MRI manifestations of adult choledochal cysts associated with biliary malignancy: a report of ten cases.

BACKGROUND: To retrospectively review the MRI imaging features of adult choledochal cysts associated with biliary malignancy. PATIENTS AND METHODS: Ten out of 72 cases of adult choledochal cysts were found to be associated with biliary malignancy between January 1, 2003 and April 1, 2011 in our hospital database. The following MRI findings of these ten patients were retrospectively reviewed: the type of choledochal cysts, the presence of anomalous union of the pancreaticobiliary duct (AUPBD), manifestations of biliary malignancy, and concomitant findings. RESULTS: Among the ten patients, there were five type I and five type IVA choledochal cysts. AUPBD was noted in four cases. The biliary malignancy was diagnosed as cholangiocarcinoma in seven cases (70.0%) and as gallbladder cancer in three cases. Cholangiocarcinoma manifested with irregularly thickened cyst wall (n = 2), mass with irregularly thickened cyst wall (n = 4), or multiple papillary nodules without thickened cyst wall (n = 1). Most of them showed mark enhancement (n = 4) after contrast administration. Gallbladder cancer appeared as mass with irregular thickening of the gallbladder wall with inhomogeneous enhancement. Concomitant findings included liver invasion or metastases in five cases, lymph node metastases in two cases, cholangitis and/or hepatic abscess in two cases, biliary stones in three cases. The type of choledochal cysts and the extent of malignant tumor invasion revealed by MRI were consistent with the surgical findings. CONCLUSION: Most malignancies associated with choledochal cysts are cholangiocarcinoma and gallbladder cancer. MRI is a reliable method for the detection of choledochal cysts with biliary malignant changes. MR features such as irregular thickening of the gallbladder wall or cyst wall, mass or papillary nodules are suggestive of biliary malignant changes.

Clinical manifestations and MRI features of vaginal endodermal sinus tumors in four children.

BACKGROUND: Vaginal endodermal sinus tumor is a rare entity. OBJECTIVE: The purpose of this study was to report the clinical manifestations and MRI features in a case series. MATERIALS AND METHODS: Children with vaginal endodermal sinus tumor admitted to our hospitals between January 2008 and August 2012 were included. MRI was performed in all four children and diffusion-weighted imaging was performed in two children. RESULTS: Four children, mean age 14 months, were included. All had a history of vaginal bleeding. Serum alpha-fetoprotein was significantly elevated on admission. Relative to muscle, the vaginal masses were uniformly isointense on T1-weighted images, heterogeneously hyperintense on T2-weighted images and heterogeneously enhancing on contrast-enhanced images. The vaginal masses were obviously hyperintense on diffusion-weighted images (b value, 800 s/mm(2)). Extravaginal invasion was observed in three children. Pelvic lymphadenopathy was noted in two children and pulmonary metastasis was found in one child. CONCLUSION: MRI may contribute in the evaluation of vaginal endodermal sinus tumors.

Hepatocellular carcinoma with bile duct tumor thrombus: dynamic computed tomography findings and histopathologic correlation.

PURPOSE: This purpose of this study was to analyze the computed tomography (CT) findings of hepatocellular carcinoma (HCC) with bile duct tumor thrombus (BDTT) and explore their correlations with pathological manifestations. METHODS: The clinical data, CT findings, and pathological manifestations of the 16 HCC patients with BDTT were retrospectively reviewed. All cases were pathologically proven. RESULTS: Most HCCs showed hyperattenuation at hepatic arterial phase (HAP) (14/16) and hypoattenuation at portal venous phase (PVP) (12/16) and equilibrium phase (9/10), and the presence of rapid washout of contrast material was noted in 11 cases. The BDTT presented as cordlike masses in the dilated bile ducts, and mostly showed hyperattenuation at HAP (12/16) and hypoattenuation at PVP (13/16) and equilibrium phase (10/10), and the presence of rapid washout of contrast material was noted in 10 cases. Four cases of BDTT showed homogeneous enhancement, which were mainly consisted of cancer cells; 9 cases showed heterogeneous enhancement, which were mainly consisted of cancer cells with flakes of necrotic tissues or abundant red blood cells. Bile duct tumor thrombus was composed of 2 different pathological tissues in 3 cases, proximal part of BDTT was composed of tumor tissue, which was uniformly enhanced on dynamic enhanced CT, whereas the distal part was composed of necrotic or debris tissue without enhancement. CONCLUSIONS: Hepatocellular carcinoma lesion and soft-tissue mass in the bile ducts with bilary dilation are usually depicted on dynamic enhanced CT in HCC patients with BDTT. Early enhancement at HAP and rapid washout of contrast material at PVP are the characteristic findings of HCC and BDTT. Dynamic contrast CT examination is very valuable for diagnosing this disease.

