Abdominal Masses In Pediatric Age Group Ultrasound Versus Computed Tomography:

Manal Hussien El-mahdy

A review of the classification of abdominal masses in infants andchildren, and the different radiological and imaging techniques used intheir investigation was included and discussed in this work.Infants and children with varieties of abdominal masses wereinvestigated using various imaging modalities. The diagnosis wasconfirmed by laboratory and pathological studies.Study of the obtained images of different modalities was carriedout. The correlation between the role of ultrasound and the role of CTin confirming, characterization and staging of the pediatric abdominalmasses was also made.It was found that each mass has a specific radiological andimaging fmdings by ultrasound and computed tomography. The valueof each of them was discussed.Plain film for the abdomen was helpful to show soft tissuetumification, calcification and stone formation. Excretory urography,including lateral film, should be the first examination to start with in allcases of abdominal masses, to evaluate the function of each kidney andprovide a map for ultrasonography. It is very valuable also in mostcases of retroperitoneal and pelvic masses, especially those of renalorigin. It could give an idea about the kidneys and ureters before any .surgical interference.Ascending cystography is indicated if excretory urographyreveal an element of lower urinary tract obstruction or vesico-uretericreflux.-102rr-------------------SUMMARY--Ultrasound is usually done after excretory urography in renalmasses.It is done first in suspected non functioningkidneys or hepaticmasses. If the mass is far anterior in the abdomen and/or associatedwith gastrointestinal vomiting or bleeding, ultrasound is the appropriatestudy followed by barium series.At last cr comes if the diagnosis of the abdominal mass is notclarified, especially if the retroperitoneum is not clear by ultrasound.In the correlation between ultrasound and CT, it is found that CTis superior to sonography in detecting retroperitoneal masses, localizingthe lesion in relation to the facial compartments; and determining theextent of the disease; because the retroperitoneum is obscured fromultrasound beam by bowel gas, fat.It is found also that CT is much higher superior in demonstrationof adrenal gland lesions. It is difficult in some circumstances byultrasound because of the relatively small size of these glands. Also,because of their deep location in the retroperitoneum and the proximityto large organs.It was noted also that CT can provide good anatomical detailsespecially if thin slices are selected on the region of interest. CTproduces only axial sections whereas US can take views in any desiredplane.On the other hand, US is much more available, more cheap, stillhas no harmfu1 effect and has no contraindication. It has also theadvantage of possible serial examination. Ultrasound is operatordependent, has wide variations in technical quality with differentexaminers and with poor bowel images because yet there is no UScontrast material available.-103-------------------SUMMARY--It was noted also that the classical limitations for US such asextensive bowel gas, obesity, ascites, residual barium, wounds anddrains is not a limitationfactor in CT.CT with enhancement can be utilized for staging of malignantmass lesions, and its extension into adjacent tissues, including theinferior vena cava.The development of new technology has led to suggest asensible, rational approach that can be used in selecting appropriateimaging studies for a child with a mass. In order to provide optimalcare to the child with the least expense and trauma, the referringphysician and the radiologist must make these imaging decisions onlyafter careful integration of all clinical and imaging data.Although both US and CT modalities were accurate, each has itsparticular advantage of specific problems. On the other hand each ofthem had its limitations. Knowing the efficiency and limitations of USand CT is the key to their use.Optimally US and CT scanning are complementary to each otherin the evaluation of pediatric abdominal masses. US appears to be thebest method for screening and follow up in patients with abdominalmasses. CT adds anatomical information which is of great value inplanning the surgical approach or in confirmingthe nature of the lesionprior to surgery in different cases. The flexible complementary use ofthese modalities affords the potential for increasing the diagnostic yieldin pediatric abdominal masses.Thorough clinical examination is very helpful in the choice of the firstdiagnostic procedure.-104--11--···--------------------SUMMARY--Plain x- ray remains an important diagnostic tool of abdominalmasses. US & CT are cansidered excellent diagnostic madalities fordiagnosing abdominal masses in children and infants.US is less expensive and has no hazards of hypothermia, US isadviced as a primary diagnosic procedure for abdominal masses. CT isdecided if necessary.