CT findings of hypervascular malignant peritoneal mesothelioma.

A case of peritoneal mesothelioma is presented in which CT demonstrated abnormal regions of increased vascularity in the omentum corresponding to hypervascular omental lesions shown by angiography. This CT appearance has not been described in prior reports of CT in peritoneal mesothelioma.

Indeterminate lung imaging. Can the number be reduced?

During a 2 1/2-year period, 1131 patients with suspected pulmonary embolism had ventilation-perfusion lung scans; 150 of these patients also underwent pulmonary angiography. In a retrospective study, these 150 patients were re-evaluated using the reference criteria of Biello and Alderson, with 62% read as indeterminate. Twenty patients who had chronic obstructive pulmonary disease with retention of Xe-133 in greater than 50% of the lung fields without corresponding radiographic abnormality were included. Ventilation/perfusion matches and mismatches could be correctly determined in 15 of these patients. These 15 of 20 studies could be correctly reclassified as low-probability, while the other five remained indeterminate. With increasing intervals between ventilation/perfusion lung imaging and the onset of symptoms, the percentage of patients with proven pulmonary emboli correctly diagnosed as high probability continuously decreased, and the percentage of studies read as indeterminate constantly increased. Serial chest radiographs suggested that the development of infiltrates in the region of the embolus convert high-probability ventilation/perfusion scans to indeterminate.

Influence of cardiac function on the quality of intravenous digital subtraction arteriograms.

In a retrospective comparison between 22 pairs of matched intravenous digital subtraction angiogram (DSA) images, five angiographers made independent determinations as to which one of each pair was superior in image quality (110 image comparisons). Matched pairs were identical for anatomic region filmed, catheter position during injection, amount of contrast material injected, injection rate, and iodine concentration of the contrast material. Each pair consisted of images from one patient with a normal (less than 1 S.D. above the mean) sodium dehydrocholate circulation time and images from one patient with a prolonged (greater than 1 S.D. above the mean) circulation time. In 85 of the 110 instances (77.3%) an image judged superior in quality to its matched counterpart derived from a DSA exam in a patient with normal circulation time; images from the exam with prolonged circulation time were judged equal in quality to the ones with the normal circulation time in 14 comparisons (12.3%); in 11 comparisons (10%) the images from the DSA with the prolonged circulation time were judged superior to the ones from the DSA with the normal circulation time. These results show that with statistically significant frequency (P less than 0.001) observers judge intravenous DSA images deriving from patients with normal circulation times superior in quality to those deriving from patients with prolonged circulation times.

Cerebral metastases from lung carcinoma: neurological and CT correlation. Work in progress.

To determine the role of brain CT in neurologically asymptomatic lung cancer patients, a review was made of the CT and clinical findings in 279 patients. Neurological status in these patients was categorized as (a) normal, (b) abnormal with specific signs and symptoms, and (c) abnormal with vague signs and symptoms. Brain metastases were found in 94.5% of patients (69/73) with specific abnormal neurological findings, 26.6% of patients (16/60) with vague neurological signs and symptoms, 11% of patients (10/92) with oat cell carcinoma and a normal neurological examination, and 40% of patients (8/20) with adenocarcinoma and a normal neurological examination. Brain metastasis was not seen on CT in the 29 patients with squamous cell carcinoma and a normal neurological examination. It is concluded that brain CT is useful for the detection of occult brain metastases, particularly oat cell carcinoma and adenocarcinoma, in neurologically asymptomatic lung cancer patients.

Leg perfusion evaluated by delayed administration of thallium-201.

Lower limb perfusion was evaluated with intravenous Tl-201 and angiography. Tl-201 was injected about 4 minutes after the cessation of stress; this resulted in increased uptake in muscles supplied by stenosed vessels. These results differ from previous studies and emphasize that differing results will be obtained with variations in the time of Tl-201 injection. Redistribution images are unchanged when Tl-201 is administered in this manner.

Osseous metastases from renal cell carcinoma: embolization and surgery for restoration of function. Work in progress.

Five patients underwent preoperative embolization of osseous metastases from renal cell carcinoma. The group consisted of four men and one woman who ranged in age from 46 to 79 years. The lesions were located in the pubic ramus and acetabulum, proximal femur, femoral midshaft, proximal humerus, and proximal tibia. All embolizations were performed within 24 hours of surgery. The internal fixation and tumor curettage was accomplished with estimated perioperative blood loss ranging from 10 ml to 1,250 ml. All patients had significant restoration of function following surgery. We suggest that preoperative embolization is an important and efficacious adjunct in the management of hypervascular renal cell osseous metastases.

Angiographic assessment of renal artery pathology: how reliable?

The accuracy of the angiographic interpretation of the histologic type of renal artery stenosis was assessed using a renal pathologist's diagnosis as the "gold standard." The angiograms of 42 renal artery stenoses were interpreted without other information, except age and gender, independently by six angiographers. This assessment indicated that angiography is not an accurate means by which to distinguish between the individual types of fibromuscular disease of the renal artery. However, it is a fairly accurate means by which to distinguish fibromuscular disease in general from atherosclerosis of the renal artery, 207 (82%) correct interpretations of 252. In addition, in the presence of renal artery stenosis, the absence of abdominal aortic atherosclerosis on angiography is an excellent predictor of fibromuscular renal artery disease, 17 (94%) of 18 specimens. Likewise, in the presence of a renal artery stenosis, angiographically demonstrable abdominal aortic atherosclerosis is a fair predictor of atherosclerotic renal artery disease, 16 (76%) of 21 specimens.

Catheter-related thrombosis and fibrinolytic therapy.

