The Different Patterns of Coronary Artery Calcification in Acute and Chronic Coronary Syndromes Determined by Electron Beam Computed Tomography

Objectives To compare the different patterns of coronary artery calcification (CAC) in acute and chronic coronary syndromes utilizing electron beam computed tomography. Background Pathologic, angiographic, and intracoronary ultrasound studies revealed sharp differences in the plaque morphology between patients with acute versus chronic coronary syndromes. Whether there are different patterns of coronary artery calcification in patients with stable angina pectoris (SAP) and in those with unstable angina pectoris (UAP) or acute myocardial infarction (AMI), however, remains unclear. Methods Two hundred and sixty - four patients, including 67 with SAP, 94 with UAP and 103 with AMI were studied with electron beam computed tomography for analysis of coronary artery calcification and with selective coronary angiography for determination of atherosclerotic lesions. CAC prevalence and calcium score were compared among three groups, and relation of CAC to the severity of atherosclerotic disease in the SAP and UAP patients was separately analyzed. Results Prevalence of CAC was 100 % in the SAP patients, significantly higher than the 87. 23 % in UAP patients and 86. 41 % among the patients with AMI ( P < 0. 05) . More patients and arteries in the SAP group had severe forms of calcium than those in the UAP and AMI group ( P < 0. 01), and the mean LN [CS + 1] (natural logarithm transformation of calcium score) of the SAP patients was much greater than that of the UAP and AMI patients (P < 0.001). The distribution of vessels with various CAC by luminal stenosis was different between SAP and UAP patients. The average CAC extent of the infarct - related arteries was less severe than that of the noninfarct - related arteries. Conclusions U-tilizing electron beam computed tomography, we demonstrated that there exist different patterns of coronary artery calcification in patients with acute versus chronic coronary syndromes, which may provide insight into the differences observed in the clinical and pathologic development between these two types of coronary artery disease.

CT-GUIDED PERCUTANEOUS TRANSTHORACIC FINENEEDLE ASPIRATION BIOPSY OF SMALL PERIPHERAL PULMONARY LESIONS

CT guided percutaneous transthoracic fine needle aspiration biopsy (PTFNAB) was performed in twenty four sputum negative cases of small peripheral pulmonary lesions smaller than 2 cm in diameter, which are not easily diagnosed or accessible to fibrobron choscopes. After thin slide scanning and localization with Somatom DR H computed tomography, pulmonary nodules were biopsied with a 20 Gauge needle guided by a ruler specially designed. Biopsy materials were used for cyto and histopathologic examinations. The diagnosis accuracy of biopsy was evaluated by the result of postoperative pathology and/or follow up for 2 years. Sixteen pulmonary lesions were proved to be malignant and 8 were benign. The sensitivity was 75.0% (12/16), speciti vity 100% (8/8) and accuracy 83.3% (20/24) according to cytopathology and 87.5% (14/16), 100% (8/8), 91.7% (22/24) by histopathology, respectively. Two cases of early stage peripheral lung cancer were detected and proved by operation. CT guided PTFNAB is safe and quick for diagnosis with high accuracy for small peripheral pulmonary lesions which are usually negative in sputum examination and bronchoscopy. PTFNAB should be routinely used in the diagnosis of lung neoplasms.

A comparative study on CT imaging and pathologic presentation of the periphery of hepatocellular carcinoma using in vivo specimens of liver transplantation

Objective:To examine CT and pathologic presentations of the periphery of hepatocelllar carcinoma (HCC) by using in vivo liver specimens from orthotopic liver transplantation (OLT) and to see whether there is any correlation between them. Materials and Methods:Forty-two patients with HCC confirmed by pathology and liver transplantation were included. Plain CT scan covering the whole liver was done, followed by arterial and portal venous phase scanning. The delay time was 25 s and 60 s after injection of contrast medium. Fresh liver samples were evaluated, sliced and stained with HE and the standard immunoperoxidase method using facterⅧrelated antigen (F8RA) monoclonal antibody to study CT presentation of the periphery of tumor and compare them with pathologic findings. Results: (1) Tumors with clear boundaries on CT scan reflected the presence of tumor capsules in pathologic sections. Most tumors with unclear boundaries had no capsules and grew in an invasive pattern; (2) Tumors with unclear boundaries or high density on dynamic enhancement usually had abundant newborn vessels in the periphery and were poorly differentiated, while those with low density had few newborn vessels and were well differentiated; (3) When microvessel density (MVD) was>30, the occurrence of intrahepatic daughter foci was higher. Conclusion: (1) CT morphologic classification of the HCC periphery can well reflect the intactness of tumor capsules, which is helpful for preoperative assessment of tumor infiltration and cancer cell grading; (2) CT enhancement presentation of the HCC periphery in arterial and portal phases may reflect pathologic changes and help predict the prognosis at large.

