Painful sclerosis of the medial end of the clavicle.

Pain and swelling of the medial end of the clavicle may be associated with radiographic sclerosis. The commonest causes are osteoarthritis, infection and condensing osteitis of the clavicle. Distinguishing between these clinically and radiologically can be difficult but computed tomography (CT) and magnetic resonance imaging (MRI) are often useful for their differentiation. In this review, the typical imaging features of these conditions are presented with an emphasis on the CT and MRI appearances. These are correlated with clinical features, which together should enable a confident diagnosis to be made.

Traumatic 'degloving' of the colon in blunt abdominal injury.

We describe two cases of traumatic 'degloving' of the colon in blunt abdominal trauma. This is an extremely rare injury with the potential to present late. The mechanism of injury appears to be a combination of focal blunt abdominal trauma associated with a shearing force. The potential diagnostic dilemma posed by colonic 'degloving' is outlined and following review of the literature we conclude that CT scanning is the most reliable way of detecting such injuries, if emergency laparotomy is not indicated.

Technical note: low density contrast in upper abdominal computed tomography.

We describe the use of a fat-based low density oral contrast agent in computed tomography (CT) of the upper abdomen. It has a CT number of -71 Hounsfield units (HU) and allows excellent visualization of the bowel wall and adjacent structures as well as reducing the artefacts seen with iodinated high density contrast.

Reactive mediastinal lymphadenopathy in bronchiectasis assessed by CT.

Mediastinal lymphadenopathy is commonly detected on CT. It is a non-specific finding, but because of its significance in the treatment in lung carcinoma it is important to know with which other disease states it is associated. We present a series of 42 patients in whom CT of the chest was used to confirm a clinical diagnosis of bronchiectasis. The size, number and distribution of mediastinal lymph nodes is documented. Lymph nodes were visible in 81% of patients. Nodes larger than 10 mm, the recognised maximum size for normal nodes in the U. K., were detected in 29%. In the absence of other recognised causes of lymphadenopathy in these patients, these findings confirm "reactive" mediastinal lymph node enlargement in bronchiectasis.

Automated measurement of tumour extent in patients with colorectal liver metastases from X-ray computed tomography.

Tumour burden is a significant prognostic factor in patients with colorectal liver metastases, and can be staged according to percentage hepatic replacement (PHR), but accurate measurements of PHR are difficult to obtain. We have used an automated computerized technique to isolate tumour and measure PHR from computed tomography images of 22 patients. Tumour identification was achieved by establishing local histogram-based thresholds at liver-tumour boundaries displaying clear bimodal histogram distributions. There was a significant association between measured PHR and independent visual estimates of PHR stage defined in quartiles (p less than 0.001). When the measured value of PHR differed from the PHR stage, the visual estimate was always higher. The accuracy of PHR measurement was assessed on stimulated liver computed tomography images. It seems likely that visual estimates of PHR from computed tomography images tend to overestimate tumour extent. The automated technique is probably more accurate and will be useful for assessing and monitoring patients.

The growing teratoma syndrome.

Thirteen patients with metastatic non-seminomatous germ cell tumours and enlarging metastases consisting of teratoma differentiated only were identified. Patients were managed with surgical resection soon after the growing lesions were documented. Surgical morbidity was minimal and 12 patients are alive (10 are disease-free) at a median follow-up of 28 months.

CT features of rounded atelectasis.

Rounded atelectasis (folded lung syndrome) is a form of pulmonary collapse associated with pleural thickening that can mimic a neoplasm on plain chest radiographs. The abnormality was diagnosed radiologically in nine patients in whom follow-up varied from 1 to 6 years. Four patients had bilateral lesions, making a total of 13 examples. The CT findings were analyzed and compared with previously published criteria for the diagnosis of this disorder. In all cases, CT showed a rounded mass, 3.5-7.0 cm in diameter, abutting a thickened pleural surface in the lung periphery. The margin closest to the hilum was blurred by the entering vessels in 92% of the cases. Our experience suggests that the CT findings of rounded atelectasis are characteristic of the abnormality.

A comparison of methods to measure the percentage hepatic replacement with colorectal metastases.

The percentage hepatic replacement (PHR) with liver metastases has been recognised as an important factor for patient management, prognosis, and clinical trial evaluation. The PHR can be assessed by various methods including ultrasound, radioisotope, or computed tomography (CT) imaging, or by inspection and palpation at laparotomy. We report a prospective study comparing these methods of PHR assessment in 56 consecutive patients with colorectal liver metastases. When all four methods were used complete agreement was achieved in only 35% of cases (9/26). The three imaging techniques agreed in only 37% of cases (14/38). Overall, the correlation between different methods was poor with a tendency for surgery to underestimate the PHR. However, CT and surgery agreed in 81% of cases (21/26), and CT gave a higher estimate than surgery in each of the other five patients. With such variability in the estimates of PHR derived from these different techniques, consideration must be given to which technique is used. It is concluded that CT is probably the most accurate for PHR assessment at present.

