Forty-four-year-old woman with flank pain.
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Adult↗
Biomedical subjects
R C Nelson
Publications and source records attributed to R C Nelson.
Comparison of ultrasonography and oral cholecystography in lithotripsy. II. Determining retreatment.
Both ultrasonography (US) and oral cholecystography (OCG) are being used to evaluate patients after extracorporeal shock wave lithotripsy (ESWL) for gallstones. Criteria for retreatment after the initial ESWL are usually related to the size of the residual fragments. This study examines the efficacy of ultrasound and OCG for determining both the size and number of stone fragments in the gallbladder in an in vitro model and in patients. Ultrasonography and OCG examinations using an in vitro ESWL phantom with ten groups of stones, and on 39 patients, were reviewed independently by three radiologists to determine both the size and number of stone fragments. For the in vitro study, the three readers estimated the correct number of fragments, or the next closest range, in 87% of observations by OCG and in 43% by US. The size of the largest fragment was measured within 1 mm of its actual size in 87% of observations by OCG and 20% by US. Correlation coefficients for the mean measurements of the three readers versus the actual fragment size and number were greater for OCG than for US. For the in vivo study, the three readers agreed in 47% of the OCG versus 32% of US examinations with respect to the number of fragments, and in 65% of OCG compared to 40% of US studies with respect to size of the largest fragment. Multiple statistical analyses demonstrate that these differences are statistically significant. A discrepancy among the readers concerning whether a patient was eligible for retreatment occurred in 15% of OCG as compared to 45% of US studies. Both the in vivo and in vitro studies indicate that there is more interobserver reproducibility for OCG than for US, and that OCG is more reliable in making the decision concerning patient eligibility for retreatment following lithotripsy.
Adult↗
Hepatic dynamic sequential CT: section enhancement profiles with a bolus of ionic and nonionic contrast agents.
The enhancement characteristics in different portions of the liver during dynamic sequential bolus computed tomography (CT) with iodinated contrast material (DSBCT) were prospectively evaluated in 75 patients by using iothalamate meglumine, iopamidol, and iohexol (25 patients received each agent). After baseline noncontrast CT was performed, DSBCT was performed with a 180-mL intravenous bolus administered at 2 mL/sec. Scanning was started 25 seconds after the bolus was initiated, by using a 3-second scan time and rapid cephalocaudal table incrementation, yielding contiguous 8-mm-thick sections at a rate of nine sections per minute. On postcontrast images, peak enhancement was 115% for iopamidol and 117% for iohexol, both of which were superior to iothalamate meglumine at 95% (P less than .05). After peaking, enhancement then decreased for all three contrast agents, although the decline was more precipitous for iothalamate meglumine. Enhancement on the more caudal sections with both iopamidol and iohexol was superior to that with iothalamate meglumine (P less than .05). The data suggest that the enhancement characteristics for the two nonionic agents may be more optimal for detection of focal hepatic lesions than the ionic agent.
Adult↗
Extracorporeal shock wave lithotripsy of gallstones: results and 6-month follow-up in 141 patients.
A study of biliary shock wave lithotripsy of gallstones sponsored by Dornier Medical Systems, Munich, began in the United States in May 1988 to evaluate the efficacy and safety of extracorporeal shock wave lithotripsy (ESWL) and the need for adjunctive therapy with ursodeoxycholic acid (UDCA). One hundred forty-one symptomatic patients with one to three gallstones 5-30 mm in diameter were randomized to treatment. One week before ESWL, patients were given either UDCA or placebo. This treatment was continued for 6 months. All patients underwent follow-up at predetermined intervals. According to the protocol, re-treatment for fragments larger than 5 mm in diameter could be performed only at 6 weeks; 26 (18%) of the 141 patients were retreated. At 6 months, the stone-free rates for single stones were as follows: patients with noncalcified stones receiving UDCA, 29%; patients with noncalcified stones receiving placebo, 24%; and patients with partially calcified stones receiving either UDCA or placebo, 6%. No significant difference was noted between the UDCA and placebo groups. At 6 months, the stone-free rates in patients with single, noncalcified stones 20 mm or less in diameter were 40% (UDCA) and 32% (placebo), which is superior to rates for those with solitary, noncalcified gallstones 21-30 mm in diameter and those with two or three stones.
