MR Imaging Findings of a Primary Cardiac Osteosarcoma and Its Bone Metastasis with Histopathologic Correlation

An osteosarcoma of cardiac origin is extremely rare, and a comprehensive description of MR imaging (MRI) findings of cardiac osteosarcoma and its metastasis in the femur have not been reported in the literature. We present a case of cardiac osteosarcoma in a 47-year-old woman and its metastasis to the femur, focusing on the description of MRI findings of the cardiac and metastatic bony osteosarcoma with a histopathologic correlation.

MR Imaging of Uncommon Soft Tissue Tumors in the Foot: A Pictorial Essay

A large variety of masses occur in the foot. The foot is a comparatively rare site of soft tissue neoplasms. MRI has greatly improved the ability to detect and delineate soft tissue lesions and is now considered the gold-standard imaging technique in their investigation. Recently, we have encountered rare soft tissue tumors of the foot. The presented cases include benign masses such as granuloma annulare, angiomyoma, neural fibrolipoma, and giant cell tumor of tendon sheath, as well as malignant tumors such as melanoma, synovial sarcoma, rhabdomyosarcoma and extraskeletal myxoid chondrosarcoma. We wish to illustrate the MR findings of these uncommon soft tissue tumors to aid in their diagnosis.

Assessment of Lymph Node Metastases by Contrast-Enhanced MR Imaging in a Head and Neck Cancer Model

OBJECTIVE: We wanted to investigate the accuracy of contrast-enhanced MR imaging for the detection of lymph node metastases in a head and neck cancer rabbit model. MATERIALS AND METHODS: The metastatic lymph node model we used was created by inoculating VX2 tumors into the auricles of six New Zealand White rabbits. T1-weighted MR images were obtained before and after injecting gadopentetate dimeglumine at three weeks after tumor cell inoculation. The sizes, signal intensity ratios (i.e., the postcontrast signal intensities of the affected nodes relative to the adjacent muscle) and the enhancement patterns of 36 regional lymph nodes (parotid and caudal mandibular nodes) were evaluated on MR images and then compared with the histopathologic findings. RESULTS: No statistical difference was found between the sizes of 12 metastatic (10.5+/-3.2 mm) and 24 hyperplastic (8.0+/-3.6 mm) lymph nodes (p > 0.05). On the contrast-enhanced T1-weighted MR images, nine metastatic and four hyperplastic lymph nodes had peripheral high and central low signal intensity, whereas three metastatic and 20 hyperplastic lymph nodes had homogeneous high signal intensity. Using a signal intensity ratio less than one as a diagnostic criterion for a metastatic lymph node, the sensitivity, specificity and positive and negative predictive values of the enhanced MR images were 75% (9/12), 83% (20/24), 69% (9/13) and 87% (20/23), respectively, with areas under receiver-operating-characteristic curve values of 0.81. CONCLUSION: This experimental study confirms that metastatic and hyperplastic lymph nodes can be differentiated using MR images on the basis of the contrast uptake patterns, but that they cannot be differentiated using any particular size criteria.

Ewing's Sarcoma Mimicking a Meningioma in Radiological Findings: A Case Report

Ewing's sarcoma is an uncommon primary bone tumor. Primary Ewing's sarcoma of the cranium is extremely rare and constitutes only 1% of all Ewing's sarcoma cases. Usually, primary Ewing's sarcoma of the carnium manifests as an expansile osteolytic malignant bone tumor with or without intracranial extension. We report here the radiological findings of a case of Ewing's sarcoma mimicking a meningioma in an 18-year-old man.

