Focal nodular hyperplasia: imaging findings.

Focal nodular hyperplasia is an uncommon benign hepatic tumor that continues to pose diagnostic dilemmas. Imaging techniques are of great value in diagnosis of this tumor. In this article we present the US, CT, MR imaging, scintigraphy, and angiography findings. The demonstration of a central vascular scar is very helpful. Although the radiologic features may be diagnostic, many atypical cases must be differentiated from other benign or malignant hepatic tumors. In these cases excisional biopsy and histopathologic examination are necessary to determine a definite diagnosis.

Comparison of CT, MRI and CT during arterial portography in the detection of malignant hepatic lesions.

BACKGROUND/AIMS: A prospective study was performed to compare the sensitivities of computed tomography, magnetic resonance imaging and CTAP (CT during arterial portography) in the detection of focal malignant hepatic lesions. METHODOLOGY: Twenty-eight (28) patients with primary and secondary hepatic malignant tumors were evaluated. All of these patients underwent hepatic resection and a lesion-to-lesion imaging-pathological analysis was performed. RESULTS: The overall sensitivities were 53% for CT, 66% for MRI sequences and 88% for CTAP. For lesions smaller than 1 cm the sensitivities were 6% for CT, 17% for MRI and 72% for CTAP. The combination of CTAP and MRI yielded an overall detection rate of 93%. The difference between the sensitivity of CTAP and that of the other two imaging techniques was statistically significant (P < 0.04) according to the McNemar test. CTAP demonstrated four false-positive lesions, two of which were correctly characterized by MRI and one by CT. In 6 patients (21.4%) the surgical plan was modified after CTAP. CONCLUSIONS: We conclude that, CTAP has the highest sensitivity and should be part of the preoperative examination. In some instances, the addition of MR imaging must be considered a helpful adjuvant. Both techniques should be considered complementary in the preoperative diagnostic algorithm.

A comparative study between Gd-DTPA and oral magnetic particles (OMP) as gastrointestinal (GI) contrast agents for MRI of the abdomen.

In the present study we compared two gastrointestinal contrast agents--Gd-DTPA, a positive signal, and oral magnetic particles (OMP), a negative signal contrast agent--in patients who were referred for MR imaging of the abdomen. Altogether 60 patients were examined with the former and 28 patients with the latter contrast before and after the administration of contrast media. Gd-DTPA was given either per os or per rectum. In comparing the results, it was shown that the diagnostic accuracy of postcontrast MRI in both groups was more or less similar to CT but much higher as compared with plain MRI. In the OMP series, first the contrast between the GI-filled lumen and the surrounding fat was much superior to that of the Gd-DTPA and, second, there was no evidence of any artifacts from bowel motion. However, the overall accuracy of the Gd-DTPA group was better compared with that of the OMP group. This was due to underfilling of the distal bowel because the OMP in those patients was administered only per os. Finally, Gd-DTPA had a more pleasant taste and fewer side effects. It is concluded that both contrast media are suitable for the upper abdomen because the results are comparable, whereas for the lower abdomen Gd-DTPA is superior because it can be used from both routes.

Familial holoprosencephaly associated with a translocation breakpoint at chromosomal position 7q36.

A familial balanced t(7;9) (q36;q34) was reported recently. Analysis of the craniofacial features of 3 of the sibs showed signs of holoprosencephaly. Two of the sibs have an unbalanced derivative chromosome leading to del(7) (q36) and dup(9) (q34), while the other has a cytogenetically balanced translocation. These findings, together with several reports associating holoprosencephaly with terminal 7q deletions, indicate that a putative locus for holoprosencephaly resides at or near 7q36. It should now be feasible to clone this locus.