MR neurography: T1 and T2 measurements in acute peripheral nerve traction injury in rabbits.

PURPOSE: To prospectively evaluate magnetic resonance (MR) signal abnormalities and the time course of T1 and T2 values in a rabbit model of acute nerve traction injury with histologic and functional recovery correlation. MATERIALS AND METHODS: All experimental protocols were approved by the institutional animal use and care committee. Acute traction injury was produced in the sciatic nerve of one hind limb in each of 28 rabbits. The contralateral sham-operated nerves served as controls. Sequential MR imaging and T1 and T2 measurements, as well as measurements of functional changes, were obtained over a 70-day follow-up period, with histologic assessments performed at regular intervals. Signal abnormalities and the time course of T1 and T2 values were observed in the proximal, traction, and distal portions of the injured nerves and the sham-operated nerves, and were compared with each other. RESULTS: Nerves with acute traction injury showed visible hyperintense signals on T2-weighted images and had prolonged T1 and T2 values. Differences of T1 and T2 values were dependent on the sites along the same injured nerve, with the most pronounced and prolonged phase of T1 and T2 increases (peak values of 1333 msec +/- 46 and 79 msec +/- 3.7, respectively) observed in the most severely damaged portion of the injured nerve. T1 and T2 values and functional changes after nerve injury showed a similar time course. A return of T1 and T2 signals to normal values correlated with functional improvement. CONCLUSION: MR imaging could be used to help predict the degree of nerve damage and monitor the process of nerve recovery in acute peripheral nerve traction injury. (c) RSNA, 2010.

In vivo MR imaging tracking of transplanted mesenchymal stem cells in a rabbit model of acute peripheral nerve traction injury.

PURPOSE: To investigate in vivo MRI tracking mesenchymal stem cells (MSCs) in peripheral nerve injures using a clinically available paramagnetic contrast agent (Gd-DTPA) and commercially available rhodamine-incorporated transfection reagents (PEI-FluoR). MATERIALS AND METHODS: After bone marrow MSCs were labeled with Gd-DTPA and PEI-FluoR complex, the labeling efficacy and longevity of Gd-DTPA maintenance were measured and cell viability, proliferation, and apoptosis were assessed. Thirty-six rabbits with acute sciatic nerve traction injury randomly received 1 × 10(6) labeled (n = 12) or unlabeled MSCs (n = 12) or vehicle alone injection. The distribution and migration of implanted cells was followed by MRI and correlated with histology. The relative signal intensity (RSL) of the grafts was measured. RESULTS: The labeling efficiency was 76 ± 4.7% and the labeling procedure did not influence cell viability, proliferation, and apoptosis. A persistent higher RSL in grafts was found in the labeled group compared with the unlabeled and vehicle groups until 10 days after transplantation (P < 0.05). The distribution and migration of labeled cells could be tracked by MRI until 10 days after transplantation. Transplanted MSCs were not found to transdifferentiate into Schwann-like cells within 14-day follow-up. CONCLUSION: Labeling MSCs with the dual agents may enable cellular MRI of the engraftment in the experimental peripheral nerve injury.

Small hepatocellular carcinoma with bile duct tumor thrombi: CT and MRI findings.

