Magnification Technique Research Articles

Amipaque dacryocystography. Biplane magnification and subtraction technique.

HomeRadiologyVol. 141, No. 2 PreviousNext Amipaque dacryocystography. Biplane magnification and subtraction technique.T El Gammal, B S BrooksT El Gammal, B S BrooksT El GammalB S BrooksPublished Online:Nov 1 1981https://doi.org/10.1148/radiology.141.2.7027313MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Article HistoryPublished in print: 1981 FiguresReferencesRelatedDetailsCited ByAnnals of Anatomy - Anatomischer Anzeiger, Vol. 224Comparative Clinical Pathology, Vol. 18, No. 1Orbit, Vol. 9, No. 2The British Journal of Radiology, Vol. 61, No. 725Recommended Articles RSNA Education Exhibits RSNA Case Collection Vol. 141, No. 2 Metrics Altmetric Score PDF download

Differential Diagnosis of the Nodular Goiter using the Direct Magnification Techniques of Soft Tissue Roentgenography and the Automatic-Mechanical Compound Scan of Ultrasonotomography

Differential Diagnosis of the Nodular Goiter using the Direct Magnification Techniques of Soft Tissue Roentgenography and the Automatic-Mechanical Compound Scan of Ultrasonotomography

Introduction to microsurgery.

An updated definition of microsurgery includes the application of magnification techniques to basic surgical principles and the functional restoration of body structures by means of the direct union of parts or transfer of tissue using microsurgical techniques. Nylen performed the 1st surgery under magnification with the use of an operating microscope in Sweden in 1921. With the expanding scope of microsurgery, it becomes obvious that it is a surgical technique clinically applicable in every surgical specialty. The equipment for microscopy is microscopes, sutures, jeweler's forceps, needle holders, scissors, and coagulators. In microsurgery, all surgical movements have been reduced to a pinch mechanism between thumb and index. The instruments have been designed with this in mind and are characterized by small precision tips, light balanced proportions, pinch closure, and nonreflective surfaces. Long handled instruments are necessary for neurosurgery and gynecology due to the depth of the working field. The perfection of the microsurgery technique begins with extensive practice in the research laboratory. Clinical microsurgical reconstruction should be attempted only when competence has been achieved in the laboratory.

Evaluation of magnification radiography in bone tumors.

The additional information obtained by direct radiographic magnification is examined in comparison to standard exposures of 50 bone tumors. A diagnostically significant increase in information is obtained in 84% of these cases. This is distributed at an irregular rate over the various decisive phases of the tumor diagnosis. In 24% of the cases the magnification exposure was helpful excluding other diseases, in 40% it permitted a differentiation between benign and malignant lesions and in 20% it permitted a classification of the type. The clinical importance of the magnification technique is relevant.

The diagnosis of early changes in the phalanges in primary and secondary hyperparathyroidism by a direct radiological magnification technique

A comparative study of direct radiological magnification technique was made of 22 patients with primary hyperparathyroidism, 15 patients with secondary hyperparathyroidism, and 17 patients without changes in bone structure. Only regarding the summation of all radiologically visible changes in bone structure, a hyperparathyroidism can be suspected. The differential diagnosis of primary and secondary hyperparathyroidism is mostly impossible. Furthermore we were able to demonstrate that early discrete changes in bone structure are more easily diagnosed in magnification technique than in standard technique. Therefore we regard the direct radiological magnification technique as an adequate method for patients, in whom hyperparathyroidism is suspected.

Coronary Artery Bypass Grafting: Simplification and Refinement of Surgical Technique

Recent advances in technique and myocardial preservation that I have used in performing the coronary bypass operation are described. Rigid adherence to basic microsuture technique and use of hypothermic hyperosmolar cardioplegic solution and wide-field optical magnification have been responsible for improving graft patency rates and markedly reducing operative mortality during the past six years. With these techniques, hospital mortality has been 0.6% (3 deaths) in the last 500 consecutive coronary bypass operations.

