Ischemic Colitis: Tc-99m HMPAO Leukocyte Scintigraphy and Correlative Imaging

Abstract

A 62-year-old woman became progressively ill after aorto-bifemoral graft surgery. A Tc-99m hexamethylpropyleneamine oxime (HMPAO) leukocyte scan was performed because of fever and suspected graft infection. The anterior abdominal and pelvic views demonstrated marked uptake within the sigmoid colon. Follow-up studies, including CT scan and contrast intestinal x-rays, confirmed the presence of an abnormal sigmoid loop. Subsequent surgical resection and pathological examination of the sigmoid colon revealed ischemic changes. To our knowledge, detection of ischemic colitis using Tc-99m HMPAO labeled leukocytes has not been reported. Clinical and routine radiological findings of ischemic colitis are typically nonspecific and may result in delayed diagnosis that can lead to high mortality. Tc-99m HMPAO leukocyte scintigraphy may be helpful in the noninvasive diagnosis of ischemic injury to the colon, especially after aortic graft surgery.

Ischemic colitis: Clinical practice in diagnosis and treatment

“…In-111 or Tc-99m-labeled leukocyte scintigraphy has been studied and has demonstrated successful imaging of bowel infarction while Tc-99m(V) DMSA was recently found to have no role in the detection and diagnosis of IC [43][44][45] .…”

Is there a role for Tc-99m (V) DMSA scintigraphy in ischemic colitis?

“…In-111 or Tc-99m labeled leukocyte scintigraphy has been studied and demonstrated successful imaging of bowel infarction, yet the localization mechanism still remains unclear. It is suggested that the presence of polymorphonuclear leukocytes in the inflammatory response to tissue ischemia, as a result of reperfusion injury may play the primary role [9][10][11][12] . However, the time-consuming preparation procedure, the handling and the reinjection of blood constitute shortcomings of radiotracer labeled leukocyte imaging.…”

“…Since mucosal inflammatory changes often coexist with bowel ischemia, radiotracers used to localise inflammation could probably play an important role in the diagnosis of IC. A few reports of the scintigraphic findings using radionuclide labelled leukocytes have been published [9][10][11][12] . Moreover, recently pentavalent Tc-99m dimercaptosuccinic acid [Tc-99m (V) DMSA] has been successfully used in the identification of intestinal inflammation [13][14][15] .…”

Der Einsatz radioaktiv markierter Leukozyten bei entzündlichen Darmerkrankungen

“…Wichtig ist, dass der Granolozytenuptake im entzündeten Darm unspezifisch ist. Mehranreicherungen wurden beschrieben bei einer Reihe von infektiösen [15], ischämischen [16] und vaskulitischen [17] Erkrankungen, so dass eine positive Szintigraphie bei den Patienten mit z. B. unerklärlicher persistierender Diarrhöe nicht notwendigerweise durch eine entzündliche Darmerkrankung verursacht sein muss.…”