Diagnosing Recurrent DVT of the Leg by Two Different Non-Contrast-Enhanced Magnetic Resonance Direct Thrombus Imaging Techniques: A Pilot Study.

Introduction Magnetic resonance direct thrombus imaging (MRDTI) is a promising technique to improve the diagnostic management of patients with a suspected ipsilateral recurrent deep vein thrombosis (DVT) by direct visualization of a thrombus. Another magnetic resonance imaging (MRI) technique, T1-weighted turbo spin-echo spectral attenuated inversion recovery (TSE-SPAIR), has the potential to image a thrombus directly with a high spatial resolution as well. The main aim of this pilot study was to investigate if adding the TSE-SPAIR sequence to an MRDTI sequence performed in patients with suspected recurrent DVT may increase the diagnostic confidence of expert MRDTI readers. Methods Fifteen patients with suspected acute recurrent DVT were included in this study. The TSE-SPAIR sequence was scanned directly after the MRDTI scan but not used to guide clinical decision making, and both scans were adjudicated post hoc two times separately by three independent expert MRDTI readers. Diagnostic confidence was scored on a 4-point Likert scale: (1) poor (definite diagnosis impossible), (2) fair (evaluation of major findings possible), (3) good (definite diagnosis possible), and (4) excellent (exact diagnosis possible). Results The diagnostic confidence of expert readers increased when adding the TSE-SPAIR sequence on top of the MRDTI sequence from "good" (median, 3.0; interquartile range [IQR], 2.66-3.0) to "excellent" (median, 3.67; IQR 3.33-3.67; p = 0.001). Evaluation of the scans in the reversed order 5 months after initial reading showed similar results. Diagnostic accuracy for proximal DVT of both scan techniques was good. Conclusion The extra TSE-SPAIR sequence may help increase diagnostic confidence of radiologists in cases of uncertain diagnosis in patients with suspected ipsilateral recurrent DVT.

Accurate diagnosis of iliac vein thrombosis in pregnancy with magnetic resonance direct thrombus imaging (MRDTI).

A pregnant woman aged 29 years, G1P0 at 21 weeks of gestation of a dichorionic diamniotic twin, presented with suspected deep vein thrombosis (DVT) of the left leg. Repeated (compression) ultrasonography was not diagnostic for DVT but showed reduced flow over the left external iliac vein, common femoral vein and superficial femoral vein. In pursue of a definite diagnosis, magnetic resonance direct thrombus imaging was performed showing a clear high signal in the left common iliac vein which is diagnostic for acute thrombosis in this venous segment. Phase contrast venography supported this diagnosis, showing no flow in the left common iliac vein. Treatment with anticoagulants was started. 6 months after the diagnosis, the patient is doing well and does not report signs of post-thrombotic syndrome.

Minimal impact of adjuvant exemestane or tamoxifen treatment on mammographic breast density in postmenopausal breast cancer patients: a Dutch TEAM trial analysis.

BACKGROUND: Mammographic breast density is one of the strongest independent risk factors for developing breast cancer. We examined the effect of exemestane and tamoxifen on breast density in Dutch postmenopausal early breast cancer patients participating in the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial. MATERIAL AND METHODS: Analogue mammograms of selected TEAM participants before start, and after one and two (and if available after three) years of adjuvant endocrine therapy were collected centrally and reviewed. Study endpoints were change in breast density over time, and correlations between breast density and locoregional recurrence (LRR), distance recurrence (DR), and contralateral breast cancer (CBC). RESULTS: Mammograms of 378 patients (181 tamoxifen, 197 exemestane) were included in the current per protocol analyses. Baseline breast density was low (breast density score<50% in 75% of patients) and not different between patients randomised to exemestane or tamoxifen (coefficient 0.16, standard error 0.17). Breast density did not change during treatment in exemestane (p=0.25) or tamoxifen users (p=0.59). No relation was observed between breast density and the occurrence of a LRR [hazards ratio (HR) 0.87, 95% CI 0.45-1.68, p=0.67], a DR (HR 1.02, 95% CI 0.77-1.35, p=0.90), or CBC (HR 1.31, 95% CI 0.63-2.72, p=0.48). CONCLUSION: The in general low breast density score in early postmenopausal breast cancer patients did not substantially change over time, and this pattern was not different between tamoxifen and exemestane users. Breast density was not a predictive marker for efficacy of adjuvant endocrine therapy.

Revised formula to determine the insertion length of umbilical vein catheters.

UNLABELLED: The method of Shukla is commonly used to predict the insertion length of umbilical vein catheters (UVCs) but often leads to over-insertion. Malposition of UVCs can lead to complications. In this study, we compared the formula of Shukla, i.e., (3 x birthweight in kg + 9) / 2 + 1 cm with a revised formula, i.e., (3 x birthweight in kg + 9) / 2 cm in determining the insertion length of UVCs. A cohort where the revised formula was used for UVC placement (revised group) was compared with a historical cohort using the conventional formula (Shukla group). We evaluated the position of UVCs stated as the corresponding vertebra level with a radiograph of the infant's chest and abdomen immediately after insertion in both groups. Positioning of the catheter tip above the ninth or below the tenth thoracic vertebra was considered too high or too low, respectively. Median position of 93 UVCs placed according to Shukla was lower (seventh thoracic vertebra, interquartile range (IQR) 6-9) when compared to 92 UVCs placed according to the revised formula (eighth thoracic vertebra (IQR 7-9)). UVCs were more often over-inserted using the Shukla formula (73%) when compared to the revised formula (54%). One UVC in the Shukla group (1%) and two UVCs in the revised group (2%) were placed too low (p = NS). CONCLUSION: The revised formula reduces the rate of over-insertion of UVCs without increasing the rate of inadequate lower positioning.

