Plain and gadolinium-DTPA-enhanced MR imaging of hepatocellular carcinoma treated with transarterial chemoembolization

Background: To assess unenhanced and gadolinium-enhanced magnetic resonance (MR) imaging patterns of hepatocellular carcinoma (HCC) treated with transarterial chemoembolization (TACE). Methods: Thirty-two patients with 48 HCC lesions underwent MR imaging before and 15 days after TACE. Fifteen lesions were then surgically resected. The remaining 33 lesions were not removed and were followed up with MR imaging at 3, 6, 12, and 18 months after treatment. Spin echo (SE) T1- and T2-weighted and gadolinium-enhanced SE T1-weighted sequences were employed. Qualitative evaluation of signal intensity pattern of the treated lesions was performed in all cases. Histological evaluation and selective hepatic arteriography were considered the gold standard of the study for the 15 resected lesions and the 33 unresected lesions, respectively. Results: On follow-up enhanced T1-weighted images of the 15 resected lesions, seven showed no area of enhancement corresponding to complete necrosis at histologic examination. The remaining eight resected lesions showed areas of enhancement; in six of these cases, viable tumor tissue was found at histology; in the other two lesions, histologic examination revealed the presence of complete tumor necrosis. In the group of resected lesions, T2-weighted images showed no pattern characteristic of necrosis. In 24 of 33 unresected lesions, loss of enhancement on follow-up enhanced T1-weighted images was a characteristic finding, which correlated to devascularization at arteriography. Of these 24 lesions, 17 were completely hypointense on follow-up T2-weighted images; the remaining seven showed small foci of hyperintensity. The other nine unresected lesions showed enhanced portions on follow-up enhanced T1-weighted images, which corresponded to hyperintense areas on T2-weighted images. These findings correlated to persistence of hypervascular areas at arteriography. Conclusion: Gadolinium-enhanced T1-weighted MR imaging is a reliable method for evaluating the outcome of TACE treatment and is more accurate than unenhanced T2-weighted MR imaging. Received: 2 June 1995/Accepted: 18 July 1995     

MR imaging of hepatocellular carcinomas with biliary tumor thrombi

We retrospectively evaluate the MR imaging findings of hepatocellular carcinomas (HCC) with biliary tumor thrombi. MR imaging was performed on six patients presenting with obstructive jaundice and/or biliary hemorrhage. T1-weighted images, T2-weighted images, MR cholangiopancreatography (MRCP), and dynamic MR images were obtained. Duodenal endoscopy was performed on all cases and hepatic resection on two cases. HCCs were 1.8–10 cm in diameter (mean 5.8 cm). Biliary tumor thrombi were detected in all patients on MR imaging. Tumor thrombi showed hypointensity on T1-weighted images, hyperintensity on T2-weighted images, and contrast enhancement on the early phase of dynamic MR images. MRCP showed intrahepatic bile duct dilatation in all cases. Biliary hemorrhage was clearly depicted by MR images in five cases and showed hyperintensity on T1-weighted images and hyperintensity or hypointensity on T2-weighted images. Biliary hemorrhage was confirmed by endoscopy in two cases. Portal vein thrombi were also associated in five of six patients. Pathologically, tumor thrombi of HCCs were demonstrated in two patients who underwent hepatic resection. In conclusion, MR imaging is useful for the diagnosis of biliary tumor thrombi from HCC and for evaluating the extension of thrombi and biliary hemorrhage.     

MR imaging of the bladder

MR imaging is a useful modality for evaluating diseases of the bladder. MR imaging can detect and stage bladder cancer by determining the presence and depth of muscle invasion.Direct multiplanar imaging and superb soft-tissue contrast make MR imaging an ideal modality for evaluating less common neoplastic diseases of the bladder, such as urachal carcinoma, and tumors that develop within bladder diverticula. Dynamic breath-held fast T2-weighted imaging can evaluate for cystocele and other components of pelvic floor relaxation.     

