Detection of focal hepatic lesions: effects of superparamagnetic iron oxide (AMI-25) on magnetic resonance imaging of the liver using T2-weighted fast spin-echo sequences and gradient-and-spin-echo sequences at 1.0 tesla.
Jung G. Krahe T. Kugel H. Gieseke J. Walter C. Lackner K.
Department of Radiology at the University of Cologne, Germany.
RATIONALE AND OBJECTIVES: The authors evaluate the value of two fast spin-echo sequences (FSE) with different T2-weighting (repetition time [TR]/echo time [TE] = 2000/90 mseconds and TR/TE = 2000/40 mseconds) and combined gradient-and-spin-echo sequences (TR/TE = 2000/90 mseconds) for contrast-enhanced liver imaging with superparamagnetic iron oxide (AMI-25). METHODS: Forty-seven patients with focal liver lesions underwent magnetic resonance imaging at 1.0 tesla. AMI-25 was administered intravenously at a dose of 15 micromol iron/kg. RESULTS: Administration of AMI-25 resulted in a significant increase of lesion/liver contrast-to-noise ratio (C/N) for all T2-weighted sequences (P < 0.001). On the precontrast images, the FSE sequence with a TE of 90 mseconds had the highest C/N (16.0 +/- 4.5) whereas the best postcontrast C/N (27.9 +/- 7.6) was obtained with the mild T2-weighted FSE sequence with a TE of 40 mseconds. CONCLUSIONS: Fast spin-echo sequences are valuable sequences for imaging of the liver at 1.0 tesla. For AMI-25-enhanced magnetic resonance imaging, a mild T2-weighted FSE sequence is recommended.
Transrectal ultrasonography in evaluation of chronic rectal complications after radiation therapy for carcinoma of the uterine cervix.
Shiojima K. Mitsuhashi N. Yamakawa M. Sakurai H. Niibe H.
Department of Radiology and Radiation Oncology, Gunma University School of Medicine, Maebashi, Japan.
RATIONALE AND OBJECTIVES: The authors studied the ability of transrectal ultrasonography (TRUS) to assess chronic rectal complications after radiation therapy for carcinoma of the uterine cervix. METHODS: One hundred twenty-five TRUSs were performed for 67 consecutive patients with carcinoma of the uterine cervix. Transrectal ultrasonography images of the rectal anterior wall and perirectal connective tissue adjacent to the uterine cervix were recorded with real-time scanner with 7.5 MHz transducer. The severity of TRUS abnormalities was graded on a scale developed by the authors. The relationships of the TRUS grade with the clinical grade of chronic rectal complications and with rectal radiation doses were analyzed retrospectively. RESULTS: Thickening of the perirectal connective tissue associated with obscuration of the submucosal echogenic layer in rectal anterior wall was observed between 6 months to 2 years after radiation therapy in all 19 patients who developed chronic rectal complications. The TRUS grade correlated with the clinical grade of chronic rectal complications, but did not correlate with rectal radiation doses. CONCLUSIONS: Transrectal ultrasonography can monitor the chronic rectal complications after radiation therapy for the patients with carcinoma of the uterine cervix.
Biphasic spiral computed tomography for detection of hepatocellular carcinoma before resection or orthotopic liver transplantation.
Lopez Hanninen E. Vogl TJ. Bechstein WO. Guckelberger O. Neuhaus P. Lobeck H. Felix R.
Department of Radiology, Virchow Clinic, Humboldt University, Berlin, Germany.
RATIONALE AND OBJECTIVES: The authors correlate computed tomography (CT) findings in biphasic spiral technique with histopathology in patients with hepatocellular carcinoma (HCC) who had undergone liver resection (LR) or orthotopic liver transplantation (OLT). METHODS: Preoperative biphasic spiral CT findings in 33 consecutive patients (23 men, 10 women, aged 43-74 years; LR group: n = 17; OLT group; n = 16) with liver cirrhosis and HCC were reviewed retrospectively by consensus of two radiologists and correlated with pathology from liver specimens. RESULTS: Of the 16 patients in the OLT group with 1 to 5 confirmed HCC lesions (total lesions: 29; mean lesion diameter: 2 cm; range: 0.6-5.0 cm), CT before OLT depicted 22 lesions in 15 patients (sensitivity for lesions with a diameter of 0.5-1.0 cm, 20%; for lesions 1.1-2.0 cm, 82%; and for lesions 2.1-3.0 cm and > 3.0 cm, 86% and 100%, respectively). Among the 17 patients in the LR group (total lesions: 21; mean lesion diameter: 5.4 cm; range: 1.0-11.0 cm), CT detected 18 lesions. Lesion-by-lesion sensitivity, as correlated with pathology, was calculated at 76% and 86% in the OLT and LR groups, respectively (overall sensitivity, 80%). The diameter of CT detected lesions, compared with liver specimens, corresponded in 90% of lesions (maximum deviation, 15%). Characteristic CT findings of HCC included unenhanced hypoattenuating focal liver lesions (32 lesions), with hyperattenuation (38 lesions) in the arterial phase of contrast material administration. CONCLUSIONS: Biphasic spiral CT for preoperative HCC detection correlated with pathology in 80%, thus proving this technique to represent a sensitive imaging modality for pretherapeutic evaluation of HCC.