Large paravaginal angiomyofibroblastoma: magnetic resonance imaging findings

Angiomyofibroblastoma (AMFB) is a rare, benign, mesenchymal tumor that occurs mainly in the female lower genital tract. We report on a large posterior paravaginal AMFB that presented as a buttock mass, describing the magnetic resonance imaging (MRI) features of the disease. The tumor displays heterogeneous signal intensity on T2-weighted MRI and fast and persistent inhomogeneous enhancement on dynamic gadolinium-enhanced MRI.     

Delayed contrast-enhanced MRI of the aortic wall in Takayasu's arteritis: initial experience

OBJECTIVE: Delayed contrast-enhanced MRI is increasingly being used for cardiac viability imaging. Takayasu's arteritis is a rare inflammatory disorder of unknown cause that affects the aorta, its major branches, and the pulmonary artery; it is characterized by inflammation and fibrosis in the arterial wall. We report our initial experience with seven patients (six women, one man; age range, 25-62 years) with delayed (20 min) gadolinium-enhanced MRI (inversion recovery prepared gated fast gradient-echo pulse sequence) in patients with known Takayasu's arteritis. CONCLUSION: Patients with Takayasu's arteritis (particularly those with abnormal laboratory values) have evidence of delayed hyper-enhancement on delayed contrast-enhanced MRI. Thus, delayed contrast-enhanced MRI might be a useful technique to identify inflammation in arterial wall.     

The Usefulness of Gadolinium-Enhanced Images on a Follow-up Magnetic Resonance Image in Suspected Multiple Sclerosis

Purpose

Multiple sclerosis diagnostic criteria include the presence of gadolinium-enhancing lesions when determining dissemination in space and time. Gadolinium is expensive, increases scan time and patient discomfort, and can, rarely, cause serious adverse effects. Our objective was to determine the usefulness of including gadolinium-enhanced images as part of a follow-up brain magnetic resonance imaging (MRI) in patients with a clinically isolated syndrome.

Methods

Consecutive patients seen between 2008 and 2010 with a clinically isolated syndrome suggestive of multiple sclerosis were prospectively enrolled, had a non–gadolinium-enhanced brain MRI, and consented to a follow-up gadolinium-enhanced brain MRI. The primary outcome was a comparison of the number of patients diagnosed with multiple sclerosis compared with the number who would have been diagnosed without the gadolinium-enhanced images.

Results

Twenty-one patients enrolled, and 2 withdrew. Follow-up MRIs were performed a median of 241 days after the initial MRI. Eleven patients met the primary outcome and were diagnosed with multiple sclerosis: 6 as a result of a second clinical attack and 5 by using imaging criteria for dissemination in space and time. If the gadolinium-enhanced images had not been obtained, then there would have been no change in the primary outcome.

Conclusions

In Canadian centers with similar MRI waiting times to those in our study, the routine use of gadolinium as part of a follow-up MRI in patients with suspected multiple sclerosis may not be clinically useful. Gadolinium-enhanced images could still be obtained on an as-needed basis for specific clinical indications.     

Hepatic adenomatosis: MRI demonstration with the use of superparamagnetic iron oxide

This case report describes a case of a 38-year-old woman with hepatic adenomatosis. MRI revealed five hyperintense nodular liver lesions on T1-weighted images which were hypo-isointense with the liver parenchyma on T2-weighted images. Serial gadolinium-enhanced images did not reveal distinctive imaging findings. With the use of superparamagnetic iron oxide (SPIO) particles, hyperintense adenomas revealed signal loss on T1-weighted images after SPIO. Two subcapsular adenomas were resected based on MRI findings and histopathology confirmed MRI diagnosis.     

Hepatocellular adenomas in men: MRI findings in four patients

PURPOSE: To demonstrate both MRI and histopathological findings of hepatocellular adenomas (HCAs) in men. MATERIALS AND METHODS: HCAs in four men are reported. All patients underwent MR studies at 1.5T including serial gadolinium-enhanced gradient echo imaging. RESULTS: Three men had solitary non-hemorrhagic adenomas that exhibited a uniform capillary blush with no central scar, and uniform fading of the tumor to near isointensity with the liver parenchyma by one minute. One of the subjects had uniform fat content as shown by uniform low signal on out-of-phase images. One patient had a solitary hemorrhagic adenoma that measured 17 cm in diameter and was heterogeneous on all sequences. Two of the four patients had a history of anabolic steroid use, and in the other two patients no underlying explanation for the tumor was found. CONCLUSIONS: Although three of the four patients had tumors that exhibited uniform homogeneous tumor blush and rapid fading of enhancement, because HCAs are rare in men and resemble hepatocellular carcinoma (HCC) in appearance, our findings suggest that histological confirmation of HCAs may not be avoidable in men.     