Ureteral Function and Healing Following Microsurgical Transureteroureterostomy in the Dog

An oblique end‐to‐side anastomosis of one ureter to the contralateral ureter (transureteroureterostomy) may permit salvage of a kidney whose middle or distal ureter is not salvageable by standard repair techniques. This procedure was done with intraoperative magnification and microsurgical techniques in 5 experimental dogs. Animals were euthanized for healing studies at 1, 3 and 5 weeks, and the results correlated with postoperative and preterminal excretory urograms. Healing of the anastomosis was organized by layers and completed both grossly and histologically in all animals at 5 weeks. Ureter function was retained except for short‐term, mild, postoperative hydroureter. Potential clinical indications for transureteroureterostomy are: 1) middle or distal ureteral transection due to trauma; 2) delayed recognition of iatrogenic intraoperative severence or ligation; 3) distal ureteral neoplasia; and 4) selected cases of ectopic ureter. Complications include dehiscence, stricture, or the dissemination of infection or neoplasia which would compromise proximal ureters and both kidneys.

Surgical relations of the orbit and optic nerve: an anatomical study under magnification.

Whether operating on soft tissue, bony tissue, or both, as in major craniofacial procedures, patient safety is enhanced by better understanding of the anatomical details of the orbit. The myth and mystery of the optic nerve is made clear here, especially by our magnification techniques.

Renal osteodystrophy: An underdiagnosed condition

With the availability of 1-alpha-hydroxycholecalciferol it is even more relevant to detect the earliest stages of renal osteodystrophy. Sixty-two patients, either on haemodialysis or recent recipients of a renal transplant and 10 controls underwent hand radiography by a standard technique and by a direct magnification technique employing a 0.1 mm focal spot. A comparison of intracortical striations, subperiosteal resorption and soft tissue calcification was made in the two groups and hand score calculated on the non-magnification radiographs. The results were assessed independently by two radiologists. In subperiosteal resorption, the non-magnification technique gave a 6% positive result compared to 47% with magnification (P less than 0.01). For intracortical striations, the non-magnification technique gave an 11% positive results, whereas magnification resulted in a 45% positive result (P less than 0.01). Soft tissue calcification was found in one patient only, and reduction in hand score was a rare occurrence. The use of a standard technique only, without magnification, for radiographing hands in patients with renal disease, will result in evidence of renal osteodystrophy being missed in a significant proportion of patients.

Modified Method In Measurements Of X-Ray Focal Spot Modulation Transfer Function

The Modulation Transfer Function (MTF) of an x-ray focal spot has been obtained without the aid of a microdensitometer. The modified method described in this study utilizes radiographic magnification techniques to eliminate the need for a microdensitometer. In this study a radiographic magnification factor of 25X or higher has been employed to obtain the slit-camera images of x-ray focal spots. The Line Spread Function (LSF) is obtained by scanning the focal spot slit-camera image acquired with the modified method on an ordinary densitometer equipped with a 0.2 mm aperture. The MTF is subsequently calculated from the LSF and compared with the MTF that was obtained by means of the traditional method. The results show good agreement between the MTFs obtained by these two methods.

Magnification mammography: evaluation of screen-film and xeroradiographic techniques.

An x-ray unit designed for conventional nonmagnification and magnification mammography has been evaluated in terms of image quality and corresponding radiation exposure levels. The technical advantages of the radiographic magnification technique can result in improved image quality and reduction of the recording-system noise. The microfocal spot allows 1.5 x magnification mammograms with minimal geometric unsharpness. However, the magnification technique requires an increased radiation dose to the breast, compared to conventional nonmagnification techniques. An additional radiation dose may be required for screen-film magnification views because of reciprocity law failure due to long exposure times. The increased-dose limitation and the small dimensions of the recording-system cassettes have precluded the use of magnification in place of nonmagnified images for routine mammographic examination. The magnification technique has proved to be beneficial in selected cases.

Magnification Mammography: A Low-Dose Technique

Image quality and radiation exposures of a mammographic technique using direct radiographic magnification at 2 X with a microfocal spot x-ray tube and a fast, double screen-film system were compared to those of conventional contact mammography with a rare-earth screen and molybdenum target tube. The results indicate that the magnification technique yields improved detection of microcalcifications and comparable visualization of soft-tissue details, with a large reduction in radiation exposure. This technique has demonstrated the feasibility of carrying out high-quality mammography with an entrance dose of 1.35 X 10(-3) Gy (135 mrad) for the average breast.

Visual evaluation of microscopic mottle.

According to Rose the resolution of an imaging system is under certain conditions limited by noise rather than by the finite geometric response as expressed by the modulation transfer function. In order to investigate whether this applies to clinical radiography as well, a technique for magnification of roentgen films has been devised, making possible visual evaluation of microscopic noise.

