Colour Doppler ultrasound of the post-phlebitic limb: sounding a cautionary note

Colour Doppler ultrasound is accurate in the diagnosis of acute lower limb venous thrombosis. Some patients, however, will re-present with recurrent lower limb swelling following the acute event, and ultrasound may also become the primary imaging modality in these patients. We, therefore, undertook a prospective study of 20 patients with a diagnosis of deep venous thrombosis proven initially on both venography and ultrasound. Sixteen patients had thrombosis in the femoro-popliteal segment and four patients had isolated calf vein thrombosis. Patients with above knee thrombosis were scanned at 1, 3 and 6 months and those with isolated calf lesions at intervals of 1 week, 1 and 3 months. Results showed that in cases of above knee thrombosis, only 50% of patients showed complete recanalization by 6 months. The remaining 50%, by this time, showed only partial recanalization of thrombus, the features of which cannot be distinguished from acute non-occlusive thrombus. With respect to the four cases of isolated calf vein thrombosis, one case showed evidence of popliteal extension of thrombus, which by 3 months had fully recanalized. The remaining three cases recanalized completely without further thrombus extension. These results show that interpretation of the ultrasonic features of the post-phlebitic limb may be difficult in patients who re-present with lower limb swelling. Based on this study, we would advise routine scanning of all patients with above knee venous thromboses at 6 months to provide a baseline scan, permitting more accurate ultrasonic assessment of any future thrombotic events. This study also highlights the question of whether isolated calf vein thrombosis can safely be regarded as a benign entity.     

Effect of running training on DMH-induced aberrant crypt foci in rat colon

PURPOSE: We examined the effects of treadmill-running training on the induction of aberrant crypt foci (ACF), which is the first step of colon cancer induction, in the colonic mucosa of rats injected with 1,2-dimethylhydrazine (DMH). METHODS: Four-week-old F344 rats (N = 38) were randomly assigned to training (19 rats) and control (19 rats) groups. After a week, all rats were given DMH (20 mg.kg(-1) body weight) once a week for 2 wk. Running training was started at age 7 wk (speed: 10 m.min(-1), 0% grade, 120 min.d(-1), 5 d.wk(-1)). After 4 wk of training, the rats were sacrificed and the colon was removed, opened, and counted for ACF with 0.2% methylene blue staining. RESULTS: Running training resulted in lower body- (P < 0.01) and adipose fat weight (P < 0.05). The numbers of ACF and total AC were significantly lower in the running training group than in the control group (P < 0.05). The occurrences of one, three, and five aberrant crypts per focus were also significantly lower in the running training group than in the control group (P < 0.05). The ratios of total AC/ACF did not significantly differ between the running training and control groups. CONCLUSIONS: The results of the present investigation suggest that low-intensity running training inhibits the DMH-induced initiation of colon ACF development.     

Randomized prospective study comparing routine versus selective use of sonography of the complete calf in patients with suspected deep venous thrombosis

OBJECTIVE: We compared patient outcomes using two protocols: one routinely and the other selectively evaluating the calves completely during sonographic assessment of the lower extremities in patients with suspected deep venous thrombosis. SUBJECTS AND METHODS: In this randomized prospective study, patients were assigned to two groups. In one group, the deep calf veins were routinely evaluated in their entirety, and in the other group the calf was not evaluated unless the patient had symptoms or physical signs in the calf, in which case only the areas of symptoms or physical signs were evaluated. Patients were followed up for 3 months by medical record review, physician surveys, and telephone calls. An adverse outcome was a propagated deep venous thrombosis into the thigh or a pulmonary embolus. Examination times were recorded when possible. RESULTS: Of the 235 patients in the group in which the deep calf veins were routinely evaluated, we saw no adverse outcomes (0.0%; 97.5% one-sided confidence interval [CI], 0.6-1.6%). Of the 261 patients in the group in which the calf was only evaluated if there were signs or symptoms, we saw two adverse outcomes (0.8%; 95% CI, 0.1-2.7%). CONCLUSION: We found no significant difference in adverse outcomes in patients undergoing a protocol in which the deep calf veins were routinely evaluated or a protocol in which the calf was evaluated only if physical signs or symptoms were present.     

