Search PubMedSearch

PubMed · 8298870

What is the nephrogram?

Abstract

One of the oldest questions in radiology, "what is the nephrogram?", has been approached in a novel manner using dynamic bolus contrast enhanced computed tomography to monitor the arrival and distribution of contrast agent in the normal kidney. A modification of a mathematical technique first developed for applications in positron emission tomography has been used to analyse the data. It is concluded that the blood pool contribution to the nephrogram is greater in the first minutes after rapid bolus contrast injection than generally supposed and that the "immediate" nephrogram is a predominantly blood pool contrast phenomenon.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P Dawson, A M Peters. 1994. What is the nephrogram?. https://doi.org/10.1259/0007-1285-67-793-21

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Successful balloon dilation of an abdominal coarctation of the aorta in patient with presumed Takayasu's aortitis.

An 11-year-old male with a severe abdominal aortic coarctation, presumably secondary to aortitis, underwent successful percutaneous balloon dilation that resulted in near-complete relief of the obstruction. Intravascular ultrasound imaging showed a major endovascular tear immediately following dilation and satisfactorily excluded significant branch (superior mesenteric) artery compromise. Arterial remodeling was demonstrated with persistence of the gradient relief over a 12-month follow-up period.

Aorta, Abdominal

Complement activation and subclassification of tissue immunoglobulin G in the abdominal aortic aneurysm.

Features of autoimmunity in abdominal aortic aneurysm (AAA) have been described, including increases in IgG content. The present experiments were carried out to determine (1) whether the increases in IgG are subclass specific and (2) whether the IgG complex is associated with an increase in the isoforms of complement C3. Seven AAA, four athero-occlusive (AOD), and two normal (NL) aortic tissue extracts were evaluated for immunoreactive complement (C3) components, both by ELISA and by Western immunoblots (probed with a polyclonal goat anti-human C3). The extracts were also assayed for each of the four subclasses of IgG by ELISA (monoclonal mouse anti-human IgGs). Compared to the amounts of IgG by subclass in normal aorta, AAAs had increases of 193-fold in IgG1, 160-fold in IgG2, 389-fold in IgG3, and 627-fold in IgG4. Increases relative to AOD by subclass were smaller, but each subclass was statistically significantly elevated (P < 0.01) over NL or over AOD. There was a 125-fold increase in immunoreactive C3 by ELISA in AAA vs NL, and Western immunoblotting techniques revealed the presence of multiple C3 degradation products. Increases in IgG1, 2, and 3 may be responsible for activation of complement in AAA by the classical pathway. Since the complement system is one of the major effector pathways of inflammation, the presence of complement-fixing IgG subclasses along with increased C3 in the aneurysm wall may be an important mechanism promoting matrix proteolysis in AAA.

Aorta, Abdominal