Evaluation of pericardial sinuses and recesses with 2-, 4-, 16-, and 64-row multidetector CT.

PURPOSE: The aim of this study was to describe visualisation rate and appearance of all pericardial sinuses and recesses and to evaluate whether there is a significant difference between visualisation of these sinuses and recesses on 2-, 4-, 16- and 64-slice multidetector computed tomography (MDCT). MATERIALS AND METHODS: We retrospectively analysed 588 MDCT scans of the chest obtained with a protocol for pulmonary embolism. RESULTS: The visualisation rate of any pericardial recess was 85.2%. The rates on 2-, 4-, 16- and 64-slice MDCT were 74.7%, 90.6%, 90.3% and 88.7%, respectively. There was a statistically significant difference in visualisation rates of pericardial recesses between 2-slice MDCT and other MDCT systems (p<0.01). Age, and 4-, 16- and 64-slice MDCT versus 2-slice MDCT and the presence of pleural effusion appeared as significant predictors of the presence of any recess. CONCLUSIONS: Visualisation rates of pericardial recesses are higher with 4-, 16- and 64-slice MDCT than with 2-slice MDCT. Therefore, radiologists need to be familiar with the different appearances of pericardial recesses on MDCT to avoid misdiagnosis.

Incidental localized (solitary) mediastinal malignant mesothelioma.

Primary mediastinal mesotheliomas are rare tumours. The mesothelial lining cells of the the pericardium are suggested as the most probable cells of origin. Most of these tumours appear either as a diffuse or nodular thickening of the pericardium that encase and even invade the heart. Localized mediastinal mesotheliomas are distinctly uncommon. We report the imaging findings of a solitary malignant mediastinal mesothelioma that presented mainly as a cystic anterior mediastinal mass. On chest radiography, the tumour appeared as a right paramediastinal soft tissue mass located adjacent to the right middle and lower lobes. On CT, a large, well-circumscribed, right anterior mediastinal mass with a central zone of fluid attenuation was observed. This mass had a thin, smooth wall of uniform thickness as well as a small component that demonstrated soft tissue attenuation. There was no plane of separation between the tumour and aorta/superior vena cava. At surgery the tumour could be dissected easily free from the pericardium and great vessels and it was removed totally. Histopathological examination of the tumour revealed a malignant epitheloid mesothelioma.

Subaortic left brachiocephalic vein: computed tomography and magnetic resonance angiography findings.

A case of anomalous (subaortic) position of the left brachiocephalic vein was incidentally detected on computed tomography images. Magnetic resonance angiography was performed to demonstrate the relationship of this vessel with other vascular structures. The anomalous vein was formed by the union of the left internal jugular and left subclavian veins. This vein passed downward along the left lateral side of the aortic arch, entered the aorticopulmonary window, descended in the mediastinum between the ascending aorta and the trachea and joined with the right brachiocephalic vein to form the superior vena cava. No cardiac anomalies accompanied the subaortic left brachiocephalic vein in the present case. We present the computed tomography and magnetic resonance angiography findings of this rare anomalous vein.

Accessory fissures of the lung: evaluation by high-resolution computed tomography.

This study was performed to classify and assess the frequency of accessory fissures of the lung by high-resolution CT (HRCT) scans. The HRCT scans of 443 patients were retrospectively reviewed. After exclusion of patients with pulmonary parenchymal distortion, pleural disease or those who had had lobectomy, 186 patients were included in the study. The HRCT scans consisted of 1.5-mm sections obtained at 10-mm intervals and reconstructed with a high-spatial-resolution algorithm. In 59 of 186 patients (32%), a total of 69 accessory fissures were detected. The most common fissure was the inferior accessory fissure ( n=40; 21%, 38 on the right, 2 on the left) followed by the left minor fissure ( n=17; 9%). Other accessory fissures observed were the right superior accessory fissure ( n=2; 1%), the azygos fissure ( n=1; 0.5%) and intersegmental fissures between the medial and lateral segments of the right middle lobe ( n=3; 2%), the superior and inferior segments of the lingula ( n=2; 1%), the anterobasal and laterobasal segments of both the right ( n=1; 0.5%) and the left ( n=3; 2%) lower lobe. In conclusion, the inferior accessory fissure and the left minor fissure were the most common accessory fissures seen on HRCT examinations.

High resolution CT in children with cystic fibrosis: correlation with pulmonary functions and radiographic scores.

OBJECTIVE: To compare the high resolution CT (HRCT) scores of the Bhalla system with pulmonary function tests and radiographic and clinical points of the Shwachman-Kulczycki clinical scoring system. METHODS: HRCT of the chest was obtained in 40 children to assess the role of HRCT in evaluating bronchopulmonary pathology in children with cystic fibrosis (CF). The HRCT severity scores of the Bhalla system were compared with chest radiographic and clinical points of the Shwachman-Kulczycki scoring system and pulmonary function tests. Only 14 of the patients older than 6 years cooperated with spirometry. RESULTS: HRCT scores correlated well with radiographic points (r = 0.80, P<0.0001) and clinical points (r=0.67. P<0.0001) of the Shwachman-Kulczycki system, FVC (r = 0.71 P = 0.004) and FEV1 (r = 0.66, P = 0.01). Although radiographic points correlated significantly with FVC (r = 0.61, P = 0.02) and FEV1 (r = 0.56, P = 0.04), HRCT provides a more precise scoring than the chest X-ray. CONCLUSION: The HRCT scoring system may provide a sensitive method of monitoring pulmonary disease status and may replace the radiographic scoring in the Shwachman-Kulczycki system. It may be helpful especially in follow-up of small children too young to cooperate with spirometry.

