Rapid Film Changer Research Articles

Arterial imaging in patients with lower extremity ischemia and diabetes mellitus

Precise, comprehensive imaging of the arterial circulation is the cornerstone of successful revascularization of the ischemic extremity in patients with diabetes mellitus. Arterial imaging is challenging in these patients because the disease is often multisegmental with a predilection for the distal tibial and peroneal arteries. Occlusive lesions and the arterial wall itself are often calcified and patients presenting with ischemic complications frequently have underlying renal insufficiency. Intra-arterial digital subtraction angiography (DSA), contrast enhanced magnetic resonance angiography (MRA), and more recently, computerized tomographic angiography (CTA) have been used as imaging modalities in lower extremity ischemia. Each has specific advantages and shortcomings in this patient population, which will be summarized and contrasted in this review. DSA is an invasive technique most often performed from a femoral arterial puncture and requires the injection of arterial contrast, which can occasionally cause allergic reactions. In patients with pre-existing renal insufficiency, contrast infusion can result in worsening renal failure; although usually self-limited, it may occasionally require hemodialysis, especially in patients with diabetes. However, DSA provides the highest degree of spatial resolution and image quality. It is also the only modality in which the diagnosis and treatment of arterial disease can be performed simultaneously. MRA is noninvasive, and when enhanced with gadolinium contrast injection provides arterial images of comparable quality to DSA and in some circumstances may uncover distal arterial targets not visualized on DSA. However, spatial resolution is inferior to DSA and erroneous interpretations due to acquisition artifacts are common. Specialized equipment and imaging techniques are necessary to minimize their occurrence in the distal lower extremity. In addition, due to the risk of inducing nephrogenic systemic fibrosis, gadolinium-enhanced MRA cannot be used in patients with renal insufficiency. CTA is noninvasive and rapidly performed, with better spatial resolution than MRA, but requires the largest volume of contrast infusion, exposes patients to high-doses of radiation, and is subject to interpretive error due to reconstruction artifacts especially in heavily calcified arteries, limiting its usefulness in many patients with diabetes. For patients in whom the planned intervention is a surgical bypass, DSA and MRA will provide high quality images of the lower extremity arterial anatomy. For patients in whom a catheter-based intervention is the likely treatment, a diagnostic DSA immediately followed by a catheter-based treatment in the same procedure is the preferred approach. In patients with pre-existing renal dysfunction, in which gadolinium-enhanced MRA is contraindicated, DSA or CTA can be performed. However, patients should have an infusion of intravenous normal saline solution or sodium bicarbonate before the procedure to reduce the incidence of contrast-induced nephropathy.

Exposure rates during special procedures with C-arm type fluoroscopic systems.

To test for regulatory compliance of free-in-air entrance air kerma rates (EAKR) in C-arm type fluoroscopic equipment, measurements are frequently made under minimum source-to-image receptor distance (SID) and at 300 mm from the image intensifier. However, this is not representative of normal patient geometry, and the automatic brightness controls on these units frequently increase tube output as SID increases. This study investigated effects of these circumstances on actual EAKRs. Typical patient geometries were observed and recorded for 23 consecutive body vascular procedures. EAKRs were measured under compliance and normal patient geometries with use of five modern C-arm type systems for special procedures. SIDs of 1 m were typical when rapid film changers were employed and the patient's entrance skin surface was typically 500 mm from the image receptor. Actual EAKRs were found to be up to 2.5 times those measured under compliance geometry. Actual patient geometries should be used to ensure correct estimates of EAKRs.

