Rapid MRI using a modified Dixon technique: a non-invasive and effective method for detection and monitoring of fatty metamorphosis of the liver.

Fatty liver and non-alcoholic steatohepatitis are frequently associated with obesity. Weight loss is the mainstay of therapy for these conditions. In this case report, we used a modification of the Dixon method to demonstrate normalization of hepatic fat content in an obese individual with fatty liver following weight reduction. This technique involves fast gradient echo instead of spin echo, which has been utilized previously, as the former provides an accurate and more rapid means of assessing hepatic fat content. This technique is recommended for the assessment of hepatic steatosis in at-risk subjects.

A multicenter, randomized, double-blind study to evaluate the safety, tolerability, and efficacy of OptiMARK (gadoversetamide injection) compared with Magnevist (gadopentetate dimeglumine) in patients with liver pathology: results of a Phase III clinical trial.

The purpose of this study was to evaluate the safety and efficacy of OptiMARK (gadoversetamide injection) compared with Magnevist (gadopentetate dimeglumine) in hepatic MRI of patients with suspected liver pathology. A Phase III, multicenter, randomized, double-blind, parallel group study was performed in adults with suspected liver pathology. All patients underwent contrast-enhanced computed tomography within 3 weeks prior to magnetic resonance scanning. Ninety-nine patients received OptiMARK, and 94 patients received Magnevist at a dose of 0.1 mmol/kg. Precontrast T1- and T2-weighted spin-echo imaging and T1-weighted gradient-echo imaging were performed, followed by T1-weighted gradient-echo imaging at 15-20 seconds, 1 minute, and 5 minutes after intravenous contrast injection. Three primary efficacy endpoints (confidence in lesion diagnosis, level of conspicuity, and lesion border delineation) were evaluated on the precontrast image set and compared with the pre plus postcontrast image set. Vital signs, physical examination, electrocardiograms (ECGs), and laboratory parameters (chemistry, hematology, and urinalysis) were measured at various time points. Adverse events were recorded. The study design and statistical analyses were chosen to demonstrate presumed equivalence of OptiMARK and Magnevist. There were no statistically significant differences in efficacy between OptiMARK and Magnevist as assessed by either blinded readers or the on-site principal investigators. No serious or unexpected adverse events were noted. Of the 193 patients receiving contrast media, 82 experienced a total of 154 adverse events. Thirty-three (21.4%) of these 154 adverse events were felt by the on-site investigators to be probably related to either study agent: 15 events in 9 patients in the OptiMARK group, and 18 events in 13 patients in the Magnevist group. Headache was the most common adverse event, occurring in 10.1% of the OptiMARK patients and 12.8% of the Magnevist patients. No clinically relevant trends were observed in any laboratory parameter or ECG findings in either treatment group. The results demonstrate the safety, efficacy, and equivalence of OptiMARK and Magnevist at a dose of 0.1 mmol/kg in hepatic magnetic resonance imaging of patients with suspected liver pathology.

Ophthalmic complications after spinal surgery.

STUDY DESIGN: A retrospective review of 3450 spinal surgeries was performed. OBJECTIVES: To review ophthalmic complications and their etiologies, as well as treatments and outcomes, in patients who have undergone spinal surgery. SUMMARY OF BACKGROUND DATA: Ophthalmic complications after major spinal reconstructive surgery are rare and have not been adequately addressed in the orthopedic literature. METHODS: In a series of 3450 spinal surgeries at three institutions, the authors identified seven patients (incidence = 0.20%) whose postoperative course was complicated by loss of visual acuity. These perioperative ophthalmic complications included posterior optic nerve ischemia, occipital lobe infarcts, and central retinal vein thrombosis. Operative time, estimated blood loss, and medical history of peripheral vascular, cardiovascular, or ophthalmic disease were obtained from the charts, as were follow-up data. RESULTS: Three patients recovered completely, and one had partial return of visual function. In the remaining three patients, significant visual loss persisted. CONCLUSIONS: The risk of ophthalmic complications with spinal surgery has not been fully appreciated. Because ophthalmic complications in spinal surgery may be reversed with prompt recognition and intervention, it is important for clinicians to be aware of their possible occurrence.

Mosaic pattern of hepatocellular carcinoma: histologic basis for a characteristic CT appearance.