MR Imaging of Endometrial Cancer that Occurs After Radiation Therapy for Cervix Cancer

PURPOSE: We wanted to describe the MR imaging findings of endometrial cancer in patients with a history of prior radiation therapy for cervical cancer (ECRT) and we compare them to the MR imaging findings of patients with spontaneously occurring endometrial cancer (SEC). MATERIALS AND METHODS: Twenty-two patients with endometrial cancer that was diagnosed by operation or endometrial biopsy were included in the study. The patients were divided into two groups according to the presence of past RT for cervical cancer: ECRT (n = 4) and SEC (n = 18). The MR images were retrospectively analyzed by consensus of two experienced radiologists. The MR imaging findings were analyzed by the size, shape and signal intensity of the mass, distension of the uterine cavity, the presence of cervical stenosis and the nature of the fluid collection. RESULTS: For the mass shape, all the ECRT lesions were polypoid masses. However, the SEC patients had 5 polypoid masses and 13 wall thickenings. The maximal diameter, signal intensity and enhancement pattern of the masses were not different between the ECRT and SEC patients. The width of the endometrial cavity varied between 3.9 cm in the ECRT patients and 0.4 cm in the SEC patients (p =0.002). All the ECRT patients had cervical stenosis. However, none of the SEC patients had cervical stenosis. CONCLUSION: MR imaging of ECRT patients demonstrated prominent distension of their uterine cavity and cervical stenosis, which may be the result of radiation fibrosis in the uterus.

MR Imaging of Mucinous Carcinoma of the Breast Associated with Ductal Carcinoma In Situ: Case Report

A mucinous carcinoma of the breast is an uncommon carcinoma containing mucin that is associated with a mucocele-like tumor or other malignant tumors. We report the MR imagingfindings of two cases, a mucinous carcinoma and ductal carcinoma in situ (DCIS), associated with mucocele-like tumor. The mucinous carcinoma showed a gradually enhancing kinetic pattern on the dynamic MR and high signal intensity on the T2-weighted images. The MR findings were indistinguishable from a common benign mass of the breast.

MR Imaging of Mucinous Carcinoma of the Breast Associated with Ductal Carcinoma In Situ: Case Report

A mucinous carcinoma of the breast is an uncommon carcinoma containing mucin that is associated with a mucocele-like tumor or other malignant tumors. We report the MR imagingfindings of two cases, a mucinous carcinoma and ductal carcinoma in situ (DCIS), associated with mucocele-like tumor. The mucinous carcinoma showed a gradually enhancing kinetic pattern on the dynamic MR and high signal intensity on the T2-weighted images. The MR findings were indistinguishable from a common benign mass of the breast.

Usefulness of preoperative breast MRI in breast cancer: Comparison with breast US

PURPOSE: The purpose of this study was to evaluate the usefulness of preoperative breast MRI compared with breast US and pathologic finding in breast cancer patients MATERIALS AND METHODS: A total of 50 patients with breast cancer underwent surgery at our institute between October 2004 and August 2005. They were examined preoperatively with MRI and US. The maximum diameter and the number of the lesions on MRI and US were measured. These measurements were subsequently compared with the pathologic results. The results were divided into the equal, overestimated and underestimated groups. Changes of the therapeutic approach, based on MRI, were also evaluated. RESULTS: Breast cancer was correctly evaluated in 38 of 50 (76%) patients with MRI and in 28 of 50 (56%) patients with US; the cancer was overestimated in 7 of 50 (14%) patients with MRI and in 8 of 50 (16%) patients with US; the cancer was underestimated in 5 of 50 (10%) patients with MRI and in 14 of 50 (28%) patients with US. The therapeutic approach was changed in 11 of 50 (22%) patients, and all the cases underwent modified radical mastectomy. The therapeutic approach was correctly changed in 9 (18%) patients. Unnecessary wider excision was performed in 2 (4%) patients. CONCLUSION: In conclusion, preoperative breast MRI may be a useful modality for preoperative evaluation, especially for the local staging of tumor and the treatment planning of patients with breast cancer.

Ultrasound, CT, and MR imaging Findings of Paraganglioma Originating at the Urinary Bladder: A Case Report

Approximately 10% of paragangliomas, which originate mainly in the adrenal gland, involve extraadrenal sites. Primary involvement of the urinary bladder is very rare. We report a case of paraganglioma originating in the urinary bladder, and describe the US, CT, and MR imaging findings.

