Michael E. Bernardino

Computed tomography of hepatic morphologic changes in cirrhosis of the liver.

Computed tomography of 75 biopsy proven cirrhotic patients was analyzed volumetrically and compared with CT on 50 normal subjects in an attempt to quantitate hepatic morphologic changes specific for cirrhosis. Our data show that the mean percentage of the total liver volume occupied by the right hepatic lobe decreased by 15.2% (p less than 0.0001) and the mean percentage of the total liver volume occupied by the medial segment of the left lobe decreased in volume by 10.9% (p less than 0.09) when compared with normals. Concomitantly, the mean percentage of the total liver volume occupied by the caudate lobe increased by 192% (p less than 0.0001) and the mean percentage of the total liver volume occupied by the lateral segment of the left lobe increased by 55.6% (p less than 0.0001). This increase in the volume of the lateral segment of the left lobe and decrease in the volume of the medial segment of the left lobe have not been described previously. The cirrhotic patients were divided according to etiology of their disease: alcoholic or nonalcoholic. No statistically significant difference was found in the morphologic changes based on etiology when the data were examined using analysis of variants.

Computed Tomographic Arteriography of the Liver

Computed tomographic arteriography (CTA) of the liver performed during intra-arterial infusion of contrast material improved the detection of hepatic lesions in 10 of 12 patients and was the only method that accurately determined the extent of disease in 6. This technique has significant advantages over conventional hepatic computed tomography with or without intravenous contrast enhancement, or selective hepatic angiography. It is recommended in the evaluation of selected patients, especially when there is a discrepancy between the findings obtained by other methods.

Percutaneous needle biopsy in the diagnosis and classification of lymphoma

Results of percutaneous needle biopsies were evaluated retrospectively in 58 patients in whom a diagnosis of lymphoma was suspected. The biopsy specimen was diagnostic in 94% of the 36 patients with lymphoma, 20 of whom had recurrent disease and 16 of whom had newly diagnosed lymphoma. Sufficient tissue was obtained in 94% of these positive biopsy specimens to allow histologic subtyping of the lymphoma. Immunohistochemical studies performed on seven of the biopsy specimens allowed immunologic subclassi‐fication into B‐cell and T‐cell types of lymphoma. Our results suggest that the percutaneous needle biopsy is a useful and reliable tool in the diagnosis and classification of lymphoma.

Hepatic iron overload: diagnosis and quantification by noninvasive imaging.

The diagnostic efficacy of magnetic resonance (MR) and computed tomography (CT) for detection and quantification of hepatic iron was assessed in a series of patients under investigation for clinical or biochemical evidence of hepatic iron overload. Thirty patients underwent MR imaging (SE 30,60/1000 or SE 30,60/2000) at 0.5 Tesla with calculation of hepatic T2 and liver to paraspinous muscle signal intensity ratios. Twenty-nine patients also had measurement of hepatic attenuation on noncontrast CT images. Results of these imaging studies were correlated in all patients with quantitative iron determination from liver biopsy specimens. The best predictor of liver iron among parameters studied was the ratio of the signal intensities of liver and paraspinous muscle (L/M) on a SE 60/1000 sequence. Both MR using L/M ratios and CT were sensitive methods for detection of severe degrees of hepatic iron overload with 100% of patients with hepatic iron on biopsy > 600 Μg/ 100 mg liver dry weight detected on the basis of L/M <0.6 or CT attenuation >70 Hounsfield units (HU). The MR parameter, however, was more specific than CT (100 vs 50%) and showed a higher degree of correlation with quantitated hepatic iron from biopsy. T2 measurements showed poor correlation with hepatic iron, due to difficulty in obtaining precise T2 measurements in vivo when the signal intensity is low. None of the parameters utilized was sensitive for detecting mild or moderate degrees of hepatic iron overload.We conclude that MR and CT are sensitive techniques for noninvasive detection of severe hepatic iron overload, with MR providing greater specificity than CT. Lesser degrees of iron deposition, however, may go undetected by our current imaging techniques.

Percutaneous renal biopsies: accuracy, safety, and indications.

Fifty-one percutaneous renal needle biopsies were performed on 46 patients. Initial biopsy was adequate for diagnosis in 89% of patients. When a second biopsy was performed, this accuracy increased to 98%. Thirty-four of 51 (67%) biopsies were for renal masses and 17 (33%) for medical indications. Computed tomographic guidance was utilized in 94% of cases. Biopsies of renal masses were performed with 18-21-gauge needles, while biopsies for medical indications were performed with an 18-gauge cutting needle or 14-gauge Trucut. A rate of serious complications of 6% was noted.

The computed tomography‐guided adrenal biopsy: An alternative to surgery in adrenal mass diagnosis

A series of 16 patients with adrenal masses were biopsied percutaneously under computed tomography (CT) guidance with 18‐ to 22‐gauge modified Chiba needles. Adrenal adenomas, cysts, metastases, melanoma, and adrenal hemorrhage were identified. Of nine oncologic patients, four had adrenal metastases, while five had other nonmalignant adrenal masses. Thus, an adrenal mass in an oncologic patient is not always metastases. No complications occurred. The diagnostic evaluation of an adrenal mass in selected cases should include CT‐guided percutaneous aspiration as a safe and reliable alternative to open surgical biopsy. CT‐guided biopsy can be performed as an outpatient procedure, avoiding the cost of hospitalization and the morbidity of surgery.

