Synchronous mucinous tumors of the ovary and the appendix associated with pseudomyxoma peritonei: CT findings

Background: To present the computed tomographic (CT) findings of synchronous mucinous tumors of the ovary and the appendix associated with pseudomyxoma peritonei (PMP). Methods: Imaging studies, mainly abdominal CT scans, of three women aged 49–75 years were reviewed. Attention was directed to the ovarian masses, peritoneal seeding, and the presence of an appendiceal mucocele. Results: The ovarian tumors and the appendiceal mucocele were clearly demonstrated in two cases, and they were part of the extensive PMP in the third patient. Ascites was found in all cases, with internal septation in one. Associated scalloping of the liver margins and hypodense peritoneal implants, with extensive bowel involvement, were seen in another one. Pathologically, there was one case of right ovarian mucinous cystadenoma and villous adenoma of the appendix, one case of right ovarian and appendiceal mucinous cystadenocarcinoma, and one case of bilateral metastatic ovarian implants of appendiceal mucinous cystadenocarcinoma. PMP was found in all. In the case with benign tumors of the ovary and the appendix, the PMP was classified as a benign mucinous spillage. This patient returned 33 months after surgery with PMP, in which epithelial cells were found. Conclusions: Radiologists should be familiar with the clinical occurrence of synchronous mucinous tumors of the ovary and the appendix associated with PMP and with the typical CT findings of the latter two entities. Alternatively, when the imaging findings suggest ovarian cystic tumor with PMP, the radiologist should be alerted to the probability of a clinically unsuspected appendiceal mucocele and should search for it. Received: 10 August 1999/Accepted: 22 September 1999     

Hepatic veno-occlusive disease: MRI findings

We present magnetic resonance imaging findings in a patient with proven hepatic veno-occlusive disease (VOD) caused by the use of “poppers,” a recreational drug used during anal intercourse. Although this report emphasizes the differential magnetic resonance imaging features between VOD and Budd–Chiari syndrome, our case is unique because the VOD was induced by unrelated substances. Received: 15 May 2001/Revision accepted: 6 June 2001     

Myxoid leiomyoma of the uterus: CT and MRI features

A myxoid leiomyoma of the uterus is radiologically described. Sonography showed a large mass extending from the renal hilum to the pelvis. Enhanced computed tomography and magnetic resonance imaging findings denoted cystic and myxoid components. Magnetic resonance imaging demonstrated flow voids between the mass and the uterus, indicating likely origin from the uterus. Exploratory laparotomy showed a huge leiomyomatous mass. Received: 30 March 2000/Accepted: 3 May 2000     

Sclerosing stromal tumor of the ovary: US,CT, and MRI findings

We present the sonographic, computed tomographic, and magnetic resonance imaging findings in a case of a sclerosing stromal tumor of the ovary with pathologic correlations. Received: 14 April 2001/Revision accepted: 26 May 2001     

Malignant fibrous histocytoma of the inferior vena cava: appearances on contrast-enhanced spiral CT and MRI

Primary malignant tumors of the inferior vena cava are infrequent. We report a very rare case of primary malignant fibrous histiocytoma of the inferior vena cava and describe the contrast-enhanced spiral computed tomographic and magnetic resonance imaging findings. Received: 16 March 1995/Accepted: 23 April 1995     

Diuretic contrast-enhanced magnetic resonance urography versus intravenous urography for depiction of nondilated urinary tracts

Diuretic contrast-enhanced magnetic resonance urography (MRU) is analogous to conventional intravenous urography (IVU) and, hence, designated as excretory MRU. It is performed with a T1-weighted fast gradient-echo sequence to obtain breath-hold, dynamic MRU after intravenous injection of low-dose furosemide (5–10 mg) and gadolinium (Gd) chelate. The combination of Gd and furosemide is the key for achieving a uniform distribution of the contrast material inside the entire urinary tract. It provides high-resolution images of nondilated urinary tracts and information about the renal function. This pictorial essay reviews the technical aspects and practical consideration of diuretic Gd-enhanced MRU and underlines its diagnostic capability in comparison with IVU in the depiction of nondilated collecting systems. We discuss its potential applications, as in young patients with anatomic anomalies, patients with renal transplants, patients allergic to iodinated contrast medium, and avoiding multimodality work-up in the evaluation of kidney donors and patients with renal and extrarenal tumor diseases. Received: 1 December 2001/Accepted: 5 January 2002     

