Stroke subtypes among Chinese living in Hong Kong: the Shatin Stroke Registry.

The Shatin Stroke Registry is a prospective study of all patients admitted with acute stroke to a general hospital in Hong Kong where the population is predominantly Chinese. Each patient was examined by a neurologist and 95.5% of the patients had a brain CT. Of 777 patients included in the study, 44.0% had a cortical/subcortical infarct, 18.5% a supratentorial lacunar infarct, 24.2% a supratentorial intracerebral hemorrhage, 5.8% brainstem/cerebellar infarct, 2.9% a brainstem/cerebellar hemorrhage, and 4.5% an uncertain diagnosis. The overall 30-day case fatality rate was 25.4%. Comparison with five stroke registries from the West suggests that intracerebral hemorrhage occurs between two and three times more frequently in the Chinese than in Westerners. Whether there is any difference in the relative frequencies for lacunar infarction remains unclear.

Are the hepatic arteries "end arteries"?

Twenty-five autopsy livers were studied for intrahepatic arterial anastomoses. Under fluoroscopy, barium suspension at various concentrations, with or without latex, was injected into the hepatic artery. One-centimeter axial or coronal liver sections were radiographed with high-resolution mammographic technique. All films were reviewed. Seven interconnecting arterial pathways were demonstrated: subcapsular and peripheral arcades, proximal and intermediate connecting vessels, periportal arterial rete and ring, a fine parenchymal network, and connections with the gallbladder arterial system. In the six cases where a branch artery was occluded, arterial filling of the entire liver was demonstrated. The authors conclude that these interconnecting networks could account for the infrequency of hepatic infarcts, are the anatomic basis for the intrahepatic spread of malignant lesions, the "duplication" and "triplication" patterns on arteriography, and may account for the outer streaks of the arteriographic "thread and streak" sign in portal vein invaded by hepatocellular carcinoma.

Demonstration of Lipiodol in paraffin sections using a modified silver impregnation technique.

To demonstrate postangiographic Lipiodol (LIP) in hepatocellular carcinoma (HCC) in paraffin sections, direct impregnation of formalin-fixed tissue blocks with silver nitrate (AgNO3) was followed by routine processing. LIP appeared as black globules in the sinusoids. Ninety-four tissue blocks from 13 postangiographic LIP HCCs and 69 from 8 non-LIP HCCs and 4 fatty livers were studied. Seventy-two of 73 negative controls and all positive blocks as seen on soft tissue radiographs (STRs) were correctly coded (specificity 98.6%, sensitivity 100%). Twenty-six of the 44 LIP-negative areas on STRs from LIP cases contained scanty globules of less than 10 microns in diameter. Fatty change gave no positive readings. Thus, modified AgNO3 impregnation is a simple, accurate means of detecting LIP in high-quality paraffin sections suitable for tumor diagnosis and, if applied to postangiographic LIP, ultrasonographically guided liver biopsy, can verify that a biopsy has reached a suspected tumor focus.

Distribution of Lipiodol and evidence for tumor necrosis in hepatocellular carcinoma.

To study the distribution and thromboembolic effect of Ultrafluid Lipiodol, 15 surgically removed hepatocellular carcinomas with selective intraarterial Lipiodol injection 7 to 10 days before surgery and 15 noninjected controls were studied radiologically and histologically. Tissue blocks were processed with an en bloc silver impregnation technique for Lipiodol localization in histologic sections. Lipiodol was distributed evenly in tumors measuring less than 5 cm in diameter and peripherally in tumors measuring 10 cm or more. Lipiodol droplets were mainly extracellular. There was no difference in tumor architecture or in hemorrhage and necrosis scores between Lipiodol-injected cases and negative controls (1.18 versus 0.92). Similarly, in injected cases, no differences were observed between Lipiodol-positive and Lipiodol-negative areas (scores of x-ray Lipiodol-positive versus Lipiodol-negative areas: 1.17 versus 1.36; scores of microscopic Lipiodol-positive versus Lipiodol-negative areas: 1.18 versus 1.14). Lipiodol-negative but hypodense areas examined by x-ray proved to be necrosis or fibrosis with or without viable tumor islands. Lipiodol has no thromboembolic effects. The uneven Lipiodol distribution may account for its failure as a carrier for chemotherapeutic agents in large tumors.

Pulmonary oedema at necropsy: a combined pathological and radiological method of study.

Fixation of lungs at necropsy by inflation with formaldehyde vapour was used in a combined radiological and pathological study of pulmonary oedema. Pulmonary oedema was found in 79% of lungs examined. The earliest phases affect the interstitial tissue with oedematous connective tissue planes and distension of pulmonary lymphatics. These changes may be associated with reduction in the compliance of the lung. Alveolar filling is a late stage in the accumulation of oedema fluid in the lungs.

Morphological basis of radiological band shadows on chest radiographs.

Lungs of unselected cadavers were fixed at necropsy using a formalin vapour technique. "Band shadows" were identified in the excised lungs and these were correlated with in vivo radiographs and with the morphological changes in the lung. Persistent shadows were produced by pulmonary infarction, subsegmental atelectasis, and septal fibrosis singly and in combination. Potentially transient shadows were seen in association with atelectasis and pulmonary oedema.

Pharmaco-radiology in barium examinations with special reference to glucagon.

The reasons for and objections to the use of drugs as adjuncts in barium meal and follow-through examinations are briefly reviewed. Physiological factors related to gastric emptying are considered, including the volume, temperature and osmolarity. The drugs considered include those that speed gastric emptying and small bowel transit such as metoclopramide, those that delay gastric emptying such as propantheline and gastrointestinal hormones such as glucagon. Glucagon first produces gastric and duodenal dilatation and subsequently speeds transit through the small bowel. The indications, contra-indications and side effects of these drugs are also considered and tabulated.

