Combination of multiple pencil-beam imaging to computed storage phosphor radiography: a new method.

Computed radiography (CR) with storage phosphors offers a wide dynamic range and improved sensitivity compared to film-screen technology. CR was combined in this study with a prototype multiple pencil-beam (MPB) imaging device which has been shown to be very effective in scatter reduction. The combination was analyzed and compared to the standard technique of grid screening in two ways: a free-response ROC (FROC) analysis was first performed followed by a blinded test arrangement for visual analysis of image quality in a series of computed radiography of the lumbar spine by both the MPB and grid modalities. The results of the FROC study showed a statistically significant (P less than or equal to 0.01) improvement in signal detection. The MPB-CR images of the lumbar spine had more contrast but also a slightly mottled or grainy appearance. Image quality was found good but contrast processing was criticized because it seemed to result in a too steep display of contrast in MPB imaging. This should be avoidable by changing the image processing parameters.

CT evaluation of acute pancreatitis: 8 years clinical experience and experimental evidence.

One hundred sixty eight patients with suspected serious pancreatitis were examined by dynamic CT. According to clinical data 103 of the patients had an oedematous pancreatitis (OP) and 65 a haemorrhagic-necrotizing pancreatitis (HP). Contrast enhancement (CE) of the pancreas was measured by dynamic CT during the first 24 hours after admission to the hospital. A control study was performed in 48 hours, if the finding on the primary CT was not definite or there was a discrepancy between CT and the clinical finding. Patients with HP showed significantly lower CE during the first minute after bolus injection of contrast material than patients with either normal pancreas or those who had OP. Only 4 out of 65 patients with HP showed normal (over 40 HU) and 8 out of 103 patients with OP showed low (less than 30 HU) CE. The method seems to be the most reliable method available to differentiate HP from OP. Before giving contrast material to the patients severe hypovolemia and respiratory distress should be excluded and treated.

Results and complications of percutaneous nephrostomy.

A series of 181 patients (158 with obstructive uropathy) treated by percutaneous nephrostomy (PN) in 1978-1987 is evaluated. In 8.3% of the patients PN did not succeed. The success rate of PN was lower when done outside normal working hours and before ultrasound guidance was used. Major complications occurred in 5.5% and minor ones in 10.5%. There was no direct mortality. The complications and the possible avoidance of them are discussed. In 68% of patients nephrostomy improved their clinical condition. The benefit of PN was closely related to the existing renal recovery potential following the relief of obstruction; a problem that has not yet been fully solved.

Computed tomography in staging of oesophageal carcinoma.

The computed tomographic (CT) findings in 45 patients with histologically proved oesophageal carcinoma are reviewed. In 20 of these patients the CT findings were correlated with findings at surgery (19 patients) or autopsy (1 patient). Correlation analysis showed that the accuracy of CT in assessing both invasion of adjacent organs and mediastinal and abdominal lymph node involvement is limited. Twenty-five patients were considered inoperable; in 15 of these the conclusion was based on CT findings of distant metastases (14 patients) or definite local invasion (1 patient). Ten patients were inoperable for other reasons (general health condition). We found the value of CT to be in detecting distant metastases, thus avoiding unnecessary radical surgery; it is not a reliable way of defining the primary tumour.

Computed tomography of pleural lesions with special reference to the mediastinal pleura.

Computed tomography (CT) and conventional chest radiography were reviewed in retrospect in 84 patients in whom pleural pathology was suggested clinically. The importance of administration of contrast medium in distinguishing between malignant lesions and other pleural diseases was given special attention. CT was found to be of value in diagnosing and establishing the extent of pleural lesions, especially in the mediastinal region. All malignancies exhibited high contrast enhancement following intravenous bolus injection of contrast medium. There were no features specific for mesotheliomas distinguishing these from other pleural malignancies. Some benign infectious lesions also showed high contrast enhancement. High contrast enhancement thus indicated malignancy only if an infectious lesion could be excluded. If contrast enhancement was absent or slight, the lesion was likely to be benign. Clinical follow-up may be regarded as justified in such cases. Indirect signs were not helpful in distinguishing between malignant and benign lesions.