Minimum blood vessel diameter measured by magnification angiography.

Visibility of small blood vessels was improved by magnification angiography of biologic specimens. Blood vessel diameter was determined for increasing magnifications by various screen-film combination. Significantly smaller vessels were recognized with the magnification technique in all screen combinations. Noisy screen-film combinations with better square wave transfer functions did not allow visualization of blood vessels as small as those screen-film combinations with poorer square wave transfer functions but less noise.

Lohnt sich die doppelseitige Durchführung der selektiven Nierenangiographie?

Since surgeons can save part of one kidney either by partial resection or reimplantation following "workbench" surgery, it has become increasingly important for the radiologist to demonstrate bilateral space-occupying lesions of the kidneys by bilateral selective angiography, magnification technique and computerized tomography of the kidneys. Fine-needle puncture of the kidney is an important additive technique to solve differential diagnostic problems of avascular, space-occupying renal lesions. Moreover it is a great comfort to the surgeon to know the appearance of both kidneys and may also modify the planned surgical procedure considerably. The incidence of 93 cases of bilateral space occupying lesions of the kidneys, diagnosed in 2721 selective renal angiographies over a period of 13 years, suggests that these entities are more frequent than previously thought.

Application of Radiographic Magnification Technique with an Ultra-High-Speed Rare-Earth Screen/Film System to Oral Cholecystography

Application of Radiographic Magnification Technique with an Ultra-High-Speed Rare-Earth Screen/Film System to Oral Cholecystography

Application of radiographic magnification technique with an ultra-high-speed rare-earth screen/film system to oral cholecystography.

2X magnification employing a 200-mu focal spot and an Alpha 8-XM screen/film system was applied to oral cholecystography and the results compared with those for the conventional contact technique with the Par-RP system. The basic imaging properties of the system, as well as phantom studies, indicated that the image quality obtained with magnification is comparable to or better than that for the conventional technique. In clinical studies on the detection of gallstones, the conventional technique revealed 5 true-positive and 17 true-negative cases and 1 false-positive and 2 false-negative cases, while the magnification technique provided 7 true-positive and 18 true-negative cases but no false cases. With the magnification technique the skin dose was reduced to approximately half that for the conventional contact technique.

RADIOGRAPHIC IMAGING SYSTEM OF THE RARE EARTH SCREEN-FILM COMBINATION : PROPERTIES OF RARE EARTH PHOSPHOR AND THE IMAGE QUALITY OF THE RARE EARTH SCREEN-FILM COMBINATION

Recently, the rare earth screen-film combination attracts attention because of decreasing the radiation dose to the patient. To improve the image quality of this combination, we recognized the fundamental properties of the rare earth phosphor fully. Further we considered the factors required to decrease the exposure and to improve the image quality. We considered physically the effective methods of using the rare earth screen-film combination. We considered the following. 1) The process of using hi-speed systems and the status quo. 2) The properties of the rare earth screen. 3) The factors of the image quality in the hi-speed range. 4) The image quality of the rare earth screen-film combination. To use this rare earth screen-film combination effectively in radiographic diagnoses, it is important that we improve the image quality by using the small focus and radiographing for a short exposure time. Particularly it is effective to apply this combination to gastrointestinal radiography, angiography and magnification technique. In future it will be effective to apply to mammography and multitomography.

Absence of vasospastic response of the anterior spinal artery to subarachnoid blood

Autologous blood (0.3 to 5.0 ml) was introduced into the lumbar subarachnoid space of nine monkeys. Serial spinal cord arteriography was performed at frequent intervals over a 24-hour period. Magnification techniques permitted direct measurement of the anterior spinal artery and posterior spinal vein. Neither immediate nor delayed spasm was observed in any animal. Similar techniques have routinely produced spasm of intracranial arteries in our laboratory.

Microsurgical techniques in free flap reconstruction

Free flap reconstruction is discussed with emphasis on microsurgical technique utilized in union of blood vessels 1 mm in external diameter. Proper microsurgical instrumentation, magnification and small vessel suture technique are all of importance in achieving a successful microvascular anastomosis. Technical maneuvers employed in identifying and avoiding small vessel thrombosis are presented. Surgical techniques, as presented here, have allowed us to successfully use free flaps to reconstruct large oral cavity defects following ablative cancer operations.