Radionuclide imaging, computed tomography, and gray-scale ultrasonography of the liver: a comparative study.

Transmission computed tomography (CT), gray-scale ultrasonography, and scinitillation-camera imaging were compared for detection of intrahepatic space-occupying processes. Fifty patients with suspected liver disease were studied by the three modalities. In the 35 cases with confirmed abnormalities, the madalities were rated on a scale of 0 to 5 in terms of their detection value; Each modality was found to have definite advantages and disadvantages. The mean score of ultrasound was highest (3.61), followed by nuclear medicine (3.11) and then CT (2.77). The combination of ultrasound and nuclear medicine identified all lesions, whereas CT alone or in combination with another technique occasionally failed to detect abnormal foci. In the future, the relative efficacy of these procedures may change with improved imaging technology and increased interpreter experience.

Chemotherapy-based control of schistosomiasis haematobia. I. Metrifonate versus praziquantel in control of intensity and prevalence of infection.

To determine the effect of targeted field administration of oral chemotherapeutic agents on the prevalence, intensity, and morbidity of Schistosoma haematobium infections, we initiated a long-term school-based program in the Msambweni area of Kwale District, Coast Province, Kenya. Prior to treatment, 69% of the children examined (ages 4-21, n = 2,628) were infected; 34% had moderate or heavy infections (greater than 100 eggs/10 ml urine). Infected individuals were randomized to receive, during one year, either metrifonate (10 mg/kg x 3 doses) or praziquantel, (40 mg/kg x 1 dose). At the end of the first year, prevalence of infection fell to 19%; only 2% of the pupils remained in the moderately and heavily infected groups. Corresponding decreases in the prevalence of hematuria (54% in 1984 vs. 16% in 1985) and proteinuria (56% in 1984 vs. 26% in 1985) were noted. These were associated with significant declines in bladder thickening and irregularities noted during ultrasound examinations, but not with decreases in hydronephrosis. There was no significant difference in the post-treatment prevalence or intensity of infection after treatment with metrifonate as compared with praziquantel. These results demonstrate that field-applied chemotherapy with either agent offers a practical strategy for the control of S. haematobium infection and its associated morbidity.

Chemotherapy-based control of schistosomiasis haematobia. II. Metrifonate vs. praziquantel in control of infection-associated morbidity.

To determine the relative efficacy of metrifonate and praziquantel in controlling urinary tract morbidity due to Schistosoma haematobium infection, a random allocation treatment trial was performed among 1,813 school age S. haematobium-infected children from the Msambweni area of Coast Province, Kenya. Following baseline examination for infection, hematuria, proteinuria, and ultrasonographic urinary tract abnormalities, oral treatment with either metrifonate (10 mg/kg, repeated at 4 month intervals) or praziquantel (1 dose of 40 mg/kg) was given to infected subjects. Prevalence of morbidity was reassessed 12 months later for each treatment group. Results indicated equivalent patient improvement in response to either regimen: prevalence of hematuria fell from 75% to 17% after either praziquantel or metrifonate therapy. Similarly, prevalence of proteinuria was significantly reduced from 73% to 29% (metrifonate) or 27% (praziquantel) after therapy. Metrifonate and praziquantel caused similar reductions in bladder granulomata and bladder thickening; however, no reduction in hydronephrosis was noted with either drug. Analysis of outcomes in population subgroups defined by age, sex, pretreatment intensity of infection, or severity of pretreatment morbidity showed no consistent advantage for either drug. In this endemic area, both agents provide effective control of morbidity due to urinary schistosomiasis.

Ultrasound in diagnosis of congenital hydronephrosis due to obstruction of pelviureteric junction.

The use of ultrasonography in the diagnosis of upper abdominal masses with nonfunctioning kidneys is described. Two cases of congential hydronephrosis due to obstruction of the pelviuretic junction are presented, both of which were diagnosed by B-scan ultrasound examination. Diagnostic ultrasound is a simple, noninvasive and reliable method of differentiating cystic from solid lesions and of assessing whether or not a mass is renal or extrarenal. It is recommended that all patients seen with an upper abdominal mass and/or nonfunctioning kidney be examined by ultrasound.

Computed tomography of gas-filled bladder: method of staging bladder neoplasms.

Current methods of staging bladder carcinoma have many disadvantages. A new method of staging bladder tumors employing computed tomography (CT) of the gas-filled bladder is presented. Representative cases are demonstrated. Direct visualization of the extent of the tumor and adjacent soft tissue structures is possible. CT scanning of the gas-filled bladder is a promising new method for staging bladder tumors and following their response to therapy.