Evaluation of the lower extremity veins in patients with suspected pulmonary embolism: a retrospective comparison of helical CT venography and sonography. 2000 ARRS Executive Council Award I. American Roentgen Ray Society

OBJECTIVE: In patients undergoing a combined CT angiographic and CT venographic protocol, the accuracy of helical CT venography for the detection of deep venous thrombosis was compared with that of lower extremity sonography. MATERIALS AND METHODS: Patients who had undergone a combined CT angiographic and CT venographic protocol and sonography of the lower extremities within 1 week were identified. The final reports were evaluated for the presence or absence of deep venous thrombosis. Statistical measures for the identification of deep venous thrombosis with helical CT venography were calculated. In each true-positive case, the location of the thrombus identified with both techniques was compared. All false-positive and false-negative cases were reviewed to identify the reasons for the discrepancies. RESULTS: Seventy-four patients were included. There were eight patients (11%) with true-positive findings, 61 patients (82%) with true-negative findings, four patients (5%) with false-positive findings, and one patient (1%) with a false-negative finding. When comparing helical CT venography with sonography for the detection of lower extremity deep venous thrombosis, the sensitivity measured 89%; specificity, 94%; positive predictive value, 67%; negative predictive value, 98%; and accuracy, 93%. Of the eight true-positive cases, five had sites of thrombus that were in agreement on both CT venography and sonography. Of the five discordant cases, four were false-positives and one was a false-negative. Possible explanations for all discrepancies were identified. CONCLUSION: Compared with sonography, CT venography had a 93% accuracy in identifying deep venous thrombosis. However, the positive predictive value of only 67% for CT venography suggests that sonography should be used to confirm the presence of isolated deep venous thrombosis before anticoagulation is initiated. In addition, interpretation of CT venography should be performed with knowledge of certain pitfalls.     

A phlebographic study of the incidence and significance of venous thrombosis in the foot.

A total of 188 foot phelbograms in 100 patients with suspected venous thrombosis or pulmonary embolism were studied. Thrombus was demonstrated in 59 (31%) of the foot phlebograms. It is concluded that foot vein thrombosis is common, that it may be a source of pulmonary embolism, and that venous thrombus may start in the foot veins and spread into the calf. Foot phlebography should become part of the routine examination of patients with suspected deep venous thrombosis or pulmonary embolism.     

Colour flow imaging of calf vein thrombosis.

Ultrasound and more recently colour Doppler ultrasound has been successfully used in the diagnosis of lower limb venous occlusive disease. Colour Doppler ultrasound has shown promise in the diagnosis of calf vein thrombosis but to date there has been no prospective trial to specifically evaluate its potential. In view of this, we carried out a prospective trial of 50 patients comparing the accuracy of colour Doppler ultrasound with venography in the diagnosis of deep venous thrombosis both above and below knee but in particular with respect to the detection of calf vein clot. Of the 50 patients studied, 10 had only one imaging modality performed as there were eight venographic failures and two ultrasonic failures. Comparison was only thus possible in 40 cases. As in previous studies, colour Doppler ultrasound was shown to be accurate in the diagnosis of thrombosis within the femoro-popliteal veins and had a sensitivity and specificity of 100% respectively. With respect to calf vein lesions, there was one false negative scan using the ultrasonic technique giving a sensitivity of 95%, specificity of 100% and accuracy of 97.5%. We feel colour Doppler ultrasound can and should be used as a first line alternative to venography and can be employed for the exclusion of both above and below knee deep venous thrombosis. Venography should now be reserved for those patients who are unsuitable for ultrasound examination or who have an equivocal ultrasound scan.     

Colour Doppler ultrasound in deep venous thrombosis: a comparison with venography

Colour Doppler ultrasound is a new technical development allowing simultaneous grey scale imaging and a dynamic colour flow vascular image. To date, many real time ultrasonic studies have been assessed in the diagnosis of lower limb venous thrombosis and have been shown to be accurate in the femoral and popliteal segments. A double blind prospective study comparing colour Doppler with contrast venography in the diagnosis of lower limb thrombosis was performed in a group of 40 patients. Of the study group, 26 venograms were negative and 27 ultrasound examinations were negative. Of the 14 positive venograms there was one false negative colour doppler scan which missed a calf and lower popliteal thrombosis. Two cases of isolated calf vein thrombosis were successfully detected by colour Doppler. Overall, the sensitivity and specificity for detection of lower limb venous thrombosis, including calf vein assessment, were 93% and 100% respectively. Colour Doppler is easy to perform; the average scanning time being 15 minutes for complete assessment of a unilateral lower limb venous system. Spontaneous flow is evident in the femoropopliteal segment, whilst proximal calf vein flow can only be appreciated with the aid of distal compression. Eccentric thrombus and partially recanalized thrombus can be shown. Although the number of isolated calf vein thromboses was small, early experience suggests colour Doppler may be useful in the assessment of proximal calf vein patency.     