Development of a ceiling-suspended angiographic unit for interventional neuroradiology

A new neuroangiographic unit was developed with a ceiling-suspended gantry, capable of rotation (110 degrees) and craniocaudal angulation (+/- 45 degrees) along the body axis. The gantry could also be rotated 225 degrees at the ceiling suspension axis and sidetracked away from the angiographic table in case of emergency. Two sets of a twin-focus X-ray tube and a 12-inch image intensifier (II) were mounted on the gantry in the isocentric and cross-firing positions. High resolution 1024 x 1024 matrix digital radiography was obtained with a speed of 30 frames/s, while conventional film-screen radiography was obtained at 4 films/s. Rapid film changers were installed and interchangeable with the IIs. The lateral II and X-ray tube could be positioned from either side of the patient. There was no angulated position of the lateral imaging system during angulated anteroposterior or Towne projection of the frontal imaging system. Automatic repositioning of the gantry was possible to the preset position. Stereoscopic, magnification and stereoscopic magnification radiography could be obtained easily in monoplane or biplane mode. Switching from fluoroscopy to radiography and vice versa was possible rapidly and easily. Neuroangiographic as well as interventional procedures were performed expeditiously with lower complication rates. Suspending the gantry from the ceiling made more space available on the floor for the anesthesiologists.

Development of a new universal neuroangiographic unit.

A new neuroangiographic unit has been developed with use of a "C" type gantry, which is capable of rotation and angulation for various angiographic projections. Two sets of a twin focal X-ray tube and an imaging system are mounted on the gantry. Each imaging system consists of a 9 inch image intensifier and a 14 X 14 rapid film changer, which can be exchanged in position rapidly. Stereoscopic magnification and stereoscopic contact angiography, fluoroscopy and DSA are performed in monoplane and biplane and switched over to each other expeditiously and easily. The detailed angiographic information is obtained with lower complication rate and lower exposure to patients. Interventional neuroradiologic procedures are performed efficiently on this unit.

Improved contrast in special procedures using a rotating aperture wheel (RAW) device.

A new scatter control technology consisting of multiple rotating aperture wheels (RAWs) is being developed to provide improved radiographic contrast and/or reduced patient dose in both single frame and dynamic procedures. The unique geometry of this system allows the conventional source-patient-image receptor geometric relationship to remain unchanged so that the device can be added to existing radiographic, fluoroscopic, and conventional tomographic installations. A prototype RAW device has been used with a rapid film changer for simulated abdominal angiography. The resulting images show improved contrast over those obtained with a standard 12:1 fixed grid.

撰択的冠状動脈造影

With recent advance of coronary artery bypass surgery, contrast visualization of the coronary artery branches and its stricture or obstruction have assumed increasing practical importance. We presented our experience at the Sapporo Hospital of Japanese National Railways that 32 coronary arteriograms have been recorded and got satisfactory diagnosable films during a year period using Amplatz's cathter and mono-phasic 500mA procedure without any special designed X-ray apparatus for examination of circulatory system expect Matsuki's MK-5B type rapid film changers.

Phlebo-arterio-urography in the diagnosis of abdominal masses in children

The technique of phlebo-arterio-urography is described as a simple, safe and quick method of investigating abdominal tumours in children. It consists of injecting contrast medium into the femoral vein and following its course through the venous, arterial and urographic phases, using a rapid film changer. The value of the method in the investigation of 15 cases of abdominal tumour is discussed.

Catheterization of the umbilical vein and its use for hepatography

The umbilical vein of the adult can easily be reopened and used for various diagnostic and therapeutic procedures such as hepato-portography, measurement of the portal pressure, chemotherapy in tumours of the liver, antibiotic therapy, for portal decompression, and for metabolic and anatomic studies. 46 catheterizations of the umbilical vein have been performed for the above mentioned purposes, chiefly for hepatography, chemotherapy and anatomic study. Excellent visualization of the portal branches in the angiographic phase, and intense homogeneous opacification of the liver parenchyma in the hepatographic phase was achieved by injection of contrast medium and use of a rapid film changer. Tumours and metastases were demonstrated as distinct defects in the homogenous liver parenchyma. Liver metastases were diagnosed with great accuracy. Following chemotherapy via the umbilical vein, reduction in the size of the liver, reduction in the size of the metastases and necroses around the metastases were demonstrated clinically, by hepatography and by post mortem examination. The embryonic intrahepatic porto-caval shunt was reconstructed in the corpses of the adults by reopening of the umbilical vein and the ductus venosus Arantii.