PURPOSE: The mosaic pattern is a characteristic CT appearance for hepatocellular carcinoma (HCC). This study was designed to assess the tissue composition responsible for the CT mosaic pattern. METHOD: Gross and whole-mount histologic sections of 10 HCC tumors from eight patients were prepared at identical levels as preoperative CT sections. CT features of the mosaic tumor pattern were spatially registered with the corresponding pathologic sections. RESULTS: CT of mosaic HCC demonstrated enhancing nodules (9/10), low attenuation areas (9/10), and internal septa (3/10). Spatial registration of CT and microscopic sections showed that enhancing tissue was viable tumor in nine of nine. Low attenuation areas were either necrotic (4/9) or of mixed tissue (5/9), including areas of necrosis, fibrosis, and hemorrhage. CONCLUSION: The variable tissue composition of HCC accounts for the mosaic CT pattern. In most patients, enhancing nodules indicate viable tumor cells, and low attenuation areas represent necrosis, fibrosis, or hemorrhage.

Fibrolamellar hepatocellular carcinoma: stage at presentation and results of aggressive surgical management.

OBJECTIVE: The purpose of this study was to report the stage of fibrolamellar carcinoma at presentation and the imaging findings of postoperative recurrent tumor in an aggressively managed population and to assess the implications of those findings relative to the patients' management. MATERIALS AND METHODS: Imaging studies in 10 patients with pathologically proved fibrolamellar carcinoma were reviewed. Preoperative studies included CT (n = 10), sonography (n = 8), and MR imaging (n = 2). Postoperative studies included CT (n = 9), sonography (n = 4), and MR imaging (n = 1). Imaging findings were correlated with clinical and surgical follow-up data. Patients were followed up for 2-75 months (median, 26 months). RESULTS: At presentation, seven (70%) of 10 patients had metastatic lymphadenopathy. Seven patients (70%), including four with lymph node metastasis, had tumor resections with intent to cure. Postoperative imaging studies revealed recurrent tumor in all seven of these patients, including six patients (86%) who had intrahepatic recurrence with or without lymph node metastasis after 6-18 months, and one patient (14%) who had distant metastases 66 months postoperatively. Recurrent lesions were subsequently resected in three (43%) of seven patients, who were disease-free at a mean of 8 months after their second resection. Five patients died after 9 months mean survival, and two patients were alive with residual tumor after 3 months mean follow-up. CONCLUSION: Fibrolamellar carcinomas are often of advanced stage at diagnosis. Recurrence after resection with intent to cure is common. Early and frequent follow-up imaging is necessary for optimizing surgical management in patients with fibrolamellar carcinoma.

CT findings in hepatocellular carcinoma: correlation of tumor characteristics with causative factors, tumor size, and histologic tumor grade.

PURPOSE: To determine computed tomographic (CT) findings of hepatocellular carcinoma (HCC) in a predominantly non-Asian population and to assess any morphologic differences with respect to causative factors, tumor size, and histologic grade. MATERIALS AND METHODS: Clinical history, pathology reports, histologic specimens, and CT findings in 100 patients with HCC were reviewed. All patients underwent contrast material-enhanced incremental dynamic CT. Findings were agreed on by consensus. RESULTS: The mosaic pattern was seen in 46% of cases, venous invasion in 33%, and tumor encapsulation in 31%; frequencies were similar to those reported with Asian patients. A mosaic pattern was more common in patients with larger tumors (P = .036). Venous invasion was more common in patients with alcohol-induced cirrhosis (P = .003) and in those with higher grade tumors (P = .043). Tumor encapsulation was more common in patients with lower grade tumors (P = .012). CONCLUSION: Reported morphologic differences between non-Asian and Asian patients with HCC may be due to differences in underlying liver disease, tumor size, and histologic grade.

Primary linitis plastica carcinoma of the colon and rectum.

Linitis plastica carcinoma of the colon and rectum is a relatively rare primary colorectal malignancy. The initial diagnosis of this disease is often difficult, and its eventual prognosis is poor. In this report, we describe a case of primary linitis plastica of the rectum in a 57-yr-old American Indian. This case is unique since it represents the first documentation of a primary rectal lesion with metastases to the stomach. The current literature is reviewed with examination of the clinicopathologic features of this neoplasm.