Low prevalence of unexpected popliteal DVT detected on routine MRI assessment of the knee

Venous thrombosis: a mimic of musculoskeletal injury on MR imaging

Clinical signs and symptoms of venous thrombosis and musculoskeletal pathologies frequently overlap. Sometimes, patients with venous thrombosis undergo MR examinations under an equivocal suspicion of muscle, tendon or articular injury. A low pretest clinical suspicion and lack of familiarity with the conventional MR imaging signs of venous thrombosis may result in failure to diagnose venous thrombosis, delaying treatment and raising morbimortality. In MR imaging, thrombosis presents as venous ectasia with intraluminal heterogeneous content. Small vein thrombosis is often identified as having a branching aspect. Perivenous edema and inflammatory soft tissue changes may be the most prominent findings. The purpose of this paper is to illustrate MR findings of venous thrombosis in patients who underwent MR examinations due to suspected musculoskeletal pathologies. Cases of venous thrombosis in different sites of the body diagnosed through MR are presented.

Deep vein thrombosis in the thigh: MR imaging in two cases with atypical presentations

Deep vein thrombosis (DVT) is a common clinical problem affecting the lower extremities. Prompt imaging of suspected DVT is helpful for rapid diagnosis and proper treatment. However, patients without clear predisposing factors for DVT may be directed to alternative diagnoses of a musculoskeletal disorder. The few case reports and studies of magnetic resonance (MR) imaging of unsuspected DVT are limited to the calf and knee. Here, we report two cases with a rare presentation of thigh MR imaging of unsuspected DVT. Identifying branching, abnormal intraluminal signals on fluid-sensitive imaging, or rim-enhancing tubular structures within the edema of the thigh muscle is important for differentiating intramuscular DVT from other thigh pathologies.

Characterization of intramuscular calf vein thrombosis on routine knee MRI

OBJECTIVE

Literature regarding intramuscular calf vein thrombosis (IMCVT) or infrapopliteal deep vein thrombosis (DVT) evaluation by magnetic resonance imaging (MRI) is limited, particularly with regard to routine unenhanced knee examinations. We attempt to correlate routine unenhanced MRI findings with ultrasound evaluations of the lower extremity deep venous system.

MATERIALS AND METHODS

The radiology information system was searched, yielding a total of 67 patients who had undergone both routine knee MRI and duplex ultrasound examinations within 14 days. The MRI examination findings recorded were the presence and pattern of edema, segmental vein dilation, intraluminal signal on fluid-sensitive sequences, and abnormal hyperintense signal on axial T1-weighted sequences. The presence and extent of thrombus more centrally (i.e., intramuscular calf vein thrombosis with or without extension into the popliteal vein) was reassessed on ultrasound.

RESULTS

When comparing patients with positive (n = 13) and negative (n = 54) ultrasound, there were significant differences in each of these parameters: perivascular edema, intramuscular edema, focal vein dilation, and abnormal fluid-sensitive signal. In the subset of patients with popliteal extension of the intramuscular calf vein thrombosis compared with those without any deep vein thrombosis, there was a statistically significant increase in peripopliteal edema, abnormal fluid-sensitive signal, and abnormal hyperintense T1 signal.

CONCLUSION

Imaging findings on routine unenhanced MRI have a high rate of concordance with duplex ultrasound performed through the calf in the detection of intramuscular calf vein thrombosis.

Prevalence and risk factors of deep venous thrombosis in patients with longitudinally extensive transverse myelitis: one center data from China

Objective

Deep venous thrombosis (DVT) is a severe complication in longitudinally extensive transverse myelitis (LETM) patients. It may interfere with LETM treatment and delay the recovery of the spinal dysfunction. However, there is less data about the prevalence and risk factors of DVT in patients with LETM. We analyzed data retrospectively to ascertain the prevalence of DVT and the clinical risk factors for DVT.

Methods

Clinical data on 255 LETM patients were collected from medical records. All patients were performed color Doppler ultrasound(US) to screen DVT in both lower extremities when admitted. Clinical characteristics of LETM patients with DVT were compared with those without DVT using corresponding statistical methods. Multivariate logistic regression was performed to identify risk factors related to DVT.

