Reporting requirements for skeletal digital radiography: comparison of soft-copy and hard-copy presentation.

PURPOSE: To assess diagnostic performance and reader preference when reporting results from digital hard-copy and two soft-copy formats of skeletal digital radiography. MATERIALS AND METHODS: The data comprised hand radiographs of patients undergoing renal dialysis. Normal hand radiographs obtained in trauma patients were assessed as control images. One hundred fifteen images acquired with a photostimulable-phosphor computed radiography system were analyzed. Image selection and initial assessment were by consensus of two experienced radiologists, who graded the radiographic changes of hyperparathyroidism with the Ritz scoring system. The images were then presented to four readers in three formats: hard-copy output and soft-copy presentations at 2K2 and 1K2 resolutions. These readers scored pathologic change and image preference. The results were analyzed with the receiver operating characteristic technique. RESULTS: There was a significant improvement in diagnostic performance for both soft-copy formats relative to the hard-copy format (P < .001). No significant difference in diagnostic performance was found between the two soft-copy formats. There was a significant preference for both soft-copy formats relative to the hard-copy format (P < .01), with the 2K2 soft-copy images preferred to the 1K2 images (P < .01). CONCLUSION: Soft-copy reporting can provide superior diagnostic performance even for images viewed at a modest (1K2) resolution. The lack of difference between the two soft-copy formats has important economic implications with respect to departmental hardware requirements.

Ductal carcinoma in situ of the breast: the clinical significance of histological classification.

One hundred and twenty-one cases of ductal carcinoma in situ, including 26 cases with T1a invasive carcinoma, were reviewed. Seventy-nine patients (65%) were treated by mastectomy and 42 (35%) had conservative surgery. Ductal carcinoma in situ was classified as well differentiated (11%), intermediately differentiated (22%) or poorly differentiated (67%) according to nuclear morphology and the presence or absence of cell polarization. Poorly differentiated lesions were significantly larger than intermediately and well differentiated lesions (P = 0.03 and P = 0.01, respectively) and were significantly associated with the presence of extensive necrosis, marked periductal inflammation and periductal fibrosis (P < 0.0001). Invasive carcinoma was more common in the poorly differentiated group (25% compared with 18% in the intermediate group and 8% in the well differentiated group) but this was not statistically significant. The spectrum of differentiation was similar in symptomatic and mammographically detected ductal carcinoma in situ. Clinical follow-up was available in 90 patients (median period 45 months in patients who had undergone mastectomy and 23 months in those who had conservative surgery). Two incidences of recurrent local disease were recorded in the mastectomy group: one patient had well differentiated and the other poorly differentiated ductal carcinoma in situ. No local recurrences were observed in the conservative surgery group, possibly reflecting the shorter follow up period. All histological grades of ductal carcinoma in situ have the potential to progress to invasive carcinoma and mastectomy does not guarantee a cure.

Direct digital mammography image acquisition.

Mammography is a branch of radiology which could benefit greatly from the assimilation of digital imaging technologies. Computerized enhancement techniques could be used to ensure optimum presentation of all clinical images. Beyond this it will facilitate powerful new clinical resources such as computer-assisted diagnosis, tele-mammography, plus digital image management and archiving. An essential precursor to all these advances is the availability of appropriate direct digital mammography (DDM) image-acquisition system(s) to capture high-quality breast X-ray image data at the outset. The only practical DDM image-acquisition system currently available is (photo-stimulable phosphor) computed radiography. Modern computed mammography (CM) uses similar radiation doses to the patient and produces equivalent, albeit different, image quality to screen-film mammography. Computed mammography offers superior rendition of the skin edge and sub-cutaneous tissue and dense parenchyma, while ensuring equivalent micro-calcification detectability. Meanwhile, a variety of new technical approaches to DDM are under active investigation and/or development which promise to supercede film-based mammography. These new (second generation) DDM technologies promise the radiologist superior image quality combined with significant dose savings compared with contemporary imaging systems. In this review we describe and compare the physical and clinical characteristics of CM and the various emerging DDM image-acquisition technologies.

Technical note: dual compression mammography using computed radiography.