Hypervascular Hyperplastic Nodules Appearing in Chronic Alcoholic Liver Disease: Benign Intrahepatic Nodules Mimicking Hepatocellular Carcinoma

PURPOSE: Hypervascular hyperplastic nodules in those patients with chronic alcoholic liver disease and who are hepatitis B and C negative have recently been reported on. The purpose of this study was to correlate the radiologic and pathologic findings with the clinical significance of these hypervascular hyperplastic nodules in chronic alcoholic liver disease. MATERIALS AND METHODS: The study included eight hypervascular nodules of seven patients with chronic alcoholic liver disease, and these patients had abused alcohol for more than 20 years. Eight hypervascular nodules were seen on the arterial phase of dynamic CT scans, but the possibility of HCC was excluded pathologically (n=4) or clinically. The radiologic and pathologic findings, and the changes of these nodules on follow up CT scans were retrospectively analyzed. RESULTS: All nodules showed good enhancement on the arterial phase. The tissue equilibrium phase of the dynamic CT scans showed isodensity in seven patients and low density in one patient. Ultrasound scans revealed hypoechoic findings for three nodules, isoechoic findings for two nodules, hyperechoic findings for one nodule, and two nodules were not detected. Angiograms (n=6) showed late incremental tumor staining, and all the nodules were well seen on the sinusoidal phase. CT during hepatic angiography (n=4) showed well stained tumor. CT during arterial portography (n=4) showed no defect in three nodules and nodular defect in one nodule. The MR images (n=3) showed low signal intensity in two nodules and iso-signal intensity in one nodule on T2WI. Five of six cases for which follow up CT scans were performed showed decrease in size and one was disappeared. CONCLUSION: Radiologically, it is often difficult to differentiate the hypervascular hyperplastic nodules seen in the chronic alcoholic liver disease from hepatocellular carcinoma, and histological confirmation is needed for excluded hepatocellular carcinoma. However, late tumor staining during the sinusoidal phase without any blood supply by feeding vessels or any arterioportal shunt on the angiogram, isodensity during the tissue equilibrium phase of dynamic CT and low signal intensity on T2WI may suggest the presence of hypervascular hyperplastic nodule.

MR Imaging of Solitary Fibrous Tumors in the Head and Neck

OBJECTIVE: Solitary fibrous tumor (SFT) is a very rare tumor. The purpose of this study is to determine the MR imaging features of SFT in the intracranial and extracranial head and neck regions. MATERIALS AND METHODS: We retrospectively reviewed six MR images and two CT images of six histologically proven cases of SFT that occurred in four men and two women, and their ages ranged from 46 to 59 years. These imaging findings were correlated with the microscopic findings of their surgical specimens. RESULTS: Six SFTs arose in the meninges (the petrous ridge and the pituitary fossa), the parotid gland, the parapharyngeal space, the buccal space and the maxillary sinus. On the MR images, SFTs in the intracranial and extracranial head and neck regions were mostly isointense to the muscle on the T1-weighted images, they were hyperintense on the T2-weighted images and they all had intense enhancement. On the T1- and T2-weighted images, hypointense lines were observed within in five SFTs. On the CT images, the SFTs were hypodense to the muscle on the unenhanced images and they were heterogeneously enhanced on the contrast-enhanced images. An exceptional case of pituitary SFT was hypointense on the T2-weighted images and it was hyperdense on the unenhanced CT images, which correlated with the increased collagenous component and the cellular compactness. CONCLUSION: The imaging features of SFT are nonspecific; however, SFT should be included in the differential diagnosis of masses involving the intracranial and extracranial head and neck regions.