Deep veins of the calf: assessment with color Doppler flow imaging

The authors studied the ability of real-time ultrasound aided by color Doppler flow imaging to demonstrate the deep veins of the calf in ten healthy subjects and 49 patients (91 limbs) with suspected deep venous thrombosis. Posterior tibial and peroneal veins demonstrated flow accentuation in 98% (74 of 75) and 96% (72 of 75), respectively, of the limbs without thrombosis and in all 20 normal limbs. Sixteen legs were involved with deep venous thrombosis. Peroneal veins could not be seen in three legs with marked calf swelling due to proximal thrombosis. There were two cases of thrombosis limited to the calf, nine of popliteal thrombosis (seven with contiguous spread of thrombus), and five of thrombosis limited to above the knee (four with sparing of the deep veins of the calf). Visualization of anterior tibial veins, achieved in 65% of all legs, did not correlate with thrombosis. The authors conclude that color Doppler flow imaging can demonstrate patency of posterior tibial and peroneal veins in most patients without deep venous thrombosis and aid in detection of below-the-knee thrombosis.     

The significance of intensity and duration of exercise on natural immunity in rats

PURPOSE: The purpose of this study was to examine a) the relationship between running distance (km x d(-1)) and b) the duration of exercise training in weeks on the effects on natural immune function in spontaneously hypertensive rats (SHR). METHODS: Exercise consisted of voluntary running in wheels for 5 or 11 wk. In vivo cytotoxicity was measured as clearance of injected 51Cr-labeled YAC-1 lymphoma cells from the lungs. RESULTS: Increased in vivo cytotoxicity was seen after 5 wk of exercise (P < 0.001) but not after voluntary exercise for 11 wk. If the wheels were locked 3 d x wk(-1) during the last 6 wk of running, thus restricting the exercise to 4 d x wk(-1), the exercise-induced immunoenhancement seen after 5 wk of exercise was maintained also after 11 wk of exercise. When compared with the sedentary controls after 5 wk of exercise, all runners regardless of running distance exhibited significantly higher in vivo clearance of tumor cells from the lungs, and no overall significant correlation was seen between running distance and retained radioactivity. However, the lowest activity runners (< 4 km x d(-1)) exhibited significantly lower in vivo clearance of tumor cells from the lungs when compared with animals running more than 4 km x d(-1). CONCLUSION: We conclude that the duration of exercise training, and to some extent the running distance, has significant effects on the training-induced increase in natural immune function in rats. Furthermore, we conclude that a resting or recovery period during long-term exercise training is important to maintain the immunoenhancing effects in response to exercise.     

彩色多普勒超声对妇科术后患者小腿肌间静脉丛血栓诊断的应用价值

目的通过彩色多普勒超声检查,探讨其对诊断妇科手术后患者小腿肌间静脉丛血栓形成的应用价值。方法分析31例妇科手术后临床考虑为小腿肌间静脉丛血栓患者,观察其小腿肌间静脉二维超声及彩色多普勒超声的声像图改变,并与健侧小腿肌间静脉及溶栓治疗后患侧进行比较。结果患侧小腿肌间静脉与健侧比较有明显区别,且溶栓治疗后,患侧小腿肌间静脉声像图接近于健侧。结论彩色多普勒超声对妇科手术后患者小腿肌间静脉血栓的诊断具有较大的临床价值,通过超声检查可直观监测血栓的存在,并且可动态观察溶栓治疗后血栓的状况。     

Occult pulmonary embolism: a common occurrence in deep venous thrombosis

Ventilation-perfusion scans were used in a prospective study to determine the prevalence of occult pulmonary embolus in proven deep venous thrombosis. Fifty-eight patients without symptoms of pulmonary embolism, but with venographically proven deep venous thrombosis, were subjected to chest radiographs, 99mTc macroaggregated-albumin perfusion scans, and 133Xe ventilation scans. Of the 49 patients with deep venous thrombosis proximal to the calf veins, 17 (35%) had high-probability scans. Of all 58 patients, only 12 (21%) had normal scans. When the study population was compared with a group of 430 patients described in reports of pulmonary perfusion in asymptomatic persons, a significantly higher percentage of high-probability scans was found in the study population with deep venous thrombosis. Baseline ventilation-perfusion lung scanning is valuable for patients with proven above-knee deep venous thrombosis.     

