AIM:To evaluate the value of multi-phasic CT arterial portography (CTAP) and CT hepatic arteriography (CTHA) in differential diagnosis of liver diseases, and to improve the specificity of CTAP and CTHA for liver cancer detection. METHODS:From January 1999 to December 2002, multiphasic CTAP and CTHA were performed in 20 patients with suspected liver disease.CT scanning was begun 25 s, 60 s and 120 s for the early-, late-and delayed-phase CTAP examinations, and 6sec, 40 s and 120 s for the early-, lateand delayed-phase CTHA examinations respectively, after a transcatheter arterial injection of non-ionic contrast material.If a lesion was diagnosed as a liver cancer, transcatheter hepatic arterial chemoembolization (TACE) treatment was performed, and the follow-up CT was performed three or four weeks later. RESULTS:All eighteen HCCs in 12 cases were shown as nodular enhancement on early-phasic CTHA.The density of the whole tumor decreased rapidly on late and delayed phases, and the edge of 12 tumors (12/18) remained relatively hyperdense compared with the surrounding liver tissue, and demonstrated as rim enhancement.All HCCs were shown as perfusion defect nodules on multi-phasic CTAP.Five tumors (5/18) were shown as rim enhancement on delayed-phasic CTAP.Rim enhancement was shown as 1 to 2-mm-wide irregular, uneven and discontinuous circumferential enhancement at late-, and delayed-phase of CTHA or CTAP.Five pseudolesions and 4 hemoangiomas were found in multi-phasic CTAP and CTHA.No pseudolesions and hemoangiomas were shown as rim enhancement on late-or delayed-phasic CTHA and CTAP.CONCLUSION: Multi-phasic CTAP and CTHA could help to recognize the false-positive findings in CTAP and CTHA images, and improve the accuracy of CTAP and CTHA of liver cancer detection.
Mediastinal lymph node staging in non-small cell lung cancer (NSCLC) is important to choose standard treatment plan and estimating prognosis. This study was to evaluate the clinical value of spiral CT in staging mediastinal lymph node in NSCLC through comparing spiral CT findings with corresponding pathology.A total of 89 patients with pathologically proven NSCLC received spiral CT and mediastinoscopic biopsy. The spiral CT findings and corresponding pathologic findings in staging mediastinal lymph node were compared. The sensitivity, specificity, and accuracy of diagnosing mediastinal lymph node metastasis were calculated.Compared with corresponding pathologic results, the overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of mediastinal lymph node staging with spiral CT were 58.9%, 70.0%, 60.5%, 68.6%, and 65.2%, respectively. The accuracy and specificity of spiral CT was relatively low in staging 4R, 5, 6, 7 lymph node groups; the false negative and false positive rates were relatively high in staging 4R, 7 lymph node groups.Spiral CT is a non-invasive clinical examination which may be used in staging mediastinal lymph node in NSCLC; however, there exists false negative and false positive rates. It should be combined with other investigations, such as mediastinoscopy, to assess a more accurate mediastinal lymph node staging.
Focal nodular hyperplasia (FNH) is a rare hepatic neoplastic lesion. This study was to evaluate the typical and atypical features of FNH of the liver on helical computed tomography (CT) images to improve the diagnosis accuracy.Helical CT images of 32 patients with 37 lesions were reviewed in Cancer Center, Sun Yat-sen University retrospectively, who were confirmed as FNH by histopathologic or clinic examinations. The number, size, margin status, density, enhancing type, presence of a center scar, and presence of a pseudocapsule of FNH lesions were analyzed.The largest diameters of 14 lesions were < or = 3 cm, of 23 lesions were > 3 cm; 20 lesions were subcapsular; pseudocapsule was presented in 7 lesions with the largest diameters of > 3 cm; 22 lesions had center scars, among them, the largest diameters of 20 lesions was > 3 cm. All lesions were hyperattenuated to the liver in hepatic arterial phase; 31 lesions were enhanced homogeneously in hepatic arterial phase; abnormally thickened vessels were presented at the border of 17 lesions.Typical helical CT features of FNH include homogeneous enhancement in hepatic arterial phase, presence of central scar, and delayed enhancement. Atypical helical CT features of FNH include heterogeneous enhancement in hepatic arterial phase, absence of central scar, and presence of pseudocapsule. The various CT features are related to the pathologic type and the largest diameter of the lesion.