Hypertrophic osteoarthropathy in a child with nasopharyngeal carcinoma.

We report a 13-year-old boy with nasopharyngeal carcinoma, skull metastases and hypertrophic osteoarthropathy. Although the metastases and the primary tumour responded well to chemotherapy, hypertrophic osteoarthropathy persisted during follow-up.

Gallbladder duplication: imaging findings and differential considerations.

Duplication of the gallbladder, a rare congenital anomaly, is important in clinical practice because it may cause some clinical, surgical, and diagnostic problems. We present imaging findings of a double gallbladder including coronal reformatted computed tomographic sections, to our knowledge not previously presented, and discuss the radiologic signs that may be helpful in diagnosis. We also present another case of a double gallbladder in which only one gallbladder was imaged 10 years after cholecystectomy.

Monitoring response to therapy with thallium-201 and technetium-99m-sestamibi SPECT in nasopharyngeal carcinoma.

UNLABELLED: This study prospectively assessed the value of 201Tl and 99mTc-sestamibi (MIBI) SPECT in monitoring disease regression/progression as compared with MRI findings in patients with nasopharyngeal carcinoma (NPC) having radiotherapy with or without chemotherapy. METHODS: Eighteen patients (age range 15-78 yr, mean 45 yr) had consecutive SPECT imaging using a dual-head gamma camera after the injection of 111 MBq 201Tl and 555 MBq MIBI before therapy and at 3 mo and 6 mo after completion of therapy. A total of 106 SPECT studies was correlated with contemporaneous MRI studies. Tumor-to-background ratios were obtained on coronal slices. Visually detectable lesions in the region of the nasopharynx and cervical lymph nodes were considered positive for residual disease. The gold standard for the presence of disease was the combination of repeat MRI scans, endoscopic examination and clinical evaluation performed 12-15 mo after completion of therapy. RESULTS: MIBI-SPECT proved superior to both 201Tl SPECT and MRI after 3 or 6 mo follow-up in predicting complete response. Accuracy rates in the detection of residual disease in the nasopharynx are 39%, 72% and 89% for MRI, 201Tl and MIBI, respectively, for the 3-mo evaluation; 71%, 71% and 94% for MRI, 201Tl and MIBI, respectively, for the 6-mo evaluation. CONCLUSION: MIBI SPECT could be used as a screening test in predicting response to therapy in patients with NPC.

Calcium within a bronchogenic cyst with a fluid level.

A 38-year-old man presented with a bronchogenic cyst which showed a high calcium content. The calcium precipitate layered in the dependent part of the cyst to form a fluid level. The CT and MRI findings of this rare case are discussed.

A comparative study of technetium-99m sestamibi and technetium-99m tetrofosmin single-photon tomography in the detection of nasopharyngeal carcinoma.

The intention of this prospective study was to compare the diagnostic potential of technetium-99m sestamibi (MIBI) and a novel radiotracer, 99mTc-Tetrofosmin (Tetro), for the assessment of primary nasopharyngeal carcinoma (NPC) and the differentiation of residual disease from post-therapy changes. A total of 38 patients underwent MIBI and Tetro single-photon emission tomography (SPET) imaging at initial presentation (n=22) or following therapy (n=16). The findings were correlated with computed tomography or magnetic resonance imaging (MRI) on a site-by-site basis. Tumour/background (Tm/Bkg) ratios were obtained on coronal sections. Biopsy (nine patients) and/or 12- to 24-month clinical follow-up data were available in the post-therapy group. All primary disease sites were accurately detected by both imaging studies. Although there was no statistical difference between the two imaging techniques in the detection of primary disease, MIBI was superior to Tetro in the detection of regional lymph node metastases (sensitivity: 95% vs 79%). Tetro and MIBI SPET were true-positive in all patients (n=7) with proven residual/recurrent disease. In nine patients who had no evidence of residual/recurrent tumour, MRI was false-positive in five while Tetro and MIBI SPET were false-positive in two and three patients, respectively. Tm/Bkg ratios were

Pulmonary involvement in adult Gaucher's disease: high resolution CT appearance.

High resolution CT findings of pulmonary involvement are described in a patient with adult type Gaucher's disease. Although the reticular pattern on the chest radiograph was typical, appearance of pulmonary involvement on high resolution CT has not been demonstrated in the literature. High resolution CT demonstrated interlobular septal and intralobular interstitial thickening, irregular interfaces at the pleural surfaces and ground-glass appearance, corresponding to both the alveolar and the interstitial components of the pulmonary involvement.

