Videodensitometric quantitation of stenosis: in vitro and in vivo validation.

Percentage of stenosis of a vascular lumen was quantitated using a digital subtraction angiography system with videodensitometric analysis. To validate the algorithm and methods, we used precisely drilled Lucite rods of three inner diameters and various reduced diameters to give known luminal reduction. Both in vitro and in vivo results of stenosis measurements resulted in an excellent correlation between actual and measured values (correlation coefficient greater than 0.

Acute pancreatitis.

The exocrine pancreas secretes into the gut on demand more than 20 proteins that are indispensable for digestion. In-vivo autodigestion is prevented by an array of natural safeguards. In acute pancreatitis, inappropriate intrapancreatic activation and release of pancreatic hydrolases occur, but the pathogenetic mechanism of autodigestion is unclear.

Multipurpose coaxial needle used for percutaneous nephrostomy.

We describe a 24-cm long coaxial needle that has a 15-cm, beveled outer sleeve and accepts a 0.038-inch (0.097-cm) guidewire.

Percutaneous transluminal carotid angioplasty in fibromuscular dysplasia. Case report.

A patient with fibromuscular dysplasia (FMD) of the internal carotid artery was treated by balloon percutaneous transluminal angioplasty (PTA). This is the sixth reported case of FMD stenotic disease which was dilated by PTA. All previous cases including the current example were treated successfully with resolution of symptoms.

Comparative hemodynamic effect of metrizamide and Renografin 76 in infants with congenital heart disease.

Twenty patients under the age of 2 years with suspected congenital heart disease received alternately Renografin 76 and metrizamide for angiocardiography. The dose was 2.0 ml/kg per injection for both contrast media into the left ventricle.

Imaging of the left ventricle in patients with ischemic heart disease: role of the contrast angiogram.

The contrast left ventriculogram is the gold standard against which all other cardiac imaging techniques are measured. In the past decade, noninvasive methods such as radionuclide angiography, echocardiography, computed tomography (CT), and digital substraction imaging have become available. This review examines the role of these techniques, and whether they will supersede the selective contrast ventriculogram.

Therapeutic embolization of the renal artery with Gianturco coils: limitations and technical pitfalls.

The Gianturco coil, with or without Gelfoam, is particularly popular and effective in occluding renal arteries to control bleeding, devascularize tumors, close arteriovenous fistulas, and infarct kidneys in end-stage renal disease. However, without special precautions, successful embolization can suddenly be transformed into catastrophe. Representative reports of complications from medical centers across North America are used to illustrate the initial technical pitfalls of coil placement, as well as the more delayed complications that produce deviations from the usual postinfarction syndrome.

Assessment of healing of long-bone fractures by intraosseous venography.

Intraosseous venography with compression of the soft tissue was performed following fracture of the radius in 13 dogs to assess the repair process. Two angiographic criteria were analyzed: (a) intraosseous venous crossing of the fracture ("medullary crossing") and (b) capillary blush of the proximal osseous fragment ("proximal blush"). The bone strength of the fractured and intact radii was compared.

Diagnosis and treatment of fluid-filled renal structures in children with ultrasonography and percutaneous puncture.

The application of ultrasonographic and percutaneous needle puncture techniques in the diagnosis of various fluid-filled renal anomalies has permitted rapid delineation of anatomic detail, more definitive physiologic evaluation, and drainage, when necessary, in a safe and cost-effective manner. Its usefulness in children is emphasized in 6 illustrated cases of male infants with minimally or nonopacified renal anomalies, one of the more difficult diagnostic problems in pediatric urology.

An angiographic assessment of left ventricular function in isolated mitral valvular prolapse.

