent can be difficult. METHODS: The authors introduce the technique of subcutaneous radionuclide venography using Tc-99m in vivo tagged red blood cells and compare it with DUS, a widely used method. Sixty patients (120 lower extremities) underwent subcutaneous radionuclide venography and DUS. RESULTS: The concordance rate was 94% in the femoral veins and 95% in the popliteal veins. Subcutaneous radionuclide venography revealed 10 iliac vein thromboses and 2 inferior vena cava thromboses that were not detected by DUS. CONCLUSIONS: Subcutaneous radionuclide venography is a useful alternative method for detecting DVT. It is particularly valuable for evaluating DVT in the iliac veins and in the inferior vena cava.     

Clinical application of Ga-67 DFO-DAS-fibrinogen

Scintigraphy with 67Ga-DFO-DAS-fibrinogen (67Ga-fibrinogen) was performed for the positive delineation of thrombi in patients with suspected venous or arterial thrombus formation. Five out of 17 patients showed 67Ga-fibrinogen accumulation corresponding to thrombus formation, as confirmed by other examination including radionuclide venography, contrast angiography, and CT scan. There was some difference in 67Ga-fibrinogen uptake between venous and arterial thrombi. With arterial thrombi, 67Ga-fibrinogen uptake was observed over one year after the appearance of clinical symptoms of dissecting aneurysm and arteriosclerosis obliterans. However, with venous thrombi, 67Ga-fibrinogen uptake occurred less than three weeks after the onset of venous edema. These results may indicate different mechanisms of thrombus organization between venous and arterial thrombi. Further, the thrombi age seems to be an important factor in analyzing the diagnostic accuracy of radioagents used for thrombus scintigraphy.     

320排CT血管造影和超声诊断下肢深静脉血栓价值比较

目的：探讨320排容积 CT 静脉造影(CTV)和超声(US)对下肢深静脉血栓(DVT)的诊断价值。方法回顾性分析经DSA 证实为下肢 DVT 的患者51例,对比直接法 CTV 及 US 对下肢不同部位栓子的检出率。结果51例患者中,CTV 共诊断DVT 48例,发现栓子124处,US 诊断静脉血栓46例,发现栓子86处。其中盆腔 DVT CTV 检出34处,US 检出10处,胫腓静脉血栓 CTV 检出25处,US 检出5处,CTV 检出股深静脉血栓2处,US 检出11处。结论直接法 CTV 及 US 对下肢 DVT 的诊断均具有较高的临床应用价值,而前者对盆腔 DVT 及胫腓静脉血栓的检出率更高,而对股深静脉血栓的显示不及后者。     

Clinical value of blood pool radionuclide venography

Blood pool radionuclide venography and contrast venography were carried out in 50 patients in whom deep vein thrombosis was suspected. The two procedures were compared on the basis of 198 individual vessel segments. The overall concordance between radionuclide and contrast venography was 92%. Using contrast venography as the standard, the sensitivity of radionuclide venography was 90% and specificity 96%. The predictive accuracy of a positive test was 77% and of a negative test was 97%. The performance of radionuclide venography improved if the calf veins were excluded from analysis. The main limiting factor affecting the performance of radionuclide venography was the moderately poor resolution of the technique. Technical manipulations to improve resolution were time consuming and added little to the accuracy of the test. Radionuclide will not replace contrast venography but may well be used to complement contrast venography when it is technically unsatisfactory or unequivocal, in patients with a history of intolerance to contrast media, and in bedbound patients.     

Scintigraphic assessment of "effort" axillary-subclavian vein thrombosis.

"Effort" axillary-subclavian vein thrombosis (Paget-Schroetter syndrome) is an uncommon deep venous thrombosis due to repetitive activity of the upper limb. Clinical suspicion is usually confirmed by contrast venography. This report describes a case where the diagnosis was made by radionuclide venography (Tc-99m DTPA). The examination was carried out in the acute phase and clearly demonstrated the presence and the site of the obstruction as well as the collateral vessels. Despite a complete clinical recovery, obtained by medical therapy, further examinations performed in the follow-up period showed persistence of the thrombotic obstruction and a rich development of collateral vessels. In the authors' opinion, radionuclide venography is worth considering as a first-choice procedure when an axillary-subclavian vein thrombosis is suspected, and contrast venography should be performed only when surgical treatment is indicated.     