Pre- and post-therapy thallium-201 and technetium-99m-sestamibi SPECT in nasopharyngeal carcinoma.

UNLABELLED: We prospectively studied the diagnostic potential of 201Tl and 99mTc-sestamibi (MIBI) SPECT for evaluating the extent of primary disease and differentiating residual/recurrent disease from post-therapy changes in patients with nasopharyngeal carcinoma (NPC). METHODS: Fifty patients (20 initial presentation, 30 post-therapy evaluation) underwent 201Tl and MIBI imaging. The findings were correlated with CT/MRI results. Tumor-to-background ratios were obtained. Biopsy confirmation (14 patients) and/or 6-12 mo clinical follow-up data (16 patients) were available in the post-therapy group. RESULTS: All primary disease sites were accurately detected by both imaging studies in the pretherapy group. However, MIBI-SPECT was superior to 201Tl SPECT (p = 0.0057) in detecting regional metastases (sensitivities of 95% versus 68%). In the post-therapy group, MIBI and 201Tl imaging were true-positive in 14 of 16 patients with proven residual/recurrent. In 17 patients who had no evidence of residual/recurrent tumor. CT/MRI was false-positive in 13 when MIBI and 201Tl imaging were true-negative in 10 and false positive in 3. MIBI, 201Tl and CT/MRI had sensitivities of 87.5%, 87.5%, 100%, specificities of 82.4%, 76.5%, 23.5% and accuracies of 85%, 82%, 61%, respectively. Tumor-to-background ratios were < or = 1.5 in all false-positive cases except one. CONCLUSION: MIBI-SPECT proves more accurate than 201Tl SPECT in detecting regional metastases at initial presentation. MIBI and 201Tl imaging have higher specificity and accuracy than CT/MRI and MIBI-SPECT is slightly more specific than 201Tl SPECT in differentiating residual/ recurrent disease from post-therapy changes in patients with NPC.

US and CT findings in the diagnosis of tuberculous peritonitis.

PURPOSE: To evaluate the ultrasonographic and CT findings of tuberculous peritonitis. MATERIAL AND METHODS: Ultrasonographic and CT findings of 11 patients with the ascitic type of tuberculous peritonitis were reviewed. RESULTS: All patients had ascites, and ultrasonography (US) demonstrated fine complete and incomplete mobile septations in 10 patients. In 5 of them, the ascites had a lattice-like appearance. Diffuse regular peritoneal thickening was detected in all patients by CT and in 10 patients by US. CT demonstrated infiltration of the greater omentum in 9 patients, whereas US showed omental thickening in only 5 patients. CONCLUSION: Peritoneal and omental thickening detected by CT and ascites with fine, mobile septations shown by US strongly suggest the ascitic type of tuberculous peritonitis. The 2 imaging modalities should be used together for accurate diagnosis of tuberculous peritonitis.

Case report: squamous cell carcinoma of the skin metastasizing to the breast--imaging findings.

An extremely rare case of metastatic squamous cell skin carcinoma to the breast is reported with imaging features. Ultrasonography and magnetic resonance imaging revealed well circumscribed, complex solid masses with papillary fronds projecting into cystic centres.

Traumatic aneurysm and arteriovenous fistula of the splenic artery.

Aneurysmal arteriovenous fistulas are rare and mostly seen in adults. A 13-year-old girl developed a subcapsular hematoma of the spleen following blunt abdominal trauma. Follow-up ultrasonography 4 months after the trauma revealed an aneurysm at the splenic hilum. Selective splenic angiography demonstrated the lesion to be an aneurysmal arteriovenous fistula. Repeat ultrasonography enabled us to be certain of the traumatic origin of the aneurysm and arteriovenous fistula which are very unusual in the pediatric age group.

CT and MR imaging of splenic leiomyoma in a child with ataxia telangiectasia.

Computed tomographic and magnetic resonance imaging findings of a splenic leiomyoma in an 8-year-old boy with ataxia telangiectasia are presented. This is the first reported case of a splenic leiomyoma in the literature.

Choledochal cysts: ultrasonographic findings and correlation with other imaging modalities.

In the past, choledochal cysts had been infrequently diagnosed prior to surgical exploration for obstructive jaundice. However, with the advance of imaging modalities, preoperative diagnosis is usually apparent. We evaluated the radiological findings of choledochal cysts in 14 patients in whom ultrasonography (US) or computed tomography (CT) were mainly used for diagnosis. In addition, oral cholecystography, intravenous (i.v.) cholangiography, scintigraphy, and percutaneous transhepatic cholangiography were performed in some of them. The diagnosis was confirmed surgically in all patients. Ultrasonographic examinations were diagnostic in 13 of 14 patients. Preoperative specific diagnosis of choledochal cyst was possible with the demonstration of direct entrance of the extrahepatic bile ducts into the cyst in most cases. When US fails to show relation of cystic mass with biliary system, other imaging modalities can be used to clarify the findings.