MRI contrast media: What clinicians need to know.

Magnetic resonance imaging (MRI) is an imaging modality that uses the differential spinning of protons (hydrogen) in the body when exposed to an external magnetic field, to produce crosssectional images of the body. The advent of MRI is a boon to mankind as it does not involve ionizing radiation and provides superior soft tissue contrast even without administration of contrast media. The contrast media used in MRI were developed many years after MRI was already in use, the first being gadopentetate dimeglumine—a non-specific extracellular gadolinium chelate. Extracellular agents are the most widely used, although tissue-specific agents have been developed and are used as problem-solving tools in specific conditions. Tolerance to gadolinium-based contrast agents is excellent. The tissue-specific agents do have some adverse effects, though none of them are life-threatening. However, identification of a condition called nephrogenic systemic fibrosis has forced a rethink about the liberal usage of MRI contrast agents.

Endovascular management of hepatic hemorrhage and subcapsular hematoma in HELLP syndrome.

Spontaneous intrahepatic hemorrhage with or without subcapsular extension is a rare and grave complication of pregnancy. We present a 22-year-old lady in whom liver rupture was noted on emergency caesarian section and later confirmed on contrast-enhanced CT scan. She gradually recovered following selective hepatic angiography and embolization.

Imaging findings in hepatic Langerhans' cell histiocytosis.

We describe ultrasonographic and computed tomographic features of hepatic lesions in two cases of disseminated Langerhans' cell histiocytosis affecting children. In the first case, hyperechoic band like periportal lesions were observed at ultrasonography, which on computed tomography was found to be hypodense admixed with fatty attenuation (HU@23 to - 57) at places. In addition, the caudate lobe was very prominent. In the second case, the hepatic parenchyma showed predominantly hyperechoic diffusely heterogeneous echogenicity. There were features of cirrhosis of liver with portal hypertension in the form of atrophy of right lobe with hypertrophy of left lobe of liver with lobulated outline, prominent main portal vein and splenoportal axis, splenomegaly and gastroesophageal varices. Both the patients were put on chemotherapy as per schedule (Protocol: DAL HX - 83) and are on follow up.