超顺磁性氧化铁(SPIO)增强MRI对原发性肝癌的诊断价值

目的：检验SPIO增强MRI对原发性肝癌的定位，定量，定性诊断价值。方法：选取经螺旋CT增强，MR平扫，SPIO增强扫描检查且有手术或穿刺活检病理或DSA血管造影资料并经随访，实验室生化检查及临床资料证实为原性肝癌者20例。结果：SPIO增强T2MRI检出79个病灶，其中经手术，穿刺活检病理证实或DSA血管造影显示有肿瘤血管团和/或肿瘤染色的原发性肝癌病灶69个；另有10个为异常信号灶，SPIO增强MRI较CT增强及MR平扫病灶检出率分别增加66%和59%，病灶-肝脏对比噪声比增加52%（P=0.004)。结论：（1）SPIO增强T2WI病灶-肝脏对比噪声比显著增加；（2）病灶检出率明显高于MR平扫及螺旋CT增强影像；（3）结合MR平扫影像，SPIO增强MR影像对肝癌病灶的定位。定量及定性诊断有重要意义；（4）SPIO增强MR影像对肝脏良恶性肿瘤的鉴别诊断有重要意义。     

四肢良性软组织肿瘤的MRI表现

四肢软组织肿瘤的发生率相对较高，确定肿瘤的解剖学定位及软组织特性对于定性诊断较为最要。MRI在评价软组织肿瘤的应用中可作为首选的无创性检查，序列包括T1WI，T2WI以及时比剂增强等。MRI检查目的是为了能够很好地显示肿瘤或肿瘤样病变，包括合适的检查视野，高信噪比以及肿块的特征。     

MR findings of hepatic cavernous hemangioma after intraarterial infusion of iodized oil

Magnetic resonance (MR) imaging was performed on five tumors of three patients who had hepatic hemangiomas. Four tumors were given an intraarterial infusion of 3–8 ml of iodized oil, while one tumor was not. MR images were obtained at 2.0 or 0.5 T. A single spin echo sequence with TE of 30 ms and TR of 500 ms and a double echo sequence with TEs of 60 and 150 ms and TR of 2000 ms, were used to produce relatively T1-, T2-weighted, and heavily T2-weighted images, respectively. Follow-up MR imaging was done 1–5 months after infusion of iodized oil. On relatively T1 weighted images, hemangiomas showed iso or hypointensity. On T2-weighted images, all tumors showed hyperintensity. However, on heavily T2-weighted images, tumors with iodized oil showed heterogeneous, slight hyperintensity, while tumors without iodized oil showed characteristic appearance of marked hyperintensity in hemangiomas. In hepatic cavernous hemangiomas with intraarterial infusion of iodized oil, familiarity with this unusual MR intensity of tumors on heavily T2-weighted images is useful to avoid the incorrect diagnosis and to reduce the frequency of inappropriate hepatic resection.     

Sclerosing hepatocellular carcinoma: Radiologic findings

The radiologic findings of seven patients with sclerosing hepatocellular carcinoma (HCC), an unusual subtype of HCC, were evaluated. Computed tomography (CT) demonstrated a hypointense mass with marked delayed contrast enhancement. Although the tumor was well-defined, the tumor capsule was not seen. Focal atrophy was seen in four patients. Ultrasound (US) showed an isoechoic to hyperechoic mass without a rim. Angiography revealed prominent tumor vessels and prolonged stains in all cases. Arterial encasement was seen in four patients. On magnetic resonance (MR) imaging, all tumors were hypointense on T1-weighted images and hyperintense on T2-weighted images. On dynamic MR study, remarkable contrast enhancement, which continued to the delayed phase, seemed to be characteristic for sclerosing HCC. In the presence of liver tumors with homogeneous architecture, hypervascularity, prolonged enhancement, absence of tumor capsule, and focal atrophy in high-risk patients of HCC, sclerosing HCC should be considered.     

Specificity of SPIO particles for characterization of liver hemangiomas using MRI

We investigated the specificity of superparamagnetic iron oxide (SPIO)â€enhanced T1-weighted spin-echo (SE) magnetic resonance (MR) images for the characterization of liver hemangiomas. When imaging liver hemangiomas, which are the most frequent benign liver tumors, a method with very high specificity is required, which will obviate other studies, follow-up, or invasive diagnostic procedures such as percutaneous biopsy. Eighty-three lesions were examined by MR imaging at 1.5 T before and after intravenous injection of SPIO particles. Lesions were categorized as follows according to the final diagnosis: 37 hemangiomas, nine focal nodular hyperplasias (FNHs), 19 hepatocellular carcinomas (HCCs), and 18 metastases. Their signal intensity values were normalized to muscle and compared. The only lesions showing a significant increase in signal intensity ratio (lesion to muscle) on postcontrast T1-weighted SE images were hemangiomas (p < 0.001). The signal intensity ratio of hemangiomas increased on average by 70%. Based on receiver operating characteristic analysis and using a cutoff level of 50% signal increase, the specificity and sensitivity of SPIO-enhanced MR imaging for the characterization of hemangiomas would be 100% and 70%, respectively. The T1 effect of SPIO particles can help differentiate hemangiomas from other focal liver lesions such as FNHs, HCCs, and metastases and may obviate biopsy. When using SPIO particles for liver imaging, it is useful to add a T1-weighted sequence to T2-weighted images, thereby providing additional information for lesion characterization.     

