Search

A case of hepatocellular carcinoma is reported in which a calculated T2 value of the tumor was exceptionally long and differentiation from cavernous hemangioma based on T2 signal intensity was difficult. Pathologically, the mass consisted of dense, homogeneous acinar formation (pseudoglandular type). The T2 prolongation of the mass was probably due to abundant fluid in the acini.

We report an unusual case of multilocular cystic hepatocellular carcinoma. The patient was a 42-year-old woman without liver cirrhosis but who had three multicystic mass lesions in the liver. Transcatheter arterial embolization was very effective and a survival time of more than 19 months was obtained.

Computed tomography (CT) was performed after 65 transcatheter arterial embolizations (TAE) in 50 patients with hepatocellular carcinoma. Nonenhanced high-density areas were seen in the tumors within 3 days in 17/25 cases (though they soon disappeared) and low-density areas within 2 weeks in 62/65. Gas bubbles were seen in these areas within 2 weeks in 60% of embolizations. Within 3 to 6 months after the first TAE, enhanced lesions developed around or inside the low-density areas in 15/22 patients. Complications appearing within 2 weeks included non-enhanced low-density areas in the liver and spleen, gallbladder thickening, swelling of the head of the pancreas, contrast retention in the kidneys and gallbladder, ascites, and pleural effusion.

Seventy-two patients with hepatocellular carcinoma (hepatoma) and 56 with hemangioma were studied with magnetic resonance (MR) imaging at 0.35 or 1.5 T to evaluate the efficacy of T2 values in differential diagnosis. T2 values were calculated with the two-point method. The mean T2 values of hepatoma and hemangioma were 58.9 msec +/- 8.9 and 101.6 msec +/- 25.8 at 0.35 T and 49.1 msec +/- 9.8 and 85.3 msec +/- 21.2 at 1.5 T. The difference in the T2 values for hepatoma and hemangioma was statistically significant (P less than .001) at both 0.35 and 1.5 T. Fifty-three of 56 lesions (94.6%) at 0.35 T and 86 of 102 lesions (84.3%) at 1.5 T were correctly classified when the T2 borderline between hepatoma and hemangioma was set at 80 msec. All misdiagnosed lesions were hemangioma, and all but one were smaller than 2 cm. However, over 90% of lesions smaller than 2 cm were correctly diagnosed when 70 msec at 0.35 T and 60 msec at 1.5 T were used as borderline T2 values. MR imaging with T2 measurement was very useful for differentiating between hepatoma and hemangioma (including small lesions) at 1.5 T as well as at 0.35 T.

This report describes the magnetic resonance (MR) demonstration of portal vein tumor thrombus (PVTT) in hepatocellular carcinoma (HCC). In two cases of HCC with PVTT diagnosed by angiography, MR demonstrated PVTT as areas of increased MR signal in the portal vein. Our limited experience suggests the potential utility of MR imaging for diagnosis of PVTT.

Transcatheter arterial embolization (TAE) was performed in 20 patients with ruptured hepatocellular carcinoma (HCC). Bleeding was improved in all patients, but only four survived for over three months. Rerupture occurred in seven patients (35%) and the prognosis was extremely poor. TAE should be considered the treatment of choice for ruptured HCC; however, long-term survival was limited to those patients without portal extension of HCC. The severity of rupture also influenced the prognosis.

Thirty-six patients with hepatic tumors (28 hepatocellular carcinomas, seven cavernous hemangiomas, one metastatic tumor) were examined with serial magnetic resonance (MR) imaging, after a bolus intravenous injection of 0.05 mmol/kg gadolinium-diethylenetriaminepentaacetic acid. A typical MR imaging pattern for hemangiomas (present in five of seven cases [71.4%]) was a lesion of diminished signal intensity on precontrast images, peripheral contrast enhancement during the bolus dynamic phase, and complete fill-in of high signal intensity on delayed scan images. Twenty-eight hepatocellular carcinomas showed a variety of contrast enhancement patterns during the dynamic phase. In 21 patients (75%), there was no area of high signal intensity within the tumor on the delayed phase. A peripheral halo with delayed enhancement was noticed in 12 patients (42.8%) Histologic correlation in hepatocellular carcinomas showed that the degree of contrast enhancement corresponded to tumor vascularity and that the peripheral halo corresponded to fibrous capsular structure.

Dynamic magnetic resonance imaging (MRI) was performed in two patients with hepatic tumors (one cavernous hemangioma and one hepatoma). A sequential timed scanning technique with spin echo images (TR: 100 msec; TE: 20 msec; data acquisition time: 26 sec) was used with a bolus injection of 0.05 mmol/kg gadolinium DTPA. Dynamic MRI findings in the two cases were similar to those obtained with dynamic CT and angiography using iodinated contrast medium. Our early experience suggested that the less invasive technique of dynamic MRI could replace conventional dynamic CT in assessing the hemodynamics of hepatic tumors.

