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.

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.

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.

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.

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.

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.

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.

[Value of magnetic resonance imaging in displaying the parotid gland segments of the facial nerve].

OBJECTIVE: To evaluate the value of magnetic resonance imaging (MRI) in displaying the parotid gland segments of the facial nerve. METHODS: Sixteen volunteers (9 males and 7 females) and 132 surgically confirmed patients with parotid tumors locating in the deep or shallow lobe of the parotid gland (including 89 with benign and 43 with malignant tumors) underwent MRI using T1WI and T2WI. The transverse images were obtained with the plane tilted 35 degrees to the foot, and the coronal images were acquired using conventional scanning. RESULTS: On transverse T1WI, the parotid gland segments of the facial nerve displayed low signal with arc-shaped curve in the cross-section, showing a symmetrical dot-like low signal in the coronal plane. The facial nerve in 63% of the patients with parotid tumors in the cross-section could be displayed, but in the coronal plane the proportion reached 83%. MRI could accurately reveal the position of the parotid tumors in the deep or shallow lobe of the parotid gland. CONCLUSION: MRI can show the major portion of the parotid gland segments of the facial nerve and has important value in locating the parotid tumors and displaying the relationship between the tumor and facial nerve.

[Magnetic resonance imaging for diagnosis of parotid malignant tumors and the pathological basis].

OBJECTIVE: To investigate magnetic resonance imaging (MRI) features of parotid malignant tumors and study their pathological basis. METHODS: Forty-seven patients with parotid malignant tumors confirmed by surgery (41 patients) or biopsy (6 patients) were enrolled in this study. A comparative analysis was conducted of the pathological and MRI findings in 30 patients with the entire lesions available. Each of the MRI features was analyzed retrospectively and the typical MRI findings of common parotid malignant tumors were summarized. RESULTS: MRI allowed accurate diagnosis of parotid malignant tumors. Four patients with low-grade mucoepidermoid carcinoma showed well-defined tumor margin and were difficult to distinguish from benign tumors. Six patients with high-grade mucoepidermoid carcinoma had obscure margin of the tumor which easily underwent necrosis with liable lymph node involvement. The 8 cases of adenoid cystic carcinoma was characterized by extensive invasion surrounding the parotid gland. Most of 8 cases of malignant pleomorphic adenoma still showed high and heterogeneous signal on T2WI, with irregular shape and poorly defined margin. Nine cases of lymphoma all had secondary lesions characterized by extensive involvement and presence of multiple nodules. The 4 cases of acinic cell carcinoma showed either regular or irregular tumor morphology, presenting with high signal intensity on T1WI and T(2)WI. CONCLUSION: MRI is an important modality for the diagnosis of parotid malignant tumors. Most of the common parotid malignant tumors have characteristic MRI and pathological features, which make possible their differential diagnosis.

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.

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.

[Value of Radiation Therapy Oncology Group guidelines based on MR imaging in diagnosing lymph node metastasis of nasopharyngeal carcinoma].

BACKGROUND AND OBJECTIVE: Radiation Therapy Oncology Group (RTOG) and other major cooperative groups endorse the consensus guidelines for the delineation of the node levels in stage N0 cases. But it is unclear if these guidelines can be extrapolated to N+ cases. This study was to explore the value of RTOG guidelines in delineating cervical target volumes for nasopharyngeal carcinoma (NPC) patients with lymph node metastasis. METHODS: Conventional magnetic resonance imaging (MRI) of the nasopharynx, including plain and contrast enhanced sequences, was performed on 254 naive NPC patients. The lymph nodes were divided into six cervical levels plus retropharyngeal nodes (RN) according to RTOG guidelines proposed in 2003. RESULTS: Anatomic boundaries of node levels were observed clearly on MRI. Of the 254 patients, 107 (42.1%) had obvious lymph node necrosis, 78 (30.7%) had extracapsular nodal spread, four (1.6%) had skipped metastasis. The levels of lymph node metastases in 51 (20.1%) patients were beyond RTOG guidelines, 42 of which were above cranial level IIb, six were behind the anterior edge of the trapezius muscle, and 23 were below the caudal of level IV; 20 patients had two regions of lymph node metastases beyond RTOG guidelines. No patient only with lymph node metastasis beyond RTOG guidelines was found. CONCLUSIONS: MRI is feasible to diagnose cervical node metastasis with RTOG guidelines. The boundaries of node levels should be enlarged rationally when delineating target volumes for the N+ NPC patients according to RTOG guidelines.

[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.

[Imaging manifestations and pathologic features of soft tissue desmoid-type fibromatosis].

