Investigation of an optimized scanning protocol for the dentomaxillofacial region using 320-slice multidetector computed tomography.

OBJECTIVES: To propose an imaging protocol that provides satisfactory image quality for oral examination while minimizing radiation dosage using 320-slice multidetector CT (MDCT). METHODS: An anthropomorphic head phantom was scanned using 320 MDCT with protocols combining different scanning modes: volume scanning (whole or local) vs helical scanning (80- or 64-slice detectors); tube voltage settings (80 kVp, 120 kVp and 135 kVp); and tube current settings (60 mA, 80 mA, 100 mA and 120 mA). A total of six anatomical bone structures and three anatomical soft-tissue structures were assessed using quantitative and qualitative analysis in the three orthographic planes (axial, sagittal and coronal). A figure of merit (FOM) was used to determine the optimal imaging protocol in terms of tube voltage, tube current and scanning mode. RESULTS: The 80-kVp setting had the worst quantitative and qualitative results (both p < 0.001) compared with the 135-kVp and 120-kVp settings, especially for soft-tissue structures. A significant difference was noted for the scores obtained using a tube current between 120 mA and 60 mA by quantitative analysis, but not by qualitative analysis. Volume scans using either whole or local modes had a significantly higher FOM than helical scanning of 80 or 64 slices. CONCLUSIONS: In 320 MDCT, a protocol using 135 kVp, 80 mA and the volume-scanning mode (whole or local) offers adequate visualization of both soft-tissue and bone structures while keeping the radiation dose as low as possible. This may therefore be considered a first choice among a wide selection of scanning protocols for dentomaxillofacial CT.

A multicentre retrospective study of transcatheter angiographic embolization in the treatment of delayed haemorrhage after percutaneous nephrolithotomy.

OBJECTIVE: The objective is to determine the timing and indications of transcatheter angiographic embolization (TAE) for delayed haemorrhage after percutaneous nephrolithotomy (PCNL). METHODS: The medical records of 144 patients who underwent arteriography and TAE for delayed post-PCNL haemorrhage at five university hospitals between January 2005 and December 2012 were reviewed retrospectively. RESULTS: The mean time to the onset of post-PCNL haemorrhage was 10.5 days (2 - 30 days). Clinical presentation included sudden onset bleeding in 51 patients (35.4 %), intermittent bleeding in 67 patients (46. 5 %), and continuous slow bleeding in 26 patients (18.1 %). Hemodynamic instability occurred in 32 patients (22.2 %). The mean haemoglobin decrease from the first post-PCNL day to the day of TAE was 49.5 g/L (31.0 - 79.0 g/L). Renal arteriography showed pseudoaneurysms in 69 (47.9 %) patients, arteriovenous fistulas in 28 (19.4 %) patients, mixed arterial and arteriovenous lesions in 17 (11.8 %) patients, arterial lacerations in 23 (16.0 %) patients, and negative angiographic finding in seven (4.9 %) patients. TAE was successful in stopping bleeding in all 137 patients with vascular lesions. There were no major complications associated with TAE. CONCLUSIONS: TAE should be the recommended treatment for delayed post-PCNL haemorrhage in patients with hemodynamic instability and/or corrected haemoglobin decrease >30 g/L following conservative management. KEY POINTS: • Delayed haemorrhage after percutaneous nephrolithotomy occurs more than 24 hours postoperatively. • Angio-embolization is a safe and effective treatment for delayed post-PCNL haemorrhage. • Angio-embolization can treat hemodynamic instability and/or corrected haemoglobin decrease >30 g/L.

[Relationship between hMSH2 and FHIT gene expression in non-small cell lung cancer].