A moving extension to augment the angiographic table in panarteriog- raphy.

Diagnostic angiography now ranges literally from “head to toe.” The femoral or axillary approach permits study of the carotid and vertebral arteries, brachiocephalic vessels, aortic arch, aortic branches, and femoral runoff either singly or in any combination. Not uncommonly, a patient will present with symptoms suggesting multivessel disease, e.g., hyper-tension with transient ischemic attacks or claudication of the lower extremities. To expedite diagnosis, the referring physician and angiographer may attempt to study each area of interest in one session. The average range of movement of the angiographic table is approximately 50 inches, which often falls short of the length necessary to move the patient from the rapid changer to the image intensifier in a muItivessel study. Therefore, the patient must be moved bodily along the table and onto the rapid film changer after placement of the catheter, e.g., in selective carotid catheterization following an aortic arch examination. Since the intracranial vessels are of a much smaller caliber than the brachiocephalic branches, the technician strives for the greatest clarity by having the head as close as possible to the surface of the changer unless magnification is used. Such movement of the patient is time-consuming, tedious and strenuous; moreover, it may also dislodge sterile drapes, intravenous tubes, electrocardiographic leads, and even catheters. Probably the greatest number of movements of the patient occur in selective catheterization of the right and left carotid and vertebral arteries following an aortic arch angiogram. The disarray of the patient's sterile field can be quite disconcerting to all involved. Movable plywood or Formica tops have been used, but they leave much to be desired because of the friction of the surfaces on the angiographic table. It is quite a strain for one technician, and additional help is usually necessary in moving the patient. With the help of a local x-ray representative, a a movable extension for the angiographic table has been devised, extending the range of the total table movement and expediting movement of the patient from the rapid changer to the image intensifier (and vice versa) with minimal effort. The range of the table has now been extended to 74 inches. Anodized aluminum stock is clamped onto the side of the angiographic table, and a Formica top from a discarded x-ray table is fitted with a series of ball-bearing rollers to facilitate easy movement of the top within the aluminum edges (Fig. 1). A clamp on the side of the aluminum side rails immobilizes the extension at any point along its course in the longitudinal axis. The superior aspect of the Formica top is cut to the outline of the upper body, permitting the head to be positioned as close as possible to the rapid changer for the lateral series of angiograms (Figs. 2–4).

Angiography in Diagnosis of Chronic Unexplained Melena

After all clinical methods, including ordinary roentgen diagnostic procedures, have been attempted, the source of gastrointestinal bleeding remains unexplained in many patients. As many as 20 per cent of massive hemorrhages are undiagnosed (8). The cause of chronic or intermittent bleeding is even more difficult to detect. In this latter group of patients, the source, though undetected at barium examination, may be revealed by selective angiography. Thus, cases of unexpected tumor (3), angioma (10), arteriovenous fistula (18), and varices (1) have been diagnosed. At the Roentgendiagnostic Department, University Hospital of Lund, 24 patients with previously undiagnosed melena have been examined with selective celiac and superior mesenteric angiography. These examinations have been reviewed to assess the usefulness of the method in these patients, who present difficult diagnostic problems. Materials and Methods The patients in this series were chosen according to the following criteria: (a) two or more positive Weber tests for occult bleeding were performed during at least two different periods of bleeding; (b) the gastrointestinal barium examination was normal. Patients in whom barium examination of the gastrointestinal tract revealed a possible source of bleeding, such as a small hiatus hernia or coarse gastric mucosa, were excluded even though there was doubt these were the sites of bleeding; (c) both selective celiac and superior mesenteric angiography had been carried out. Thus, the material was highly selected to include only those patients with undiagnosed, chronic gastrointestinal bleeding, in whom complete angiographic examinations had been made. Catheterization was performed by the percutaneous technic via the femoral arteries, usually with a thin-walled KIFA red catheter (I.D./O.D. = 1.4/2.2 mm). Filming was done with a rapid film-changer, usually two exposures per second for four seconds, one per second for five seconds, and then one every other second for ten seconds. Injections of approximately 30 cc of 76 per cent Urografin (Schering, Germany) were made into the celiac and superior mesenteric arteries in the anteroposterior and right posterior oblique projections. A pressure injector was used, and the contrast medium was injected at approximately 11 cc/second. Findings The abnormal angiographic findings in these patients have been grouped into five general classifications, although some patients had abnormal findings in more than one classification (TABLE I).