To study the computed tomographic findings of adrenal adenoma with the maximal diameter greater than 5 cm and to discuss whether such tumor can be differentiated from adrenal carcinoma by CT examination. Fourteen consecutive patients with adrenal adenoma with the maximal diameter larger than 5 cm, proven pathologically, were enrolled. All patients underwent non-enhanced and contrast-enhanced CT examination. The CT findings, including size, shape, edge, density on non-enhanced CT and schedule of reinforcement after contrast administration for each lesion were retrospectively analyzed. CT data of 13 patients with adrenocortical carcinoma were also evaluated to determine whether differentiating characteristics existed. The maximal diameter of the 14 masses of adenoma ranged from 5.5 cm to 20 cm (mean, 10 cm). One mass showed lobulated, the rest 13 masses showed rounded or ovoid. Eleven and 3 masses appeared well-circumscribed and ill-circumscribed, respectively. All of 14 masses presented heterogeneous density on non-enhanced CT images with patchy low-attenuation foci or stippled calcification. All of 14 masses revealed moderately to markedly heterogeneous enhancement after contrast administration. None of 14 masses developed local invasion and distant metastasis. Except for recurrence, metastasis and venous tumor emboli which only occurred in the cases of adrenal carcinoma, no definite computed tomographic features could be found that enabled the identification of adenomas with the maximal diameter greater than 5 cm with adrenal carcinomas. The characteristic CT findings of adrenal adenoma with the maximal diameter greater than 5 cm include bulky, well-circumscribed, rounded or ovoid masses, heterogeneous attenuation with low-attenuation foci on non-enhanced CT images and heterogeneous enhancement after contrast administration. The differential diagnosis between such tumor and adrenal cortical carcinoma by CT examination is relatively difficult, such findings as recurrence, metastasis and venous tumor emboli may be of some significance.
Blood flow patterns with CT perfusion imaging (CTPI) had been innovated to delineate abnormal hemodynamic lesions in the liver, brain, and kidney. This study was to evaluate the blood flow patterns of pulmonary masses by CTPI, and determine the value of CTPI in differential diagnosis among benign, malignant, and inflammatory masses.Fifty-two patients with previously diagnosed pulmonary masses (37 with malignant masses, 7 with benign masses, and 8 with inflammatory masses) underwent dynamic CTPI. Time-density curves (TDC) of artery, vein, and pulmonary masses as well as mass perfusion images and parameters including perfusion volume (PV), peak height (PH), mean transit time (MTT) and blood volume (BV) were obtained by Phlips CT-perfusion software.The values of PV, PH, and BV were significantly higher in malignant masses and active inflammatory masses than in benign masses [(27.63+/-15.06) ml.min(-1).ml(-1) and (30.80+/-20.33) ml.min(-1).ml(-1) vs. (11.81+/-3.74) ml.min(-1).ml(-1), (28.46+/-12.07) Hu and (32.15+/-15.89) Hu vs. (10.41+/-3.77) Hu, (21.64+/-10.97) ml/100 g and (28.38+/-14.55) ml/100 g vs. (10.61+/-5.33) ml/100 g, P<0.01]. However, the differences of MTT among malignant, inflammatory, and benign masses were not significant [(28.39+/-21.66) s, (25.91+/-14.57) s, and (29.86+/-13.57) s, P=0.928]. No significant differences in the 4 parameters were found between malignant and inflammatory masses. When PV >20 ml.min(-1).ml(-1) and pH >15 Hu were set as a diagnostic threshold (excluded active inflammatory masses), the sensitivity, specificity, and accuracy were 91.9%, 100%, and 84.1%, respectively.CT perfusion imaging provides quantitative information about blood flow patterns of pulmonary masses and is an applicable diagnostic method for differentiating pulmonary masses.