Intratumoral steatosis in focal nodular hyperplasia coinciding with diffuse hepatic steatosis: CT and MRI findings with histologic correlation

Focal nodular hyperplasia (FNH) is a benign tumorlike condition that is thought to be a hyperplastic response to increased blood flow in an arterial malformation rather than a true neoplasm. Radiologically, FNH usually shows typical findings on unenhanced and enhanced computed tomography (CT) and magnetic resonance images (MRI), with atypical features being the exception rather than the rule. We report an unusual case of FNH with extensive fatty infiltration of the lesion illustrated on CT and MRI and proven by histopathology. Received: 21 December 1998/Revision accepted: 5 May 1999     

Giant benign cystic peritoneal mesothelioma: US, CT,and MRI findings

Benign cystic peritoneal mesothelioma (BCPM) is a rare tumor, primarily affecting young women; approximately 130 cases have been described mainly in the pathological and surgical literature. We present imaging findings of a giant BCPM in a male patient and discuss the radiological differential diagnosis with a brief review of the literature. Received: 3 June 1997/Accepted: 9 July 1997     

卵巢纤维瘤的CT和MRI影像特征

目的 探讨卵巢纤维瘤的CT及MRI特征。方法 回顾性分析经手术病理证实的42例卵巢纤维瘤的CT及MRI资料,21例患者接受CT检查,26例接受MR检查,5例同时接受CT和MR检查,分析其CT和MR特征。结果 42例卵巢纤维瘤中单纯型29例,变性型11例,特殊型2例。肿瘤均单发,呈圆形、类圆形或分叶状,边界清晰40例,部分边界模糊2例,伴钙化3例,出血1例。肿瘤最大径1.4~26.7 cm,中位值5.5 cm。单纯型CT平扫呈等密度,MRI上T1WI及T2WI均呈低信号;变性型CT呈斑片状、裂隙状低密度区,T2WI呈高信号,增强扫描肿瘤实质几乎无强化或仅轻微强化;特殊型1例内见大量出血,1例明显强化,均误诊为恶性肿瘤。结论 卵巢纤维瘤的CT及MRI表现具有一定的特征,但确诊仍需依靠病理。     

Polyorchidism and rete testis adenoma: ultrasound and MR findings

Polyorchidism is an uncommon congenital anomaly. It is associated with an increased frequency of testicular malignancy, cryptorchidism, inguinal hernia, and torsion. Sonography may be used to confirm the clinically suspected diagnosis. We present a case of polyorchidism in which a rete testis adenoma was present in one of the testicles. Sonographic and magnetic resonance findings are illustrated. Received: 21 August 1995/Accepted: 24 August 1995     

Cavernous hemangioma arising from the lesser omentum: MR findings

We report the magnetic resonance findings of an unusual hemangioma in the lesser omentum. A well-circumscribed, large mass was identified between the stomach and the left lobe of the liver, with compression of adjacent liver parenchyma. The mass showed low signal intensity (SI) on T1-weighted images, high SI on T2-weighted images with multiple septa, and slightly decreased SI on out-of-phase T1-weighted images. After gadolinium contrast administration, septa within the mass showed minimal enhancement on 30-s T1-weighted images and mild enhancement on 5-min T1-weighted images. The mass was histopathologically diagnosed as a cavernous hemangioma comprised of multiple vascular spaces, fibrotic tissue, and adipocytes. Received: 1 December 1999/Accepted: 12 January 2000     