Magnetic resonance imaging of the genitourinary tract.

MRI is in its infancy as a clinical imaging tool. It is undergoing intensive investigation in various areas of the body. Evaluation of the brain and spine is superb, and in some areas of the brain, like the posterior fossa, it is thought to be superior to CT. Evolving indications for body scanning include staging of pelvic malignancies, evaluation of liver malignancy, evaluation and staging of musculoskeletal problems, and, to a lesser degree, staging of renal malignancies and evaluation of vascular disease. The main problem in body imaging stems from image degradation because of respiratory motion that is transmitted to upper abdominal organs. Respiratory gating of image acquisition or utilization of short heavily T1-weighted pulse sequences will likely overcome this problem in due time. Minimizing motion artifact will make MR images comparable to, if not better than, CT images with regard to transverse anatomic display, and MR images have the added advantage of multiplanar scanning, which can be done directly, without need of additional computer reconstruction time and without having to move the patient. The second major problem in MRI is the lack of understanding of equipment potential. Unlike conventional radiography and CT, in which the behavior of the X-ray beam is understood with regard to image formation, in MRI new parameters are used to generate images. As stated earlier, MR signal intensity is due to hydrogen concentration, T1 and T2 relaxation times of the tissue, and flow of protons through the imaged volume. How these factors are weighted depends on pulse sequence selection, and thus image contrast and information content of the scans change. On the surface, these images display anatomic information as do other imaging modalities, but manipulation of pulse sequences may ultimately lead to the ability to demonstrate physiologic and chemical parameters previously unavailable in imaging. Current research is geared to help extract this data by testing new pulse sequences, using different types of receiver RF coils, and using MR-specific contrast materials. Minor MRI problems such as long scan times are being dealt with to decrease time to an acceptable length. The nonvisualization of soft tissue calcifications will probably remain a problem that may have to be weighed against other known advantages. At this time further research and clinical experience are the key to what is needed in MRI, to gain further knowledge with regard to imaging physiologic phenomena, such as flow and spectroscopy, and possibly to monitor the chemical basis of disease.(ABSTRACT TRUNCATED AT 400 WORDS)

Magnetic resonance imaging of the pelvis.

Magnetic resonance imaging (MRI) is a very promising modality for evaluation of the pelvis. Its major role appears likely to be the staging of known malignancies. In this article, the appearance of normal pelvic anatomy on MR scans is presented, as well as a discussion of the use of MRI in the detection and evaluation of pathologic conditions and a comparison of MRI with CT.

Magnetic resonance imaging of rectal carcinoma.

Five patients with a diagnosis of rectal carcinoma were examined by magnetic resonance and computerized tomography (CT) to determine if magnetic resonance imaging (MRI) added any information to that obtained by computerized tomography. In each case, the imaging studies agreed with the surgical description of the tumor. The studies agreed on the presence of perirectal fat invasion and tumor position. Both modalities were positive for involved lymph nodes in the patient with metastatic disease to pelvic nodes, but both studies underestimated the number of nodes involved. These five cases were examined using two magnetic resonance scanners. The older one operated at 0.3 tesla (T) while the newer scanner operated at 1 T. Spatial resolution was improved with the newer scanner. In addition, the difference in signal intensity between tumor tissue and normal tissue was greater on the 1 T scanner. Tissue differentiation was useful in one case in which CT suggested extension of tumor into the vagina. The extension was confirmed on the MRI scan.

Development of new ethanologenic Escherichia coli strains for fermentation of lignocellulosic biomass.

Two new ethanologenic strains (FBR4 and FBR5) of Escherichia coli were constructed and used to ferment corn fiber hydrolysate. The strains carry the plasmid pLOI297, which contains the genes from Zymomonas mobilis necessary for efficiently converting pyruvate into ethanol. Both strains selectively maintained the plasmid when grown anaerobically. Each culture was serially transferred 10 times in anaerobic culture with sugar-limited medium containing xylose, but no selective antibiotic. An average of 93 and 95% of the FBR4 and FBR5 cells, respectively, maintained pLOI297 in anaerobic culture. The fermentation performances of the repeatedly transferred cultures were compared with those of cultures freshly revived from stock in pH-controlled batch fermentations with 10% (w/v) xylose. Fermentation results were similar for all the cultures. Fermentations were completed within 60 h and ethanol yields were 86-92% of theoretical. Maximal ethanol concentrations were 3.9-4.2% (w/v). The strains were also tested for their ability to ferment corn fiber hydrolysate, which contained 8.5% (w/v) total sugars (2.0% arabinose, 2.8% glucose, and 3.7% xylose). E. coli FBR5 produced more ethanol than FBR4 from the corn fiber hydrolysate. E. coli FBR5 fermented all but 0.4% (w/v) of the available sugar, whereas strain FBR4 left 1.6% unconsumed. The fermentation with FBR5 was completed within 55 h and yielded 0.46 g of ethanol/g of available sugar, 90% of the maximum obtainable.