BACKGROUND: Small hepatocellular carcinoma (sHCC) with bile duct tumor thrombi (BDTT) is rare and easily misdiagnosed as cholangiocarcinoma. This study was to analyze the imaging features of sHCC with BDTT. PATIENTS AND METHODS: CT and/or MRI examinations were performed on seven patients who had sHCC with BDTT. One patient received CT scan, one received CT and MR scan, and five received MR scan. Magnetic resonance cholangiopancreatography (MRCP) was performed in five patients. The diagnosis of sHCC with BDTT was based on surgical specimens in all patients. RESULTS: The sHCC lesions and BDTT were presented on CT or MRI scans in all the seven cases. The BDTT is presented as soft tissue mass in the bile duct with biliary dilatation above the obstruction. In the two patients who had received dynamic contrast CT scan, the sHCC lesions showed atypical enhancement pattern of HCC. The BDTT showed similar enhancement pattern as sHCC in one of the two patients. The sHCC and BDTT showed homogenous hypointense signals on T1W images and hyperintense signals on T2W images in all six cases. In the three patients who had received dynamic enhancement MR scan, the enhancement patterns of sHCC lesions and BDTT were similar. Early enhancement of sHCC lesion and BDTT at hepatic arterial phase with hyperintense signals was observed in one patient, while two other patients had no early enhancement. All sHCC lesions and BDTT showed hypointense signals at portal venous phase, equilibrium phase, and delayed phase. Six patients showed hyperintense signal of hemorrhage in the dilated bile ducts on both T1W and T2W images. Five cases of BDTT presented as filling defect in the bile ducts on MRCP. The BDTT were directly connected with sHCC lesions in all the seven patients, without bile duct wall thickening or extra-bile duct invasion. CONCLUSION: CT or MRI is a safe, reliable, and valuable method for the detection and diagnosis of sHCC with BDTT.

[Adenovirus mediated gene transfer of tyrosinase gene on HepG2 cell by magnetic resonance imaging].

OBJECTIVE: To evaluate the transfect results of recombinant adenovirus vector carrying tyrosinase gene (Ad-tyr) in vitro by magnetic resonance imaging (MRI) after the Ad-tyr was transfected into HepG2 cell. METHODS: The Ad-tyr which carried the full-length cDNA of tyrosinase gene was transfected into HepG2 cell. The transfected cells were scan by MRI sequences of T1 weighted image (T1WI) , T2 weighted image (T2WI) , and short time inversion recovery (STIR) to observe the MRI signals of expressed melanin. Masson-Fontana staining was performed to search for melanin granules in transfected cells. Real-time PCR method was used to search for cDNA of tyrosinase gene. RESULTS: Ad-tyr was transfected into HepG2 cells and synthesized a large amount of melanin inside. The synthesized melanin of 1 x 10(6) cells which had been transfected by Ad-tyr with the 50, 150, and 300 multiplicity of infection separately were all sufficient to be detected by MRI and showed high signals in MRI T1WI, T2WI, and STIR sequences. The signal intensities of MRI were positively correlated to the amounts of transfected Ad-tyr. The melanin granules were found in HepG2 cells in Masson-Fontana staining. The cDNA amount of tyrosinase gene in transfected HepG2 cells, which was detected by real-time PCR, was remarkably higher than that in nontransfected cells. CONCLUSION: The synthesized melanin of HepG2 cells, which controlled by expression of exogenous gene, can be detected by MRI, indicating that the adenovirus vector can efficiently carry the tyrosinase gene into HepG2 cells.

[Clinical significance of diffusion-weighted MRI with STIR-EPI in differential diagnosis of cervical lymph nodes].

OBJECTIVE: To evaluate the feasibility and efficacy of a new MRI imaging method--diffusion weighted imaging (DWI) with short TI version recovery-echo planar imaging (STIR-EPI) sequence in differentiating benign cervical lymph nodes from malignant ones. METHODS Twenty nasopharyngeal carcinoma patients and fourteen volunteers received both conventional MRI and DWI with STIR-EPI. Ability of detecting lymph nodes between conventional MRI and STIR-EPI-DWI was compared, and the difference of apparent diffusion coefficient (ADC) value between metastatic lymph node and normal lymph node was analyzed. RESULTS: DWI was more sensitive in detecting lymph node than conventional MRI. ADC value of metastatic lymph node (0. 766 +/- 0. 119) x 10 (-3) mm(2)/s was significantly lower than that of normal lymph node (0. 975 +/- 0. 179) x 10 - mm2/s (P < 0. 01). CONCLUSION: As a new MRI imaging technique in detecting cervical lymph nodes, diffusion weighted imaging ( DWI) with short TI version recovery-echo planar imaging ( STIR-EPI) sequence is more reliable and sensitive than conventional MRI imaging, providing an alternative way to differentiate benign lymph nodes from malignant ones.