Adult↗
Liver transplant biopsies with a biopsy gun.
The authors evaluated the safety and efficacy of a biopsy gun for performance of image-guided percutaneous biopsy of hepatic allografts in liver transplant recipients. Two hundred fifty-two liver biopsies were performed in 58 transplant recipients over a 27-month period by using this instrument with an 18-gauge needle. Major complications occurred in two of the 252 biopsies (0.8%): One hemopneumothorax necessitated drainage with a chest tube, and one hemorrhage necessitated transfusion. No patient required surgical exploration because of a complication of the biopsy. Specimens were adequate for accurate histopathologic diagnosis in 248 of 252 procedures (98.4%). The authors conclude that image-guided percutaneous biopsy of hepatic allografts with use of the biopsy gun is a safe and accurate method of obtaining hepatic tissue from liver transplant recipients for histopathologic analysis.
Adolescent↗
Shock wave lithotripsy of gallstones: results and 12-month follow-up in 174 patients.
At the authors' institution, as part of the on-going Dornier National Biliary Lithotripsy Study, 174 patients with gallstones were randomly assigned to receive either ursodeoxycholic acid (UDCA) or placebo for 6 months after undergoing extracorporeal shock wave lithotripsy (ESWL). Six weeks after ESWL, 40 (23%) patients were re-treated for gallstone fragments larger than 5 mm in diameter. No significant difference in the UDCA- and placebo-treated patients was noted. The overall 6- and 12-month stone-free rates for all patients with initially noncalcified stones were as follows: UDCA patients, 31% and 36%, respectively, and placebo patients, 21% and 23%, respectively (P less than .05). In patients with a single, noncalcified gallstone that was at most 20 mm in diameter, the 12-month stone-free rates were as follows: UDCA patients, 60%, and placebo patients, 33% (P less than .01). Patients with noncalcified stones that were 11-20 mm in diameter who were treated with UDCA had a higher rate of stone clearance than placebo patients. At 6 months, the authors' previous study demonstrated no significant difference in the two groups of patients. However, the stone-free rate at 12 months was noted to be significantly higher for patients with a single, noncalcified stone that was at most 20 mm in diameter begun on UDCA than for all other groups of patients.
Adolescent↗
Manganese dipyridoxyl diphosphate. Effect of dose, time, and pulse sequence on hepatic enhancement in rats.
We used an animal model to investigate the hepatic enhancement characteristics of manganese dipyridoxyl diphosphate (MnDPDP) related to time, dose, and pulse sequence. The contrast doses selected were in the human tolerance range. Using an SE 300/15 pulse sequence, maximum mean hepatic enhancement of 45% (8 mumols/kg) and 58% (12 mumols/kg) over baseline was seen during a plateau maintained between 5 and 50 minutes postinjection in the 8 mumols/kg group, and between 10 and 90 minutes in the 12 mumols/kg group. This plateau was followed by a very gradual decline in hepatic enhancement. Using either 4 or 8 mumols/kg, there was a significant increase in postcontrast hepatic intensity on all relatively T1-weighted pulse sequences (spin echo [SE] 300/15, inversion recovery [IR] 1400/20/400, gradient echo [GE] 47/13/80 degrees, and GE 60/20/30 degrees) except GE 47/13/80 degrees at 4 mumols/kg. At 8 mumols/kg there was superior enhancement, with IR 1400/20/400 and SE 300/15, but at 4 mumols/kg there was no consistently superior sequence. None of the relatively T2-weighted pulse sequences (SE 2000/50, SE 2000/100, or GE 100/30/20 degrees) demonstrated a significant change in hepatic intensity using either dose of contrast. The data suggest that the best combination of dose, pulse sequence, and time for hepatic imaging with MnDPDP is 8 mumols/kg using heavily T1-weighted sequences 5 to 60 minutes following contrast administration.
Animals↗
Techniques for computed tomography of the liver.