Finding the origin of pulmonary emboli with a total-body magnetic resonance direct thrombus imaging technique.

Pulmonary embolism is considered to originate from embolization of a deep-vein thrombosis, resulting in two manifestations of one disease: venous thrombosis. However, in up to 50% of patients with pulmonary embolism no deep-vein thrombosis is found with ultrasonography. An explanation for this low proportion is currently lacking. Other imaging modalities may increase the yield of detection of deep-vein thrombosis in the calf or in the abdominal region. Alternatively, not all pulmonary emboli may originate from deep-vein thromboses in the extremities. We searched for the origin of pulmonary emboli, by performing total-body magnetic resonance imaging-scans to visualize thrombi. Ninety-nine patients with a first pulmonary embolism confirmed by computed tomography underwent a magnetic resonance direct thrombus imaging-scan, a validated technique using endogenous contrast. Additionally, acquired and genetic risk factors were assessed. No thrombus was found in 55 patients, whereas a thrombus was identified in 44 patients. The commonest thrombus location was the lower leg; 12 patients had isolated calf vein thrombosis and five had isolated superficial vein thrombosis. A peripheral thrombus was found by magnetic resonance imaging in less than half of patients with pulmonary embolism. We propose several hypotheses to explain the absence of thrombi, such as a cardiac thrombus origin or embolization of the whole deep-vein thrombus. The possibility that pulmonary embolism arises de novo in the lungs, due to local inflammation-driven coagulation, needs to be considered.

Magnetic resonance imaging and computed tomography developments in imaging of venous thromboembolism.

Venous thromboembolism (VTE) is a disease that causes high morbidity and mortality in the population. At present the first-line imaging test for a suspected pulmonary embolism (PE) is computed tomography (CT) pulmonary angiography, and ultrasonography is widely used for the diagnosis of deep-vein thrombosis (DVT). Although these modalities are proven to be safe and accurate, unresolved issues remain, such as whether CT scanning in patients with a suspected PE should be extended to the legs. Another issue is the diagnosis of recurrent DVT. Magnetic resonance imaging (MRI) offers a number of advantages in the imaging of VTE. Recent developments of scanning protocols with shorter acquisition times, sometimes complemented by navigator gating or making use of endogenous contrast, offer new perspectives for the use of MRI. This review provides an overview of state of the art MRI techniques for the diagnosis of PE and DVT. Furthermore, the use of new contrast agents such as fibrin labeling to detect thrombi are addressed.

The effect of aging on venous valves.

OBJECTIVE: Age is the strongest risk factor for venous thrombosis. Vessel wall changes such as thickening of venous valves may be one of the contributing mechanisms. We determined thickness and function of venous valves in the popliteal vein with ultrasound in 77 healthy individuals. METHODS AND RESULTS: The study included 6 age groups ranging from 20 to 80 years old. Thickness of the valves was compared between age groups. Valve closure time was assessed as an indicator for valve function. In 69 of 77 participants, valve parameters could be measured. We found an increasing thickness of the valves with age, with a mean thickness of 0.35 mm (range, 0.25 to 0.44 mm) in the group of 20 to 30 years and 0.59 mm (range, 0.30 to 1.21 mm) in the group of 71 to 80 years. The increase in valve thickness per year (linear regression coefficient) was 0.004 mm (95% CI, 0 to 0.009). Valve function was not directly associated with age. Valve thickness, however, was inversely associated with valve function. CONCLUSIONS: Our results show that deep venous valves change with age, with thicker valves in older individuals. The increase of valve thickness with age may be part of the explanation for the age gradient seen in the incidence of venous thrombosis.

US features of the normal appendix and surrounding area in children.

PURPOSE: To evaluate prospectively the frequency of depiction with ultrasonography (US) of the appendix in children without clinical suspicion of acute appendicitis and to evaluate the US appearance of the normal appendix. MATERIALS AND METHODS: Between March 2003 and July 2003, 146 consecutive patients (62 boys and 84 girls; mean age, 7 years; age range, 2-15 years) without clinical suspicion of acute appendicitis were examined with US. Patients with cystic fibrosis and those with acute abdominal pain were excluded from the study. Outer diameters, mural thickness, and color Doppler flow were measured. Appendiceal lumen and surroundings of the appendix were determined. The overall diameter and mural thickness of the appendix were examined for relationship to age, weight, or height of the patient. For statistical analysis, the Mann-Whitney test, Student t test, and linear regression analysis were applied. RESULTS: In 120 (82%) children, the appendix was depicted with US; in 26 (18%) children, this was not possible. In 114 (95%) of the depicted appendices, the position was classical; we observed six (5%) retrocecal appendices. All appendices were compressible. Mean diameter of the appendix was 0.39 cm (range, 0.21-0.64 cm), and the mean mural thickness was 0.18 cm (range, 0.11-0.27 cm). The appendiceal lumen was empty in 74 (62%) children. The others were filled with fecal material, gas, or both. In 75 (51%) of the 146 children, lymph nodes were present in the right lower quadrant of the abdomen. We found no relation between the age, weight, or height of the examined child and the overall diameter or wall of the appendix. CONCLUSION: The results of this study show that a normal appendix can be depicted with US in 82% of asymptomatic children.