The tilted left anterior oblique position in the study of congenital cardiac anomalies.

Selective cineangiocardiography is widely used for the demonstration of congenital cardiac anomalies. Selective opacification of a cardiac chamber is performed after a diagnosis has been proposed or established by physical examination, radiographic and fluoroscopic examination of the chest, and study of data derived from external electrocardiography and cardiac catheterization. The selection of the injection site is determined by (a) the diagnosis established from the data and (b) the ability to introduce a catheter into the desired chamber. The roentgenographic positions chosen for selective angiocardiography depend upon the type of available equipment and the nature of the presumed cardiac anomaly. In the use of biplane rapid film changers, Kjellberg et al. (2) first called attention to the advantages and disadvantages of conventional positions for examination of congenital cardiac anomalies. Because of the complexities of cardiac anatomy, these investigators experimented with various positions of the patient. In addition to rotating the patient, Kjellberg tilted the x-ray tube so that the atrial and ventricular septa could be optimally outlined. Routine use of this maneuver was abandoned because of distortion projected on the biplane angiocardiograms. Kjellberg, therefore, recommended conventional postero-anterior and lateral projections for examination of virtually every cardiac lesion. These projections are the usual ones when biplane rapid film-changers are employed. On the other hand, the use of oblique positions is required for most examinations performed with a single-plane rapid film-changer or a cine unit. The right anterior oblique position is useful in the demonstration of atrioventricular valves (i.e., mitral stenosis) and in the separation of aorta and pulmonary artery (i.e., tetralogy of Fallot). The left anterior oblique position is preferred in study of the atrial and ventricular septa in presence of intracardiac shunts. Rationale for Use of Tilted Left Anterior Oblique Position In the postero-anterior and true lateral projections of the angiographic image, there is inevitable overlap of the central portions of the atrial and ventricular chambers and the atrioventricular valves. With atrial septal defects, the overlap of the cardiac chambers precludes precise localization of a defect site (2). Correlation of the frontal projection with the lateral is necessary for localization of high ventricular septal defects (1). In the conventional left anterior oblique position, the ventricles lie nearly directly in front of their respective atria. As a result, the interventricular septum is foreshortened and superimposed on the atrial septum. The atrioventricular valves are not visible when the atria are opacified because the contrast medium overlaps the valvular plane.

VOIDING CYSTOURETHROGRAPHY IN CHILDREN

Sixty-eight voiding cystograms were obtained on 61 patients with a rapid film changer. In 7 examinations, or approximately 10 per cent, the patients could not void.Abnormalities were noted in 36 of the 61 cases, or 59 per cent. Bladder outlet abnormalities were demonstrated in 27 of the 61 cases, or 44 per cent, and vesicoureteral reflux in 19, or 31 per cent.We feel that serial roentgenograms during voiding are necessary because of our 19 reflux cases, 6 refluxed only during voiding and of the 6, 5 refluxed only at the end of the series or in a delayed study. It is also of interest to note that 4 of our 19 cases had prior cystograms under general anesthesia which showed "no reflux."

Angiographic determination of the size of the ascending aorta in congenital heart disease.