The role of 67Ga in the early detection of spinal epidural abscesses

In this study, we evaluated the role of 67Ga whole-body and single photon emission tomographic (SPET) imaging in the early diagnosis and lesion localization of spinal epidural abscess before confirmation by gadolinium-enhanced magnetic resonance imaging (MRI). Six patients with fever of unknown origin had a 67Ga whole-body scan, four of whom also underwent SPET imaging. For further confirmation of a spinal epidural abscess, gadolinium-enhanced MRI was performed in all patients. All patients had increased 67Ga uptake in a spinal or paraspinal area on the whole-body scan. They were later confirmed to have a spinal epidural abscess after gadolinium-enhanced MRI. Of these six patients, five underwent surgical drainage plus parenterally administered antibiotics, and had complete or partial recovery. One died before operation due to sepsis. In conclusion, we suggest performing a 67Ga whole-body survey as early as possible in patients with fever of unknown origin, fever and back pain and/or the spinal syndrome, before MRI is performed. If a spinal epidural abscess is strongly suspected, SPET is needed for further confirmation of spinal versus non-spinal and contiguous versus non-contiguous lesion(s). If MRI is unavailable, then 67Ga scintigraphy is a satisfactory method for investigating spinal epidural abscesses.     

Magnetic resonance imaging for extramammary Paget’s disease: radiological and pathological correlations

Extramammary Paget’s disease (EMPD) is a rare cutaneous neoplasm that is thought to represent intraepithelial adenocarcinoma developing in an area rich in apocrine glands. Magnetic resonance imaging (MRI) findings for this disease are not well established. We report three cases of pathologically confirmed EMPD in which MRI was performed before surgery. The lesions were widespread in the epidermis and the dermis. Lesions were sharply well enhanced on gadolinium-enhanced T1-weighted imaging and appeared hyperintense on diffusion-weighted imaging in all cases. Areas with enhancement in depth corresponded well with the pathological lesion. In addition, different malignant legions were found on the same images from MRI in two cases, indicating potential associations with other malignancies. We describe the MRI findings and their pathological correlation. MRI could be useful for preoperative evaluation of disease spread and detection of associated malignancies.     

Athletic injuries of the extensor carpi ulnaris subsheath: MRI findings and utility of gadolinium-enhanced fat-saturated T1-weighted sequences with wrist pronation and supination

Objective  

To report the magnetic resonance imaging (MRI) findings in athletic injuries of the extensor carpi ulnaris (ECU) subsheath, assessing the utility of gadolinium-enhanced (Gd) fat-saturated (FS) T1-weighted sequences with wrist pronation and supination.     

Distinction of well-differentiated liposarcoma from lipoma in two patients with multiple well-differentiated fatty masses

This case report describes the features of gadolinium-enhanced MRI in well-differentiated liposarcoma with histologic correlation and addresses the usefulness of this imaging technique in distinguishing well-differentiated liposarcoma from lipoma. Gadolinium-enhanced MRI revealed significantly enhanced signal in well-differentiated liposarcoma in a background of multiple well-differentiated benign fatty masses by showing the increased vascularity in the septa of well-differentiated liposarcoma. Although such signal enhancement can be seen in some types of benign lipomatous tumors with increased blood vessels, this technique is helpful in selection of biopsy site, especially in a clinical setting of multiple fatty masses.     