Thymic epithelial tumors have a broad spectrum of biologic and morphologic features. This study was to assess the CT features of various subtypes of thymic epithelial tumors on the basis of the 1999 World Health Organization (WHO) classification.CT features of thymic epithelial tumors in 94 patients were retrospectively analyzed. All cases were confirmed histologically according to the 1999 WHO classification, including 7 cases of type A, 24 cases of type AB, 16 cases of type B1, 13 cases of type B2, 16 cases of type B3, and 18 cases of type C.In the 94 cases, the long- and short-axis diameters of type A and type AB tumors were significantly shorter than those of type C tumors (P<0.05). All type A tumors had smooth contours, type A, AB, and B1 tumors were likely to have smooth contours (P<0.05), while type B3 and C tumors were likely to have irregular contours (P<0.05). Type A tumors had less necrotic areas than any other types (P<0.05). Multiple calcifications were more frequently seen in type B2, B3, and C tumors than in type A, AB, and B1 tumors (P<0.05). Homogeneous enhancement was more frequently seen in type A, AB, B1, and B2 tumors than in type B3 and C tumors (P<0.001). Type B3 and C tumors significantly preferred to infiltrate into mediastinal fat than any other types (P<0.05).Though CT features of different subtypes of thymic epithelial tumors according to WHO classification are overlapped, short diameter, smooth contour, round shape, homogeneous density, and homogeneous enhancement are most suggestive for type A tumor; large diameter, irregular contour, necrosis and multiple calcifications in the lesion, heterogeneous enhancement, mediastinal fat infiltration, and great vessel infiltration are most suggestive for type B3 and C tumors.
With the general using of computed tomography (CT) and magnetic resonance imaging (MRI), it is important to determine which method is more sensitive in detecting the skull base encroachment in clinic. This article was designed to investigate the diagnostic value of CT and MRI in detecting the skull base erosion in nasopharyngeal carcinoma patients.Sixty-one cases pathologically proven as nasopharyngeal carcinoma were selected from August 1993 to September 2001. three-dimensional reconstruction with spiral CT thin slices scan were performed in 8 cases. CT scan was performed with Elscient CT Twin Flash; axial scan was parallel to the OM line routinely from soft palate to the suprasellar cistern. There were 13 cases with enhancement scan. MRI scan was performed by Philips T5-II super-conducting magnetic resonance imaging system (0.5T). The standard quadrature head coil was used. Routine axial, sagittal, and coronal image with SE sequences were obtained. Scanned field ranged from the soft palate to the suprasellar cistern. After plain scan, enhanced scan was performed in 55 of 61 cases.MRI discovered the skull base encroached more precisely than CT, 17 cases by CT and 26 cases by MRI, respectively. The early bone marrow infiltration was seen at clivus, basilar pterygoid, and basilar sphenoid in 6 cases by MRI scan while CT scan showed no abnormal lesion at these sites. In addition, MRI revealed nasopharyngeal carcinoma tissue infiltrated along the mandibular nerve (3 cases) while CT scan showed no change of these structures.Both CT and MRI can reveal that the tumor encroaches on the skull base by either destroying the bony structure or breaking through the natural foramen. MRI is more sensitive than CT in detecting the skull base encroachment. MRI could reveal the early infiltration of the bone marrow and tumor infiltration along the mandibular nerve. MRI confirms the dimension of nasopharyngeal carcinoma more precisely than CT. The three dimension reconstructional spiral CT was directer in discovering the dimension of the tumor.
The helical double-phase CT scan imaging features of hepatocellular carcinoma (HCC) overlap those of other hepatic lesions. This study was to investigate the helical double-phase CT scan imaging features of HCC to improve diagnosis accuracy.Double-phase CT data and pathologic data of 52 HCC patients, received resection in Cancer Center of Sun Yat-sen University from Dec. 2000 to Dec. 2002, were analyzed. The double-phase CT features of HCC lesions were summarized. The pathology of false-positive lesions was analyzed.CT scan showed 56 lesions in the 52 patients: 51 were cancer lesions, including 49 HCC lesions and 2 mixed lesions of HCC and cholangioma, 5 were false-positive lesions. Arterial phase of these HCC lesions showed obvious heterogeneous enhancement, and the portal vein phase showed heterogeneous low dense. Necrosis was seen in all massive lesions, but was seldom seen in nodular and small lesions. Most lesions had clear borders and amicula. The pathologic diagnoses of the 5 false-positive lesions were hepatic cirrhosis with hepatocellular nodular hyperplasia, regenerative nodule, hepatic cirrhosis, bile duct calculus companied with inflammatory reaction, and fibrosis hyperplasia.Helical double-phase CT scan can be used to diagnose typical HCC lesions. There are no obvious differences in helical double-phase CT scan between HCC lesions and false-positive lesions. The diagnosis of HCC must be based on clinical information, follow-up or biopsy.