On mammography most malignant growths may be seen as a tethered mass or architectural distortion. Benign lesions such as cysts and fibroadenomas have no focal tethering and are usually well circumscribed. Computed radiography (CR) is a direct digital system which may be used for mammography. One of the main advantages of CR is its wide exposure latitude allowing images to be acquired at lower exposures than required for film-screen systems. A technique was developed, utilizing the exposure latitude of CR, to acquire two mammograms of the same breast at two slightly different compressions, but using approximately the same exposure as a single film-screen mammogram. These images were then "animated" on a computer allowing the fibrous septa movement to be visualized. The movement of the fibrous septa in the presence of an abnormality was used to help confirm whether a lesion was benign or malignant. This technique may have clinical application in classifying architectural distortions and masses which are ultrasonically benign but later found to be malignant. Microcalcifications cannot be used as a diagnostic indicator with this technique because of the increased noise associated with the lower exposures. The increased noise did not affect the visualization of masses.

Clinical aspects of direct digital mammography.

Since 1990, computed radiography (CR) has been used routinely in our symptomatic mammography service, imaging approximately 2,000 patients per year. Careful selection of the appropriate image processing parameters results in high-quality images of diagnostic value equivalent to conventional film-screen mammograms. Problems encountered included dust artifacts, black films, and white films, but these constituted only a very small proportion of images obtained and the remedies are discussed. Hard-copy reporting is used and improved image presentation is considered. New processing algorithms and the development of soft-copy reporting at dedicated workstations are expected in the near future.

A clinical comparison between conventional and digital mammography utilizing computed radiography.

Previous work utilizing a specially designed mammographic test object has indicated that the image quality of computed radiography (CR) approaches that of a conventional film-screen technique of equivalent radiographic speed. In an attempt to correlate these results with the clinical situation a subjective rating study of the primary physical parameters of noise, sharpness, and contrast has been conducted. Using a randomized viewing sequence two radiologists experienced in mammography were asked to score these parameters utilizing a 5 point scale. A total of 138 images was used, 62% containing no abnormalities and 38% containing either microcalcifications, masses or both. Additionally, the observers scored their confidence of correct classification, and these results were then used to construct receiver operating characteristic (ROC) curves. The subjective rating of the physical parameters results produced similar results to those obtained using the test object, with CR images providing greater contrast than film. The resolution of CR, however, was lower than for film. Overall the noise levels were similar for both modalities, but the digital images occasionally contained high levels of dust artefacts. In one case these artefacts were mistaken for a cluster of microcalcifications. The test object results and the parameter rating results indicate that CR approaches the performance of film-screen images. Statistically the ROC curves produced indicate CR images to be comparable to the film-screen combination. This may be because the increased contrast compensates for resolution limitations and these findings correlate with our clinical experience.

A preliminary investigation of the imaging performance of photostimulable phosphor computed radiography using a new design of mammographic quality control test object.

Leeds Test Object TOR[MAM] has been designed to supplement the current FAXIL mammography test object TOR[MAX]. It contains a range of details that have a more natural radiographic appearance and has been designed as a test that more closely approximates the image quality achieved in clinical mammography. Physical aspects of the design and implementation of TOR[MAM] are presented. The TOR[MAM] has been used in a preliminary physical evaluation of the comparative image qualities produced by conventional (screen-film) and photostimulable phosphor computed mammography and the results are discussed. TOR[MAX] results are also presented. The influence of digital image processing (enhancement) on the image quality of computed mammograms is also considered. The results presented indicate the sensitivity of TOR[MAM].

Skeletal toxicity with isotretinoin therapy: a clinico-radiological evaluation.

Skeletal toxicity is known to occur with high doses of isotretinoin (greater than 2 mg/kg/day). We have attempted to evaluate the clinical significance and document the extent of musculoskeletal toxicity associated with a relatively low dose of isotretinoin (0.5 mg/kg/day) used in the treatment of severe acne. Radiographs of 120 patients were examined. Twelve per cent showed minor changes (four patients had spinal hyperostoses and 10 had calcaneal hyperostoses). None of the musculoskeletal changes we observed was clinically significant. Comparison with matched control X-rays showed 8% of the controls to have similar non-significant changes. Follow-up of 11 of the patients with abnormal X-rays showed minor deterioration in one patient, no change in four and improvement in six. Thus, doses of 0.5 mg/kg/day isotretinoin in such patients did not produce any significant long-term musculoskeletal changes. With increasing use of this beneficial drug in acne, radiologists and dermatologists should be aware of its skeletal toxicity.

A comparison of barium sulphate preparations used for the double contrast barium meal.