Well-differentiated hepatocellular carcinoma: findings of US, CT, and MR imaging

Background: To elucidate the imaging characteristics of well-differentiated hepatocellular carcinomas (HCCs) on ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging. Methods: Ultrasonograms, CTs, and MR images of 18 histopathologically proven well-differentiated HCCs in 15 patients were reviewed. The findings of these images were correlated with histopathologic findings. Results: On US, seven tumors were depicted as a hyperechoic area and eight as a hypoechoic area. Three tumors were not visualized. On precontrast CT, four tumors were depicted as a low-density area, but 14 were not visualized. On conventional contrast-enhanced CT, 12 tumors were depicted as a low-density area but six were not visualized. On T1-weighted MR images, 10 tumors had high signal intensity and two had low signal intensity. Six tumors were not visualized. On T2-weighted MR images, five tumors had high signal intensity and two had low signal intensity. Eleven tumors were not visualized. Tumors with fatty change and/or clear cell formation were frequently hyperechoic on US and hyperintense on T1-weighted MR images. Conclusions: Well-differentiated HCCs show different findings on US, CT, and MR imaging. Therefore, reliable diagnosis of well-differentiated HCCs by these imaging techniques may be difficult. Received: 29 April 1998/Revision accepted: 15 July 1998     

CT and MRI findings of multifocal hepatic steatosis mimicking malignancy

We present two rare cases of multifocal hepatic steatosis as a variant of fatty liver. Multifocal hepatic steatosis can cause misleading findings in the differential diagnosis when using ultrasound and computed tomography. This case report describes the atypical findings of focal fatty liver infiltrations, which were misdiagnosed as diffuse metastatic disease. The correct diagnosis was established with magnetic resonance imaging using T1-weighted gradient-echo and T2-weighted Turbo spin-echo sequences with spectral fat suppression. Multifocal hepatic steatosis was proven by biopsy. Received: 28 December 2001/Accepted: 30 January 2002     

卵巢纤维瘤的MRI表现与病理对照分析

目的 结合病理表现,探讨卵巢纤维瘤的MRI分型及其影像特点.方法 回顾分析经手术病理证实15例卵巢纤维瘤的临床、MRI和病理资料.结果 15例中,所有肿瘤边缘均清楚,发生在绝经后10例,伴有腹水6例.卵巢纤维瘤MRI表现拟分为三种类型:①均质型6例;②变性型7例;③出血型2例.结论 卵巢纤维瘤MRI表现呈多样化,在T2WI上瘤体大部或部分呈现明显低信号为其特征性的MRI表现.     

Littoral cell angioma of the spleen: US and MR imaging findings

In this article, we describe the ultrasound and magnetic resonance imaging findings of a littoral cell angioma of the spleen. This benign vascular neoplasm of the spleen has been described, but to our knowledge there has been no case published in the literature that describes its imaging features. Received: 26 January 1998/Accepted: 11 March 1998     

Unusual liver MR findings of Wilson's disease in an asymptomatic 2-year-old girl

We describe the unusual magnetic resonance (MR) findings of a case of Wilson's disease (WD) in an asymptomatic 2-year-old girl. Preenhanced computed tomography revealed multiple hyperdense areas in the liver. These lesions were hyperintense on T1-weighted and hypointense on T2-weighted MR images, results that might be ascribed to the paramagnetism of copper deposited in liver at a relatively early stage of the disease before severe liver cirrhosis had evolved. Received: 9/10/96/Accepted: 10/16/96     

Focal nodular hyperplasia of the liver: detection and characterization with plain and dynamic-enhanced MRI

