Skip to main content

SCANNING RULES - ORIENTATION of the image , Background of the image | ACOUSTIC enhancement and SHADOWING, ULTRASOUND BEAM | Frequency and resolution

 Orientation of the image
Woman left shocked by what she discovered in her ultrasound photo ...

Orientation of the image
It is possible for teh images on the monitor to be reversed so that, on transverse scans, the left side of the patient is seen on the right side of the screen. Although there may be an indicator on the transducer , it is essential before scanning to check visually which side of the transducer produces which side of the image . This is the best done by putting a finger at one end of the transducer 180° and check again .on the longitudinal scans,the head of the patient should be on the left side and the feet on the right side of the screen.

(Fig:1a). Two axial images
Of the same fetal head, but aligned 180° differently .

Background of the image
    The image on the screen may be predominantly black or predominantly white. It may have a white background with black echoes or a black background with white echoes showing as spots or lines . There is usually a switch to make this change; if not, an engineer should adjust the machine so that it always shown a black background with white echoes.

         (Fig:1b). Transverse image of an enlarged uterus with background change .

 Acoustic enhancement and shadowing

 Clear liquids allow ultrasound to pass directly through without much alteration, so that echoes that come from tissue behind liquid are usually enhanced (brighter). This is known as "acoustic enhancement". Drinking enough water to fill the stomach will displace gas-filled bowel, providing an acoustic window. This is particularly useful in visualizing the body and tail of the pancreas. 

• Gas in the bowel or elsewhere can present a variety of sonographic patterns. The beam can be scattered, reflected, absorbed and refracted, making it very difficult to image underlying structures. For this reason, ultrasound can not be used to image the normal lungs or to demonstrate lung disease other than peripheral masses. A chest X-ray provides much better information.

     (Fig:2a). A liquid-filled structure, the gallbladder, with posterior enhancement due to low ultrasound attenuation. The walls of the gallbladder cause two lateral shadows.

    (Fig:2b). When liver and ascites are imaged through the ribs, the ribs cast two shadows and there is a layer of reverberation in the ascites .

 Focus of the ultrasound beam

Because the organs or parts of the body that are of interest will be at different depths, the focous of the transducer should ideally be adjustable. If the focal distance is fixed, the most suitable transducer must be chosen for the particular examination. The best choice is described in each section of the manual.

Frequency and resolution

The higher the frequency of ultrasound, the better the resolution . this mean that smaller details become visible when higher frequency is used. however, the penitration of the ultrasound into the body will be less.

         (Fig:2c). Images of uterus made at different scanner frequencies. Quality is best judge by comparing the details of the endometrium. There is reverberating in the liquid-filled urinary bladder............


More posts

How to Preform an Abdominal Ultrasound, Guide for Technician (sonographer)

What is abdominal ultrasound?An abdominal ultrasound is a safe and painless test that uses sound waves to make make images of the abdomen (belly).
During the examination of abdominal area. The black-and-white images show the internal structures of the abdomen such as: LiverGall bladderPancreasSpleenKidneyAppendixIntestineUrinary bladder
Why It's done, Symptoms Abdominal painRepeated vomitingAbnormal liverKidney function testSwollen bellyAbdominal ultrasound test can show the size of the abdominal organs and can help evaluate injuries to or disease of the abdominal organs. Specific conditions that ultrasound can Help Diagnose include:Localized abdominal pain with indefinite clinical featuresAppendicitis (inflamation of the appendix)Non specific abdominal masses such as tumors, cysts, or abscesses Suspected intra- abdominal fluid (ascites)Abdominal trauma.Abdominal ultrasounds also are used to monitor the growth and development of a baby in the uterus during pregnancy. PreparationPreparat…

Gynaecology गैर- गर्भवती महिला श्रोणि (non-pregnant femail pelvis)

 पेल्विस दर्द, जिसमें डिसमेनोरोहे (दर्दनाक मेस्ट्रुटियन) शामिल हैं।श्रोणि द्रव्यमान।असामान्य योनि से खून बह रहा है।असामान्य योनि स्राव।रक्तस्राव (मिस्ड या अनुपस्थित गर्भनाल चक्र)एक गर्भनिरोधक उपकरण की उपस्थिति की जांच करना और उसकी पुष्टि करना।बांझपन: हिस्टेरोसाल्पिंगोग्राफी की हमेशा जरूरत हो सकती है।मूत्राशय या मूत्राशय के लक्षणपेट दर्द फैलाना।बांझपन की जांच में कूपिक निगरानी।scanning technique 
अनुदैर्ध्य स्कैन के साथ शुरू करें, पहले नाभि और जघन सिम्फिसिस के बीच में। फिर, बाद में और अधिक दोहराएं, पहले बाईं ओर और फिर दाईं ओर। एंगल से ट्रांसड्यूसर को साइड से और लॉन्गिटुंडली से गर्भाशय की पहचान के लिए।अगला, ट्रांसवर्सली स्कैन करें। जघन सिम्फिसिस के ठीक ऊपर शुरू करें और नाभि तक ऊपर जाएं। अनुप्रस्थ स्कैन निचले श्रोणि के ऊपर महत्वपूर्ण हैं लेकिन गर्भाशय के स्तर से कम प्रभावी हैं।यदि आवश्यक हो, तो अंडाशय की पहचान करने के लिए रोगी को बारी-बारी से देखें, प्रत्येक अंडाशय को स्कैन करें। पेट के विपरीत पक्ष से, विशेष रूप से।

The pre- pubertal uterus
जैसा कि बच्चा गर्भाशय ग्रीवा के अनुपात …

Abnormal uterus- Abnormal ovary, How to verify the image

Abnormal uterus
Myomas (fibroids)

Myomas appear in various ways on ultrasound examination. Most will be seen as multiple, well defined,homogenous, hypoechogenic, nodular masses, either subserosal or interstitial. Older maymoas become hyperechogenicand some will develop a complex echo pattern as a result of central necrosis. There may be bright echoes from classification. Rapidely growing myomas, as may occur in pregnancy, may simulate hypoechogenic cysts.myomas may also contain calcium, which can present as hyperechogenic structure with distal shadowing. Myomas are almost always multiple and frequently distort the normal contours and the endomaterial canal of the uterus.Myomas can also originate in the cervical part of the uterus and may cause distortion or blockage of the cervical canal.

Developmental variants

A bicornuate uterus may be identified by the presence of two endomaterial canals or two uterine fundi on transverse scans. care must be taken not to confuse a bicornuate uterus wi…