Progress in the diagnosis of deep venous thrombosis: the efficacy of real-time B-mode ultrasonic imaging

Seventy-six limbs with clinically suspected acute deep venous thrombosis (DVT) were evaluated by means of ultrasonic imaging (UI) to define the ability of this technique to detect acute and chronic venous obstruction and to determine the origin and distribution of venous thrombi. UI was compared with ascending contrast phlebography in 46 limbs and was found to be 100% accurate in detecting both acute and chronic venous thrombosis. Overall, acute DVT was present in 63 of 76 limbs (83%) studied. Acute DVT was found in 24% and recurrent acute DVT in 76%. Our results indicate that although the calf veins are the most common site of involvement (89%), thrombi may frequently arise simultaneously in multiple anatomic sites. All limbs with recurrent acute DVT had evidence of previous calf thrombi but only 13% had previous proximal disease. This suggests that asymptomatic calf DVT is common and the prevalence of recurrent acute DVT is significantly greater than previously believed. We found UI is a practical, accurate, non-invasive method for investigating the pathogenesis of venous disease.     

Use of ultrasonic venography in the evaluation of venous valve function

Forty healthy limbs and 31 limbs with suspected deep venous insufficiency were imaged with real-time B-mode ultrasound to determine valve location, anatomic characteristics, and function. Valve function was evaluated by comparison with Doppler ultrasonographic techniques, and the data clearly indicated that ultrasonic venography accurately localized and determined the extent of deep venous reflux. Ascending contrast venography was performed in 15 postphlebitic limbs for assessment of valve location. The results indicate that ultrasonic venography is a more accurate method for visualization of valves in this group of patients. Therefore, ultrasonographic imaging is a valuable technique for evaluating limbs with chronic venous insufficiency.     

Cultural Traditions as “Protective Factors” Among Latino Children of Illicit Drug Users

Family bonding was examined among Hispanic adolescents whose fathers are illicit drug users to ascertain whether such adolescents maintain close affective family ties or alienate themselves from their families given their father's use of illicit drugs and referral to a drug screening and treatment program. It was hypothesized that high levels of paternal drug use would be associated with the youth's alienation from the family. In addition, it was postulated that the adolescent's endorsement of traditional cultural values and social responsibility would protect her or him against this effect in relation to family bonding. These hypotheses are based on prior research that suggests that youth bonding to prosocial institutions, such as family, school, church, and community organizations, can be “protective” against drug use. More specifically, our analyses examined the role of level of acculturation in middle school, family traditionalism, American orientation, Latino orientation, and social responsibility in predicting adolescents' family bonding. Results indicated that the father's level of marijuana and/or methamphetamine use was unrelated to youth family bonding. Additionally, Latino and American cultural orientations and level of acculturation in middle school were not associated with family bonding. By contrast, social responsibility (the youth's citizenship and responsibility to the community) and family traditionalism (endorsing conservative cultural values regarding the maintenance of family traditions and respect for elders and family) were significantly associated with family bonding. In other words, among children of Latino illicit drug users, the youth's conservative family values and a responsible attitude toward community traditions were dual factors related to family bonding, perhaps operating also as sources of “protection” against youth problem behaviors.     

Quantitative tissue oxygen measurement in multiple organs using 19F MRI in a rat model

Measurement of individual organ tissue oxygen levels can provide information to help evaluate and optimize medical interventions in many areas including wound healing, resuscitation strategies, and cancer therapeutics. Echo planar ¹⁹F MRI has previously focused on tumor oxygen measurement at low oxygen levels (pO₂) <30 mmHg. It uses the linear relationship between spin‐lattice relaxation rate (R₁) of hexafluorobenzene (HFB) and pO₂. The feasibility of this technique for a wider range of pO₂values and individual organ tissue pO₂ measurement was investigated in a rat model. Spin‐lattice relaxation times (T₁= 1/R₁) of hexafluorobenzene were measured using ¹⁹F saturation recovery echo planar imaging. Initial in vitro studies validated the linear relationship between R₁ and pO₂ from 0 to 760 mmHg oxygen partial pressure at 25, 37, and 41°C at 7 Tesla for hexafluorobenzene. In vivo experiments measured rat tissue oxygen (ptO2) levels of brain, kidney, liver, gut, muscle, and skin during inhalation of both 30 and 100% oxygen. All organ ptO₂ values significantly increased with hyperoxia (P < 0.001). This study demonstrates that ¹⁹F MRI of hexafluorobenzene offers a feasible tool to measure regional ptO2 in vivo, and that hyperoxia significantly increases ptO2 of multiple organs in a rat model. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.     

Imaging of iris lesions with high-speed optical coherence tomography.

BACKGROUND AND OBJECTIVES: To image and measure iris tumors with optical coherence tomography (OCT). PATIENTS AND METHODS: High-speed (2,000-4,000 axial-scan/sec and 4-16 frames/sec) 1.3-micron wavelength anterior segment OCT prototypes were used to image 6 eyes of 6 patients with a variety of iris lesions, including focal iris nevus, diffuse iris nevus, amelanotic iris nevus, iris melanocytosis, and iris melanoma. OCT images were compared with slit-lamp photography and ultrasound biomicroscopy. RESULTS: OCT at 1.3-micron wavelength could penetrate the full thickness of the iris lesions and allow three-dimensional measurement of lesion size. Internal reflectivity is correlated with pigmentation. OCT is a convenient non-contact method that provides imaging of the clinically important angle structures (scleral spur and angle recess). CONCLUSIONS: OCT is a new imaging modality that complements slit-lamp photography and ultrasound biomicroscopy for serial evaluation of iris     

A comparative review of in situ versus reversed vein grafts in the 1980s

In patients requiring an infrainguinal bypass who have an ipsilateral intact GSV, the choice between the reversed and in situ vein graft should be determined by the operative findings and the site of the distal anastomosis. When the ipsilateral GSV has either been removed or is of poor quality, ectopic autologous vein should be used in most circumstances and certainly for bypass to the infrapopliteal arteries. In reviewing the results of the two types of vein bypass to the popliteal artery, the results of two prospective, randomized studies and recent retrospective, nonrandomized reports suggest that there is no difference in patency rates between the two techniques. When performing a bypass to this level, the surgeon should not routinely use one method, but tailor the operative management to the individual patient. However, when the two bypass procedures to the infrapopliteal arteries were compared, the results of a prospective, randomized study and recent retrospective, nonrandomized reports furnish strong evidence that ISVGs provide better long term patency rates than RVGs. These results favoring use of distal ISVGs in nonrandomized reports are even more impressive, since the in situ technique was often preferentially chosen over the reversed vein method when only small diameter GSVs were available and when the bypass was performed to the distal tibial or pedal arteries. Many vascular surgeons agree with the conclusion that the ISVG is the bypass of choice for infrapopliteal bypass when an intact GSV is available. Although both the in situ and reversed vein techniques provide excellent long term patency rates for infrainguinal bypasses, and the vascular surgeon should be able to adapt this technique and approach for the individual patient, further randomized, prospective studies with extensive follow-up evaluation and a large number of patients are necessary to definitively resolve which technique provides optimal patency rates for arterial reconstruction of the lower extremity.     

Sizing up HEDIS: experts take system's measure

NCQA's performance measurement system is well established in the industry. But is it really addressing the questions that matter? In this article, industry experts discuss how HEDIS has made its mark.