Angiographic studies demonstrating alterations in left ventricular contraction have been cited as evidence that isolated mitral valve prolapse (MVP) may be associated with a cardiomyopathy. We studied 17 patients with isolated MVP undergoing cardiac catheterization who had chest pain, palpitations, and/or a murmur of mitral regurgitation. Eleven of 13 patients (85%) with no or mild (Grade 1+) mitral regurgitation had normal left ventricular hemodynamic measurements, while three of four patients (75%) with moderate or marked (Grades 2+-4+) regurgitation had abnormal left ventricular hemodynamic measurements.

Role of peripheral vasodilation in the hypotensive response to left ventriculography in anesthetized dogs.

Hypotension after left ventriculography (LVG) is believed to result from direct myocardial toxicity, peripheral vasodilation, or a combination of both. The contribution of each has not been established. Thus, LVG was performed in anesthetized dogs under conditions in which peripheral vascular reactivity (PVR) was altered pathophysiologically (aortic coarctation) or pharmacologically (acetylcholine infusion).

Permanent percutaneous antegrade ureteral stent placement without transurethral assistance.

A simple, one-step, permanent, percutaneous, antegrade insertion of a ureteral stent is described, utilizing a double, pigtail catheter. No transurethral assistance is necessary. The advantages of this simplified technique are presented, and the necessary prerequisites for its application are discussed.

Inability to show clot: one limitation of ultrasonography of the abdominal aorta.

Ultrasonography is accurate for diagnosis of abdominal aneurysms and clots within them. However, due to technical factors, occlusive clots within the aorta can be missed even at high gain. The authors report three cases in which total occlusion of the abdominal aorta was misdiagnosed as a free lumen occupied by a small clot.

Reliability of doppler scanning of the carotid bifurcation: angiographic correlation.

The results of continuous wave Doppler scanning of 96 common carotid arteries and their immediate branches were compared with those of selective angiography. The overall accuracy of the Doppler technique for the assessment of the common, internal and external carotid arteries was 98%, 81% and 86%, respectively with a sensitivity of 60%, 70% and 54%, and a specificity of 100%, 93%, and 96%. When stenoses of 50% were considered hemodynamically insignificant, the overall accuracy of the assessment of the common, internal and external carotid arteries rose to 100%, 93% and 93%, but the sensitivity was only 100%, 83% and 53%, whereas the specificity was 100%, 96% and 96%.

Diverticulosis of the left ventricle.

Nine patients, 4--60 years old, had single or multiple left ventricular outpouchings, best seen during diastole, and believed to represent congenital diverticula. The 14 diverticula, 5--28 mm long, were either along the diaphragmatic or anterior ventricular wall. Only one patient had his diverticulum surgically removed; the wall was lined by thick endocardium surrounded by normal myocardium.

Myocardial accumulation of labeled phosphate in malignant pericardial effusion.

Recognition of the presence of a malignant pericardial effusion is important because of the insidious onset and life-threatening potential. This report presents data on three patients with metastasizing carcinoma of the breast, all admitted with a presumptive clinical diagnosis of malignant pericardial effusion. Two of the three revealed a diffuse concentration of Tc-99m PPi within the myocardium.

Pitfalls in the plain film evaluation of the thoracic aorta: the mimicry of aneurysms and adjacent masses and the value of aortography. Part I. Transverse aortic arch.

In five instances, transverse aortic arch aneurysms were found that had initially, clinically and radiographically, mimicked thoracic neoplasms. Transverse aortic arch aneurysms display a wide spectrum of presentation: they may be asymptomatic, or they may cause symptoms secondary to esophageal, bronchial, vascular, or neural compression within the mediastinum and so mimic neoplasms. Conventional radiography in four projections and tomography are important components of the diagnostic evaluation of middle mediastinal masses.

A proposed mechanism for transient increases in arterial pressure and flow during angiographic injections.

In a series of animal experiments, we have confirmed the observation that arterial pressure and flow increase distal to the injection site during power injections through non-obstructing catheters. Our data suggest that the phenomenon is secondary to the transient production of turbulence. Thus, for a given injection rate, catheters with smaller end holes create more fluid velocity, which increases the Reynolds number and causes augmentation of downstream pressure and flow.