Computed tomography in unilateral extremity swelling of unusual cause.

Computed tomography (CT) were used in the evaluation of unilateral soft tissue swelling of unusual cause. Three patients with unilateral myositis are described and the diagnostic information provided by the CT scan is discussed. A fourth patient with lymphedema praecox and unilateral extremity swelling is presented.

Isodense masses on CT: differentiation by gray scale ultrasonography.

Alterations in echo patterns enable isodense structures and lesions to be clearly identifiable by gray scale ultrasonography when they are not distinguishable by computed tomography (CT). In certain clinical situations this capability is a distinct advantage of ultrasound over CT. Findings in three cases with abnormalities visualized by ultrasound, but not by CT, are presented. In addition, a cadaver was scanned with CT and ultrasound and then sectioned in corresponding transverse planes for anatomic correlation.

MR imaging of uterine inversion.

Inversion of the uterus is a postpartum complication that is an obstetric emergency. This report describes a case of inversion of the uterus in which clinical evaluation was inconclusive, and magnetic resonance (MR) of the pelvis revealed findings virtually pathognomonic of incomplete inversion of the uterus with far greater conspicuity than on corresponding ultrasound. The MR findings directly resulted in earlier therapeutic intervention with a possible decrease in morbidity.

Magnetic resonance imaging of the prostate.

Magnetic resonance imaging was utilized in 18 patients with prostatic cancer and compared with the findings in normal volunteers (Pontes et al., 1985), benign prostatic hyperplasia (Hricak et al., 1983), acute prostatitis (Walsh and Jewett, 1980) and chronic prostatitis (ACS, 1986). Sixteen of the 18 patients with carcinoma demonstrated inhomogeneous signal intensity, however, a similar appearance was also seen in 5 patients with benign prostatic hyperplasia. It does not appear that magnetic resonance imaging is able to reliably differentiate benign from malignant prostatic disease. Extra-prostatic tumor extension and pelvic adenopathy was demonstrated and the technique offers promise for the pre-operative staging of patients with known prostatic carcinomas.

Hypernephroma embolisation--is it worthwhile?

Transcatheter embolisation was performed in 16 patients with hypernephroma, using either Oxycel, Gelfoam, or steel wire coil(s). Thirteen patients proceeded to early nephrectomy. Surgery was facilitated in four patients with large hypervascular tumours, three of whom had vena caval occlusion. Patients with small, or only moderately vascular tumours, did not benefit from the technique as assessed at nephrectomy. The technique was used as a palliative procedure in three patients, haematuria stopped in two, and abolition of high-output heart failure was achieved in one. Owing to the danger of this technique, it is suggested that its use be restricted to (a) rendering patients with large hypervascular tumours more suitable for surgery, and (b) in palliation of inoperable patients who have symptoms such as severe haematuria. The effect of the technique on survival time remains uncertain.

Pancreatic pseudocyst: management by ultrasonically guided aspiration.

Five pancreatic pseudocysts were managed by percutaneous transabdominal needle aspiration under ultrasound guidance. Thirteen aspirations were performed without complication. In four cysts this was the sole treatment required. None of these cysts have recurred, with a follow-up of between 6 and 12 months. Surgery of acute pseudocysts can be postponed or eliminated by this technique. Relief of pain and of obstructive symptoms can be obtained and time gained, when necessary, for maturation of the cyst wall.

Spontaneous regression of infantile hemangioendotheliomatosis of the liver: demonstration by ultrasound.

Ultrasonic and computed tomographic appearances of infantile hepatic hemangioendotheliomas are described. Ultrasonic documentation of spontaneous regression is demonstrated.

Secondary infection of an endometrioma following fine-needle aspiration.

A Clostridium infection occurred in an endometrioma following fine-needle aspiration. Fine-needle aspirations are clinically useful and safe. The authors conclude, however, that this procedure may rarely result in a secondary infection. Specific recommendations to avoid such complications are stated.