[Imaging and pathological features of gastrointestinal stromal tumors].

OBJECTIVE: To investigate the imaging features and pathological manifestations of gastrointestinal stromal tumors (GISTs). METHODS: The imaging characteristics and pathological manifestations of 26 surgically treated patients with histologically confirmed GISTs were retrospectively analyzed. RESULTS: The tumors were found to originate from the small bowel (n=10), stomach (n=8), colon (n=6), mesentery (n=1) and omentum (n=1). The imaging and pathological features of GISTs were (1) most of GISTs were well-defined and exophytic (n=19, 73.1% ), which usually compressed the adjacent tissues but no invasion. The tumor diameter ranged from 5.1 to 23.5 cm with a mean diameter of 11.6 +/- 5.9 cm, (2)most tumors had an inhomogenous density or signal intensity due to necrosis(n=21, 80.8%), hemorrhage (n=15, 57.7%) or calcification (n=3, 11.5%) within the tumor, (3) on the CT or MR images, heterogeneous enhancement pattern presented as peripheral or intra-tumor patchy enhancement was common (n=21, 80.8%). Furthermore, enhanced striped vessels were seen in 12 patients. However, homogenous enhancement pattern was rare (n=5, 19.2%), (4) the most common site where GIST metastasized to was the liver (n=7), followed by the peritoneum (n=4), but rarely to lymph nodes, (5) of these 26 patients, spindle-cell type was observed in 69.2% (n=18), epithelioid-cell type in 23.1% (n=6), and mixed cell type in 7.7% (n=2). Immunohistochemical studies showed positive CD117 expression in all of these 26 patients, but positive CD34 expression in only 22 patients. CONCLUSION: Gastrointestinal stromal tumor usually presents as a exophytic, well-defined large tumor, with internal striped vessels, necrosis or hemorrhage within. It usually metastasizes to the liver or the peritoneum but rarely to lymph nodes. Pathologically, most of gastrointestinal stromal tumors consist of spindle-cells, while a small portion of the tumors are composed of epithelioid-cells or mixed ones. Both CT and MRI play an important role in the diagnosis of gastrointestinal stromal tumors.

Treatment of severe acute respiratory syndrome with glucosteroids: the Guangzhou experience.

STUDY OBJECTIVE: To investigate the efficacy and safety profiles of corticosteroid therapy in severe acute respiratory syndrome (SARS) patients. DESIGN: Four hundred one of 1,278 SARS cases treated in Guangzhou China between December 2002 and June 2003 fulfilled the diagnostic criteria issued by the World Health Organization for confirmed identification of SARS. Among them, the diagnosis of critical SARS was defined by criteria of SARS guidelines incorporated with a low oxygenation index (OI) [< 300 mm Hg]. Data of these patients retrieved from a database were retrospectively analyzed by logistic regression and Cox regression for the effect of corticosteroid therapy on death, hospitalization days, and complication presentation. RESULTS: Among the 401 SARS patients studied, 147 of 249 noncritical patients (59.0%) received corticosteroids (mean daily dose, 105.3 +/- 86.1 mg) [+/- SD], and all survived the disease; 121 of 152 critical patients (79.6%) received corticosteroids at a mean daily dose of 133.5 +/- 102.3 mg, and 25 died. Analysis of these 401 confirmed cases did not show any benefits of corticosteroid on the death rate and hospitalization days. However, when focused on 152 critical SARS cases, factors correlated with these end points indicated by univariate analysis included use of corticosteroid, age, rigor at onset, secondary respiratory infections, pulmonary rales, grading of OI, and use of invasive ventilation. After adjustment for possible confounders, treatment with corticosteroid was shown contributing to lower overall mortality, instant mortality, and shorter hospitalization stay (p < 0.05). Incidence of complications was significantly associated with the need for invasive ventilation but not with use of corticosteroids. CONCLUSION: This Guangzhou retrospective study revealed that proper use of corticosteroid in confirmed critical SARS resulted in lowered mortality and shorter hospitalization stay, and was not associated with significant secondary lower respiratory infection and other complications.