BACKGROUND & OBJECTIVE: Abnormality of FHIT gene has been proved to be frequent in certain malignant tumors closely related to environmental oncogenic factors, such as lung cancer. Foreign scholars have begun to explore the relationship between FHIT gene and other tumor suppressor genes, which are implicated in the pathogenesis of lung cancer. This study was designed to investigate the relationship between hMSH(2) and FHIT protein expression and to explore the correlation of hMSH(2) and FHIT protein expression with clinicopathologic features of lung cancer. METHODS: Immunohistochemical analysis of hMSH(2) and FHIT protein expression in 40 lung cancer cases and 15 adjacent non-cancer lung tissues was performed; the positive rates of FHIT and hMSH(2) proteins were measured by image analysis system. RESULTS: (1)The positive rates of FHIT and hMSH(2) proteins were 58.2% and 45.8% respectively in lung cancer tissues compared with 89.1% and 65.3% in non-cancer lung tissues. The expression levels of FHIT and hMSH(2) proteins were significantly lower in lung cancer tissues than that in non-cancer lung tissues (P< 0.01). (2)Reduced expression levels of both proteins were significantly related to tumor histology. The positive rate of the FHIT protein was 52.2% in squamous cell carcinoma compared with 63.4% in adenocarcinomas(P< 0.01), whereas the positive rate of the hMSH(2) protein was 35.6% in adenocarcinomas compared with 53.2% in squamous cell carcinoma(P< 0.01). (3)A correlation between FHIT reduced expression and lymph node metastasis was observed(P< 0.01). The positive rate of the FHIT protein was 54.1% in lung cancer tissues with metastasis compared with 60.5% in lung cancer tissues without metastasis. No association was found between hMSH(2) reduced expression and nodal metastasis(P >0.05). (4)Loss of FHIT protein correlated significantly with lasting and heavy smoking(P< 0.01). The positive rate of the FHIT protein was 53.1% in smoking group compared with 66.1% in non-smoking group. The reduction of hMSH(2) expression was not associated with smoking(P >0.05). (5)An inverse correlation was found between hMSH(2) reduced expression and FHIT protein loss (P< 0.01, RR=-0.54). CONCLUSION: FHIT gene may be a negative regulatory gene of hMSH(2) gene, and play an important role in the inactivation mechanism of hMSH(2) gene.

[Helical dual-phase CT scan in evaluating blood supply of primary heptocellular carcinoma after transcatheter hepatic artery chemoembolization with lipiodol].

OBJECTIVE: To evaluate the blood supply of low density viable area of primary heptocellular carcinoma after transcatheter hepatic artery chemoembolization using lipiodol (LP-TACE), by helical dual-phase CT scanning and three dimensional CT (3DCT). METHODS: Thirty-four patients with primary heptocellular carcinoma after LP-TACE were examined by hepatic helical dual-phase CT. 3DCT model of the maximum intensity projection (MIP), surface shaded display (SSD) reconstruction of the hepatic artery and portal vein were simultaneously done in 5 cases. RESULTS: Viable tumor areas of 34 cases of primary heptocellular carcinoma after LP-TACE were divided into four types: peripheral, lateral, central and diffused types. Enhanced tumor vessel or tissue in viable tumor area was found during hepatic dual-phase in 17 cases, during hepatic artery-phase only in 8 and hepatic portal vein-phase only in 3. The viable tumor areas were found to have blood supply from the hepatic vein in 2 cases. The viable tumor area unenhanced during hepatic dual-phase was found in 6 cases. In 5 cases, the relation between the viable tumor area and branches of hepatic artery and portal vein was showed by MIP and SSD of hepatic artery and portal vein. CONCLUSION: Hepatic helical dual-phase CT scan with 3DCT is effective in evaluating the blood supply of viable tumor areas and the therapeutic effect of primary heptocellular carcinoma after LP-TACE.

[Expression of HIF-1 alpha and its relationship to apoptosis and proliferation in lung cancer].

BACKGROUND & OBJECTIVES: Hipoxia-inducible factor-1 is a transcriptive factor that regulates genes involved in metabolism, angiogenesis, proliferation, and apoptosis. This study was designed to investigate the expression of hypoxia inducible facter-1 alpha(HIF-1 alpha) and its relationship to bcl-2, Bax, PCNA in lung cancer. METHOD: Immunohistochemical streptavidin/peroxidase(SP) was used to examine the expression of HIF-1a, bcl-2, Bax, and PCNA in 60 cases of lung cancer. RESULTS: In 60 cases of lung cancer, positive rate for HIF-1a was 28.3% (17/60), specially the positive rate of small cell lung cancer(66.7%) was significantly higher than non-small cell lung cancer (21.6%). HIF-1a expression increased as clinical stage and metastasis increased(P < 0.01). The positive rate of bcl-2, Bax, and PCNA were 31.7% (19/60), 40.0% (24/60), 76.7% (46/60), respectively. Inverse relationship was found between the expression of HIF-1 alpha and bcl-2; while the correlation of HIF-1 alpha and Bax was positive(P < 0.01). The relationship between HIF-1 alpha and Bax was positive(P < 0.01). The relationship between HIF-1 alpha and PCNA was not observed(P > 0.05). CONCLUSION: HIF-1 alpha is correlated with apopotosis, but has no relationship with proliferation.