Fifty-seven local transcatheter infusions of low doses of fibrinolytic agents for the treatment of occlusive vascular disease were performed in 49 patients. Thrombosis developed around the infusing catheter in 15 (26%) of these cases. Patients with occlusive vascular disease are at increased risk for the development of thrombosis around indwelling catheters because of the low flow state that exists proximal to the occlusion.

Low-dose fibrinolytic therapy. Results and new concepts.

The authors report their experience with the first 57 infusions (50 patients) in an ongoing study of local low-dose fibrinolysis for treatment of thromboembolic disease. Complete lysis occurred in nearly half of cases, while some therapeutic effect was demonstrable in more than two thirds. Success seems to be most directly related to the type of vessel infused, with the greatest success seen in vessels with no alternate pathways for egress of the fibrinolytic agent. Chronic fibrin deposits could also be treated with this technique. Since new thrombus formation occurs in a significant percentage of patients during local fibrinolytic therapy, the authors recommend cautious use of concomitant continuous intravenous heparin at a dosage sufficient to maintain the partial thromboplastin time at 1.5 times normal. While fibrinolytic therapy is usually not curative, it frequently facilitates detection of the underlying lesion, permitting definitive therapy.

Cerebral histoplasmoma. Case report.

A 55-year-old man presented with dementia and seizures of recent onset. A computerized tomography scan revealed a ring-like lesion in the left occipital lobe, which on resection was found to be a histoplasmoma. Cerebral histoplasmoma is rare and simulates a metastatic brain tumor. Only eight cases of this entity have been reported.

Renal tumor infarction with absolute ethanol.

Sixteen renal tumors were infarcted with intraarterial absolute ethanol. Renal tumor infarction was performed for one of three indications: for palliation of symptoms in patients with metastatic disease, as a preoperative measure to reduce blood loss during radical nephrectomy, or as a primary therapy in selected circumstances. In most cases, absolute ethanol was injected into the main renal artery through a balloon occlusion catheter. In all cases, ethanol produced effective infarction of the renal tumor. Only one complication developed, a perinephric abscess that developed several weeks after the infarction. Results indicate that absolute ethanol is a safe and effective agent for the infarction of renal tumors.

Imaging of brain tumors and other lesions utilizing Tc-99m phosphates and Tc-99m pertechnetate.

The intensity of parenchymal brain lesions was compared using Tc-99m pertechnetate and Tc-99m phosphate. The following conclusions were made: 1. If the Tc-99m phosphate intensity is greater than the intensity of the Tc-99m pertechnetate scan, and the patient is evaluated within four weeks of ictus, the lesion is a CVA (P less than .001). 2. If the Tc-99m phosphate intensity is less than or equal to the intensity of the Tc-99m pertechnetate scan, and the patient is evaluated within four weeks of ictus, the parenchymal lesion is not a CVA (P less than .001). 3. If the evaluation takes place longer than six weeks after ictus, then no evaluation about the nature of the lesion can be made based upon uptake of Tc-99m phosphate and Tc-99m pertechnetate.

Efficacy of balloon catheter dilatation for lower extremity atherosclerosis.

Since there are few data regarding complications and long-term efficacy of balloon catheter dilatation for advanced lower extremity atherosclerosis, we are reporting our experience with 132 attempted dilatations in 88 patients. Dilatation was attempted on 51 aortoiliac-common femoral lesions, 80 superficial femoral-popliteal lesions and 1 peroneal lesion. Twenty procedures were technically unsuccessful and led to urgent surgery in three patients. Thirty-one complications in the 109 technically successful dilatations led to emergency surgery in only one, but another required closure of an arteriovenous fistula at the site of catheterization. There were three episodes of embolism, but none required operation. In 109 dilatations monitored for 1 month, there was significant hemodynamic improvement in 52 and mild to moderate improvement in 37; 10 had no change; 10 occluded at the site of dilatation. Of the 42 patients observed 6 months or longer, 11 maintained a significant increase, and 15 had mild to moderate improvement; 11 reverted to predilatation levels; 1 had progressive worsening; 4 occluded. Sixteen patients who had significant increases in flow after dilatation and were followed longer than 6 months showed a trend to restenosis as the length of follow-up increased. We conclude that dilatation is a useful adjunctive procedure in treating lower extremity atherosclerosis, that the early results are good, and that the incidence of recurrent stenosis is high. Indications for dilatation and its complications are similar to those for operations. It should not be done without hemodynamic monitoring.

Contrast extravasation through Dacron grafts: a sequela of low-dose streptokinase therapy.

Local transcatheter administration of low-dose streptokinase for the treatment of thrombosed Dacron grafts was performed in four patients. Angiography after the infusion revealed extravasation of contrast material through the interstices of the graft. In each case the graft material was knitted Dacron, Surgically placed 1 month to 6 years before infusion with streptokinase. The fibrinolytic activity of streptokinase is likely responsible for lysis of the fibrin in the interstices of the graft with resultant extravasation of contrast material.

Comparison of CVA imaging with 99mTc phosphates, 99mTc pertechnetate, and computed tomography.

A retrospective study was made of 111 patients who underwent computed tomography (CT) and nuclear brain scans, with both pertechnetate and phosphate bone agents (PHOS), within 7 days of each other. Specifically, 78 patients who had a recent cerebral vascular accident (CVA) were compared. There were no significant sensitivity differences between the methods. While these studies appear complementary, the most important criterion is the time after onset when the studies were performed. The axiom "if the intensity of the phosphate scan exceeds that of the pertechnetate, the lesion must be a CVA" is true, only if the study is performed within 4 weeks of onset. The most economical method for optimum detection of CVA, with avoidance of frequent errors, is an early CT followed by a PHOS brain scan about 14 days after ictus in those that have initial negative CT.