BACKGROUND & OBJECTIVE: Soft tissue desmoid-type fibromatosis is a type of benign, infiltrative tumors which are rarely seen. This study was to analyze CT and MR manifestations and pathologic features of soft tissue desmoid-type fibromatosis to improve its diagnostic accuracy. METHODS: A total of 34 soft tissue desmoid-type fibromatosis from 29 patients, including 20 primary and 14 recurrent tumors were analyzed. Eight were scanned with CT, and 26 were scanned with MRI. Features of the growth pattern, CT or MRI findings and pathologic appearances of the tumors were studied. RESULTS: The mean size of the 34 tumors was 6.5 cm. Of the 34 tumors, 31(91.2%) had an ill-defined or partially ill-defined margin, 31(91.2%) had a lobulated or irregular contour, 17(50.0%) had neurovascular involvement, 15(44.1%) had bone involvement, 23(67.6%) had extra-compartmental extension. Among the eight tumors scanned by CT, six showed slight hypodensity on the non-enhanced CT scan, and seven were inhomogeneously enhanced after contrast injection. Twenty-six tumors scanned by MRI appeared either iso-or slightly hyperintense on T1W images, hyperintense on T2W images, and moderate or intense enhancement after gadolinium administration. Heterogeneous signal intensity was detected in 88.5%(23/26) tumors. Linear and curvilinear areas of signal void interspersed throughout the tumors were found in 22 tumors(84.6%) on both T1W and T2W images. Histologic analysis revealed that the tumor was composed of spindle cells and collagen bundles, with a variable amount of intermingled collagen surrounding the spindle cells. Nuclear atypia was not seen,and occasional mitoses were present in the tumor cells. CONCLUSION: The characteristic manifestations of CT or MR images of desmoid-type fibromatosis provide important evidence to discriminate benign and malignant soft tissue tumors.

Semi-quantitating stiffness of breast solid lesions in ultrasonic elastography.

RATIONALE AND OBJECTIVES: To explore whether strain ratio measurement could semi-quantitatively evaluate the stiffness of breast lesions. MATERIALS AND METHODS: From January 2008 to May 2008, 148 patients with 254 solid lesions (183 benign, 71 malignant) in the breast were included in the study. Ultrasound sonography found the lesions and ultrasonic elastography obtained the strain images. By using the strain ratio measurement method together with the ultrasound machine, the strain index of the lesion was calculated. Different depths of breast tissue were selected as the reference. The strain indexes of malignant and benign solid lesions were calculated with the same level of breast tissue as the reference. RESULTS: The strain indexes of breast lesions were different compared to the same depth of breast tissue and the superior level of fat tissue (P = 0.000). The strain indexes of breast lesions were different compared to different depths of breast glandular tissues (P = 0.003). At the same level of the breast lesions, 212 lesions were glandular tissue, 11 were fat tissue, and 40 were both. In the lesion plane, six lesions had almost no glandular tissue and 20 had almost no superior fat tissue. Compared to the same depth of breast tissue, the strain indexes of benign lesions (range, 0.62-11.07) and malignant lesions (range, 3.12-39.28) were different (P = 0.000). CONCLUSION: Using the strain ratio measurement, stiffness of breast lesions could be semi-quantitated with the same depth of breast tissue as the reference. This method may provide another diagnostic method in addition to the 5-point scoring system used with ultrasonic elastography in the future.

[Dynamic contrast-enhanced MR imaging and digital subtraction angiography manifestation of hepatic focal nodular hyperplasia].

BACKGROUND & OBJECTIVE: Focal nodular hyperplasia (FNH) is a rare benign hepatic tumor and its imaging diagnosis remains difficult. This study was to analyze dynamic contrast-enhanced MR imaging and digital subtraction angiography (DSA) manifestation of FNH, and to improve the diagnostic accuracy of FNH. METHODS: The MRI and DSA imaging data of 30 patients with FNH proved by pathology were reviewed. Conventional contrast-enhanced MRI was completed in 11 patients; dynamic contrast-enhanced MRI was completed in 15 patients. DSA was completed in 10 patients. RESULTS: On dynamic contrast-enhanced MRI scan, 18 lesions in 15 patients showed obvious enhancement at arterial phase and prolonged enhancement at delayed phase. Central scars were found in 11 lesions, and showed enhancement since portal vein phase till delayed phase. The time-signal intensity curves of the 18 lesions were ascended rapidly at arterial phase, and descended slowly at portal vein phase and delayed phase. On DSA examination, 13 lesions in the ten patients showed dilated feeding arteries, and radiate feeding arterial branches were seen in eight lesions. CONCLUSIONS: Dynamic contrast-enhanced MRI can fully show abnormal signal of the central scar of FNH. The time-signal intensity curve of FNH ascends rapidly and descends slowly. On DSA imaging, the feeding arteries of FNH spread radially. Dynamic contrast-enhanced MRI and DSA could improve the diagnostic accuracy of FNH.