We recommend that the CT technique of choice for routine screening of the liver, especially when there is potential for neoplasia, is dynamic CT using a single monophasic bolus of not less than 150 mL of a 60% iodinated contrast agent and a dynamic incremental package yielding at least 7 sections/minute. Routine use of noncontrast CT prior to dynamic CT is not indicated unless there is suspicion of a hypervascular tumor. We prefer to examine these particular patients with delayed CT 4 to 6 hours after receiving at least 60 g of iodine, as lesion to liver contrast is superior to noncontrast CT. Other indications for delayed CT include indeterminate lesions on dynamic CT or CTAP and perfusion defects on CTAP. In patients who are possible candidates for hepatic tumor resection, more invasive techniques such as CTAP are indicated as they yield the highest sensitivity to focal hepatic lesions, especially small lesions. A combination of CTAP and MR, however, demonstrates a superior lesion detection rate than either modality alone. CT-Lipiodol is a useful technique for detecting and palliating hepatocellular carcinomas, especially in patients with concomitant cirrhosis.
Contrast Media↗
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 greater than 600 micrograms/100 mg liver dry weight detected on the basis of L/M less than 0.6 or CT attenuation greater than 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.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Assessing sincerity of effort in maximal grip strength tests.
Injuries to the upper extremities sometimes result in a loss of work capacity. One of the methods for measuring this loss of work capacity is the grip test. Such measurements may be compromised by an insincere effort (faking) by the subject. Smith et al. (Am J Phys Med Rehabil 1989;68:73-80) developed a protocol to identify sincere and faking efforts with the use of a modified dynamometer. The present investigation was designed to evaluate the applicability of the previously developed protocol to subjects with hand injuries. The investigators also compared the force-time characteristics for contractions at different percentages of maximum (100, 75, 50, and 25%). Sixty subjects (30 male and 30 female) were tested during two sessions while performing both faking and sincere efforts. The five discriminators previously developed were found to be good detectors for both noninjured and injured hands and provided the basis for cutoff values for the five discriminators. Single discriminator prediction gave at best an 85% faking detection rate (by using D3) for men and a 79.2% detection rate (by using D5) for women. Better results were obtained, when a multiple variable prediction was used. It can be concluded that the protocol developed by Smith et al. for detection of an insincere effort can be used successfully with persons who have sustained upper extremity injuries. Furthermore, sincere and faking grip strength "maxima" can be correctly identified across a wide range of applied force levels.
Adult↗
Diagnostic approach to hepatic hemangiomas.
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Biopsy↗
Preoperative localization of focal liver lesions to specific liver segments: utility of CT during arterial portography.
The authors retrospectively studied 36 hepatic masses in 20 patients who underwent computed tomography during arterial portography (CTAP) and subsequent hepatic tumor resection. The authors used the right main and left main portal veins as landmarks for the transverse scissura, along with the hepatic veins, the gallbladder fossa, and the umbilical fissure to blindly predict the segmental location of each tumor confirmed at surgery. The right main and left main portal veins were found to be consistently near the middle sections through the liver. CTAP findings and surgical descriptions agreed on the primary segmental location of 33 of 36 focal lesions (92%) but disagreed on the extent of 11 of 36 lesions (31%). Further review of the CTAP scans of the 11 lesions revealed that the extent of the lesion was more correctly described at surgery in six masses and at CTAP in four masses; in one lesion, opposite margins of the same mass were correctly described at both surgery and CTAP. Since it may be difficult or impossible to localize deep hepatic lesions intraoperatively by means of palpation or inspection, CTAP is a helpful preoperative tool for determining the segmental location of lesions and for planning the surgical approach.
Adult↗
Biliary lithotripsy: in vitro analysis of gallstone fragmentation for equivalent stone volumes.
The relationship between gallstone fragmentation during extracorporeal shock wave lithotripsy (ESWL) and gallstone volume is poorly understood. Clinical results of ESWL show that the highest stone-free rate at 6 months occurs with radiolucent single gallstones 20 mm or less in diameter. In an in vitro study, individual gallstones from cholecystectomy specimens were divided by size and composition into nine single- and nine multiple-stone groups; the stones were then paired on the basis of similar volume. ESWL was performed in a phantom and the size of the largest fragment was measured at 500, 1,000, and 1,500 shock waves. At 1,500 shock waves, sandlike particles were present in six of nine single stones versus two of nine multiple stone groups; the mean size of the largest fragment at 1,500 shock waves was 2.1 mm (single) and 4.4 mm (multiple) in diameter. When corrected for volume, the authors' data suggest that single stones are more easily broken into fragments smaller than 5 mm in diameter than multiple gallstones. The implication, especially when spark-gap technology is used, is that more shock wave energy (ie, an increased number of shock waves at a higher kilovoltage) will be necessary to achieve the same results when treating patients with multiple stones versus a single gallstone with a similar stone volume.
