Use of two-dimensional multiple-slice magnetic resonance hydrography for diagnosis of hepatic hemangiomas and cysts.

BACKGROUND/PURPOSE: Although hepatic hemangiomas and cysts display very high signal intensities on conventional T2 images, their appearances are quite distinct using magnetic resonance hydrography (MRH). We examined the feasibility of using MRH in distinguishing hepatic cysts from hemangiomas. METHODS: We recruited 97 patients with hepatic hemangiomas and 65 with hepatic cysts. All patients underwent magnetic resonance imaging (including two-dimensional multiple slice MRH, TR/TE: 8000/800) and the results were reviewed independently by two radiologists. The signal intensities of the lesions were measured. For each lesion, the variation in signal to noise ratio between MRH and the fat-saturated T2-weighted images was calculated, and the results were validated using a receiver operating characteristic curve. RESULTS: There was a significant difference between the signal to noise ratio of hepatic hemangiomas and cysts using MRH (p < 0.001). This difference could be identified by visual inspection. The receiver operating characteristic curve revealed that the ideal cut-off value for the signal intensity reduction ratio between hepatic cysts and hemangiomas was -0.1. Using this ratio, the derived sensitivity was 95.4%, specificity 99.0%, and accuracy 99.7%. CONCLUSION: Hepatic hemangiomas and cysts have significantly different signal intensities on non-contrast two-dimensional multiple-slice MRH. This approach uses a non-invasive, reliable, and accurate imaging technique to differentiate the two diagnoses.

Incidentally detected enhancing breast lesions on chest computed tomography.

OBJECTIVE: To evaluate the nature and imaging appearance of incidental enhancing breast lesions detected on a routine contrast-enhanced chest CT. MATERIALS AND METHODS: Twenty-three patients with incidental enhancing breast lesions on contrast-enhanced chest CT were retrospectively reviewed. The breast lesions were reviewed by unenhanced and enhanced CT, and evaluated by observing the shapes, margins, enhancement patterns and backgrounds of breast lesions. A histopathologic diagnosis or long-term follow-up served as reference standard. RESULTS: Sixteen (70%) patients had malignant breast lesions and seven (30%) had benign lesions. In 10 patients, the breast lesions were exclusively detected on contrast-enhanced CT. Using unenhanced CT, breast lesions with fibroglandular backgrounds were prone to be obscured (p < 0.001). Incidental primary breast cancer showed an non-significant trend of a higher percentage irregular margin (p = 0.056). All of the four incidental breast lesions with non-mass-like enhancement were proven to be malignant. CONCLUSION: Routine contrast-enhanced chest CT can reveal sufficient details to allow for the detection of unsuspected breast lesions, in which some cases may be proven as malignant. An irregular margin of incidental enhancing breast lesion can be considered a suggestive sign of malignancy.

Value of sonographically guided needle sampling of cystic versus solid components in the diagnosis of complex cystic breast masses.

BACKGROUND: The common practice for diagnosis of complex cystic breast masses (CCBM) may be imaging-guided aspiration or biopsy of cystic or solid components. PURPOSE: To assess the diagnostic value of sonographically guided needle sampling of cystic and solid components for CCBM. MATERIAL AND METHODS: Twenty patients with 20 CCBM underwent sonographically guided fine-needle aspiration biopsy (FNAB) for cystic components, followed by core needle biopsy (CNB) for residual solid components. The diagnostic results of each were evaluated. Excisional biopsy or mastectomy served as a reference standard. RESULTS: Fourteen (70%) masses were malignant. Needle sampling for cystic components of the 14 malignant tumors showed malignancy in one (7%), atypia in four (29%), benign findings in four (29%), and insufficient samples in five (36%). Needle sampling for residual solid components showed malignancy in 11 (79%), atypia in two (14%), and insufficient sample in one (7%). The diagnostic yield of needle sampling of solid components was significantly higher than that of cystic components for malignant CCBM (P<0.05). Sixteen (80%) of 20 CCBMs showed bloody fine-needle aspirates. There was no significant difference between the rates of bloody aspirates of malignant and benign CCBM (86% vs. 67%, P=0.55). CONCLUSION: Sonographically guided needle sampling of solid components may help to identify most malignant CCBMs, and the aspirated fluid may be discarded due to low diagnostic value.

Atypical pulmonary metastases from a true malignant mixed tumor of the parotid gland.

A 58-year-old male patient presented with a recurrent true malignant mixed tumor of the parotid gland. Patchy pulmonary opacities were identified with a chest radiograph. Subsequently, a CT scan of the chest showed pulmonary parenchymal consolidation with amorphous calcifications. This abnormality was confirmed to be the result of a metastatic true malignant mixed tumor by using CT-guided biopsy. The current case demonstrated an extremely rare example of atypical pulmonary metastases from a true malignant mixed tumor of the parotid gland showing an air-space pattern and calcification.