Value of MRI in symptomatic patients treated with tamoxifen

PURPOSE: To assess the MR imaging (MRI) findings in symptomatic tamoxifen treated-women with abnormal transvaginal sonography. PATIENTS AND METHODS: From january 1997 to june 2000, 32 consecutive symptomatic tamoxifen treated-women with abnormal transvaginal sonography were prospectively studied by MRI. T1-weighted, T2-weighted, post-contrast T1-weighted and dynamic gradient-echo T1-weighted sequences were used. All patients underwent uterine sampling within one month of MRI. RESULTS: Endometrial thickness at sonography ranged from 5 to 48 mm (mean thickness 19 mm), and on T2-weighted imaging ranged from 3 to 50 mm (mean=25 mm). Three MRI patterns were found. Pattern 1 (13 patients) was defined as homogeneous high signal intensity of the endometrium on T2W images, and signal void in the lumen on gadolinium-enhanced images. Pattern 2 (8 patients) was defined as heterogeneous endometrial signal on T2W images, and latticelike enhancement traversing the endometrial canal on gadolinium-enhanced images. Pattern 3 (11 patients) was defined as heterogeneous signal on T2W images with masses or nodules which were better seen on dynamic gadolinium-enhanced images. In pattern 1 we found 13 atrophic endometrium, in addition there were 4 polypoid glandulo-cystic proliferation (PGCP), and 1 adenomyosis. In pattern 2 we found 3 PGCP, 4 atrophy and 1 polyp without hyperplasia. The 2 carcinomas and the polyps with hyperplasia were found in pattern 3 (11 patients). CONCLUSION: In our experience MRI allows differentiation of lesions which may require surgery from other lesions in which noninvasive follow-up is possible.     

Can unenhanced multiparametric MRI substitute gadolinium-enhanced MRI in the characterization of vertebral marrow infiltrative lesions?

Purpose

To assess the diagnostic effectiveness of unenhanced-multiparametric magnetic resonance imaging (mp MRI) as an alternative to gadolinium (Gad)-enhanced MRI in the characterization of vertebral marrow infiltrative lesions.

Patients and methods

A prospective evaluation of fifty-six patients with suspected or untreated vertebral metastases undergoing MRI of the spine at 1.5 T was carried out. Two groups of sequences were assigned and compared for the characterization of marrow infiltrative lesions: group [A] unenhanced-mp MRI (including T1-weighted, T2-weighted, short time inversion recovery (STIR), diffusion weighted imaging (DWI) and in/opposed phase sequences) and group [B] gadolinium-enhanced MRI (including T1-weighted, T2-weighted, STIR and T1-weighted fat-suppressed gadolinium-enhanced sequence). Qualitative and quantitative image analysis was performed and compared. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for both imaging techniques were calculated.

Results

There was no statistical significant difference between unenhanced-multiparametric MRI and gadolinium-enhanced MRI as regards their diagnostic performance in differentiating benign from malignant vertebral marrow infiltrative lesions (p > 0.05) with calculated sensitivity (94% vs. 97%), specificity (92% vs. 88%), positive predictive value (94% vs. 91%), negative predictive value (92% vs. 95%) and (93% vs. 93%) accuracy.

Conclusion

Unenhanced-multiparametric MRI is compatible with gadolinium-enhanced MRI in reliable characterization of marrow infiltrative lesions. The routine MRI protocol of cancer patients should be altered to accommodate the evolving MRI technology and cost effectively substitute the need for a gadolinium enhanced scan.     

腰椎间盘早期退变定量MRI研究的新进展

腰椎间盘退变引起的下腰痛是影响人们健康的重要原因,MRI 技术是诊断腰椎间盘退变的主要手段,特别是MR扩散加权成像、T2 mapping成像、T1ρ加权成像、钠MRI、软骨延迟钆增强MRI 和MR 波谱成像等新技术能够通过对蛋白聚糖、水等椎间盘细胞外基质成分进行检测,从而达到早期诊断腰椎间盘退行性变的目的。从上述几个方面综合论述MRI技术用于定量分析研究早期腰椎间盘退变的新进展,并就各自的优缺点进行比较。     

Isolated solitary vertebral body tuberculosis--study of seven cases

AIM: To describe the magnetic resonance imaging (MRI) findings in isolated solitary vertebral body tuberculosis. Also to emphasize tuberculosis as an important entity, besides neoplasms, in the differential diagnosis of pathologies involving a single vertebral body. MATERIAL AND METHODS: The clinical and imaging features of seven patients (four men and three women; age range 18-60 years), with proved solitary vertebral body tuberculosis were retrospectively studied. RESULTS: Isolated solitary vertebral body tuberculosis is seen in only 1.69% of the total proven cases of spine tuberculosis seen in our institute between 1993 and 2002. All patients presented with constitutional symptoms and localized pain and tenderness. MRI showed decreased signal intensity on T1-weighted images and increased signal intensity on T2-weighted images. Cortical break was seen in three patients of whom epidural and pre-vertebral extensions were seen in one each. CONCLUSIONS: Although tuberculosis affecting a solitary vertebral body is rare it should be considered as an important differential diagnosis, besides neoplasms. In these cases MRI serves as the best imaging technique available for diagnosis. However, confirmation can only be made on histopathology or culture of the specimen.     

