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The authors discuss the use of transverse axial tomography in target localization, treatment simulation, and computation of dose distribution, including three-dimensional display. This technique facilitates accurate and rapid treatment planning for the individual patient. Limitations encountered during the application of this method over a period of two years are described.

Ultrasound, B scanning, computerized axial tomography, and radioisotope bone scanning have enhanced the armamentarium of the pediatric radiologist. An important question raised by some of these newer methods – and applicable to routine radiologic procedures as well – is the issue of informed consent.

Computerized axial tomography was found to be extremely informative in evaluating intracerebral and intraventricular hemorrhage. The precise anatomic extent of the hematoma, associated cerebral edema, ventricular deformity and displacement, and hydrocephalus are all readily assessed.

The results of 300 computerized axial tomographic (CT scanning) examinations are reviewed. This new technique involves the use of an EMI brain scanner. The patient's head is placed in a “cap” which projects into a water-containing box, and the head is scanned with a slit x-ray beam. A completed study consists of 28,000 absorption values which are analyzed by density. Certain physical properties of normal cerebral tissue and many pathological lesions, including gliomas, meningiomas, metastatic neoplasms, craniopharyngiomas, pituitary adenomas, and others, can be evaluated. The accuracy of CT scanning is exceptional. It is anticipated that this safe noninvasive method will decrease use of such techniques as cerebral angiography and pneumography.

General views on the physical aspects, mathematical image reconstruction methods and algorithms, and associated detection electronics are given. Transmission techniques are emphasized; however, the technique can be applied to emission studies, for instance in positron camera.

Axial tomography of the optic canals utilizing hypocycloidal polytomography is a simple method of investigation of lesions in and around the optic canal in children. This roentgenographic projection can be accurately reproduced in the serial investigation of patients, and both optic canals are demonstrated simultaneously. With the addition of air into the chiasmatic cisterns, axial tomography facilitates the investigation of parasellar mass lesions but is inaccurate in determining intracranial extension of optic nerve gliomas because of associated adhesions.

The technique for obtaining radiographs of horizontal sections of the thorax or trunk was invented in 1937 by Watson. It did not find favour in this country; but in 1950 Stevenson, having acquired fresh equipment and restudied the method, put on record the theory behind the method and the details which would enable those interested to use and study transverse axial tomography. I had not appreciated the value of the method until, in 1956, it seemed that it must surely prove of value in a cancer-treating hospital where rotation therapy was being undertaken, if it could clearly show in three dimensions the size and exact site of a tumour—particularly within the thorax. I decided to revive the method because I considered that at a cost of about £1,000 we (in a large cancer-treating hospital) could not “lose” since firstly, demonstration of malignant lesions in the thorax in the third dimension was almost certain to prove of value to radiotherapists at a period when rotation therapy was in vogue (and even for ...

The technique and application of axial tomography of the orbit and paranasal sinuses are described. Hypocycloidal tomography has been employed using the Philips Massiot Polytome. For optimal demonstration of the optic canals and soft tissue structures of the orbit, an inclined plane technique has been used with the head in the sub-mento vertical position. Axial tomography is the best method of demonstrating bone destruction in the posterior wall of the maxillary antrum and is the most accurate way of showing the extent of a tumour in the ethmoid and sphenoid sinuses. The method has also been used to demonstrate the optic canals in the axial plane and to show the optic nerve during orbital pneumography. In the orbit the technique will not only demonstrate bone destruction but can also show tumours as soft tissue masses. Normal orbital structures are also demonstrable, including the lateral rectus muscle, the intraconal space and optic nerve.

An unusual traumatic dislocation of the inferior angle of the scapula between the fourth and fifth ribs is presented. The diagnosis of locked scapula was suspected on physical examination but could be confirmed only by anterior oblique roentgenographic views of the chest cage and by axial tomography. Operative reduction two months after injury produced a full return of function.