Gd-enhanced subtraction MR venography

We succeeded in distinctly imaging the calf veins using Gd-enhanced subtraction MR venography (Gd SMRV). Gd SMRV was performed in 15 normal legs, 33 varicose legs and 22 legs with suspected deep venous thrombosis. Conventional venography was performed in 46 legs in all. The deep veins of the calf, greater saphenous vein, and intramuscular veins had high rates of demonstration in normal legs and varicose legs (84, 100%, 87, 97%, 67, 73%). The varices were also well demonstrated (100%). When Gd SMRV was compared with conventional venography in terms of diagnosis of calf venous thrombosis, the sensitivity of this method was 100%, specificity was 92% and accuracy was 93%. We found high intensity thrombi on precontrast images in most cases, a finding that was important for the diagnosis of local thrombi. This method was non-invasive and was able to clearly visualize veins in the calf. We concluded that Gd SMRV was useful for calf venous disease, especially calf venous thrombosis.     

Deep venous thrombosis: complete lower extremity venous US evaluation in patients without known risk factors--outcome study.

PURPOSE: To determine the diagnostic value of venous ultrasonography (US) that includes examination of calf veins in symptomatic patients suspected of having deep venous thrombosis (DVT) of the lower extremities. MATERIALS AND METHODS: A retrospective cohort study of the prevalence of DVT included 977 consecutive patients with possible DVT but without known risk factors for DVT. Color flow and compression US were performed. The outcome was the frequency of overlooked, clinically important DVT after negative initial results from bilateral venous US of above- and below-the-knee veins. Patient records (904 patients), mailed questionnaires (61 patients), and telephone contacts (12 patients) were used to establish a diagnosis of clinically relevant DVT. RESULTS: The prevalence of DVT was 15% (142 of 977), with DVT in 15% (21 of 142) restricted to the below-the-knee veins. Follow-up (median, 34 months) in 835 patients with negative US findings showed one occurrence of venous thrombosis (superficial thrombophlebitis) during the first 3 months of follow-up. Three other cases of venous thrombosis occurred at 17, 18, and 48 months of follow-up but were believed not to be linked to the initial complaint. The incidence of overlooked DVT was 0% (95% CI, 0.0%, 0.4%). CONCLUSION: In patients without risk factors for DVT, a negative venous US study can help exclude the presence of clinically important DVT if the examination includes careful evaluation of the calf veins.     

Phlebographic findings in venous thrombosis following total hip replacement

The specific appearance of venous thrombosis following total hip replacement was analysed by reviewing 45 positive phlebograms from 122 patients participating in a concurrent trial against thromboembolism. Almost all thrombi were asymptomatic and non-occlusive. Forty-four per cent of the thrombi were exclusively confined to the calf. The muscular veins were the most common location, followed by the fibular and posterior tibial veins. Ipsilateral thrombi predominated over thrombi in the non-operated leg. Thirty-six per cent were located in the ipsilateral thigh and the major part was found in the proximal part of the femoral veins. Nearly all were related to valve cusps, free-floating and were of small size. In 20 per cent, thrombi were found in both the calf and the thigh. Neither contralateral thigh thrombi, nor pelvic thrombi were found. Of 25 patients with pulmonary embolism, all but 3 asymptomatic, 64 per cent had thigh thrombi. A multifocal location of thrombi was present but two major types of thrombosis were distinguished; calf vein thrombosis probably due to venous stasis and femoral thrombosis caused by the local surgical trauma.     

names and faces

Although usually considered a disease of sedentary people, deep venous thrombosis can occur in active patients. Physical findings may be difficult to differentiate from those of muscle trauma, a Baker's cyst, or hematoma. A high index of suspicion must be maintained, because delay in making the diagnosis and initiating anticoagulation may have fatal consequences. Doppler flow studies are required in all cases of limb pain or swelling in runners when deep venous thrombosis is even remotely suspected, as in this case of a 40-year-old man who developed ankle and lower-leg pain 1 month after a 10-km run. If promptly treated, patients can make a safe return to training without adverse consequences.     