Detection of hepatocellular carcinoma and its metastases with various pulse sequences using superparamagnetic iron oxide (SHU-555-A)

Background: To identify the most useful combinations of various pre- and postcontrast magnetic resonance (MR) image sequences in detecting hepatocellular carcinoma (HCC) and its intrahepatic metastases before and after injection of SHU-555-A. Methods: Thirty-eight lesions in 16 patients were evaluated before and after administration of SHU-555-A by using fast spin echo (FSE), gradient echo (GRE), and echo planar (EP) imaging sequences using a 1.5-Tesla superconducting MR system. The signal intensity ratio (SIR) and contrast-to-noise ratio (CNR) of the lesions, signal-to-noise ratios, and other parameters were calculated. Results: Tumors were better detected after injection of SHU-555-A on all pulse sequences except on out-of-phase T1-weighted (T1W)-GRE sequences. Tumor detectability was higher for precontrast EP imaging and T2*-weighted (T2*W)-GRE sequences, whereas detectability at postcontrast was higher for T2*W-GRE, proton-density-weighted-FSE, and in-phase T1W-GRE sequences. The SIR and CNR at precontrast were highest for EP imaging, and those at postcontrast were highest for T2*W-GRE. Conclusion: SHU-555-A will increase the detectability of HCC and its liver metastases. T1W- and T2*W-GRE sequences would be the sequences of choice. Received: 21 December 1998/Revision accepted: 5 May 1999     

Detection and characterization of focal liver lesions using superparamagnetic iron oxide-enhanced magnetic resonance imaging: comparison between ferumoxides-enhanced T1-weighted imaging and delayed-phase gadolinium-enhanced T1-weighted imaging

Background: Double contrast magnetic resonance (MR) imaging using superparamagnetic iron oxide (SPIO) and gadolinium (Gd) is performed to detect and characterize focal liver lesions. However, this technique is a costly and lengthy process. The purpose of this study was to determine the usefulness of SPIO-enhanced MR imaging including SPIO-enhanced T1-weighted imaging in diagnosing focal liver lesions. Methods: Eighty-four focal liver lesions were examined with a 1.5-T MR unit. Transverse precontrast T1- and T2-weighted images and SPIO (ferumoxides)-enhanced T1- and T2-weighted images were obtained, followed by Gd-enhanced T1-weighted imaging. The Gd set (i.e., precontrast T1- and T2-weighted and delayed-phase gadolinium-enhanced T1-weighted images) and ferumoxides set (i.e., precontrast T1- and ferumoxides-enhanced T1- and T2-weighted images) were reviewed by two independent readers. Results: More lesions were detected from the ferumoxides set than from the Gd set. Ferumoxides-enhanced T1-weighted imaging showed enhancement patterns of the lesions similar to those of delayed-phase Gd-enhanced T1-weighted imaging. The diagnoses of hepatic metastasis and cyst by the ferumoxides set were similar to those by the Gd set. However, a dynamic study may be inevitable for the diagnosis of hepatocellular carcinoma and hemangioma. Conclusion: The ferumoxides set was useful for the detection of focal hepatic lesions. Ferumoxides-enhanced T1-weighted imaging may replace delayed-phase gadolinium-enhanced T1-weighted imaging in the diagnosis of hepatic metastasis and cysts.     

Small hepatocellular carcinoma: differentiation from adenomatous hyperplasia with color Doppler US and dynamic Gd-DTPA-enhanced MR imaging