CT Manifestations of Lung Changes and Complications in Patients with Severe Acute Respiratory Syndrome

Objective:To investigate the rol e of CT scanning in diagnosing severe acute respiratory syndrome(SARS). Methods: One hundred and twelve times of spiral CT scanning, 106 t imes on the chest with standard pulmonary and mediastinal window, 5 on the brain and once on the abdomen, were performed in 82 patients (37 males and 45 females ) of SARS. Results: Bilateral shadows showed in 66 patients (80.48%) and unil ateral shadow in 16 (19.52%). The lung CT findings were sub pleural focal con solidation in 26 patients (31.70%), flaky cloudy opacity in 53 (64.63%), large a rea consolidation in 9 (10.97%), ground glass blurry shadow in 31 (37.80%), a lveolar substantive shadow in 14 (17.07%) and interstitial changes in 16 (19.51% ). The pulmonary CT signs of SARS were relatively characterized by: (1) The lesi ons tending to multiply occur, mostly to be bilaterally distributed and commonly involved in the lower lung field. (2) The lung shadows mostly showed as sub pleural focal consolidation, flaky cloudy shadow, large area consolidation, grou nd glass blurry shadow, and often accompanied with signs of broncho inflat ion. (3) Having opacified nodular shadows in the alveolar cavities. (4) Rapid pr ogressions or changes on the size, amount, and distribution of the lesions likel y to be found in dynamic observation of chest X ray and CT scanning, i.e., ma rkedly dynamic changes found within 24 to 48 hrs. Lesions with these characteris tics may be recognized as pulmonary changes possibly induced by SARS. Complicati ons were found in 6 patients (7.31%), including tuberculosis of lung and brain a ccompanied with pneumomediastinum in one patient, secondary infection of lung in 2, pneumothorax in 1, pulmonary fungus in 1, and pyothorax in 1.Conclusion: CT scanning is a sensitive method for diagnosis of SAR S, by which more accurate assessment of the abnormal changes of lung and occurre nce of complications in SARS patients can be made.

Computerized tomography pleurography: a new method for detecting minor pleural lesion

Objectives To evaluate the ability of CT pleurography (CTP) in detecting minor pleural lesions in patients with pleural effusion and to assess its value in distinguishing malignant from benign pleural lesions. Methods A prospective study of 50 patients with pleural effusion was conducted using conventional CT and CTP. CT scan was run after injecting an appropriate amount of contrast medium into the pleural cavity. Results In 24 patients, all lesions detected by conventional CT were demonstrated by CTP. In 13 of 24 patients, CT pleurography detected additional lesions. In 20 of 26 patients with negative findings on conventional CT, CTP was capable of demonstrating the presence of pleural lesions. The sensitivity, specificity and accuracy of detecting pleural lesions were 25%, 100% and 30% for conventional CT, 86%, 100% and 87% for CTP, respectively. Conclusion CTP is superior to conventional CT in detecting and for the differential diagnosis benign and malignant pleural lesions.

Clinical and imaging findings in patients with severe acute respiratory syndrome

Objective To investigate the clinical and imaging characteristics of severe acute respiratory syndrome (SARS), and to study their relationship Methods Forty six SARS confirmed patients were admitted to our hospital from February to April, 2003 X ray examination documents were available in all cases and chest CT scanning was acquired in 6 cases, which were analyzed retrospectively, accompanied by their clinical features Results Fever was found in 97 8% of the patients Clinical symptoms were mild, but X ray and CT findings were distinct CT scanning demonstrated ground glass like lesions and large patchy exudation and consolidation at the early stage in 6 cases Different findings on radiography and CT were related to the different phases of the disease After treatment, most lesions were absorbed completely, but slowly in patients with multi lobe consolidation and/or extensive interstitial infiltration Conclusion Special clinical and imaging findings could be found in SARS cases The prognosis of SARS patients is related to the degree of lesions detected by radiography and CT

CT and MRI diagnosis of acute traumatic hepatic rupture:analysis of ten cases

In order to verify whether magnetic resonance imaging (MRI) is superior to computed tomography (CT) in the detection and characterization of intrahepatic hematoma in its acute stage, the MRI and CT features of acute traumatic hepatic rupture (ATHR) were retrospectively studied and compared. Methods: In the 10 cases of ATHR admitted to our institute, 3 were examined with CT, 1 with MRI and 6 with both CT and MRI in the first 24 hours post injury and 9 cases out of the 10 were checked up with MRI in the first week after injury of surgery. The shape of the traumatic lesions, the damages of the intrahepatic vessels and the severity of hepatic rupture displayed with CT and MRI were compared. Results: It was found that in the first 24 hours post injury, 66.6% of hepatic injuries were shown as hypointensity on T1 weighted images and low or high density on noncontrast CT. 100% of the lesions were identified as well marked hyperintensity on T2 weighted images. Damages of the hepatic and/or portal veins were observed in 7, 4 and 3 cases on T2 and T1 weighted images and noncontrast CT figures respectively. The severity of hepatic injuries were graded in 100%, 66.7% and 44.4%of cases with these 3 procedures respectively. Conclusions: On the basis of our findings, it is concluded that T2 weighted MRI is a more sensitive and reliable imaging modality in the detection and differentiation of the type and severity of acute hepatic rupture than T1 weighted imaging and noncontrast CT.