Significance of extrapancreatic findings in computed tomography (CT) of acute pancreatitis.

Computed tomography (CT) has proven reliable in the early detection of acute haemorrhagic pancreatitis. In the present study the extrapancreatic changes at CT were studied in 60 patients with acute pancreatitis. The CT findings were correlated to the early "prognostic signs" by Ranson and the clinical course of the disease. All the patients with minor extrapancreatic changes recovered without complications. When moderate to severe extrapancreatic changes were seen the incidence of haemorrhagic pancreatitis and the risk of development of pseudocyst or abscess was high. In these patients a dynamic contrast enhanced CT should be done in order to select the patients with haemorrhagic pancreatitis.

Pancreatic blood flow and contrast enhancement in computed tomography during experimental pancreatitis.

The pancreatic blood flow and contrast enhancement in computed tomography (CT) were studied in 10 piglets weighing 17-25 kg with experimental pancreatitis. Each animal served as its own control. CT and blood flow measurements were made both before induction of pancreatitis and 5-6 h after the onset of the disease. Cardiac output was measured by thermodilution, and was kept constant throughout the study by infusion of dextran and saline. Although the pancreatic blood flow remained constant in this experiment, CT showed a significant decrease in contrast enhancement.

Diagnostic value of ultrasound, computed tomography, and angiography in ruptured aortic aneurysms.

Some ruptural aneurysms cause nonspecific symptoms and the patients are referred for radiological examination because of the problems of differential diagnosis from conditions such as renal colic, diverticulitis, herniated disc, aortic dissection etc. Seven such patients have been examined either with ultrasonography, computed tomography or angiography. The diagnostic methods are compared. The more recent US and CT imaging methods are sufficiently rapid and reliable for diagnostic purposes, which should improve the prognosis for patients requiring immediate surgery for ruptured aortic aneurysms.

Differential diagnosis of anterior upper mediastinal expansions by contrast-enhanced computed tomography.

This study investigated the potential of contrast-enhanced CT in the differential diagnosis of the most common anterior upper mediastinal expansions. CT examinations of 29 patients with an upper anterior mediastinal mass lesion of unknown origin were reviewed retrospectively and compared with the clinical data obtained. The density, contrast enhancement and invasive nature of the tumors were recorded. Thyroid tissue was enhanced most and lymphomas least. Contrast medium injection helped to distinguish great vessels and cystic lesions from surrounding areas. Thyroid tissue was most heterogeneous and lymphomas most homogeneous. All except one of the malignant neoplasms (a lymphoid mass lesion) were infiltratory in nature. Contrast-enhanced CT gives clues as to the origin of a neoplasm and whether it is benign or malignant.

A new method for the diagnosis of acute hemorrhagic-necrotizing pancreatitis using contrast-enhanced CT.

Twenty-eight consecutive patients with a first attack of alcohol-induced pancreatitis were studied using contrast-enhanced CT. The findings on CT were then related to the course of the disease. The patients with acute hemorrhagic-necrotizing pancreatitis showed significantly lower enhancement values of the pancreatic parenchyma than those with milder forms of the disease. The next 20 patients with severe pancreatitis were scanned using a slightly modified procedure. The enhancement values were calculated and plotted on the graphs for the 2 former groups. Two categories of pancreatic enhancement were found: "low enhancement" and "high enhancement." In all 10 patients with "low-enhancement" values surgery revealed hemorrhagic-necrotizing pancreatitis. In the 10 patients with "high-enhancement" values conservative treatment was continued, and the clinical course was nonfulminant in all of them.

Contrast-enhanced computed tomography of the gallbladder in acute pancreatitis.

The gallbladder findings encountered in 59 patients examined because of a first attack of acute, alcohol-induced pancreatitis, are reported. Abdominal contrast-enhanced computed tomography was technically acceptable in 54 patients. In 85% of the patients the gallbladder finding was pathological. The density increase in the gallbladder contents was more than twice normal. Possible reasons for this phenomenon are discussed. Intense contrast enhancement of the gallbladder wall was found in 87% of the cases. Increased wall thickness was observed in 64% of the patients.