Background: To investigate the usefulness of color Doppler ultrasound (US) and dynamic Gd-DTPA-enhanced magnetic resonance (MR) imaging in the differentiation of small hepatocellular carcinoma (HCC) and adenomatous hyperplasia (AH). Methods: Thirty-eight small (3 cm or less) nodular lesions (in 38 cirrhotic patients) with US features consistent with HCC underwent evaluation with color Doppler US and MR imaging. Breath-hold T1-weighted rapid acquisition spin echo MR sequence after bolus injection of 0.1 mmol/kg gadopentetate dimeglumine was used to evaluate dynamic enhancement. US-guided tissue-core percutaneous biopsy established the diagnosis: HCC in 28 cases and AH in 10. Results: Color signals with pulsatile or continuous Doppler spectrum were demonstrated in 19 of 28 HCCs (68%) but in none of the AHs. Although there was considerable overlap in signal intensity between HCC and AH on both unenhanced T1- and T2-weighted images, early enhancement on breath-hold T1-weighted images obtained 40 s after starting contrast administration was observed in 22 of 28 HCCs (79%) but in none of the AHs. In 26 of 28 HCCs (93%), pulsatile or continuous flow at color Doppler US, early enhancement at dynamic MR imaging, or both were observed. Conclusion: Findings with color Doppler US and dynamic Gd-DTPA-enhanced MR imaging enable a reliable distinction between small HCC and AH. Received: 8 August 1994/Accepted after revision: 27 January 1995     

MR imaging of hepatocellular carcinoma

In this article, MR imaging features of hepatocellular carcinoma (HCC) are described. To better understand the MR imaging features of HCC, recent progress regarding its etiology, treatment, carcinogenesis, histology, and gross pathology will be described. Currently, T2-weighted fast spin-echo with fat saturation, and multiphasic dynamic gadolinium-enhanced two-dimensional and three-dimensional T1-weighted gradient echo imaging provides excellent results for detection and characterization of HCC.     

Bile duct involvement in hepatocellular carcinoma: MR demonstration

Background: To determine the magnetic resonance (MR) features of hepatocellular carcinoma (HCC) with associated bile duct involvement. Methods: MR examinations of six patients (mean age, 62 years) demonstrating bile duct involvement due to HCC were retrospectively reviewed and compared to surgical and pathologic findings. Results: Three of the tumors were solitary, and three were multifocal. In two patients, MR showed direct biliary duct invasion by tumor. On T1-weighted MR images, four tumors were hypointense compared to the liver and two were isointense. On T2-weighted MR images, four tumors were hyperintense, and two were isointense. The two tumors studied with dynamic T1-weighted MR images obtained after intravenous administration of a gadolinium chelate, displayed enhancement similar to that of the liver. There was no evidence of a tumor capsule on either unenhanced or enhanced MR images. Intrahepatic bile duct dilatation was seen in five patients. The extrahepatic bile duct was normal in all cases. Conclusion: Although rare, HCC should be included when considering the etiology of intrahepatic bile duct obstruction. Imaging features suggestive of the diagnosis by MR include intrabiliary tumor or bile duct obstruction with an associated hepatic mass.     

Clinical Value of Image Fusion from MR and PET in Patients with Head and Neck Cancer

Purpose  This study aimed to evaluate the clinical value of image fusion from magnetic resonance (MR) combined with positron emission tomography (PET) imaging, using 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) in head and neck cancer. Methods  Sixty-five consecutive patients underwent MR and FDG-PET scans before or after the treatment of known or suspected head and neck cancer. T1-weighted and T2-weighted images were first assessed by MR interpretation, and then, the fused images of T2-weighted images from MR and PET were evaluated in a blind manner. Diagnostic performance was compared. Procedures  For initial staging, in 48 patients, malignant tumors were histologically confirmed in 45 patients. The interpretation sensitivities of MR alone and fused images for primary tumors were 98% and 100%, respectively. For lymph node metastasis, the sensitivity and specificity of both methods were 85% and 92%, respectively. Of 15 patients with suspected recurrence, ten patients had recurrent tumors, three patients developed second malignant tumors, and two patients had no recurrence. For these patients, the overall sensitivity of MR alone was 67%, whereas that of the fused images was 92%. Eight additional lesions were accurately diagnosed by image fusion only. In two patients with lymph node metastasis from unknown origin, the primary site was not detected in one patient, while tonsilar cancer was identified only by image fusion interpretation. Conclusion  Image fusion from MR with PET might be useful in evaluating head and neck cancer, especially in suspected recurrent cases rather than in fresh cases.     

MR imaging in intracystic hemorrhage of simple hepatic cysts

Intracystic hemorrhage of simple hepatic cysts is one of the most frequent complications. Ul-trasonography (US) and computed tomography (CT) may show abnormal findings and mimic other diseases. We describe magnetic resonance (MR) imaging in four patients with intracystic hemorrhage confirmed by surgery or percutaneous aspiration. In all cases the lesions were hyperintense on both T1- and T2-weighted sequences. In three of the four cases the signal was heterogeneous on T1-weighted sequences. Two cases of a thickened wall and one case of a fluid-fluid level were also observed. We suggest that MR imaging may be helpful to differentiate intracystic hemorrhage from other cystic lesions by showing high signal on T1- and T2-weighted sequences.     