Hepatic Metastasis of Thymoma: A Case Report

Thymoma is the most common neoplasm in the anterior mediastinum, and extrathoracic involvement is rare. Moreover, cystic liver metastasis is extremely rare; few cases have been reported in the literature to date. We report here on a case of cystic liver metastasis of thymoma treated with surgical resection, describing the ultrasonography, CT and MRI findings.

MRI Findings of Cavernous Hemangioma of the Uterus: A Case Report

Hemangioma is the most common soft tissue tumor in the body. Though it may occur anywhere in the body, hemangioma of the uterus is a very rare tumor. Hemangioma is almost asymptomatic, but it is sometimes clinically important because it can cause massive hemorrhage and this is a life-threatening condition. We report here on the magnetic resonance imaging and pathologic findings of cavernous hemangioma of the uterus in a 32-year-woman with menorrhagia.

Usefulness of Dynamic MR Imaging for the Evaluation of the Solitary Pulmonary Nodules Smaller than 15 mm: Differentiation between Benign and Malignant Nodules

PURPOSE: We wanted to evaluate the usefulness of dynamic magnetic resonance (MR) imaging for differentiating between benign and malignant solitary pulmonary nodules (SPNs). MATERIALS AND METHODS: Sixteen patients who had an undetermined SPN (<15 mm) upon chest computed tomography (8 males and 8 females; mean age: 55 years; age range: 40-76 years) underwent dynamic MR imaging. After the bolus injection of contrast material, the arterial (20-35 seconds), portal (45-60 seconds) and equilibrium (3-5 minutes) phase T1-weighted axial images were obtained with using a volumetric interpolated breath-hold examination. For discriminating the benign from malignant SPNs, the maximum relative enhancement ratio (MER) and the slope of the enhancement (SLE) were calculated and then they were statistically compared. With varying the threshold of the two indexes, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated. RESULTS: The mean MER of the malignant SPN group was significantly higher than that of the benign SPN group (malignant; 0.56+/-0.17, benign; 0.43+/-0.17). With 0.33 as the threshold of MER for distinguishing the malignant SPN group from the benign SPN group, the sensitivity, specificity, positive predictive value and negative predictive value were 100%, 70%, 50%, and 100%, respectively. The mean SLE for the benign SPN group was higher than that for the malignant SPN group (malignant; m= 0.008+/-0.006/sec, benign; m=0.013+/-0.008/sec). With 0.025 as the threshold of the SLE, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 100%, 60%, 62.5%, 100% and 69.2%, respectively. CONCLUSION: Dynamic MRI was useful for differentiating between benign and malignant SPNs. Moreover, MER and SLE might be good indexes for distinguishing benign SPNs from malignant SPNs.

Double Contrast Media enhanced MRI with Ferumoxides-Gadolinium on Hepatocellular Carcinoma

PURPOSE: To evaluate the effects of Ferumoxides on Gadolinium (Gd) enhanced dynamic liver magnetic resonance imaging (MRI) in cirrhotic patients and also for the diagnosis of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: 29 patients with liver cirrhosis were examined at 1.5T. 12 patients had HCC. The imaging protocol included GE T1 in and opposed phases, and a breath-hold TSE T2 before and 30-60 min following 0.05 ml/kg Ferumoxides. Four dynamic in-phase GE series were also acquired after an injection of 20 ml of Gd at 2 ml/sec. SNR and CNR were calculated for liver lesion relative to the muscle and background liver respectively. Statistical analysis was performed using the paired t-test. RESULTS: The SNR of the liver decreased by 8.6+/-1.20 (p<0.001) after Ferumoxides injection. At the peak of the Gd effect, the liver increased by 6.09+/-1.15 relative to the post Ferumoxides, but it was not significantly different from the pre-Ferumoxides study (p<0.01). Although there was no significant change in post Ferumoxides SNR of HCC, CNR of HCC relative to the liver increased by 7.54+/-1.61 (p<0.05). After the Gd injection, CNR of HCC increased by 15.6+/-3.87 (p<0.05). CONCLUSION: The administration of Ferumoxides made HCC CNR increase, and it canceled the effect of Gd enhancement of the cirrhotic liver. The combination of Ferumoxides and Gd makes HCC CNR increase.