A late complication of augmentation mammoplasty by polyacrylamide hydrogel injection: ultrasound and magnetic resonance imaging findings of huge galactocele formation in a puerperal woman with pathological correlation.

Polyacrylamide hydrogel (PAAG) was widely used for injection augmentation mammoplasty in Eastern Europe and China although uncommon in the western countries. However, the safety of this procedure remained controversial. Herein, we report a 30-year-old woman with a history of augmentation mammoplasty by PAAG injection developed galactoceles during her pregnancy. Ultrasound and magnetic resonance imaging showed huge cystic lesions in bilateral breasts; as a result, the normal breast tissue was almost completely replaced. On the basis of the imaging findings, the patient underwent mastectomy as well as immediate breast reconstruction with satisfactory outcome. It is important to be familiar with the imaging findings of this rare yet severe complication after augmentation mammoplasty in order to make an accurate diagnosis and a proper management.

T2-weighted and T1-weighted dynamic superparamagnetic iron oxide (ferucarbotran) enhanced MRI of hepatocellular carcinoma and hyperplastic nodules.

BACKGROUND/PURPOSE: Iron oxide contrast medium (ferucarbotran) shortens both T1 and T2 relaxation time. We used the T2- and the T1-weighted dynamic ferucarbotran-enhanced magnetic resonance (MR) imaging to predict the histologic grade of hepatocellular carcinoma (HCC) and to distinguish HCC from hyperplastic nodules. METHODS: Forty-three patients with 48 representative hepatic lesions (13 well differentiated HCC, 19 moderately differentiated HCC, 4 poorly differentiated HCC, 12 hyperplastic nodules) were included in the study. T1-weighted image, T2-weighted turbo spin echo, and T2*EPI (echo-planar) images were obtained before and after ferucarbotran injection. The percentage T2 signal intensity loss (T2 PSIL) of the tumors was calculated at 5 minutes and 25 minutes after contrast injection. The enhancement in dynamic T1 images was interpreted by two independent radiologists. RESULTS: The T2 PSIL of well differentiated HCC was 39.5 +/- 8.23%, moderately differentiated HCC was 26.4 +/- 13.78%, poorly differentiated HCC was 4.4 +/- 9.42%, and hyperplastic nodules was 44.3 +/- 11.04%. Comparison of T2 PSIL showed significant differences in the three histologically graded HCCs (p < 0.001), but not between the well differentiated HCCs and hyperplastic nodules (p > 0.05). Delayed post-contrast (25 minutes) T2-weighted images were not necessary and shortened the examination time. In the post contrast dynamic T1 study, no significant differences between all the groups was seen. CONCLUSION: Ferucarbotran MR images help in differentiating the different histologic grades of HCC but T2 PSIL could not differentiate hyperplastic nodules from well differentiated HCC. Dynamic post contrast T1-weighted images provide no additional information.

Enhancement characteristics of ultrasmall superparamagnetic iron oxide particle within the prostate gland in patients with primary prostate cancer.

OBJECTIVE: To analyze the enhancement of the prostate using ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance imaging in patients with prostate cancer. METHODS: Sixty patients were enrolled. The signal-to-noise ratios (SNRs) of the central and peripheral zones (CZ and PZ, respectively) of the prostate were evaluated on T2- and T2*-weighted magnetic resonance imaging before and 24 hours after USPIO-enhanced MRI. The changes in SNR after USPIO-enhanced MRI were analyzed and correlated with serum prostate-specific antigen and histopathologic Gleason scoring based on surgically removed prostate gland. RESULTS: Decrease in SNR was noted in each zone of the prostate after USPIO-enhanced MRI (P < 0.001). Mean SNR decrease in the CZ was higher than that in the PZ (P < 0.05). High-grade prostate cancer was associated with a higher decrease in SNR (P < 0.05). The SNR change was negatively correlated with serum prostate-specific antigen at low or intermediate levels (P < 0.05). CONCLUSIONS: Enhancement of the prostate gland after USPIO administration may be associated with primary prostate cancer.

Differentiation of soft tissue benign and malignant peripheral nerve sheath tumors with magnetic resonance imaging.