The size of the aorta is considered to play an important role in the differential diagnosis of congenital heart disease. Conventional roentgenograms and fluoroscopic examination are helpful in ascertaining aortic size, but several conditions make their interpretation difficult. In infancy the size of the aorta cannot be estimated with certainty when the thymus is hypertrophied, a frequent occurrence. Mild dilatation of the ascending aorta is often missed on routine roentgenograms. Even when the esophagus is filled with barium to outline the aorta, the index of accuracy for evaluating its size is not high. Moreover, if a single telecardiogram is taken, the exposure may sometimes be made in diastole when the caliber of the vessel is less than in systole. When serial angiocardiograms are performed with very rapid film changers, however, the aorta is always outlined, not only in diastole but in systole, and even mild systolic dilatation of the ascending aorta may be detected. This paper is concerned with the ...

Congenital Heart Disease

The planning of therapy of patients with congenital heart disease requires a reasonably accurate diagnosis of the anatomy of the defect and the resultant pathophysiologic effects. During the last decade, remarkable advances have occurred in the laboratory armamentarium available to the cardiac physiologist. The measurement of intravascular pressure and flow as determined by intermittent blood sampling for oxygen can be complemented with more sophisticated methodology including indicator dilution techniques using dyes, gases, or polarographically active materials, intracardiac phonocardiography, and fiberoptics. These methods may be used to study patients at rest or by evaluating effects produced acutely by exercise or drugs. In most patients, it is necessary to visualize parts of the intracardiac chambers or great vessels with selective angiocardiography using motion picture techniques or rapid film changers. The two volumes by Drs. Edwards, Carey, Neufeld, and Lester entitled, Congenital Heart Disease have an important subtitle. The major emphasis of the

THE ODELCA ONE HUNDRED MILLIMETER CAMERA AND RAPID FILM-CHANGER: ITS APPLICATION TO ANGIOGRAPHY.

It is well recognized that sequential films are necessary for the appreciation of all phases of vessel filling during vascular contrast examinations. This can be accomplished by radiographic and/or photographic reproduction of opacified vessels with any reliable device that records extensive information in a short period of time in serial fashion. An optical camera recording of the fluoroscopic image coupled to a compact, serial cut-film changer permits the recording of images of opacified vessels at rates of up to six films per second. The Odelca film camera and changer3 is such an instrument, with the advantage of mobility when employed beneath a portable examining table. It can be used with any overhead or ceiling-mounted, mobile x-ray tube in any of several adjointing rooms during angiography. Only the x-ray tube and generator capacities effectively limit the total number of exposures that can be made with the system. The camera employs a fixed grid in front of a curved, fluorescent screen which fluoresces when struck by the impinging beam of x-ray photons and sends light impulses through a special condensing mirror system to a curved surface in contact with 100 × 100-mm.-size film. These small individual films are transported serially and rapidly from a light-tight magazine across the aperture of the condensing system at a speed set b y a programming device. The fluorescent are a at the front of the camera covers a total of 14 × 14 in., allowing complete coverage of even large adult fields during thoracic and abdominal angiography. Figure 1 illustrates the camera beneath an examination table during intravenous aortography by the percutaneous catheter technic. The programming device can be set to deliver up to 40 consecutive films at rates of from 1 every two seconds to 6 per second. Different speeds can be selected for each set of 5 sequential films. Because of the small size of the transport mechanism and no need for bulky intricate parts, the film-changer-camera combination suffers little from transport breakdown or mechanical failures, problems more common to larger automatic film-changers when careful maintenance is not practiced. A red light on the side of the camera warns the operator if all preliminary operational steps have not been carried out. This safeguard helps to prevent most operational failures. The only problem encountered during nineteen months of continuous use was an occasional sticking together of the films in the magazine, preventing their transport during operation. To correct this, film packages are opened and stored in a dry dark room. Then, before the magazine is loaded, the individual films are ruffled like playing cards to reduce surface tension associated with slight moisture and to assure dry, separated films. These procedures and careful attention to film positioning in the magazine have prevented film jams during the past several months of operation.

Angiography in the general practice of radiology.