Follow-up Results After Negative Findings on Unenhanced Hepatic MR Imaging for Hepatic Metastasis from Rectal Cancer

OBJECTIVE: To assess the follow-up results after negative findings on unenhanced hepatic MR imaging in rectal cancer patients who have undergone locally curative surgery. MATERIALS AND METHODS: From all pertinent imaging reports and medical records, we selected 255 patients who had negative results on unenhanced hepatic MR imaging. When selecting patients who had undergone curative resection, the following patients were excluded from the study: 1) patients in whom extrahepatic metastases were detected on preoperative staging work-ups, 2) patients in whom the surgery was judged to be non-curative due to peritoneal seeding or local aggressiveness. Cases with follow-up periods of less than 18 months were also excluded, as these cases were considered insufficient to confirm the negative outcomes. Thus, a total of 149 patients were ultimately enrolled in our study. The follow-up results of unenhanced MR imagings were assessed according to the assumption that the newly developed hepatic metastases had been false-negative lesions on preoperative MR image. RESULTS: During a median follow-up period of 29.3 months, 25 hepatic metastases were detected in 13 patients (8.7%), which indicated a negative predictive value of 91.3%. CONCLUSION: Unenhanced hepatic MR imaging provides a high negative predictive value with regard to the detection of hepatic metastasis in the preoperative evaluation of rectal cancer.

US, CT and MR Imaging Findings of Leiomyoma of Urinary Bladder: Case Report

Leiomyomas are the most common benign tumors of the uterus, and although they can occur at any site in the genitourinary tract, they very rarely originate from the urinary bladder. We report a case in which a leiomyoma occurred at that site, deseribing the US, CT, and MRI findings.

Development of VX-II Carcinoma Model in Rabbit Uterus: Evaluation with MR Imaging and Histopathology

PURPOSE: To develop a VX-II carcinoma model in the rabbit uterus and to describe the MR imaging findings of an experimentally induced VX-II uterine carcinoma along with the histopathologic findings. MATERIALS AND METHODS: 13 New Zealand rabbits were included in this study. Two pieces of tissue suspension (1 mm3x2) of VX-II carcinoma were loaded in an 18 gauge disposable needle and the tissue embedded in the wall of each horn of the rabbits' uterus. We obtained the MR images at 2 weeks in group A (n=5), or at 2 and 4 weeks in group B (n=8). T2-weighted images were obtained using an extremity coil. On MR imaging, we measured the signal intensity of the tumor and the uterine wall. We also measured the size and shape of the tumor and we compared this with the histopathologic results. RESULTS: On MR images obtained 2 weeks after inoculation, all the rabbit uteruses (group A and B, n=13) show a thick tubular wall, and the uteruses demonstrated a high signal intensity on T2-weighted images. The thickened uterine walls were measured as 3-10 mm (mean: 6.5 mm). Peritoneal nodules were observed in 3/13 rabbits (23%), the nodules measured 1.5-1.8x3.0 cm; uterine masses were observed in 3/13 rabbits (23%), and they measured 0.6-1.5x1.3-1.5 cm. On MR images obtained 4 weeks after the inoculations (group B, n=8), rabbit uteruses that had VX-II carcinoma show thick tubular wall in all cases (n=8, 100%) and round uterine masses (n=6, 75%). The thickened uterine walls measured 5-14 mm (mean 7.6 mm) and uterine masses measured 1.3-3.0x1.5-6.0 cm. All the rabbit uteruses having VX-II carcinoma showed high signal-to-noise ratios along the thickened uterine walls or masses on T2WI. On the histopathologic exam after sacrificing the rabbit, a few viable tumor cells were found because of necrosis in the inner portion of the uterine tumors, and abundant viable tumor cells were found at the periphery of the uterine tumors. CONCLUSION:We can develop an animal model with uterine tumor in rabbit uterus using VX-II carcinoma. Experimentally induced VX-II carcinomas in rabbit uterus demonstrated central necrosis, and MR imagings of experimentally induced uterine VX-II carcinomas were well correlated with the histopathology.