神经纤维瘤病Ⅰ型累及脊柱脊髓的MR表现

目的：研究神经纤维瘤病Ⅰ型患者的脊柱和脊髓内肿瘤的MRI表现，提高对其认识。方法：回顾性分析15例经临床及病理证实的神经纤维瘤病Ⅰ型患者的脊柱MRI影像资料。结果：MRI显示肿瘤仅位于脊髓2例，髓外硬膜内和硬膜外3例，同时累及髓内和髓外的多发病变10例。肿瘤位于椎旁5例。MRI表现：脊髓、脊神经根局部梭形或结节样增粗，T1WI为等或低信号；T2WI为高信号；增强有明显强化。结论：MRI能很好的显示神经纤维瘤病Ⅰ型患者的脊柱和脊髓内病变的形态、部位和范围，是评价神经纤维瘤病累及脊柱和脊髓多个平面的最佳选择。     

MR增强剂维影钆胺在颅内占位病变的应用

本文分析了MR造影剂维影钆铵的增强效果和对颅内占位病变的诊断作用,从30例鼻甲和36例颅内占位病变T_1加权成像增强前后信号强度变化来看,维影钆铵是一种很有效的MR增强剂,增强后能对颅内占位病变提供更多有用的诊断资料,尤其对显示转移的数目,肿瘤复发的边界及提供肿瘤血供情况更好。     

肝脏局灶性病变MR动态增强扫描的临床应用

目的：探讨肝脏局灶性疾病ＭＲ动态增强扫描的方法和临床应用。方法：回顾性分析６８例肝脏局灶性病变：包括原发性肝细胞癌２４例,周围型肝管细胞癌２例,转移瘤１６例,海绵状血管瘤２４例,局灶性结节增生２例。     

Thoracic esophageal carcinoma: evaluation in the sagittal section with magnetic resonance imaging

Among 54 patients with thoracic esophageal carcinoma (53 squamous cell carcinoma, 1 adenosquamous carcinoma), the usefulness of MR sagittal imaging for evaluating local extent (T factor) was examined by measuring the anteroposterior (AP) diameter of the tumor. The MR examination was performed using ECG gated scans with a 3 mm slice at 1.5 Tesla. T1-weighted sagittal images were obtained. In 10 patients the appearance of the esophagus was normal, and in 44 patients a tumor was detected in the sagittal section. Thirty-seven lesions were histologically proved (Tis, 1; T1, 3; T2, 3; T3, 15; T4, 15). Lesions classified as <T2 were not visible, and the appearance of the esophagus was normal. The tumors detected in sagittal section were T3 (15 tumors) or T4 (15 tumors). The mean diameter of T4 lesions (34.0 ± 7.9 mm, range 24–57 mm) was larger than that of T3 lesions (25.0 ± 4.4 mm, range 18–33 mm) (p < 0.05). Only two masses with an AP diameter > 30 mm were resected. They were located in the lower esophagus. It is concluded that lesions detected in MR sagittal images might be T3 or T4 tumors, and masses of >30 mm might extend to adjacent organs, although two tumors with an AP diameter < 25 mm also invaded the trachea. Received: 30 August 1995/Accepted: 10 October 1995     

乳头状肾细胞癌MRI分析

目的：探讨乳头状肾细胞癌的MRI表现及特点。材料及方法：回顾性分析10例经手术病理证实的乳头状肾细胞癌MRI表现。回顾性阅读手术记录及病理报告单，并将结果与MRI表现对照。结果：肿瘤信号不均匀（9/10，90％）；T1WI 6例呈混杂信号，4例呈中低信号；T2WI及T2WI/SPIR肿瘤信号相仿，9例呈混杂信号，1例T2WI及T2WI/SPIR呈低信号；轻度强化6例（60％），中度强化4例（40％）。4例实性肿瘤为不均匀强化，1例均匀轻度强化。病理上，5例肿瘤完全呈囊性（3例）或部分区域有囊性变（2例），其中4例囊液内可见不同程度不同时期出血；5例肿瘤呈实性，4例内部伴出血及坏死灶。结论：乳头状肾细胞癌的MRI表现较有特点，对肾细胞癌亚型诊断与鉴别诊断有一定帮助。