pearls for diagnosis

1-• Be sure the veins fully compress.
2-Be sure to apply pressure evenly along the transducer face (perpendicular to skin surface). 3-Avoid pressing at an angle, as this may result in uneven compression and a false positive finding. 3-In patients who are obese, decreasing the transducer frequency to 3.5-5 MHz increases the depth of penetration and can assist the examiner. Overall image quality, however, is reduced.
4- If no vein is visible at the appropriate anatomic sight, the transducer may already be compressing the vein. Reduce the amount of pressure being applied and reexamine the area of interest.
5-Care must be taken to not over-interpret vessel echogenicity as clot. Both normal blood flow and vessel artifact can appear hyperechoic. Cysts, especially Baker cysts, are commonly encountered in the popliteal region.
6-These can be readily distinguished by their confluence with the joint space and their lack of flow on color flow Doppler ultrasonography.
7-Lymph nodes are particularly common in the femoral region and can be identified by their superficial location, their characteristic appearance (hyperechoic center with hypoechoic rim), and their high vascularity on color flow Doppler ultrasonography
8- Duplicate popliteal and femoral veins are not uncommon. Special attention must be paid to rule out a DVT in patients with a duplicate vessel because the potential decrease in flow velocity may increase the risk for clot development.
9- Utilizing the dual-image picture or split-screen option before and after compression may make comparison easier. In addition, the split-screen option may be useful in hospitals that use still images for documentation. If the examination site is wounded, the ultrasound transducer may be covered with a sterile probe cover with gel applied to both the inside and the outside of the cover.If an adequate examination cannot be obtained secondary to patient body habitus, patient compliance, or skill limitation, the patient requires a formal ultrasonographic study. In addition, if the study results are indeterminate, then a formal ultrasonographic study should be obtained.


http://www.google.com.eg/imgres?imgurl=http://img.medscape.com/pi/emed/ckb/clinical_procedures/79926-104340-1362989-1383583.jpg&imgrefurl=http://emedicine.medscape.com/article/1362989-treatment&usg=__ZZqorDtsU0B_SDuAwNfox0jcGUE=&h=306&w=311&sz=40&hl=ar&start=7&zoom=1&itbs=1&tbnid=OvfkZRH5cvC8mM:&tbnh=115&tbnw=117&prev=/images%3Fq%3Dposterior%2Btibial%2Bvein%2Bthrombosis%26hl%3Dar%26sa%3DG%26gbv%3D2%26tbs%3Disch:1

-Position the patient as noted above for examination of the femoral vessels. The study begins with an examination of the common femoral vein just distal to the inguinal ligament. The femoral vessels are located just inferior to the inguinal ligament and approximately midway between the pubic symphysis and the anterior superior iliac spine. The femoral artery is usually palpable. This is the initial point of examination.
-Apply gel to the transducer, the patient’s leg, or both, and position the transducer transversely, just distal to the inguinal ligament, as shown below. Remember, the indicator on the probe should point toward the patient’s right. In this transverse view, the vein is imaged in cross-section.

Probe positioning for assessment of the femoral vein.
-Drag or fan the transducer in a cephalad or caudad direction until the junction of the common femoral vein and the greater saphenous vein can be visualized, as shown below. The common femoral artery is lateral to the common femoral vein.

Ultrasonographic image of femoral vessels without compression.

-Using the transducer, apply direct pressure to completely compress the vein.

-If the vein compresses completely, then a DVT at this site can be ruled out.

-Be sure that enough pressure is being applied and being applied evenly. Apply enough pressure so that slight deformation of the artery is noticeable.

-If the vein is still not completely compressible, a DVT is present. See the image below.

Ultrasonographic image of femoral vessels with compression.

-Complete compression of the vein rules out a DVT, while the inability to completely compress the vein rules in a DVT. Thus, compressibility is the rule in/rule out criterion for DVT on ultrasound. (See Results below for more details.)

-Compressibility must be present in both the femoral veins and the popliteal vein. Sometimes, the angle of the transducer may need to be adjusted in order to completely compress the vein. The greater saphenous vein is a superficial vein. A clot in the greater saphenous vein near its junction with the common femoral vein, however, can easily propagate.

-The examination of the common femoral vein should extend from 2 cm proximal to 2 cm distal to the intersection of the common femoral and greater saphenous veins.

-Distal to the greater saphenous vein, the common femoral vein splits into the deep and superficial femoral veins. Despite its name, the superficial femoral vein is indeed a deep vein. Once collapse of both the deep and superficial femoral veins is confirmed, the examination may move on to the popliteal vein.

http://www.google.com.eg/imgres?imgurl=http://img.medscape.com/pi/emed/ckb/clinical_procedures/79926-104340-1362989-1383583.jpg&imgrefurl=http://emedicine.medscape.com/article/1362989-treatment&usg=__ZZqorDtsU0B_SDuAwNfox0jcGUE=&h=306&w=311&sz=40&hl=ar&start=7&zoom=1&itbs=1&tbnid=OvfkZRH5cvC8mM:&tbnh=115&tbnw=117&prev=/images%3Fq%3Dposterior%2Btibial%2Bvein%2Bthrombosis%26hl%3Dar%26sa%3DG%26gbv%3D2%26tbs%3Disch:1

Posterior tibial vein
-This longitudinal view reveals that more than half of the venous lumen is occluded by thrombus (black area). Areas of blood flow within the vein appear red. This imaging technique renders a thrombus as black, while areas of blood flow are colorised.


http://www.thrombosisadviser.com/scripts/pages/en/resources/image-library/index.php

severe rickets

Here is an example of severe rickets. There has been a lack of vitamin D for a long enough period of time for skeletal deformities to develop. The growth plate is not normal (compare to previous image). The growth plate is no longer smooth and has a ragged apperance. This is an indication that bones are not being calcified properly. The bones have lost their reticular pattern and have developed coarse trabeculations. The cortex has linear lucencies that are indicative of pseudofractures. These are simply poorly mineralized areas across the bone.


http://rickets.stanford.edu/pages/case04.html‎

mild rickets

There is a ragged metaphyseal side to the growth plates of the radius and ulna. These bones are affected because they are undergoing rapid growth. The cartilage continues to grow abnormally in the physis. Calcification spicules occur at the ends of the bone, creating the appearance of a little cup holding a bowl of cartilage, with the epiphyseal center (calcified bone) present as a ball in the bowl.

This patient was treated with vitamin D. This x-ray was taken a month later. The cartilage that had piled up near the growth plate has begun to calcify.

http://rickets.stanford.edu/pages/case04.html‎

This x-ray shows a widened growth plate with an irregular pattern on the metaphyseal side.

This is an x-ray of the same patient taken after treatment with calcium and vitamin D. The growth plate has been reduced to its normal width as the cartilage has begun to calcify. The margin is smooth and clean on the end of the ulna. The calcification bands are visible on both radius and ulna.

http://rickets.stanford.edu/pages/case04.html‎

This is and anterior-posterior view of a patient with rickets involving the skull. The sutures are relatively wide in this skull due to an increase in intracranial pressure bfore the sutures have united. The sutures are approximately 4 cm wide which is abnormal.

This is a lateral view of the same skull. The sutures are wider than normal and can also be seen from this angle.

http://rickets.stanford.edu/pages/case04.html‎

rickets

This is an anterior-posterior view of a growing child. This bowing results from chronic illness with prolonged stress. The weight-bearing tibiae, soft with excess cartilage, bend easily.

This is a lateral view of the same patient. The curving of the tibia is easily visible. The growth plate looks normal since treatment has begun, but the bowing of the legs remains.

rickets.stanford.edu/pages/case04.html‎