Background: We compared nonenhanced and dynamic gadolinium (Gd)–enhanced magnetic resonance imaging (MRI) appearances of hepatic focal nodular hyperplasia (FNH) as depicted with breath-hold MR sequences and assessed the detectability of the individual MR sequences used. Methods: We retrospectively reviewed 48 consecutive patients with FNH. All patients underwent nonenhanced (T1 fast low-angle shot [FLASH] and T2 half-Fourier acquisition [HASTE]) and dynamic Gd-enhanced (T1 FLASH) MRI between December 1997 and March 2000. Individual MR sequences were analyzed separately for number of lesions, signal intensity features, dynamic enhancement pattern, and the presence and enhancement profile of a central scar. Ninety-five percent confidence intervals of absolute discrepancy were calculated to define differences in lesion detection. Results: Seventy-seven lesions were found in 48 patients. Nonenhanced FLASH imaging depicted 59 (76.6%) lesions in 45 patients. HASTE images showed 55 (71.4%) lesions in 44 patients. On T1- and T2-weighted images, lesions appeared predominantly hypointense (69.5%) and hyperintense (72.7%), respectively. Arterial and portal venous dominant phase Gd-enhanced MRI demonstrated all 77 lesions (100%), most of which showed hypervascular (94.8%), homogeneous (97.4%), and incomplete (except the central scar: 58.4%) enhancement in the arterial phase. Portal venous phase images showed lesion isointensity (50.6%) or moderate hyperintensity (46.8%) with complete enhancement (central scar: 94.8%). A central scar was detected on nonenhanced T1-weighted images (hypointense: 100%), T2-weighted images (hyperintense: 100%), arterial phase (hypointense: 59.7%) and portal venous phase (hyperintense: 71.4%) Gd-enhanced images in 78%, 69.1%, 77.9%, and 75.3% of tumors, respectively. Conclusion: Arterial and portal venous phase Gd-enhanced T1-weighted sequences are superior to nonenhanced images in the detection of FNH. Typical MRI appearances include hypointensity on T1-weighted and hyperintensity on nonenhanced T2-weighted images. Most commonly, FNH shows a homogeneous (without scar) and strong enhancement during the arterial phase, with lesion isointensity or slight hyperintensity during the portal venous phase. Received: 15 May 2001/Revision accepted: 22 August 2001     

Ovarian cyst rupture causing hemoperitoneum: imaging features and the potential for misdiagnosis

Background: To describe the spectrum of imaging findings and clinical presentations produced after rupture and hemorrhage of an ovarian cyst. Methods: Imaging studies and hospital records of nine patients who were ultimately diagnosed with hemoperitoneum from a ruptured ovarian cyst were reviewed and categorized. Results: Hemoperitoneum from a ruptured ovarian cyst presented a range of imaging findings. Although the imaging findings were dominated by hemoperitoneum, at least a vestige of the cyst could be identified in seven patients. The diagnosis of hemoperitoneum from a ruptured ovarian cyst was favored in only four of nine patients after the initial imaging study. Conclusions: A ruptured ovarian cyst can produce massive hemoperitoneum, with clinical symptomatology and sonographic features that closely mimic those of other disorders, in particular ectopic pregnancy. Considering the likelihood of both clinical and radiologic misdiagnosis, the radiologist should consider and pursue the diagnosis of a ruptured hemorrhagic ovarian cyst in a woman of child-bearing age who presents with pelvic pain and a large amount of complicated intraperitoneal fluid. Received: 12 February 1998/Accepted: 6 May 1998     

MR imaging of cervical carcinoma: comparison among T2-weighted,dynamic, and postcontrast T1-weighted images with histopathological correlation

Background: To identify the reasons for misdiagnosis of the degree of stromal invasion by uterine cervical cancer with various magnetic resonance sequences. Methods: T2-weighted, dynamic, and postcontrast T1-weighted images were obtained in the sagittal plane in 20 patients with uterine cervical cancer. After evaluating these sequences for the degree of stromal invasion, histologic specimens were directly correlated with these images. Results: The degree of stromal invasion was correctly diagnosed in 15 of the 20 cases on T2-weighted images, in 12 on dynamic images, and in eight on postcontrast T1-weighted images. All misdiagnoses were due to overestimation. Histologically, peritumoral stroma showed inflammation or edema in two patients, whereas no histological abnormality was found in the other patients. A hyperintense rim, i.e., a peritumoral enhanced ring-shaped structure, was observed on the enhanced images of five patients. The hyperintense rim corresponded to the periphery of the tumor in three patients and to the cervical stroma in two patients. Conclusion: T2-weighted images permitted the most accurate evaluation of stromal invasion by uterine tumors. Overdiagnosis may be due to an abnormal intensity of the cervical stroma, which was observed more frequently on dynamic and postcontrast T1-weighted images than on T2-weighted images. Received: 10 November 1995/Accepted after revision: 13 March 1996