The Usefulness of Dynamic MR Imaging for the Evaluation of Cervical Cancer

PURPOSE: We wished to evaluate the diagnostic usefulness of dynamic MRI in assessing tumor visualization and the parametrial invasion of cervical cancer, and we also wished to determine the most adequate enhancing time by comparing the T2-weighted image (T2WI) and enhanced T1-weighted image (Gd-T1WI). MATERIALS AND METHODS: Fifty-three women with histopathologically proven cervical cancer underwent a preoperative MRI. Using a 1.5 T magnet, the fast spin echo axial T2WI without fat saturation was taken; after contrast administration, 20, 40, 60, 90, 120 sec-dynamic MRIs were taken using fast SPGR and spin echo axial Gd-T1WI. Tumor conspicuity and parametrial invasion in each pulse sequence and the most adequate enhancing time for the evaluation of the tumor on dynamic MRI were evaluated prospectively by three radiologists working at three separate sessions. The results were then correlated with the histopathologic findings. RESULTS: The conspicuity of tumor on dynamic MRI (99.4%) and T2WI (95.6%) were better than on Gd-T1WI (89.3%). In the assessment of parametrial invasion of the tumor, the diagnostic accuracy of dynamic MRI, Gd-T1WI and T2WI was 79.9%, 78% and 76.1%, respectively; the highest values were for the dynamic MRI, but there was no statistically significant difference among three pulse sequences. The most adequate enhancing time on dynamic MRI was between 90 seconds and 120 seconds. CONCLUSION: Dynamic MRI is useful for the assessment of tumor visualization of cervical cancer, and the most appropriate scan time on dynamic MRI is between 90 seconds and 120 seconds. For the determination of parametrial invasion, the dynamic MRI revealed a higher diagnostic accuracy than that of T2WI or Gd-T1WI, but the differences were statistically insignificant.

Functional MR Imaging Using BOLD Technique in Patients with Brain Tumors

PURPOSE: To reveal clinical usefulness of functional MRI (fMRI) using sensorymotor and language stimuli for demonstrating anatomic relationship between sensorimotor or language cortices and lesions in the planning of brain tumor surgery. MATERIALS AND METHODS: This study included 12 right-handed patients with brain tumors in or around sensorimotor or language cortices. Eleven patients were evaluated with primary motor and sensory stimuli. Of these patients, six patients were also evaluated with language stimuli. One patient was evaluated with language stimuli only. For fMR imaging, a 1.5T scanner was used and the EPI BOLD technique was employed. For postprocessing image, the SPM99 program and a program made by our department was utilized. We evaluated whether sensorimotor and language stimuli activate sensorimotor and language cortices. And also, clinical efficacy of revealing anatomic relationship between cerebral cortices and lesions for planning neurosurgical operation were evaluated. Finally, we compared post-operative neurologic function with pre-operative neurologic function in same patients. RESULTS: The fMRI examination was successful in identifying the functional cortices and depicting anatomic relationship between functional cortices and lesions in all patients. In nine patients of 11 patients with identified sensorimotor cortices, postoperative grade of manual motor test was not changed, compared with preoperative grade. Whereas postoperative improved than preoperative grade in one patient of remaining two patients, postoperative aggravated than preoperative grade in the other. This result was due to atherosclerotic lacunar infarction, regardless of tumor resection. Postoperative deficit of language function was not found in seven patients with identified language cortices. CONCLUSION: fMRI could be a helpful method for determining the best approach to neurosurgical treatment in patients with brain tumors in or around sensorimotor or language cortices.