Nodule-in-nodule appearance of hepatocellular carcinomas: comparison of gadolinium-enhanced and ferumoxides-enhanced magnetic resonance imaging

PURPOSE: To perform comparison of gadolinium-enhanced and ferumoxides-enhanced magnetic resonance imaging (MRI) in the detection of nodule-in-nodule appearance of hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: During a recent 45-month period, we had eight patients (five men and three women; age range, 63-84 years; mean, 71 years) with HCCs with nodule-in-nodule appearance who underwent gadolinium-enhanced MRI, ferumoxides-enhanced MRI, and computed tomography during arterial portography (CTAP) and computed tomography during hepatic arteriography (CTHA), combined and separately, within an interval of two weeks. Two blinded radiologists in consensus retrospectively evaluated three sets of sequences: unenhanced T1- and T2-weighted MR, gadolinium-enhanced MR, and ferumoxides-enhanced MR images in random order of patients and imaging sequences. The depiction degree of nodule-in-nodule appearance of HCC was evaluated in a semiquantitative fashion. The sensitivities of unenhanced T1- and T2-weighted, gadolinium-enhanced, and ferumoxides-enhanced MR images were compared with McNemar's test. RESULTS: The eight HCCs with nodule-in-nodule appearance ranged in size from 16-26 mm (mean, 20.0 +/- 4.0 mm), and there existed nine internal HCC foci ranging in size from 5-14 mm (mean, 7.9 +/- 3.5 mm). On gadolinium-enhanced MR images, the nodule-in-nodule appearance of HCC was typically seen as hypervascular foci in an iso- or hypovascular area: the depiction degree of nodule-in-nodule appearance was distinct in two lesions, equivocal in three, and absent in three. On ferumoxides-enhanced MR images, it was typically seen as hyperintense foci in a hypointense area: the depiction degree was distinct in four, moderate in one, and absent in three. The sensitivities for detection of nodule-in-nodule appearance were 25%, 25%, and 63% on T1- and T2-weighted, gadolinium-enhanced, and ferumoxides-enhanced MR images, respectively, but there was no significant difference in sensitivity. CONCLUSION: Nodule-in-nodule appearance of HCCs can be seen on ferumoxides-enhanced MR images, in some cases more clearly than on gadolinium-enhanced MR images, particularly when the background nodule shows hyperintensity on precontrast T1-weighted images. Ferumoxides-enhanced MRI may be considered when development of malignant foci is suspected during routine examinations.     

Renal Tumors: Technical Success and Early Clinical Experience with Radiofrequency Ablation of 18 Tumors

Purpose To evaluate the feasibility, safety, and technical efficacy of image-guided radiofrequency ablation (RFA) for the treatment of small peripheral renal tumors and to report our early results with this treatment modality. Methods Twenty-two RFA sessions for 18 tumors were performed in 11 patients with renal tumors. Indications included coexistent morbidity, high surgical or anesthetic risk, solitary kidney, and hereditary predisposition to renal cell carcinoma. Ten patients had CT-guided percutaneous RFA performed on an outpatient basis. One patient had open intraoperative ultrasound-guided RFA. Technical success was defined as elimination of areas that enhanced at imaging within the entire tumor. With the exception of one patient with renal insufficiency who required gadolinium-enhanced MRI, the remaining patients underwent contrast-enhanced CT for post-treatment follow-up assessment. Follow-up was performed after 2–4 weeks and then at 3, 6, 12 months, and every 12 months thereafter. Results Fourteen (78%) of 18 tumors were successfully ablated with one session. Three of the remaining four tumors required two sessions for successful ablation. One tumor will require a third session for areas of persistent enhancement. Mean patient age was 72.82 ± 10.43 years. Mean tumor size was 1.95 ± 0.79 cm. Mean follow-up time was 10.91 months. All procedures were performed without any major complications. Conclusions Our early experience with percutaneous image-guided radiofrequency ablation demonstrates it to be a feasible, safe, noninvasive, and effective treatment of small peripheral renal tumors.     