Effect of phlebography on 125I uptake test.

Increased 125I fibrinogen uptake counts were encountered in 30 of 55 limbs after a normal ascending phelbogram. In most cases, the abnormal 125I fibrinogen uptake test occurred within 72 hr after phlebography, and the elevated counts were most frequently seen around the ankle, with contiguous involvement of the calf seen less often. Inly three patients with positive counts subsequently became symptomatic and were treated for deep venous thrombosis. The presence of deep venous thrombosis was confirmed by repeat ascending phlebography in two of these cases. Ascending phlebography was not performed on the other positive postphlebographic fibrinogen uptake test limbs.     

Low-dose P32 therapy in essential thrombocythemia

We present a case of an 85-year-old woman with medically refractory essential thrombocythemia and subsequent venous thrombosis. She received conservative phosphorus-32 sodium phosphate therapy for 3 mCi, approximately half the usual dose. One month later, she received a second intravenous phosphorus-32 treatment of 3.5 mCi. She responded successfully to both treatments with drops in her platelet count and experienced no adverse effects. Our case is noteworthy in the effectiveness from a conservative dose while avoiding hematologic complications.     

Effects of training on delayed muscle soreness and serum creatine kinase activity after running

We studied the effects of progressive, short-term training on the delayed muscle soreness (DMS) and serum creatine kinase (SCK) responses to downhill (-10%) running for 45 min. Prior to the experimental run, subjects in training groups (N = 38) ran for 5 min to 15 min.d-1 on either -10% or +10% incline for either 1 wk (5 d) or 2 wk (10 d). Twelve control subjects did not train. DMS was reduced, although not totally prevented, by the 1 wk, and especially, 2 wk of downhill running training. Training by uphill running had little effect in preventing DMS. Mean SCK values 24 h after the experimental run were not significantly different among the groups (range: 99 to 340% of pre-exercise values), indicating no effect of any training regimen. Relatively large differences existed among subjects in terms of soreness and SCK responses to the experimental running. It was suggested that DMS may be difficult to totally avoid if exercise with a large eccentric component is performed. Prevention of such DMS may be most likely if prior training involves exercise with a substantial eccentric component, starts with bouts of very small quantities, and progresses in small increments over more than 2 wk.     

Dynamic evaluation of lower limb arteries using the ECTRICKS MRI technique

PURPOSE: This article presents a new MR angiography technique, Elliptic Centric Time Resolved Imaging on Contrast KineticS (ECTRICKS), which allows dynamic evaluation of the lower limb arteries opacification when venous return prevents adequate diagnostic evaluation of calf arteries. PATIENTS AND METHODS: Comparative examinations could be compared. Additional arteries in 59 patients using a standard MRA technique and the ECTRICKS technique. RESULTS: A total of 33 examinations could be compared. Additional arteries could be evaluated in 10% of our patient population using the ECTRICKS technique, and in 20% for our diabetic population. Arterial evaluation was better with the ECTRICKS technique in patients with diabetes and venous insufficiency. CONCLUSION: ECTRICKS is a good complementary sequence for evaluation the calf arteries in patients with diabetes or early venous return.     

直接法多层螺旋CT静脉造影诊断下肢深静脉血栓简

目的：探讨直接法多层螺旋CT静脉造影（MSCTV）诊断下肢深静脉血栓的临床应用价值。方法直接法多层螺旋CT（MSCT）下肢静脉造影17例,同期均行彩色多普勒超声血流显像（CDFI）检查。直接法MSCTV检查后,所得图像经处理后传送至工作站进行多平面重建（MPR）、最大密度投影（MIP）、表面遮盖（SSD）及容积再现（VR）重建。结果直接法MSCTV检查显示13例存在下肢深静脉血栓（DVT）,彩色多普勒超声检查显示10例,2例髂静脉及1例胫腓静脉血栓彩色多普勒超声未能检出。直接法MSCTV上DVT主要表现为静脉腔内造影剂充盈缺损、静脉节段性不显影、栓塞静脉远端扩张及其周围侧支循环静脉迂曲扩张、周围软组织肿胀、皮肤增厚。结论直接法MSCT能清晰显示DVT形成的部位、范围、侧支静脉情况及病变血管周围的解剖结构,对彩色多普勒超声不易检出的盆腔及小腿深静脉栓塞也能清晰显示,可以作为下肢深静脉血栓检查的常规方法。