Forty-two patients with hepatocellular carcinoma (hepatoma) and 18 patients with hemangioma were studied with MR imaging at 1.5 T to evaluate the efficacy of single-slice breath-hold FLASH (fast low-angle shot) images in distinguishing between the lesions and to compare with T2 differentiation using conventional spin-echo images. The difference between mean tumor-to-liver signal ratio on FLASH imaging of hepatocellular carcinoma (1.46 +/- 1.06) and hemangioma (0.86 +/- 0.45) was statistically significant (p less than .01). Fifty-one (82%) of 62 lesions were classified correctly when the borderline of tumor-to-liver signal ratio between hepatoma and hemangioma was set at 0.9. The mean T2 values of hepatomas and hemangiomas were 48 +/- 10 msec and 89 +/- 20 msec, respectively. Fifty-seven (92%) of 62 lesions were correctly diagnosed with the T2 borderline of 80 msec. The five misdiagnosed lesions with the T2 borderline were hemangiomas smaller than 2 cm with tumor-to-liver signal ratios less than 0.9. FLASH images appear promising for differentiating between hepatoma and hemangioma, and they complement T2 values in characterizing small lesions.

The magnetic resonance findings of two hepatomas treated by embolization are presented. The T2-weighted spin echo images showed an increase in signal intensity in the tumor after embolization. This phenomenon corresponded to a decrease in tumor density on CT and to necrosis observed histologically. Magnetic resonance also demonstrated gas bubbles as low signal foci within the embolized tumor.

In 6 patients with spontaneous rupture of hepatocellular carcinoma complicating liver cirrhosis, but with no occlusion of the main portal trunk, transcatheter arterial embolization was performed within 7 days of the rupture. All 6 patients were thought to be inoperable because of shock state or severe hepatic dysfunction. In all 6 patients, the progressive decrease in the hematocrit ceased soon after the embolization. Five patients survived for 31-168 days after the embolization; 1 patient who developed septicemia died 10 days later. We conclude that transcatheter arterial embolization is beneficial as a procedure of first choice for ruptured hepatocellular carcinoma when the portal blood flow is maintained.

Among 224 hepatomas treated with transcatheter arterial embolization, ten patients who survived for three years are presented. All cases had nodular lesions and the volume ratio of tumor to liver was less than 10% in nine cases. Eight cases had no large venous extension, however, one had 90% occlusion of the portal trunk and the other had tumor thrombus within the inferior vena cava. Laboratory data showed liver function was largely spared in eight cases, whereas the other two had severe liver cirrhosis. CT and/or angiography showed an increase in tumor volume in eight cases after three years of survival. Beneficial factors for long-term survival and the limitations of embolization are also discussed.

Fifty-three patients who had hepatic tumors (24 hepatomas, ten metastases, and 19 cavernous hemangiomas) underwent MR imaging using a 0.35-T superconducting imager. The transverse relaxation time (T2) was calculated from a pair of spin echo images (repetition time [TR] of 1600 msec) with echo delay times (TE) of 35 and 70 msec. The computed T2 value was obtained in a fashion similar to that used to obtain CT numbers with region-of-interest cursors. The mean T2 was 59 +/- 9 msec in hepatomas, 64 +/- 15 msec in metastases, and 100 +/- 30 msec in hemangiomas. The difference between the T2 of hemangioma and that of liver malignancies was statistically significant (P less than .001); however, differentiation between hepatoma and metastases was not possible. The T2 was shorter than 80 msec in all 24 hepatomas and in nine of ten metastases, and was longer than 80 msec in 16 of 19 hemangiomas. Forty-nine of 53 cases (92%) were correctly classified when the borderline of T2 between hemangioma and hepatic malignancies was set at 80 msec. MR with T2 calculation was valuable in differentiating between hemangioma and hepatic malignancies.

In seven primary liver cancers (HCC 5, CCC 1, mixed 1), MR images (0.35 Tesla super-conducting) were compared with macroscopic appearances, and relaxation times (T1 and T2) with microscopic characteristics. MRI was able to reveal the gross appearance of five nodular lesions, but did not reveal one diffuse HCC and one nodular HCC with marked extracapsular extension. T2-weighted SE images could not demonstrate fibrous capsules around the tumor in four nodular HCCs. The T1 and T2 values of the tumors were longer than those of the surrounding liver parenchyma, and the T1 elongation corresponded roughly to the degree of necrosis and fibrosis within the tumors.

Early experience in magnetic resonance (MR) images of the liver tumors is reported, based on 25 cases examined by a 0.35T superconducting machine (Magnetom, Siemens) using the spin echo technique. All main liver tumors were demonstrated as high intensity areas of varying degree in the spin echo image with a TR of 1,600 msec and a TE of 70 msec. All of them had prolonged T2 and T1. The smallest lesion detected on MR was 0.8 cm in diameter in the cases of multiple liver cysts and 1.5 cm in the cases of a solitary solid tumor. Normal vasculature of the liver was well-delineated, despite a far longer acquisition time compared with respiratory holding period. MR is a promising modality for liver imaging.