[Diagnostic value of multi-slice spiral CT three dimensional reconstruction in maxillofacial diseases].

OBJECTIVE: To evaluate the diagnostic value of multi-slice spiral CT (MSCT) three dimensional (3D) reconstruction for maxillofacial diseases. METHODS: Sixty patients with maxillofacial diseases underwent the scanning of MSCT with 3D reconstruction. Among them, 34 patients with maxillofacial fracture, 10 patients with maxillofacial tumors and tumor-like diseases, and 16 patients with congenital deformities. The MSCT scanned with slice thickness of 2 mm. The methods of 3D reconstruction included multi-planar reconstruction (MPR), shaded surface display (SSD), and volume rendering (VR). The results were compared with what was observed during operations. RESULTS: Totally 36 cases of maxillofacial fracture were shown by 2D or 3D imaging and were validated by the observations during operation. The MSCT with 3D reconstruction imaging was significantly superior to 2D axial imaging in maxillofacial fracture. Three dimensional imaging could clearly show the spacial anatomy of facial, fragment displacement, and tracing fracture lines. However, 2D imaging had better effectiveness than 3D imaging in observing deep structure and fine fracture. In maxillofacial tumors and tumor-like diseases, 3D imaging was significantly superior to 2D axial imaging in showing the tumor shape and spacial relationships between tumors and surrounding structures. Two dimensional imaging and MPR imaging were excellent to reveal internal structure and pathological changes of tumors. 2D imaging and MPR imaging also achieved better results in showing tumors extended to soft tissues. In maxillofacial congenital deformities, 3D imaging were superior than 2D imaging. CONCLUSION: 3D imaging has an important value in the diagnosis and clinical assessment of maxillofacial fracture, tumor-like diseases, and congenital deformities.

[Investigation of proximal femoral marrow with magnetic resonance imaging in recovered patients with severe acute respiratory syndrome].

OBJECTIVE: To determine the effect of corticosteroid treatment and severe acute respiratory syndrome (SARS) infection itself on the marrow conversion in the proximal femoral marrow in the recovered patients of health care workers with SARS. METHODS: The distribution of proximal femoral marrow on MR imaging of 148 health care workers with recovered SARS including 106 cases treated with varied dosage of steroids and 42 cases without steroid, and 97 age and sex matched health adults as controls were observed. The index of marrow conversion (signal intensity of the femoral neck and intertrochanteric area divided by signal intensity of the greater trochanter multiplied by 100%) was quantitatively measured and compared between SARS patients treated with steroid and without steroid and the normal control group. RESULTS: In 106 cases treated with steroid of the 148 health care workers, femoral head osteonecrosis was found in 4 cases, bilateral femoral marrow edema in 2 cases, femoral marrow infarction in 1 case. The index of marrow conversion in the normal controls, in SARS patients treated without and with steroids was (79.4 +/- 6.8)%, (86.9 +/- 7.4)%, (88.6 +/- 5.9)%, respectively. There was significantly statistical difference between groups (P < 0.05). CONCLUSION: In addition to fat conversion in the proximal femoral marrow due to steroid treatment, the infection of SARS itself may promote an excessively conversion of the red marrow to yellow marrow of the femoral neck in SARS patients.

[The risk factors and preventive strategies of heterotopic ossification after artificial disc replacement in lumbar spine].