Strontium-89 therapy: measurement of absorbed dose to skeletal metastases.

We report measurements of absorbed dose to vertebral metastases in ten patients referred for 89Sr therapy for disseminated prostatic carcinoma. Patients received a tracer dose of 85Sr at the time of 89Sr treatment and metastatic strontium retention was monitored scintigraphically for 6 mo. Metastatic 85Sr activity corrected for tissue attenuation was measured using the conjugate view principle, with special care taken to eliminate errors due to the selection of the metastatic region of interest. Metastatic volume was determined from high resolution CT images, and density inferred from Hounsfield number using the QCT bone mineral calibration of Genant and Cann. The mean absorbed dose was 850 rad/mCi (23 cGy/MBq) with a range from 220-2260 rad/mCi (6 to 61 cGy/MBq). The wide range found was consistent with the variation expected to arise due to differences in strontium renal plasma clearance (range 0.1-11.81/day) and extent of skeletal metastatic disease (varying from two small metastases to a superscan on [99mTc]MDP images) among the patients studied.

The demonstration of true hermaphroditism by computed tomography.

Intersex states are rare but if unsuspected may cause diagnostic confusion. We describe one such patient with true hermaphroditism which was misdiagnosed on computed tomography (CT). Laparotomy revealed a female genital tract and histology confirmed the presence of ovatestes, despite a male phenotype.

Bleomycin-related lung damage: CT evidence.

Computed tomography (CT) examinations of the chest were evaluated in 100 patients treated with bleomycin. The CT findings were compared with those of conventional chest radiographs and lung-function tests. Lung damage due to bleomycin was detected in 38% of patients by CT, while damage was detected in only 15% by radiography. Changes in appearance seen on CT scans due to bleomycin damage were compared with measurements of lung volume and gas transfer per unit lung volume. There was good correlation between severity of damage shown on CT scans and changes in lung volume (P less than 0.01). Gas transfer capabilities were reduced in most patients regardless of changes observed on CT scans. Sequential CT studies showed that complete resolution of bleomycin damage may occur within 9 months in patients with minor or moderate damage. Residual abnormalities were seen in all patients with severe damage. CT can confirm lung damage in a patient with suspected toxicity but a normal chest radiograph and can define the anatomic extent of disease in a patient with an abnormal lung-function test.

The use of a general purpose computed tomography unit.

Two thousand five hundred and forty computed tomography (CT) examinations over a three year period were studied to determine the number of examinations of the body being performed, the use of body CT by clinicians from different specialties and the proportion of such patients with known or suspected malignant disease. Examinations were divided into head and body categories, the latter being sub-divided into groups on the basis of known neoplastic, suspected neoplastic and non-neoplastic disease. Forty-eight percent of examinations were of the body, and of these 44% were of patients with suspected neoplasia referred by general clinicians. The number of patients with known extracranial neoplasia referred by oncologists or radiotherapists was similar to the number of patients in whom there was no suspicion of malignancy. There is a significant demand for CT in the management of non-malignant conditions as well as in known or suspected malignant disease. The figures provided should be of value to those involved in establishing or updating CT units in general hospitals.

Computed tomography in acetabular trauma.

In a retrospective study of 16 acetabular fractures computed tomography (CT) clarified the type and extent of the injury. Computed tomography demonstrated intra-articular fragments of varying size in seven out of eight patients with fractures of the posterior acetabular margin. Abnormalities of the femoral head were also shown in six patients and the possible aetiology of these is discussed. The additional information provided by CT is likely to help in the management of patients with acetabular injuries.

The CT appearances of hepatic oil embolism following lymphography.

Four instances of lymphography complicated by hepatic oil embolism are presented. The subsequent computerised tomography appearances can be misleading: the oily contrast medium mimics hepatic calcification and this may be mistakenly thought to indicate calcified hepatic metastases. The correct diagnosis will become apparent if a history of lymphography is sought, and it is important to realise that, even on conventional radiography, hepatic oily contrast medium may remain visible for several months. Computerised tomography is a much more sensitive indicator of the presence of oily contrast medium in the liver, so the absence of detectable oil on conventional radiography is unhelpful. The mechanisms which are thought to lead to hepatic oil embolism are discussed because recognition of the circumstances leading to hepatic oil embolism and appreciation of the associated findings will provide further clues to the correct diagnosis.