：Objective To study theimaging features of Kimura disease to improve diagnostic ability prior to surgery.MethodsThe clinical manifestations and CT and MR findings of 11 patients with histologicallyconfirmed Kimura disease were retrospectively analyzed.All 11 tumors originated from (orinvolved)the parotid region in 7 cases, the maxillofacial region in 2 cases, the palate inone case and the groin in one case.Clinically, the lesions showed asymptomatic tumors withthe mean clinical course over 2 years.The increase of cosinophilic granulocyte was foundin all 11 cases.Results On CT and MRI,5 patients were single masses and others weremuhi-nodular masses.The smallest lesion was 6 mm×3 mm,and the largest lesion was 60 mm ×34 mm.The lesions were almost ill-defined in the subcutaneous tissue,especially 10locating underlying superficialfascia in head and neck.On CT,the lesions showedhomogeneous hypodense to the muscle in 9 patients.The lesions appeared isointeuse signalor slightly hypointense on MR T1WI and slightly hyperinteuse on T2WI in 3 patients.Alllesions revealed moderate or marked, and homogeneous or inhomngeneous enhancement.Regionallymph nodes (eight cases in the maxillofacial region and one in the groin) enlargedwithout necrosis and fusion, and with marked enhancement.Conclusion The clinical andimaging findings of Kimura disease have some characteristics, the diagnosis can be madecombined with the laboratory examination.
Objective To characterize the features of Nasopharyngeal non-Hodgkin's lymphoma (NHL) on MR imaging and find the main points to differentiate it from the other nasopharyngeal tumors.Methods The MR images of 41 patients with pathologically and immunohistochemically proven nasopharyngeal NHLs were reviewed retrospectively. Images were assessed by the size, invasive extent,signal intensity of primary nasopharyngeal tumor, and the distribution of cervical lymphadenopethy. The difference of regional tissues invasion and cervical lymphadenopathy distribution between the patients with B-cell NHLs and the patients with T-cell or NK/T-cell NHLs were analyzed by Pearson's Chi-Square test or Fisher's exact test Results Of the 41 patients, 26 patients had mature B-cell lymphoma, two patients with mature T-cell Iymphoma, and thirteen patients showed Nature killer/T-cell lymphoma in nasopharynx. MRI revealed that NHLs of nasopharynx can be showed as thickening of nasopharyngeal mucosa and (or) lumps in nasopharynx, which were slightly hyper-intensity on T2-weighted images, and intermediate signal intensity (similar to muscle) on T1 -weighted images, with mild or moderated enhancement following contrast medium administration. Twenty four cases had symmetrical disease of all walls of nasopharynx, and 17 cases had unsymmetrical tumor. Of all cases, 5 cases had superficial ulcerations, 9 cases had exceed nasoharynx invasion spreads superficially along the mucosa, 23 cases had invasion of lingual and (or) palatine tonsils,20 cases showed invasion of parapharygeal muscles, 12 cases suffered from skull base bone infiltration,25 cases had retropaharyngeal lymphadenopathy, and 27 cases had cervical lymhadenopathy. Patient with nasopharyngeal Nature killer/T-cell lymphoma had a higher incidence of exceed nasopharynx invasion,parapharyngeal structures invasion, and superficial ulcerations (the cases were 8, 11, 4 in patient with T-cell or N K/T-cell lymphoma, and 4, 10, 1 in patients with B-cell lymphoma, respectively). Patients with nasopharyngeal B-cell lymphoma had a higher incidence of inasion of lingual and (or) palatine tonsils.Conclusions Nasopharyngeal NHL is a homogeneous tumor that tends to diffusely involve all walls of the nasopharynx and spread in an exophytic fashion to fill the airway, rather than infiltrating into the deep tissues. Different pathological types of nasopharyngeal NHLs have some different appearance on MRI between each other. A large tumor in nasopharynx that fills the nasopharynx cavity, with no or minimal invasion into deep structures, but with invasion extend down into the lingual and(or)palatine tonsils, may suggest the diagnosis of nasopharyneal NHL.
Key words:
Lymphoma,non-Hodgkin; Nasopharyngeal neoplasms; Magnetic resonance imaging
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