Results

DVT were found in 11.8% patients with LETM. Univariate analysis showed that age, muscle force and elevated baseline D-dimer were risk factors for DVT. After multivariate logistic regression, age, dyslipidemia, segments of lesions, and elevated baseline D-dimer remained significant independent risk factors.

Conclusions

DVT is common in patients with LETM and related to patient’s age, dyslipidemia, segments of lesions, and elevated baseline D-dimer. Early recognition of DVT and thrombosis prophylaxis are appropriate in patients with LETM.

IQCA-TAVV: To explore the effect of P-selectin, GPIIb/IIIa, IL-2, IL-6 and IL-8 on deep venous thrombosis

Deep vein thrombosis (DVT) associates with considerable morbidity, functional disability and mortality. Due to the lack of suitable inhibitor the correlation of various factors in DVT onset remains unknown. In this context we analyzed the structure of anti-platelet aggregation agent, P-selectin down-regulator, GPIIb/IIIa down-regulator and anti-inflammatory agent, thereby designed N-(3S-1,2,3,4-tetrahydroisoquinoline-3-carbonyl)- Thr-Ala-Arg-Gly-Asp(Val)-Val (IQCA-TAVV) as an inhibitor of DVT to receive evaluations. The docking predicted that IQCA-TAVV can target P-selectin and GPIIb/IIIa. The UV showed that IQCA-TAVV can act on P-selectin and GPIIb/IIIa. ELISA indicated that IQCA-TAVV concentration dependently inhibited activated platelets to express P-selectin and GPIIb/IIIa, and the minimal effective concentration was 1 nM. IC50 of IQCA-TAVV against platelet aggregation induced by arachidonic acid, adenosine diphosphate and platelet activating factor fell within a range of 0.13 nM to 0.30 nM. In vivo IQCA-TAVV dose-dependently inhibited venous thrombosis and the minimal effective dose was 1 nmol/kg. On ear edema model the anti-inflammation activity of 10 nmol/kg IQCA-TAVV equaled that of 1.1mmol/kg aspirin. The concentration of IL-2, IL-6 and IL-8 in the serum of the ear edema mice were also significantly decreased by 10 nmol/kg IQCA-TAVV. Even at 1 μmol/kg of dose IQCA-TAVV still did not injure the kidney, the liver, and the nerves of healthy mice. Thereby IQCA-TAVV depicts a relationship of three levels (inhibiting platelet activation, targeting externalized membrane receptor, decreasing serum inflammatory factor) for the down-regulation of P-selectin, GPIIb/IIIa, IL-2, IL-6 and IL-8 in DVT.

Deep vein thrombosis is accurately predicted by comprehensive analysis of the levels of microRNA-96 and plasma D-dimer

The aim of the present study was to investigate the association between platelet microRNA-96 (miR-96) expression levels and the occurrence of deep vein thrombosis (DVT) in orthopedic patients. A total of consecutive 69 orthopedic patients with DVT and 30 healthy individuals were enrolled. Ultrasonic color Doppler imaging was performed on lower limb veins after orthopedic surgery to determine the occurrence of DVT. An enzyme-linked fluorescent assay was performed to detect the levels of D-dimer in plasma. A quantitative polymerase chain reaction assay was performed to determine the expression levels of miR-96. Expression levels of platelet miR-96 were significantly increased in orthopedic patients after orthopedic surgery. miR-96 expression levels in orthopedic patients with DVT at days 1, 3 and 7 after orthopedic surgery were significantly increased when compared with those in the control group. The increased miR-96 expression levels were correlated with plasma D-dimer levels in orthopedic patients with DVT. However, for the orthopedic patients in the non-DVT group following surgery, miR-96 expression levels were correlated with plasma D-dimer levels. In summary, the present results suggest that the expression levels of miR-96 may be associated with the occurrence of DVT. The occurrence of DVT may be accurately predicted by comprehensive analysis of the levels of miR-96 and plasma D-dimer.