Computerized tomography using the EMI general purpose scanner.

The EMI general Purpose Scanner is briefly described, with particular reference to the use of window height and window width variations. Patient preparation in relation to movement artefacts and contrast medium is considered, and a method of localization of tomographic sections is described. The Scanner produces brain examinations of high quality. Because a head water bath is no longer required, the base of the skull can also be examined. In the thorax computerized tomography is particularly valuable in showing pleural disease in the forms of thickening, plaques or tumours, and in demonstrating retrosternal lymph node enlargement. Small peripheral metastases can be identified when not shown by conventional tomography. In the abdomen lymph node masses, retroperitoneal tumours and pancreatic disease has been identified, often more completely than by other methods, or where other methods have failed. This has proved particularly valuable in the grading of malignant disease and in the monitoring of subsequent treatment. It is particularly helpful in the planning of radiotherapy. Metastases in liver and bone can be clearly defined when still quite small (0-5.1 cm), but comparison with other methods of diagnosis such as grey scale ultrasound and isotope scanning will be needed before the role of computerized tomography in evaluating these lesions is known.

Comparison of ultrasound and computer-assisted tomography in pancreatic diagnosis.

In a series of patients suspected of having pancreatic disease both ultrasound and computerized tomography (CT) were performed. The diagnosis has been confirmed in 50 patients. Computerized tomography visualized the pancreas in all 50 (100%) whereas ultrasound was successful in 40 patients (80%). The ultrasound failures were due to bowel gas anterior to the pancreas. The overall diagnostic accuracy was 84% for computerized tomography and 64% for ultrasound; however, in those cases where ultrasound successfully detected the pancreas the diagnostic accuracy was 80%.

Asymptomatic temporal lobe injury after radiotherapy for nasopharyngeal carcinoma: incidence and determinants.

Computed tomography (CT) scans were performed on a cohort of 60 patients for detection of temporal lobe injury (TLI) at 1-3.5 years after radiation therapy for nasopharyngeal carcinoma. Nine cases of TLI were identified, five of which were asymptomatic. The earliest case of asymptomatic TLI was found at 2.2 years after radiation therapy and the earliest symptomatic case at 2.3 years. A significantly higher incidence of TLI was found in patients with decreased temporal lobe shielding consequent to omitted eyeshield to the anterior photon beam and in patients treated with a hyperfractionation schedule giving 67.2 Gy in 42 fractions in 6 weeks. The incidence in these subgroups at 2-3.5 years after radiation therapy was 56% (5/9 patients) and 35% (8/23 patients), respectively. No patient in this study had TLI in the absence of these two factors. The implications of the results are discussed.

The radiological (CT) and clinical sequelae of primary intracerebral haemorrhage.

To determine the radiological and clinical outcome of primary intracerebral haemorrhage, a prospective study was carried out involving computed tomography (CT) of 388 consecutive Chinese patients admitted with acute stroke to a large public hospital in Hong Kong. Further CT and functional assessment were performed 3 months later in 71% of survivors. The patients were admitted over a 6 month period. 120 (31%) were found to have had presumed primary intracerebral haemorrhage. Of these, 64 patients (53%) died within 3 months. From 40 of the 56 survivors who returned for a follow-up study at 3 months, 30 were functionally independent and five mildly disabled; only five were significantly disabled. Follow-up CT showed no residual lesion in 27%, low attenuation areas in 37%, slit-like lesions in 25% and calcification in 10% of patients. The size of residual lesions correlated statistically with the degree of residual disability, although the association was not close. It is concluded that primary intracerebral haemorrhage accounts for a high percentage of strokes among Hong Kong Chinese with more than half of the patients dying within 3 months. Many survivors, in whom follow-up CT appearances are variable, show good functional recovery.

[The normal pancreas as seen on the computerised tomogram (author's transl)]. / Das normale Pankreas im computerisierten Tomogramm.

The normal appearances of the pancreas as seen on computerised tomograms (EMI) has been demonstrated in fifty normal patients and correlated with fifteen post mortem studies on patients with a normal pancreas. The problems of optimal demonstration of the pancreas on computerised tomograms and possible sources of error in the interpretation of transverse pancreas tomograms are discussed.

Radiology of nasopharyngeal carcinoma.

Plain film radiography and pluridirectional tomography have been displaced by CT and MRI for imaging NPC. The latter techniques are to some extent complementary, since MRI is particularly useful for defining soft-tissue components and CT accurately delineates bone erosion. CT, however, also provides good soft-tissue definition in conjunction with contrast enhancement. Nuclear isotope scanning is valuable in detecting bone metastases. These imaging techniques are of particular value in detecting submucosal tumors not visible clinically and are also essential to accurate tumor staging.

Computed tomography contrast enhancement of cervical lymphadenopathy.

In a prospective study of 51 cases of lymphadenopathy (44 with cervical metastatic nasopharyngeal carcinoma, NPC) using intravenous contrast and computed tomography (CT), a ring enhancement was observed. A retrospective review of 105 cervical carcinomatous lymph nodes (64 with metastatic NPC) showed a prominent peripheral hypervascular pattern not seen in 48 lymphomas and 60 normal controls. We conclude that in carcinomatous cervical lymphadenopathy, enhancement can be achieved by intravenous contrast and CT; and the peripheral hypervascularity is the anatomical basis for the ring appearances seen radiographically.