Transdiaphragmatic perforation of pancreatic pseudocyst with lung herniation. A case report.

A 34-year-old woman with a rupture of a pancreatic pseudocyst into the left pleural cavity and with a transdiaphragmatic lung herniation is described. According to literature, this type of condition seems to be extremely rare. The diagnostic and therapeutic problems of the situation are discussed as well.

The clinical significance of contrast enhanced computed tomography in acute pancreatitis.

58 patients with alcohol-induced acute pancreatitis were studied by contrast enhanced computed tomography (CT). The patients were divided into groups both on the basis of the clinical course and the prognostic signs. The contrast enhancement curves were then plotted for these patients. All patients with uncomplicated pancreatitis had increased or normal contrast enhancement, whereas all those with fulminant pancreatitis had decreased contrast enhancement of the pancreas. The patients with three, or more prognostic signs had lower enhancement values than those with fewer prognostic signs, but the prognostic signs did not correlate as well with the clinical course as did the contrast enhancement.

Lobar liver anatomy. Definition by CT.

A method for identifying the physiological border between the hepatic lobes on an enhanced CT scan is described. The definition is based on combined information from the gall bladder fossa--vena cava line and the middle hepatic vein line.

Early detection of acute fulminant pancreatitis by contrast-enhanced computed tomography.

Twenty-eight consecutive patients with a first attack of acute alcohol-induced pancreatitis were examined by computed tomography (CT). After a survey scan of the abdomen a rapid contrast bolus (400 mg I/kg) was given intravenously, and the contrast enhancement of the pancreatic parenchyma was measured from a consecutive series of pancreatic scans. Nine patients with a fulminant course of the disease were operated on, and haemorrhagic necrotizing pancreatitis was found in eight. In all of these the contrast enhancement was decreased or absent. Patients recovering by conservative treatment showed normal or increased enhancement. The contrast enhancement seems to constitute a useful criterion for the early differentiation of acute fulminant pancreatitis from less severe forms of the disease.

Patency of sequential versus single vein grafts in coronary bypass surgery.

The patency and graft flow of sequential (seq. SVBG) and single saphenous vein bypass grafts (single SVBG) in coronary bypass surgery were compared angiographically (mean follow-up 26 months) in 76 patients with 36 seq. SVBG (75 distal anastomoses) and 85 single SVBGs. The late patency of all seq. SVBGs anastomoses (94.7%) was higher than that of single SVBGs (80.0%). No early or late graft occlusions were seen in the side-to-side (SSA) anastomoses of the seq. SVBGs. The cine-angiographically determined mean volume flow in the proximal segments of the seq. SVBGs was significantly higher (p less than 0.001) than that in the distal segments of the seq. SVBGs or in the single SVBGs at both early and late follow-up. Despite the higher late patency rate (88.9% vs 80.0%) in the end-to-side anastomoses (ESA) of the seq SVBGs, the mean graft flow was significantly lower in the distal segments of seq SVBGs than in the single SVBGs (71 ml/min vs. 109 ml/min, p less than 0.05).

Lymphographic findings in multiple myeloma.

The lymphographic appearances of the retroperitoneal lymph nodes in 10 patients with multiple myeloma have been analyzed. None of the patients had any signs of extramedullary involvement of myelomatosis before lymphography. In 3 cases irregular filling defects suggestive of myelomatous involvement were found. In one case they were close to a myelomatous bone lesion, whereas in the others the lymphographic abnormality was totally unexpected. In all 3 patients other nodes showed reactive hyperplasia. Such nonspecific hyperplasia was also encountered in 3 other cases. In 2 cases the myelomatous involvement of lymph node was detected before the diagnosis was recognized which is contrary to the belief that multiple myeloma involve nodes late in the disease. In addition to diagnostic aid the lymphographic demonstration of the myelomatous spread into lymph nodes may influence on the selection of the therapeutic approach to the disease.