The need and demand for extracardiac angiography are increasing in our community hospitals. Since angiography is a special radiographic procedure, more satisfactory examinations will be possible if our radiologists prepare themselves to accept full responsibility as angiographers (1). A few relatively inexpensive additions to existing equipment will enable any radiology department to undertake peripheral vascular angiography. It has been shown that, once the equipment and a radiologist-angiographer become available, case material grows continuously. In St. Paul, the demand for these examinations has shown a considerable increase during the author's two-year experience. From Jan. 1, 1961, to Nov. 12, 1962, 587 angiographic procedures were personally performed in similarly equipped hospitals having an average daily census of 60, 200, 230, 250, and 300 patients (Table I). The angiographic facilities and technics developed for use in these community hospitals form the basis of this report. Automatic Equipment Owing to the prohibitive cost, none of the community hospitals covered by this report is equipped with an automatic rapid film changer. These machines are a convenience in angiography, but they are not a prerequisite to accurate extracardiac diagnosis. With suitable catheters and contrast media, most extracardiac examinations can be performed with a hand injection, though efficiency is enhanced when the speed of injection and the timing of exposures are automatically controlled. The Amplatz (2) injector2 provides these features and is particularly useful for studies above the diaphragm and in some patients with hypertension. One such injector was available and was transported from hospital to hospital. Manual Equipment The additions to existing manual equipment can be obtained at a cost of $400.00 or less. Most of the materials can be constructed in a hospital maintenance shop. These removable additions should be designed for use with a fluoroscopy table so that the position of the catheter tip can be checked under direct vision by a small test dose of contrast medium. The rear of the table Bucky slot should be opened. The usual Bucky tray is removed and a 17 × 52-inch metal or plywood tray is inserted in the fashion of the Paessler-Wentzlik table.3 This tray will hold three 14 × 17-inch or four 10 × 12-inch film cassettes. The tray is successively advanced to film-centering markers which are placed along its edge. Film fogging is eliminated by horizontal 5-inch strips along both sides of the table top. In addition, an 18-inch vertical wood or rod support is clamped to both sides of the table, and lead aprons are draped to overlap the horizontal lead strips (Fig. 1). Brachiocephalic and Abdominal Studies: Brachiocephalic and abdominal studies can be performed with the arrangement described above, and films can be obtained without motion at one-second intervals with exposures of two-tenths of a second or less. This filming rate has proved adequate for mapping collateral channels and rate of blood flow where there is occlusion of carotid, innominate, subclavian, celiac, hepatic, or renal arteries.

Ultrashort (millisecond) timing and a rapid film changer in pediatric radiography; evaluation of dynapulse and impulse timing.

During the past 20 months an x-ray timer capable of exposures as short as 1/1000 second has been used to determine whether ultrashort exposures are more advantageous than those obtained with conventional timers, including the impulse timer.* The average impulse timer does not function faster than 1/60 second, but specially built ones produce exposures as short as 1/120 second, and, for practical purposes, the usable portion of this interval is probably 1/200 second. The Dynapulse timer is five times faster than the shortest possible exposure with an impulse timer.* Dynapulse exposures are produced by a controlled-electron-flow vacuum tube placed in the high-tension, or secondary, circuit of an ordinary rectified x-ray generator with a filter condenser across its output. This differs from conventional timers, which operate in the primary, or low-tension, circuit. Power from the condenser is released to the x-ray tube by the timer. It has been claimed that ultrashort

Recording timer for arteriography.

The timing of films made rapidly during arteriography is difficult with a stop watch and, at best, an estimate is all that can be achieved. The timer herein described was developed to overcome this difficulty. A simple electric clock motor was mounted in a case and a plastic disk was mounted on the shaft. Small lead numbers and serrated markings were placed around the edge of this disk, which projected just beyond the margin of the clock case. The placement of the numbers on the disk was made after timing its rotation. A handy switch was placed in the line cord of the clock to turn it on. In use, after the patient has been positioned, the timer is so placed that its image will be on the film. The switch is located near the operator of the rapid film changer and is closed at the beginning of the injection of opaque material. Thereafter, the time after injection is recorded on each film as it is taken. This timer has been used for approximately a year and a half for over 200 arteriograms with satisfactory r...