Cholelithiasis↗
Gallstone extracorporeal shock-wave lithotripsy: time and treatment considerations.
We evaluated 30 gallstone lithotripsy procedures performed on 27 patients with the Dornier MPL-9000 Lithotripter to determine how time was spent in the lithotripsy suite and to evaluate the various technical reasons for interrupting the administration of shock waves during the treatment. The procedure averaged 98 +/- 32 min total time in the lithotripsy suite. This included an average of 22 +/- 6 min before the treatment, 70 +/- 28 min for administration of shock waves, and 6 +/- 2 min after the treatment. The time required to deliver the shock waves did not correlate with patient age, sex, or weight; the number of gallstones; or the number or date of the treatment. However, a trend was seen toward an association between shorter treatment times and larger stone volumes. On the average, the administration of shock waves was interrupted every 48 shock waves for various reasons. Electronically changing the imaging plane of the in-line sonographic transducer to retarget the stone in the focal zone was by far the most frequent reason for interrupting shock-wave delivery, averaging 56 shock waves between changes. We conclude that extracorporeal shock-wave lithotripsy of gallstones is a time consuming and technically demanding procedure that requires continuous monitoring and frequent interruption in order to optimize targeting and fragmentation of the stone(s) while maintaining the patient's comfort.
Adult↗
Falls in the elderly.
Finally, we conclude with a reminder that the causes of falls in the elderly are multifactorial and that some of these factors may be summative. Most falls result from interaction of intrinsic and extrinsic (environmental) factors. In the Emergency Department, it is very important to take a detailed history of the circumstances leading to the fall and to perform a thorough physical examination. Every attempt should be made to identify predisposing factors for the fall and for preventive measures to be initiated. These may include geriatric consultation or a home visit to evaluate home environment. There is a great need for additional research in this field. Falls are one of the syndromes common in the elderly that deserve more careful attention and are considered amenable to both primary and secondary prevention measures.
Accidental Falls↗
A segmental approach to computerized tomographic portography for hepatic resection.
Surgical treatment has proved to be of benefit to patients with primary and metastatic tumors of the liver. However, the ability to localize tumors preoperatively to particular segments within the liver has not been emphasized. The large size of this organ and its complex vascular structure have not allowed the surgeon either to determine accurately the hepatic segment occupied by the tumor or to identify major vascular structures adjacent to the tumor. We have expanded the use of a new roentgenologic technique to determine preoperatively with more clear definition the segmental anatomy of the liver. Computerized tomographic portography (CT-P) images hepatic veins and the segmental branches of portal vein and identifies the anatomic location of tumor nodules. To read the roentgenograms, one first identifies the middle CT-P slice that will cut the transverse scissura. Slices cephalad to the transverse scissura are through segments 7, 8, 4a and 2 in a clockwise order; slices caudad to the transverse scissura are through 6, 5, 4b and 3. Selected CT-P cuts from a series of patients show the typical CT-P configuration of the hepatic vasculature anatomy and the structures that can be identified roentgenologically. The CT-P provides valuable information not previously available preoperatively to the surgeon operating upon the liver.
Contrast Media↗
Magnetic resonance imaging in hemochromatosis: extrahepatic iron deposition.
The magnetic resonance (MR) appearance of the liver in hemochromatosis has been previously described. We report a case in which iron deposition in the pancreas, spleen, and lymph nodes is demonstrated by MR.
Adult↗
Nutrition and aging.
Aging is multifactorial and is dependent on genetic, life-style, and environmental factors. Successful aging relies upon a nutritionally complete diet and adequate exercise to counteract some of the physiologic changes related to age. A nutritionally sound diet for wellness in normal elderly is outlined which usually does not require additional vitamin supplements. Protein-calorie malnutrition is very prevalent in older patients with chronic disease, living alone, and receiving low income. Nutritional assessment and early intervention in the hospitalized elderly patient is extremely important to reduce the morbidity associated with this disease.
Aged↗