Diagnostic Modalities Radiologic Procedures

Small Bowel Series/Enteroclysis

The overall yield of barium examination of the small bowel is extremely low. These techniques are employed after negative enteroscopy or when enteroscopy is not immediately available. In the absence of obstructive symptoms, small bowel follow-through (SBFT) leads to a diagnosis in about 5% of patients with OGIB. The yield with enteroclysis, although better (about 10%), is still minimal, because these methods are inadequate for detecting mucosal lesions like vascular ectasia, which are overwhelmingly the most frequent cause for small bowel bleeding. Comparison of WCE with small bowel enteroclysis in patients with OGIB has shown the superiority of WCE for the detection of lesions (Liangpunsakul et al, 2003).

Radionucleotide Studies

Scintigraphy with technetium-labeled red blood cells may help to confirm hemorrhage that may be originating in the small bowel; however, it does not accurately locate the site of bleeding. Despite high sensitivity for detection of bleeding (positive if bleeding is less than or equal to 0.1 mL/min) (Alavi, 1982), its low specificity limits its usefulness. Its role, therefore, continues to be controversial. Delayed scans, performed at 12 to 24 hours postinjection, may be misleading by identifying luminal blood that is pooled at sites other than the bleeding source. The Meckel's scan is based on an isotope labeled compound that localizes in the ectopic gastric mucosa found in Meckel's diverticulum. As this isotope normally accumulates in the stomach and bladder, both should be empty at the time of examination to increase its diagnostic yield. Increased sensitivity is achieved by using histamine-2 receptor antagonists, which causes increased activity in the ectopic parietal cells. This test has a more specific role in the examination of patients with OGIB who are below the age of 40 years.

Angiography

Selective mesenteric angiography is expensive and invasive, yet offers both diagnostic and therapeutic modalities. Although it is not as sensitive to low rate or intermittent bleeding as bleeding scans (rate 0.5 to 1 mL/min), angiography has the potential ability to localize and treat bleeding lesions. Provocative maneuvers performed at the time of exam include the use of anticoagulants and/or vasodilators, both of which may precipitate bleeding and improve the diagnostic yield of angiography. The large arcade of mesenteric vasculature makes identification of smaller vascular ectasia difficult. The use of nuclear scans to select those actively bleeding patients who will undergo angiog-raphy is controversial but may improve diagnostic yield and lower overall cost by avoiding unnecessary exams.

Constipation Prescription

Constipation Prescription

Did you ever think feeling angry and irritable could be a symptom of constipation? A horrible fullness and pressing sharp pains against the bladders can’t help but affect your mood. Sometimes you just want everyone to leave you alone and sleep to escape the pain. It is virtually impossible to be constipated and keep a sunny disposition. Follow the steps in this guide to alleviate constipation and lead a happier healthy life.

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