OBJECTIVE: To analyze the risk factors of heterotopic (HO) ossification after total lumbar disc replacement and probe the preventive strategies for it. METHODS: The radiographs and clinical data of 78 discs in 65 patients who received artificial lumbar disc replacement (ADR) from April 1998 to December 2003 were analyzed retrospectively by two radiologists and one orthopaedic surgeon and then postoperative HO were graded according to McAfee system. The bony formations in disc spaces, time of HO were found, and range of motion (ROM) of the operated levels were measured on radiographic films. In addition, the risk factors such as preoperative peri-annulus ossification, bony endplates injuries, and subsided or mal-position of the prostheses were also analyzed by Logistic regression analysis. RESULTS: Postoperative HO was found in 10 spaces of 9 cases. Class I of HO were occurred in 7 patients at means 2.1 years postoperatively with normal range of motion preserved. Three of them turned into class II or III with 10 degrees of mean ROM in the following 2.5 years. Another 2 (2/9) cases with preoperative peri-annulus ossification had bridging trabecular bone (class III) between the endplates and 9 degrees of ROM 2 years after surgery, then turned into class IV at 6 years with 0 degrees and 4 degrees of motion in the operated levels. As the risk factors of HO, preoperative annulus ossification (2 cases), bony endplates injuries (5 cases), mal-positioned prostheses (2 cases) and subsided prostheses (2 cases) were found simultaneity with significant positive relation to HO occurred (P < 0.05). CONCLUSIONS: Factors such as preoperative ossification of annulus, endplate injuries, prosthesis subsided and mal-position would have higher risks to have HO occurred after ADR, but ROM of most affected levels are preserved. Strict control indication and avoid all above risk factors can prevent HO occurring effectively.

[Proton spectroscopy findings of meningioma].

OBJECTIVE: To evaluate the characteristics of 1HMRSI and its diagnostic value on meningioma. METHODS: The findings of conventional MRI and of 1HMRSI from 11 cases of clinically proven meningiomas and from 12 normal volunteers were comparatively analyzed. The imaging sequences included T1-weighted imaging and T2-weighted imaging; additionally T1-weighted imaging with injection of the contrast agent of Gd-DTPA was performed in all meningioma cases. Two-dimensional phase encoding of proton magnetic resonance spectroscopic imaging (2D 1HMRSI) were obtained in all cases. RESULTS: On conventional pre-contrast MRI, the signals in 8 meningioma cases showed medium or faintly low intensities and in 3 cases showed mixed intensities on T1WI. On T2WI, the signals in 7 cases showed medium or faintly high intensities and in 4 cases showed mixed intensities. After injection of Gd-DTPA, the solid portion of tumors exhibited obvious enhancement in all meningioma cases. "Dural trail sign" was revealed in 7 cases. Peri-tumor edema was evident in 11 meningioma cases. Compared with control group, 1HMRSI of all meningiomas revealed different spectral peaks, including absent acetylaspartate (NAA), prominent choline (Cho), and reduced phosphocreatine (Pcr). The ratios of Cho/Pcr obviously increased. The peak of lactate (Lac) was visualized in 2 meningioma cases. CONCLUSION: Most cases of meningioma can be diagnosed with conventional magnetic resonance imaging (MRI). 1HMRSI can yield more informative findings about meningioma via the observed metabolic materials changes in tumor cells. So conventional MRI is the most important technology for diagnosing meningioma and 1HMRS combined with MRI can improve the diagnostic accuracy. 1HMRSI can be an important supplemental means in the diagnosis of meningiomas.

[MR cholangiopancreatography and MR imaging in the diagnosis of extrahepatic cholangiocarcinoma].

OBJECTIVE: To evaluate the imaging features of MR Imaging (MRI) and MR cholangiopancreatography (MRCP) and their clinical value in the diagnosis of extrahepatic cholangiocarcinoma. METHODS: MRI was performed in 54 patients with extrahepatic cholangiocarcinoma proved surgically and pathologically, MRCP in 44 patients, Gadolinium-enhanced in 29 patients. MRI, MRCP and pathological findings were analyzed retrospectively. RESULTS: By MRI, the mass was shown (n = 39) and all bile duct thickened (n = 13) in extrahepatic cholangiocarcinoma. Gadolinium-enhanced ones revealed calcified focus (n = 22). By MRCP, interrupted, abruptly cut-off or cone-like changes of the bile duct (n = 16), beak-like or mouse tail changes (n = 26) or tumbler mouth appearance (n = 2) were shown. The bile duct distal to the obstruction was observed in 29 patients. Of the 54 patients examined by MRI in combination with MRCP, correct tumor localization was made in 52 (96.3%) and correct judgement of tumor nature in 50 (92.6%). CONCLUSION: Conventional MRI is an effective supplement to MRCP in the diagnosis of extrahepatic cholangiocarcinoma. MRCP combined with MRI is able to significantly improve the diagnostic accuracy of MR examination.