A spate of letters on the subject of lumbar puncture (LP)1 2 3 to the Journal during the last year attest that despite 80 years of experience, controversy still surrounds such basics as indications, technic and avoidance of post-LP headache. Indications for the LP are somewhat on the decline as technical neurodiagnostic methods improve. In the diagnosis of suspected intracranial mass lesions minimal-risk studies such as electroencephalography and radioisotopic brain scan, or definitive procedures such as angiography, pneumoencephalography, or computerized axial tomography, have reduced the utility of the LP except to detect a non-neoplastic process. With intracranial mass lesions, it is rare . . .

Key words: extradural haematoma; Glasgow Coma Scale; pupillary dilatation; computerized axial tomographydoi: 10.3329/jcmcta.v19i1.3843Journal of Chittagong Medical College Teachers' Association 2008: 19(1):8-10

Transverse axial tomography of the spine is a radiographic technique in which one can portray any level of the spine in cross section in the living patient. The examination provides a nondistorted magnified axial view of a preselected area of the spine and is a valuable adjunct to standard radiographic techniques.

Computer-assisted transverse axial tomography employing the EMI scanner (E.M.I. Ltd., Hayes, Middlesex) is a non-invasive radiological investigation potentially capable of analysing the physical properties of sections of normal brain and many pathological processes which may affect the brain. Details of the technique and equipment are well documented together with evaluations of early clinical series (Hounsfield, 1973; Ambrose, 1973). The method has been employed in Manchester for a year, during which time 1,500 examinations have been undertaken in a wide variety of neurological disorders. Clinical and radiological management of neurological and neurosurgical patients has been significantly affected by the new procedure. The large quantity of information produced for each reconstructed section of brain presents problems of storage, display and analysis. No photographic medium can record reliably the available range of data. Analysis employing the machine's own display and controls can be performed on site...

Transverse axial tomography of the spine is a technique to evaluate the entire spinal column. The technique is being used to study spondylosis, lumbar stenosis, intraspinal foreign bodies, and congenital anomalies. The method is safe, and the views obtained are reproducible. The radiographic unit we are using is the Toshiba transverse axial tomography.

Fundamentally X-ray photography has not improved since Rontgen photographed his wife’s hand almost eighty years ago. If one looks at radiological journals of the first decade of this century, one can see that such structures as the sella turcica and mastoid cellular system were just as sharply defined then as today. Certainly more care and attention was required to immobilise the structure being X-rayed because the weak X-ray tubes demanded a long exposure, and the processing of the glass plates needed technical skill.

With most of the apparatus in use for transverse axial tomography, the patient is in an upright position. For the localisation of inhomogeneities in patients for whom radiotherapy is being planned, it is recognised that more relevant information would be obtained with a recumbent patient (I.A.E.A., 1966). Transverse tomographs of a recumbent patient can be obtained with the apparatus described by Takahashi and Matsuda (1960), which rotates the tube and film round the patient, and which can now be obtained commercially. The same principle can be realised by an appropriate design of simulator.

Xeroradiography improves the quality of the image in transverse axial tomography, though the radiation dose to the patient is increased. This technique is useful for planning of radiation therapy in the head and neck region.

Many new and exciting diagnostic modalities are being introduced into radiology, and some of them are beginning to have an impact on pediatric practice. Most of these modalities are noninvasive techniques which can be performed with ease and safety in the pediatric patient. For example, the application of axial tomography with computer integration of the radiologic image (EMI Scanner, ACTA Scanner) may revolutionize the practice of neuroradiology as we now know it. Nuclear medicine is only beginning to blossom in its many physiologic and morphologic applications, particularly with the introduction of Gamma Cameras and short half-lived scanning agents associated with minimal radiation dose. The use of ultrasonography is becoming particularly important in the evaluation of acquired and congenital heart disease and in the evaluation of abdominal masses. Thermography and xeroradiography have yet to find a significant use in pediatric practice. Fine tuning and modification of diagnostic radiologic procedures used routinely in adult medicine have made the application of such modalities as angiography relatively safe in skilled hands when they are used for children. These newer diagnostic modalities must be subjected to the same critical analyses regarding efficacy, cost, and safety that currently are demanded and accepted for the introduction of new drugs and other forms of therapy. They will have to be evaluated to establish whether or not they are simply duplications of more conventional methods of diagnosis and fail to improve patient care. Publication of their availability and use, and even advertisements, should be considered carefully before they are accepted for application in pediatrics.