Radiologists' opinions of the properties of six barium suspensions with their recommended gas-producing agents designed for upper gastrointestinal use were assessed, using a linear analogue scale. Five radiologists independently assessed mucosal coating of stomach and duodenum, areae gastricae, gaseous distension and bubble formation in a total of 258 patient examinations. Preparation 1 (EZHD) was judged to give best overall results, coating stomach and duodenum particularly well. Preparation 2 (X-Opaque) gave good distension and also coated mucosa fairly well, as did preparations 3 and 4 (Medebar XAC and Field 2C). The latter two preparations produced good distension at the expense of bubble formation. Preparations 5 and 6 (Micropaque DC and Baritop G) were judged, by comparison, to have performed poorly as regards mucosal coating. None of the preparations delineated areae gastricae well, even in the presence of good, bubble-free gastric distension.

The diagnosis of primary bile duct carcinoma (cholangiocarcinoma) in the jaundiced patient.

One hundred and ten patients with obstructive jaundice were investigated in the established manner; an initial abdominal ultrasonic B scan was followed by fine needles percutaneous transhepatic cholangiography (PTC) and/or endoscopic retrograde cholangiography (ERC). This yielded 15 cases of histologically proven primary bile duct carcinoma (cholangiocarcinoma), which is an incidence of 13.6%. Primary bile duct carcinoma is suggested on ultrasonic examination by: (i) Attenuation of the ultrasound beam in the bile duct area especially if the shadowing is multiple and/or from the intrahepatic ducts. (ii) Delineation of a mass associated with the bile ducts. (iii) A high level of duct obstruction with a normal pancreatic appearance. On direct cholangiography a stricture of the duct system which is branched, short, multiple or tapering also suggests primary bile duct malignancy. It is possible to diagnose primary bile duct carcinoma on ultrasonic examination alone once this condition is recognised as occurring with significant frequency. PTC and ERC aid delineation of the extent of the tumour and exclude biliary duct stone as the cause of jaundice.

The role of upper abdominal ultrasonography in suspected acute cholecystitis.

Ultrasonic investigation of the upper abdomen was performed as an initial imaging procedure in 117 consecutive patients regarded on clinical examination as probably suffering from acute cholecystitis. All patients were studied within 72 h and the majority within 48 h of admission. All were followed up for a minimum of 12 months and the ultimate clinical diagnosis recorded and compared with the initial ultrasonic diagnosis. Despite the clinical suspicion at referral, only about half were ultimately found to have biliary tract or closely related pathology. In a further 10% totally unexpected and unrelated causes for the symptoms were detected. 87% of gallstones were detected on the initial ultrasonic examination, which compares well with previously reported series. In all cases where there was a right upper quadrant mass at presentation, the organ from which this arose was demonstrated. The results of this initial study indicate that upper abdominal ultrasonic examination is a valuable inital screening procedure in patients presenting with acute right upper abdominal symptoms.

The role of diagnostic radiology in the diagnosis and management of rhabdomyosarcoma in young persons.

Rhabdomyosarcoma is a rare tumour of mesenchyme-like tissue in which differentiation of rhabdomyoblasts has occurred. It is found mainly in infants and children. The prognosis, until recent years very grave, has been improved by a combination of chemotherapy and radiotherapy occasionally with surgery. Survival depends on the extent of the disease at the time of diagnosis. Diagnostic radiology has an important role to play in the demonstration of this, illustrations of which are given from a series of seven cases. The primary tumour has no pathognomonic appearances and is demonstrated essentially as a soft tissue mass lesion which displaces adjacent soft tissue structures such as arteries, veins, bladder and colon, or erodes adjacent bones whether in the extremities or the skull. The main role of diagnostic radiology is the detection of metastases. Chest radiography and skeletal survey are mandatory. Lymphangiography may reveal filling defects in regional lymph nodes but these are indistinguishable from any other metastases. Arteriography as well as revealing displacement of larger vessels, may show typical tumour neovascularity in the lesion. Serial skeletal radiographs are of help in assessing response of metastases to therapy.

Simplified cholangiography using ioglycamide.

Intravenous cholangiograms were performed on 100 unselected nonicteric patients using methylglucamine ioglycamide (Biligram). Fifty patients received 10.5 g of contrast medium and 50 received 5.25 g of medium. The contrast medium was injected evenly over five minutes. Side effects were recorded in only 13% of patients and all were mild. Radiographs were taken 10, 30, 60, 90, and 120 minutes after injection and were assessed without the authors being aware of the dose of contrast medium injected.Better statistically significant results were obtained using the higher dose.In patients in whom the gallbladder is present, films taken at 60 minutes and 90 minutes after injection give the maximum available information in 97% of cases. If the gallbladder has not become opacified by 60 minutes, cystic duct obstruction is indicated. In postcholecystectomy patients, films at 30 minutes and 60 minutes after injection give the maximum available information in 95% of cases.