[Report on the investigation of lower extremity osteonecrosis with magnetic resonance imaging in recovered severe acute respiratory syndrome in Guangzhou].

OBJECTIVE: To report the occurrence of lower extremity avascular abnormalities in 124 cases of recovered severe acute respiratory syndrome (SARS) health care workers of four hospitals in Guangzhou and preliminary investigate the correlation with the treatment of steroid. METHODS: 124 health care workers with recovered SARS from four hospitals in Guangzhou were examined with MR imaging of the lower extremity including bilateral hips and knees. In 124 health care workers, 38 cases have not treated with steroid, while 86 cases have treated with varied dosage. The imaging protocol was consisted of screening and full examination. Coronal T1-weighted imaging and short tau inversion recovery sequence were defined as the screening examination. The full examination was defined as images from the screening examination plus three additional imaging sequences: transverse and coronal T2-weighted imaging and short tau inversion recovery sequence. RESULTS: In 86 health care workers, 5 cases were found positive in the lower extremity. Osteonecrosis was found in 3 cases. One was involved in bilateral femoral head, and another was unilateral femoral head, and the remaining one was bilateral femoral heads and unilateral femoral condyle and tibial condyle. Bilateral femoral and tibial marrow edema were found in one case. Femoral infarction with significant calcification occurred in one health care worker. Logistic regression analysis indicated that the presence of avascular abnormalities was related with maximum daily dosage. CONCLUSION: Osteonecrosis definitely exists in the minority of health care workers with recovered SARS in Guangzhou, who had treated with steroid. The maximum daily dosage of steroid may significantly influence on the occurrence of avascular abnormalities.

Synergistic anticancer effect of rAd/P53 combined with 5-fluorouracil or iodized oil in the early therapeutic response of human colon cancer in vivo.

Exogenous wild-type p53 (wt-p53) tumor suppression increases the sensitivity of tumor cells to radiotherapy and chemotherapy. An iodized oil emulsion was used as a p53 vector for intra-arterial gene delivery to treat hepatic tumors. Whether the chemotherapeutic agent or the iodized oil affects exogenous wt-p53 activity remains poorly understood. In the present study, the early therapeutic response of rAd/p53, combined with 5-fluorouracil (5-FU) or with iodized oil, was observed in a human colon cancer model. Allograft models in 82 nude mice with human colon carcinoma SW480 were divided randomly into four groups and administered with physiologic saline, rAd/p53, rAd/p53+5-FU, and rAd/p53+iodized oil by intratumoral injection. At 24, 48, 72, 120, and 168 h after treatment, p53 expression, the Ki-67 index (KI), and the degree of tumor necrosis were assessed. The p53 expression and tumor necrosis in the therapeutic groups were higher than those in the control group. p53 expression reached its peak at 120 h in the rAd/p53 group, at 72 h in the rAd/p53+5-FU group, and at 48 h in the rAd/p53+iodized oil group. The p53 expression in the rAd/P53+5-FU group and the iodized oil group was significantly higher than those in the rAd/P53 group at 24 and 48 h. The results revealed that tumor necrosis is positively correlated with p53 expression. The KI of the rAd/p53+5-FU group increased significantly at 24 h. 5-FU and iodized oil increase the anticancer effect of rAd/p53, and 5-FU combined with rAd/p53 has a synergistic anticancer effect.

Juxta-adrenal schwannoma: dynamic multi-slice CT and MRI findings.

BACKGROUND: We retrospectively analyzed the MSCT and MRI findings of three cases of juxta-adrenal schwannoma and reviewed literature. METHODS AND RESULTS: Three patients were male, and showed no signs for endocrine activity. The three cases of juxta-adrenal schwannoma were all well-circumscribed, oval masses with cystic components, and one case with hemorrhage. Hypointense signal capsules were observed on T2-weighted images in two cases, and the capsule in one case showed rim enhancement. The tumors displayed mild enhancement in the arterial phase and progressive enhancement during the portal venous phase and equilibrium phase. Computed tomography angiography clearly showed the tumor feeding vessels arising from the abdominal aorta. CONCLUSIONS: MSCT and MRI are valuable imaging modalities for diagnosis of juxta-adrenal schwannoma.

