Michael H. Reid

Organ and lesion volume measurements with computed tomography

Useful clinical information will often result from determinations of organ and lesion tissue volumes from measurements of computed tomographic (CT) cross sections. This paper discusses simple applications of stereology to volume estimations of organs and disease processes. The method is applied to CT sections and, for equivalent accuracy, is less time cosuming than planimeter or CT scanner region of interest outlining and measurements.

The Role of Computed Tomography and Ultrasound Imaging in Biliary Tract Disease

In 1981, the precision of ultrasound in detection of cholelithiasis and dilated bile ducts is approximately 95 per cent. With the advent of newer generation computerized axial tomography (CT) machines, the resolution of the bile ducts, gallbladder, liver parenchyma, and peribiliary structures has improved to such a degree that the precision of CT is 90 to 95 per cent. Presently, ultrasound remains the preferred first examination of choice of the biliary tree over CT because of the ease of performance of the examination in multiple planes, availability, and cost.

Quantitative stereology and radiologic image analysis. Part I: Computerized tomography and ultrasound

The interpretation of two-dimensional radiographs or computerized tomography (CT) or ultrasound (US) sections with inferences made about three-dimensional anatomy is the foundation of diagnostic radiology. A large variety of estimation methods which can be applied to two-dimensional CT/US sections to estimate their three-dimensional properties is presented. The techniques are easily utilized in a research or clinical setting, do not require computerization, and can provide statistically accurate three-dimensional information based on two-dimensional sampling with a minimum of effort. Although the examples are directed at diagnostic radiology, the estimation procedures may be employed in analogous fields such as microscopy or section anatomy.

Computed tomography of liver trauma due to surgical retraction

Focal hepatic abnormalities demonstrated with computerized tomography (CT] and related to trauma have been reported [l-5]. One case of diffuse hepatic infarction secondary to vascular compromise has also been reported [6]. We wish to describe a case of surgically induced liver trauma and emphasize that the CT image changes in the appearance of the liver parenchyma may be secondary to such trauma and not represent metastatic disease, infection, or focal fatty infiltration in the early postoperative period.

Quantitative stereology and radiologic image analysis. Part II: Transmission (projection) radiography

This paper extends the results of Part I to estimates of three‐dimensional anatomy and morphology obtained form measurements on a projection plane. Ambiguities and overlap obscuration in projections are discussed. Estimates of vascular (angiography) network geometry are easily obtained and applications to particle volume, surface area, spacing, and number are possible.

Outpatient low-dose computed tomography metrizamide myelography and evaluation of lumbar disk disease

Outpatient low-dose computed tomography metrizamide myelography (CTMM) for the evaluation of lumbar disk disease is described in 55 patients. Ten individuals (group 1) were studied using 3.5 ml of 150 mg I/ml (525 mg I total) of metrizamide. Forty-five additional patients (group 2) were examined with 5 ml of 110 mg I/ml (550 mg I total) concentration of metrizamide. Group 2 experienced less post-procedure headache (6.6%) and nausea (2.2%) than did group 1 (30% and 10%, respectively). Group 2 demonstrated a lowered rate of headache (p less than .01) and showed a trend to less nausea (p less than .09) than a recently published study describing full-dose lumbar myelography. In addition, CTMM in group 2 produced more uniform mixing of metrizamide than in group 1. Overall, low-dose CTMM increased accuracy and reduced morbidity, patient cost, and inconvenience as compared with routine full-dose lumbar myelography.

Statistical detection of nonvisible isodense subdural fluid collections.

An analytic method for detecting isodense subdural fluid collections from computed tomography (CT) scan pixel attenuation data is presented. Analysis of 44 CT scan levels from 8 patients with isodense subdural hematomas (ISDH) and 50 CT scan levels from 15 patients without ISDH indicates 6% false positive and 3% false negative errors if the analysis is restricted to noncontrast CT scans that demonstrate subcalvarial bilateral cortical attenuation symmetry in the pictorial display.