Radiographic and HRCT Findings of Pneumocystis Carinii Pneumonia

PURPOSE: To analyze the radiographic and HRCT findings of Pneumocystic carinii pneumonia. MATERIALS AND METHODS: We reviewed the medical records and retrospectively analysed the chest radiographs(n=31) and HRCT scans(n=17) of 31 patients with Pneumocystis carinii pneumonia who had been followed up at our institute between, 1993 and March 1998. Pneumocystis carinii pneumonia was confirmed by cytologic evaluation of sputum stained with methenamine silver(n=25) or on the basis of clinical history(n=6). The study group included 17 men and 14 women aged 28 -78(average, 53.6) years. Twenty-eight patients had underlying conditions such as hematologic diseases(n=13), AIDS(n=8), malignancy(n=2), DM(n=2) and malnutrition(n=1), and three were free from underlying diseases. RESULTS: Twenty patients had pure Pneumocystis carinii pneumonia and 11 had combined lung diseases, namely pulmonary tuberculosis(n=4), pulmonary metastasis(n=2), bacterial pneumonia(n=2), atypical mycobacterial infection(n=1), pulmonary edema(n=1), and Kaposi's sarcoma(n=1). Chest radiographic findings of 20 cases of pure Pneumocystis carinii pneumonia included consolidation(n=12), l inear-reticular opacity(n=8), ill defined haziness(n=7), and nodules(n=6), with bilaterality in is cases and zonal predominance in ten [central(n=5), lower(n=5)]. Ancillary findings included pleural effusion(n=10), cysts(n=5), lymphadenopathy(n=4) and pneumothorax(n=1). In two patients, findings were entirely normal. HRCT findings in ten cases of pure Pneumocystis carinii pneumonia included ground-glass opacity(n=6), consolidation(n=6), linear-reticular opacity(n=8), and nodules(n=5), with bilaterallity in seven cases and zonal predominance in five [central(n=5), lower(n=2)]. Ancillary findings among these cases included pleural effusion(n=4), lym-phadenopathy(n=2), cysts(n=1), and pneumothorax(n=1). HRCT findings in seven cases of Pneumocystis carinii pneumonia combined with other lung diseases included nodules(n=6), ground-glass opacity(n=5), linear-reticular opacity(n=4), and consolidation(n=3). CONCLUSION: Although ground-glass opacity in both pure Pneumocystis carinii pneumonia and this same condition combined with other lung diseases is a common radiologic finding, the possibility of variable radiologic findings in cases of Pneumocystis carinii pneumonia and other lung diseases with which it frequently combines is essential for approximate diagnosis of Pneumocystis carinii pneumonia.

CISS MR Imaging Findings of Epidermoid Tumor: Comparison with Spin-Echo Images

PURPOSE: To evaluate CISS MR imaging findings of epidermoid tumor in comparison with conventional spin-echoimages. MATERIALS AND METHODS: We studied 6 cases of epidermoid tumor in the subarachnoid space. We used a 1.5TMR unit to obtain CISS images(TR/TE/FA ; 12.3msec/5.9 msec/700) and T1- and T2-weighted spin-echo images. CISS MRimaging findings were evaluated with respect to tumor's signal intensity, contour, and relation with adjacentstructures. Conspicuity of the tumor was compared between CISS and spin-echo images. A quantitative analysis wasperformed by measuring tumor to CSF contrast. In qualitative analysis, three radiologists independently comparedCISS image and conventional spin-echo images for visibility of the tumor and graded them into three categories(poor, good, and excellent). RESULTS: Epidermoid tumors were located in the cerebellopontine angle in 4 cases, theprepontine cisstern in 1 case, and the cerebellopontine angle-prepontine cistern in 1 case. The tumors werehyperintense relative to brain parenchyma and hypointense relative to CSF on CISS images, were lobulated, encasedadjacent cranial nerve and vessels, and invaginated into brain parenchyma. In qualitative analysis, CISS imagesshowed clear demarcation between tumor and CSF, exact tumor extension, and tumor's relation with cranial nervesand vessels better than conventional spin-echo images. In quantitative analysis, the mean contrast values of tumorto CSF on T1-, T2-weighted images, and CISS images were 0.12, 0.06, and 0.52, respectively. The contrast value forCISS images was significantly higher than that for T1- and T2-weighted images (P<0.05) . CONCLUSIONS: Epidermoid tumors in the subarachnoid space are better demonstrated on CISS images than on conventional spin-echoimages. This special MR sequence can be added as a routine protocol in the diagnosis of subarachnoid epidermoidtumor.