对比剂浓度递减不用压迫带MSCT静脉成像的临床应用

目的：探讨对比剂浓度递减不用压迫带MSCT静脉成像的临床应用价值。方法-对151例下肢静脉曲张和／或下肢肿胀患者采用不用压迫带绑扎下肢法,直接在足背或内外踝部静脉以2ml／s流率注射稀释对比剂,采用双筒双流高压注射器双筒双流连续注入稀释对比剂360-80ml,浓度从12％递减至5％,注射至半量时（约90s）行Ⅰ期扫描,对比剂剩余约30ml时（约170s）行Ⅱ期扫描。从两期横轴面图像结合曲面重建、VR和MIP后处理图像,观察静脉曲张程度,对比剂滞留,静脉瓣的关闭状态,静脉血管有无中断、狭窄、压迫、充盈缺损和侧支循环。动态分析股静脉至下腔静脉内充盈缺损的密度和形态,判断其是否为血栓并与分流、边流、涡流相鉴别。结果：下肢静脉曲张无深静脉血栓92例;下肢静脉曲张合并深静脉血栓28例;下肢静脉曲张合并对比剂滞留69例;静脉瓣膜功能不全21例;下肢深静脉血栓合并深浅静脉侧支回流17例;髂总静脉压迫综合征3例;髂总静脉口膜性狭窄1例;髂静脉扁细狭窄3例;股静脉转移瘤浸润致血管阻塞2例;下肢增粗软组织肿胀但静脉血管未见异常4例;下肢静脉和软组织未见异常1例。结论：对比剂浓度递减不用压迫带绑扎法下肢MSCT静脉成像能较好显示下肢深浅静脉,尤其是股静脉至下腔静脉血管的形态和病变,为临床提供可靠的影像学诊断依据。     

Radionuclide venography of lower limbs by subcutaneous injection: A clinical evaluation

SC-RNV, radionuclide venography by subcutaneous injection of Tc-99m pertechnetate at acupuncture points K-3, a new alternative of lower limb venography, was recently developed in our clinical laboratory. In some of the previous studies, we have proved its superiority to radionuclide venography by intravenous injection. The current investigation was conducted to understand the reliability of SC-RNV in the diagnosis of deep vein thrombosis (DVT). Fifty-seven cases with lower leg edema, from Nov., 1989 through Oct., 1990, received both SC-RNV and duplex US for causative evaluation. As a result of duplex US, 26 were considered normal (non-DVT), 19 were classified as unilateral DVT, and 12 as bilateral DVT. In nineteen cases (61%, 19/31) with DVT also a XCT and/or a CV (contrast venography) was taken, that showed compatible results. All of the non-DVT had a normal pattern of SC-RNV, all of the unilateral DVT had unilateral impairment of deep vein drainage in SC-RNV, and all of the bilateral DVT had impaired deep venous drainage bilaterally in SC-RNV. It is therefore concluded that SC-RNV is one of the best choices among available non-invasive lower-limb venographic methods.     

An animal model of radionuclide venography.

Experimental venous thrombi were created in 19 dogs, using either thrombin or sodium morrhuate. Eighteen thrombi (95%) were identified by radionuclide venography; however, an 85% false-positive rate was found when nonoperated limbs were studied. The models employed were considered unsuitable for studying the accuracy of labeled particles in diagnosing deep venous thrombosis for the reasons discussed in the text.     

Deep venous thrombosis: detection by high-resolution real-time ultrasonography

High-resolution real-time ultrasonography was performed in 11 patients with clinically suspected deep venous thrombosis (DVT) of the lower extremity. Contrast venography was performed in all patients within 24 hours of sonographic examination. The common femoral vein at the groin and the popliteal vein in the popliteal fossa were evaluated for presence or absence of intraluminal soft-tissue mass (thrombi), compressibility of the veins, and response to performance of the Valsalva maneuver. Of the 11 patients, six were shown to have DVT by contrast venography. In all six cases there was complete agreement between sonography and contrast venography as to the presence or absence of thrombi in the common femoral vein or the popliteal vein.     

Heterotopic bone formation (myositis ossificans) and lower-extremity swelling mimicking deep-venous disease

A quadriplegic patient with a swollen leg was suspected of having deep-venous thrombosis, and was studied with radionuclide venography (RNV) and contrast venography. Focal narrowing of the femoral vein, seen on RNV, was due to extrinsic compression. Although soft-tissue radiographs were normal, Tc-99m diphosphonate imaging established the diagnosis of early heterotopic bone formation (myositis ossificans), which was responsible for the venous compression. Clinically this inflammatory process can mimic deep-venous thrombosis, and should be considered in evaluating patients at risk for both heterotopic bone formation and deep-venous thrombosis.     