Detection of hepatocellular carcinoma: combined T2-weighted and dynamic gadolinium-enhanced MRI versus combined CT during arterial portography and CT hepatic arteriography

PURPOSE: The purpose of this study was to compare the preoperative detectability of hepatocellular carcinomas (HCCs) using combined T2-weighted and dynamic gadolinium-enhanced MRI and combined CT during arterial portography (CTAP) and CT hepatic arteriography (CTHA). METHOD: Thirty-three patients with 43 HCCs underwent T2-weighted and dynamic gadolinium-enhanced MRI and combined CTAP and CTHA. The diagnosis was established by pathologic examination following surgical resection in 26 patients and by biopsy in 7 patients. The MR protocol included fast SE with two TEs (including T2-weighted imaging) and precontrast and gadolinium-enhanced T1-weighted fast multiplanar spoiled gradient-recalled echo images with dynamic study. The MR images of all sequences and the paired CTAP and CTHA images were independently reviewed by three radiologists. Image review was conducted on a segment-by-segment basis. Diagnostic accuracy was evaluated with receiver operating characteristic analysis. RESULTS: The accuracies (Az values) of MRI of all sequences and combined CTAP and CTHA for all observers were 0.960 and 0.959, respectively. The mean sensitivities of MRI and CT were 90 and 94%, respectively. The differences were not statistically significant. The mean specificity of MRI (99%) was significantly higher than that of combined CTAP and CTHA (92%). CONCLUSION: Combined T2-weighted and dynamic gadolinium-enhanced MRI is as accurate as combined CTAP and CTHA for preoperative detection of HCCs.     

Case report: solitary haemangioblastoma of the fourth ventricle in an adolescent male.

We report a solitary haemangioblastoma arising from a pedicle in the wall of the fourth ventricle of the brain, which we believe to be the first report of haemangioblastoma occurring in this location. Computed tomography (CT), angiography and magnetic resonance imaging (MRI) made possible accurate pre-operative tumour identification and localization which facilitated a minimally invasive surgical resection.     

Intravenous pyogenic granuloma of the finger

Intravenous pyogenic granuloma is a rare solitary form of lobular capillary hemangioma that usually occurs in the veins of the neck and upper extremities. We report two cases of intravenous pyogenic granuloma localized in the finger, giving details of the magnetic resonance imaging (MRI) findings. These two cases had similar locations in fingers and identical MRI findings. The differential diagnoses of this rare entity are also discussed.     

Usefulness of dynamic contrast-enhanced MRI in the evaluation of the viability of acute scaphoid fracture

Objective

To evaluate the usefulness of dynamic gadolinium-enhanced magnetic resonance imaging (MRI) for assessing the viability of the proximal pole of the scaphoid in patients with acute scaphoid fractures.

Methods

Eighteen consecutive patients with acute scaphoid fracture who underwent dynamic gadolinium-enhanced MRI 7 days or less before surgery were prospectively included between August 2011 and December 2012. All patients underwent MR imaging with unenhanced images, enhanced images, and dynamic enhanced images. A radiologist first classified the MRI results as necrotic or viable based on T1- and T2-weighted images only, followed by a second blinded interpretation, this time including analysis of pre- and post-gadolinium administration images and a third blinded interpretation based on the time–intensity curve of the dynamic enhanced study. The standard of reference was the histologic assessment of a cylindrical specimen of the proximal pole obtained during surgery in all patients. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for unenhanced, enhanced, and dynamic gadolinium-enhanced MRI studies.

Results

The sensitivity, specificity, PPV, and NPV were 67, 67, 50, and 80 % for unenhanced images, 83, 100, 100, and 92 for enhanced images, and 83, 92, 83, and 92 for dynamic contrast-enhanced images.

Conclusions

Our data are consistent with previously reported data supporting contrast-enhanced MRI for assessment of viability, and showing that dynamic imaging with time–intensity curve analysis does not provide additional predictive value over standard delayed enhanced imaging for acute scaphoid fracture.