[Value of multi-slice spiral CT with three-dimensional reconstruction in the diagnosis of neoplastic lesions in the jawbones].

OBJECTIVE: To assess the value of multi-slice spiral CT (MSCT) with three dimensional (3D) reconstruction in the diagnosis of neoplastic lesions in the jawbones. METHODS: Thirty-three patients with neoplastic lesions of the jawbones underwent MSCT scanning with 3D reconstruction. Of these patients, 14 had ameloblastoma, 8 had hemangioma, 3 had osteosarcoma, 3 had ossifying fibroma, 2 had chondrosarcoma, 2 had fibrosarcoma, and 1 had odontogenic myxoma. Preoperative MSCT scanning was performed with the slice thickness of 2 mm, and 3D reconstruction of the images was conducted by means of multi-planar reconstruction (MPR), curved-planar reformation (CRP), and 3D volume rendering technique (VRT). The results were compared with those observed during the operations. RESULTS: In the 33 cases, the neoplastic lesions of the jawbones were displayed by 2D or 3D imaging and confirmed by intraoperative findings. Two-dimensional imaging allowed better observation than 3D imaging of the deep structures, whereas 3D imaging was superior in visualizing the morphological changes of the compromised bones and the spatial relationship between the tumors and surrounding structures. Two-dimensional imaging and MPR were excellent in revealing the internal structures and pathological changes of tumors, having also better performance in showing the tumors involving the soft tissues. Benign tumors were most visualized as bone expansion changes with well defined ovoid or lobulated borderlines, and malignant ones often resulted in adjacent bony destruction and soft tissue masses. CONCLUSION: MSCT examination is useful in defining the scope of tumor involvement and bony changes to help in the definite diagnosis, differential diagnosis and choice of clinical treatment. Two-dimensional imaging, MPR, VRT and CRP have their respective advantages and limitations in showing jawbone tumor, and their combination can be of great clinical value.

[Correlation of MRI features to histopathologic grade of soft tissue sarcoma].

BACKGROUND & OBJECTIVE: Peripheral tumor growth pattern plays an important role in the local recurrence and metastases of soft tissue sarcoma. This study was to determine the peripheral growth pattern of soft tissue sarcoma by magnetic resonance imaging (MRI), explore its correlation to histological grade, and assess biological features of soft tissue sarcoma before operation. METHODS: MRI was performed in 59 patients with soft tissue sarcoma. T1- and T2-weighted images were obtained using a spin-echo (SE) pulse sequence. Tumor margin, peritumoral high signal intensity sign and peritumoral low signal intensity capsule-like sign were evaluated on MR images. All patients were confirmed and graded by histopathology. RESULTS: The histological grade of soft tissue sarcoma was closely related to the margin appearance (P<0.05): the margin was well defined in 60.0% grade I tumors, and poorly defined in 60.0% grade III tumors. No significant difference in the occurrence rates of peritumoral high signal intensity sign and peritumoral low signal intensity capsule-like sign was found between grade II and grade III tumors (P>0.05). The occurrence rate of peritumoral high signal intensity sign was significant lower and that of peritumoral low signal intensity capsule-like sign was significant higher in grade I tumors than in grade II-III tumors (10.0% vs. 74.4%, 80.0% vs. 15.4%, P<0.05). CONCLUSION: The peripheral tumor growth pattern is related with histological grade, and may reflect the biological behaviors of soft tissue sarcoma.

Bone marrow MR imaging as predictors of outcome in hemopoietic stem cell transplantation.

The purpose of this study is to investigate the role of femoral marrow MR imaging as predictor of outcome for hemopoietic stem cell transplantation (HSCT) in beta-thalassemia major. MR imaging of the proximal femur, including T1- and T2-weighted spin echo and short-tau inversion recovery and in-phase and out-of-phase fast field echo images, was prospectively performed in 27 thalassemia major patients being prepared for HSCT. The area of red marrow and its percentage of the proximal femur were measured, and the presence of marrow hemosiderosis was assessed. Age-adjusted multivariate logistic regression was used to determine the relationship between red marrow area percentage and marrow hemosiderosis and HSCT outcome. Red area percentage were less in patients with successful (90.25 +/- 4.14%) compared to unsuccessful transplants (94.54% +/- 2.93%; p = 0.01). Red marrow area percentage correlated positively with duration of symptoms(r = 0.428, p = 0.026) and serum ferritin (r = 0.511, p = 0.006). In multivariate-adjusted logistic regression analyses, red marrow area percentage was significantly inversely associated with successful HSCT (OR = 1.383, 95% CI: 1.059-1.805, p = 0.005). Marrow hemosidersosis and duration of sympotms and serum ferritin were not associated with HSCT outcome(p = 0.174, 0.974, 0.762, respectively). Red marrow area percentage of proximal femur on MR imaging is a useful predictor of HSCT outcome.