Radionuclide venography in iliac and inferior vena caval obstruction

Thirteen cases are presented to demonstrate normal and various abnormal radionuclide venographic patterns following obstruction of the inferior vena cava or common iliac veins. In these patients, obstruction was due to surgery, thrombosis, or neoplasm. Contrast venography was also performed in seven patients to confirm the radionuclide findings. Radionuclide venograms did not visualize the same collateral patterns that contrast venograms did. Most notably, the anterior parietal vessels were seen in many cases with radionuclide venography, and the paraspinal veins were seen more commonly with contrast venography.     

Radiolabeled peptides in the detection of deep venous thrombosis

Venous thrombosis and pulmonary embolism are major clinical problems that result in significant morbidity and mortality. It is estimated that 600,000 cases of pulmonary embolism occur each year in the United States, resulting in the death of approximately 100,000 patients. Most of these pulmonary emboli arise from deep venous thrombosis (DVT). The clinical diagnosis of DVT is unreliable. Only a third of patients with a clinical suspicion of DVT have objective evidence of the disease, and half of patients with proven DVT do not have any clinical symptoms. Although ascending contrast venography is the present standard for the diagnosis of DVT, duplex ultrasonography, which is increasingly used in combination with color Doppler flow imaging, is accepted as a useful clinical afternative to contrast venography. Both contrast venography and ultrasonography are imaging procedures that detect changes in venous anatomy that are caused by the presence of an intraluminal thrombus that is sufficiently formed either to reduce vascular filling with contrast medium or to resist compression. However, these imaging procedures do not reflect the metabolic activity of the clot, and therefore, they may overestimate the presence of active clots. The sensitivity of ultrasonography is also limited by various disease-related and technical factors. An alternative approach to the diagnosis of acute DVT is to detect a molecular marker of acute DVT that is not present in old, organized DVT. Recent advances in biotechnology permit the use of highly specific synthetic peptide or small molecular markers, which are involved in the acute stages of DVT formation and can be labeled efficiently with 99mTc. 99mTc-apcitide, a glycoprotein (GP IIb/IIIa) receptor antagonist previously known as 99mTc-P280, has been approved recently by the Food and Drug Administration for the clinical detection of acute DVT. Two other agents are currently under clinical investigation: 99mTc-DMP 444, which is another GP IIb/IIIa receptor antagonist, and 99mTc-Fibrin-Binding Domain (FBD), a radio-labeled fibrin-binding domain of fibronectin. Different clinical studies have shown a high diagnostic accuracy with these synthetic 99mTc-labeled peptides in the detection of acute DVT. Although further studies are needed to fully appreciate all of the diagnostic potential of these radiopharmaceuticals, the clinical introduction of 99mTcapcitide scintigraphy will certainly be helpful in expanding the use of nuclear medicine in a specific field in which it used to play a relatively marginal role.     

Infradiaphragmatic Spinal tumours demonstrated by transfemoral epidural venography

Summary During the last few years transfemoral epidural venography has increasingly been used for diagnosing lumbar disc herniation. Occasionally this method may reveal an unexpected malignant tumour with the clinical symptoms of lumbar disc disease. Therefore it is of interest to be acquainted with the venographic signs of malignancy in this area. Moreover transfemoral epidural venography can be of help in the delineation of a tumour in the vertebral canal. If the double-catheter method is used, the anterior epidural venous plexus will, as a rule, be adequately shown up to the level of T₁₀. Occasionally higher thoracic levels also are visualised. The procedure can easily be performed on an out-patient basis and is well tolerated by the patient. The complication rate is very low. The use of ioxaglate (Hexabrix) minimizes the post-injection reactions to the contrast medium.     

Diagnostic value of technetium-99m radionuclide angiography for detecting thrombosis in left atrial appendage.