Dual contrast enhancement of both T1- and T2-weighted sequences using ultrasmall superparamagnetic iron oxide

BMS 180549 (previously AMI-227), an ultrasmall superparamagnetic iron particulate agent, was investigated to determine its utility as a contrast agent on T1-weighted, as well as T2-weighted sequences, as a function of route of administration, (intravenous versus selective arterial) and concentration. Twelve farm pigs were divided into three groups of four each by route of administration (intravenous, selective superior mesenteric, or selective hepatic arterial injection). 10 mumol/kg and 20 mumol/kg dosages were given and evaluated both immediately after and 20-24 hr after contrast infusion, using both spin-echo and gradient-echo T1 and T2-weighted sequences. Significant postcontrast liver and spleen enhancement was noted at both concentrations, regardless of route of administration on both T1- and T2-weighted sequences. The earliest postcontrast T1-weighted sequence obtained during the 1-3 min interval following IV administration of high dose (20 mumol/kg) contrast demonstrated an average of +42.8% liver and +249.0% spleen enhancement; 24 hr later this decreased to 0 and 7.2%, respectively. The earliest postcontrast T2-weighted sequence obtained during the 8-17 min interval post high-dose IV contrast showed an average of -75.8% decrease in liver and -28.7% decrease in spleen signal intensity; 24 hr later the magnitude of these changes diminished to -33.1% and +2.5%, respectively. No significant difference was noted in liver or spleen enhancement, regardless of route of contrast administration (intravenous versus intraarterial).

Hepatic Metastases: CT Versus MR Imaging at 1.5T

A prospective multi-institutional study was performed to compare the sensitivity of computed tomography (CT) and high-field magnetic resonance (MR) imaging (1.5T) in the detection of hepatic metastases, T1-weighted and T2-weighted spin-echo (SE) MR images were compared with noncontrast, dynamic, and delayed CT. Sixty-nine oncology patients were studied. Non-contrast CT showed an overall sensitivity of 57%, dynamic CT 71%, delayed CT 72%, T1-weighted SE MR 47%, and T2-weighted SE MR 78%. Although there was no statistically significant (p}<0.05) difference among dynamic CT, delayed CT, and T2-weighted SE MR, these three methods were significantly more sensitive (p< 0.005) than non-contrast CT or T1-weighted SE MR. T2-weighted SE MR was significantly more sensitive (p< 0.006) than CT or T1-weighted SE MR in the detection of small (<1 cm) lesions. CT was more sensitive in the detection of extrahepatic disease. These data confirm the superiority of T2-weighted SE over T1-weighted SE pulse sequences at 1.5T.

Percutaneous drainage of multiseptated hepatic abscess.

Thirteen patients with multiseptated, hepatic abscesses were initially treated by percutaneous drainage using computed tomographic guidance. One of these 13 patients required surgery because of failure of percutaneous drainage due to the viscosity of the debris within the multiseptated cavities. Another patient required a second percutaneous drainage procedure due to recurrent hepatic fluid collection. Eleven of the 12 successful drainages were accomplished with one catheter because there was communication between the multiseptated “pockets.” Our approach to hepatic abscess drainage is discussed with specific attention to the multiseptated abscess. The multiseptated abscess should not discourage an attempt at percutaneous catheter drainage.

A multisite phase iii study of the safety and efficacy of a new manganese chloride-based gastrointestinal contrast agent for mri of the abdomen and pelvis

The purpose of this study was to evaluate the safety and efficacy of a manganese chloride‐based oral magnetic resonance (MR) contrast agent during a Phase III multisite clinical trial. Two hundred seventeen patients were enrolled who were already scheduled for MRI of the abdomen and/or pelvis. In this group of patients, it was postulated that the use of an oral agent would better allow discrimination of pathology from bowel. Patients with known gastrointestinal pathology including peptic ulcer disease, inflammatory bowel disease, obstruction, or perforation were excluded to minimize confounding variables that could affect the safety assessment. Of these 217 patients, 18 received up to 900 mL of placebo, and 199 patients were given up to 900 mL of a manganese chloride‐based oral contrast agent, LumenHance® (Bracco Diagnostics, Inc.). Safety was determined by comparing pre‐ and post‐dose physical examinations, vital signs, and laboratory examinations and by documenting adverse events. Efficacy was assessed by unblinded site investigators and two blinded reviewers who compared pre‐ and post‐dose T1‐ and T2‐weighted MRI scans of the abdomen and/or pelvis. In 111 (57%) of the 195 cases evaluated for efficacy by site investigators (unblinded readers), MRI after LumenHance provided additional diagnostic information. Increased information was found by two blinded readers in 52% and 51% of patients, respectively. In 44/195 cases (23%) unblinded readers felt the additional information would have changed patient diagnosis and in 50 patients (26%), it would have changed management and/or therapy. Potential changes in patient diagnosis or management/therapy were seen by the two blinded readers in 8–20% of patients. No clinically significant post‐dose laboratory changes were seen. Forty‐eight patients (24%) receiving LumenHance and four patients (22%) receiving placebo experienced one or more adverse events. Gastrointestinal tract side effects were most common, seen in 29 (15%) of LumenHance patients and in 3 (17%) of the placebo patients. LumenHance is a safe and efficacious oral gastrointestinal contrast agent for MRI of the abdomen and pelvis.J. Magn. Reson. Imaging 1999;10:15–24.