Intraspinal primitive neuroectodermal tumor: imaging findings in six cases.

PURPOSE: To retrospectively review CT and MRI findings in a series of six intraspinal primitive neuroectoderal tumors and to find out their radiological features. METHODS: CT and MRI of six patients with surgically and pathologically proved intraspinal primitive neuroectoderal tumor were retrospectively reviewed. The tumor location, morphological features, signal intensity, calcification, contrast enhancement characteristics, involvement of paraspinal soft tissues and adjacent bony structures were assessed. RESULTS: Of six patients, four had extradural lesions and two had intradural, extramedullary lesions. Most lesions were well defined and manifested heterogeneous iso- or hypo-intense signal on T1-weighted imaging and hyper-intense signal on T2-weighted imaging and moderate attenuation on CT, and were heterogeneously enhanced after contrast enhancement. The lesion extending through the intervertebral foramen with a large paraspinal soft tissue mass formed was found in four patients and vertebral bone involvement was seen in four patients. CONCLUSIONS: Although imaging findings are not specific of intraspinal primitive neuroectoderal tumor, this diagnosis could be suggested when MR imaging depicts an intradural, extramedullary or extradural large well-circumscribed mass which extends out from intervertebral foramen and invades paraspinal soft tissues or vertebral bones in a young patient.

Optimal technique of three-dimensional MRI of the lumbar nerve root and its radicular vein in normal and lumbar disc herniation patients.

BACKGROUND: Although three-dimensional MRI (3D-MRI) of short T1 inversion recovery turbo spin-echo (STIR TSE) has showed superior to two-dimensional MRI (2D-MRI) in showing the spinal cord and lumbar nerve roots, it remains difficult in demonstrating radicular vein at present. We have found that short T1 inversion recovery long time echo (STIR LONG TE) was better in showing radicular vein. To further study the methods and character of the 3D-MRI of lumbar nerve root, ganglions and radicular vein in normal and lumbar disc herniation (LDH) adults, in the present study, we evaluated two 3D-MRI techniques, STIR TSE and STIR LONG TE for demonstrating lumbar nerve roots and especial radicular vein in normal and LDH adults. METHODS: Twelve normal adult persons and 19 LDH patients were included in this study; special oblique coronal location was adopted. STIR TSE and STIR LONG TE were performed in all participants, and the detection rates of radicular vein and nerve root of L3, L4, L5, S1 were calculated. The grading system was used in grading compromise of the intraspinal extradural lumbar nerve root, ganglion and radicular vein in LDH patients, and all the grading injury of nerve root, ganglion and radicular vein had been evaluated. RESULTS: The definite rate of radicular vein (DRRV) of 3D-MRI of STIR LONG TE was significantly different from that of STIR TSE. DRRV of STIR LONG TE was L3, 91.7%, L4, 100%, L5, 100%, S1, 100% and that of STIR TSE was L3, 33.3%, L4, 37.5%, L5, 58.3%, S1, 45.8% in normal adults. It showed no difference between STIR LONG TE and STIR TSE in the detection rate of nerve root. The different patho-injuries of nerve root, ganglion and radicular vein could be seen in all LDH patients by the 3D-MRI of STIR LONG TE. The mean score of Japanese Orthopaedic Association (JOA) was 16.16, and 29 nerve roots were calculated in all the study. The mean grading injury of nerve root was 2.17, that of nerve root ganglion was 1.28, that of radicular vein was 1.83, and the mean co-grading injury of nerve root, ganglion and radicular vein was 5.31. The correlation coefficient was 0.478 (P = 0.010) between the score of JOA and that of radicular vein. CONCLUSION: The 3D-MRI of STIR LONG TE is superior to STIR TSE for not only detecting the lumbar nerve root, ganglion and especial radicular vein in normal adults, but also displaying their patho-injuries degree in LDH patients.