In mitral valve disease, it is important to know whether thrombi are present in the left atrium when deciding upon a course of treatment. The left atrial thrombus usually locates in the left atrial appendage. In most cases of mitral valve disease, the left atrial appendage is clearly demonstrated by radionuclide angiography using 99mTc-labeled red blood cells and it can be speculated that the cases in which left atrial appendage are not demonstrated by RNA have left atrial thrombi. On the basis of this hypothesis, the diagnostic accuracy of radionuclide angiography to detect left atrial thrombi was evaluated retrospectively in 60 patients with mitral valve disease who had undergone surgery. The sensitivity of first-pass and equilibrium radionuclide angiography to detect left atrial thrombi was 83% and 67%, the specificity 79% and 54%, and the accuracy 80% and 57%, respectively. Although there were two false-negative cases in which the left atrial thrombi did not locate in the appendage and 10 false-positive cases in which left atrial appendages were not dilated, the negative predictive value was so high that a clearly demonstrated left atrial appendage can be translated into the absence of left atrial thrombi.     

May-Thurner综合征的医学成像研究进展

May-Thurner综合征（MTS）是引起下肢静脉血栓形成和肺栓塞等并发症的主要原因之一,发病率常被低估。血管内超声诊断结果可靠,同时能进行腔内治疗,但费用昂贵;MR成像在判断髂静脉受压程度上有明显夸大;CT和DSA应用较广,是诊断MTS的主要标准;间接法CT静脉成像操作方便,应用较广;直接法CT静脉成像存在边流效应,应用较少;DSA能同时实施支架置入术或球囊扩张术以进行治疗。就以上几种医学成像方法研究进展予以综述。     

Density analysis of scintigram with flow dynamics at bolus radionuclide venography: Count correction with velocity

The authors analyse the difference in the density of dynamic scintigrams produced in radionuclide venography. The difference in density is always connected with the velocity of the radionuclide flow. The lost activity is found after multiplying the count difference calculated from the time activity curve by velocity. The importance of the investigation is that the capacity of different venous channels can be determined in radionuclide venography by this method of calculation.     

Density analysis of scintigram with flow dynamics at bolus radionuclide venography: count correction with velocity

The authors analyse the difference in the density of dynamic scintigrams produced in radionuclide venography. The difference in density is always connected with the velocity of the radionuclide flow. The lost activity is found after multiplying the count difference calculated from the time activity curve by velocity. The importance of the investigation is that the capacity of different venous channels can be determined in radionuclide venography by this method of calculation.     

Diagnosis of deep venous thrombosis. A review of radiologic, radionuclide, and non-imaging methods.

Accurate diagnosis of deep venous thrombosis (DVT) can be achieved through appropriate use of the various imaging and non-imaging techniques currently available in clinical practice. This paper summarizes the roles of imaging techniques such as duplex ultrasound, contrast and radionuclide venography, and magnetic resonance imaging, as well as clinical prediction models and D-dimer testing, in the evaluation of patients with suspected DVT. Recent data examining the prognostic value of several of these tests, alone and in combination, are also reviewed. The associations of testing for DVT and pulmonary embolism, and the controversies which sometimes surround them, are also briefly examined.     

Positive imaging of venous thrombi and thromboemboli with Ga-67 DFO-DAS-fibrinogen

A newly developed thrombus imaging agent, 67Ga-DFO-DAS-fibrinogen (67Ga-fibrinogen), was used for 22 studies in 20 cases of suspected deep venous thrombosis. Increased accumulation of 67Ga-fibrinogen in venous thrombi was depicted at 48 h after injection in 10 of the 15 cases (10 of 17 studies) who showed abnormal findings in radionuclide venography. A hot spot in the lung emboli was visualized in two cases. Seven of the eight cases having anticoagulant therapy showed increased 67Ga-fibrinogen uptake, while follow-up 67Ga-fibrinogen scintigraphy after the administration of heparin and urokinase did not reveal an abnormal hot spot in one case. 67Ga-fibrinogen can be made available simply by adding 67Ga solution to a vial containing fibrinogen-DAS-DFO conjugate. In conclusion, 67Ga-fibrinogen is considered to be a promising agent for detecting active venous thrombi and to assess the effect of anticoagulant therapy.     

Double inferior vena cava or iliac vein occlusion? A diagnostic problem in radionuclide venograms.

Radionuclide venography in two patients with suspected deep venous disease revealed double channel drainage with cross-pelvic collateral circulation. Contrast inferior venacavograms revealed that one patient had persistent right and left supracardinal veins (double inferior vena cava) and the other had iliac vein occlusion with ascending lumbar collateral circulation. The similarity of radionuclide venographic findings in these two patients emphasizes the importance of contrast venacavography in patients with this appearance on radionuclide venography.