PURPOSE: The objective of this study was to differentiate the magnetic resonance (MR) imaging appearance of benign peripheral nerve sheath tumors (PNSTs) from that of malignant PNSTs. MATERIALS AND METHODS: Twenty-six patients who underwent MR imaging and had a histologic diagnosis of benign (schwannoma, n=16; neurofibroma, n=1) or malignant (n=9) PNST were retrospectively reviewed. The size, location, shape, margin, and signal intensities of the tumors on precontrast and gadolinium-enhanced MR imaging were analyzed. In each patient, the presence or absence of split fat, target, and fascicular signs was determined. RESULTS: The mean size of the benign PNSTs (3.4 cm, S.D.=2.5 cm) was significantly smaller than that of the malignant tumors (8.2 cm, S.D.=3.1 cm) (P<.001). Seventeen (65.4%) of the 26 tumors were spindle shaped or ovoid (12 benign and 5 malignant tumors). Contiguity with specific nerves was identified in 15 (88.2%) of the 17 benign PNSTs but in none of the malignant tumors (P<.05). Well-defined margins were noted in all 17 benign PNSTs but in only 3 (33.3%) of the 9 malignant tumors (P<.001). Five (55.6%) of the 9 malignant PNSTs but none of the benign tumors showed signal intensity change in adjacent soft tissue (P<.05). There was no significant difference in signal intensity between the benign and malignant tumors on T(1)-weighted, T(2)-weighted, and contrast-enhanced MR images. The split fat and target signs were present more frequently in the benign PNSTs than in the malignant PNSTs (P<.05). CONCLUSIONS: Benign and malignant PNSTs are often spindle shaped. Recognition of contiguity with adjacent nerves, a well-defined margin, and the presence of the split fat sign may suggest benignity. Imaging features suggestive of malignancy can be a larger size and an infiltrative margin.

Value of automated coronal reformations from 64-section multidetector row computerized tomography in the diagnosis of urinary stone disease.

PURPOSE: We determined the value of automated coronal reformation using 64-detector computerized tomography for the detection of urinary stones. MATERIALS AND METHODS: A total of 72 patients underwent unenhanced 64-detector computerized tomography to diagnose urinary stones. Two radiologists independently reviewed coronal reformations and axial images at separate reading sessions. The stone detection rate, reader confidence and interpretation time per radiologist were recorded. Two radiologists reviewed coronal and axial images in consensus and served as the reference standard. RESULTS: A total of 175 stones were diagnosed by consensus. Using coronal reformations 162 stones (92.6%) were detected by reader 1 and 157 (89.7%) were detected by reader 2. Using axial images 157 stones (90.3%) were detected by reader 1 and 155 (88.6%) were detected by reader 2. The reading time of coronal reformations was significantly shorter than that of axial images for each reader (p <0.01). Using coronal imaging to complement axial imaging 12 additional stones were detected and 23 were diagnosed with increased confidence by reader 1, while an additional 15 were detected and 8 were diagnosed with increased confidence by reader 2. The mean size of stones detected with coronal reformations alone was significantly smaller than that of the total stones. Excellent interobserver agreement was noted for coronal reformations and axial images (kappa coefficient: 0.91 and 0.904, respectively). CONCLUSIONS: Review of automated coronal reformations allows equally accurate and more rapid detection of urinary stones compared with axial images alone. In addition, coronal reformation of 64-detector computerized tomography adds value when used in conjunction with axial data sets.

Magnetic resonance imaging appearance of well-differentiated hepatocellular carcinoma.

OBJECTIVE: To investigate the magnetic resonance imaging (MRI) features of well-differentiated hepatocellular carcinoma (HCC). METHODS: We reviewed the MRI of 32 patients with 33 pathologically confirmed well-differentiated HCC. The MRI protocol included T2-weighted imaging with and without fat saturation, dual-phase T1-weighted imaging, and gadolinium-enhanced dynamic study. The signal intensity of each lesion was categorized as hyperintense, isointense, and hypointense with reference to the surrounding liver parenchyma. RESULTS: Thirty-one (93.9%) of 33 well-differentiated HCC were demonstrated on the MRI. The remaining 2 were isointense in all magnetic resonance sequences and, therefore, could not be identified. Most of them were hyperintense (n = 15 [45.4%]) or isointense (n = 16 [48.5%]) on T1-weighted imaging, and hyperintense (n = 12 [36.4%]) or isointense (n = 17 [51.5%]) on T2-weighted imaging. On the dynamic study, 17 lesions (51.5%) were enhanced. CONCLUSIONS: MRI may identify most well-differentiated HCC; however, the imaging appearance is diverse. Biopsy should be performed if magnetic resonance study is inconclusive.

Peritumoral fat-spared area is well correlated with the presence of temporal peritumoral enhancement in hepatic hemangioma in fatty liver.

PURPOSE: To assess the relationship between temporal peritumoral enhancement and peritumoral focal fat sparing adjacent to hepatic hemangiomas. MATERIALS AND METHODS: On the basis of MRI and sonographic imaging follow-up, 51 hepatic hemangiomas were identified in 37 patients, who had both hepatic hemangiomas and focal fat-sparing areas in fatty liver. Among them, 36 tumors were associated with peritumoral focal fat spares. The association between the temporal peritumoral enhancement in the early arterial phase of dynamic MRI and peritumoral fat sparing in the same hemangioma was investigated. Furthermore, the configuration of the temporal peritumoral enhancement was correlated with that of the peritumoral focal fat-sparing area. We used Chi square and Fisher's exact test for statistic analysis. RESULTS: A total of 31 out of 36 hemangiomas (86.1%) showed both peritumoral focal fat spares and temporal peritumoral enhancement. The presence of temporal peritumoral enhancement is significantly related to that of peritumoral focal fat-sparing (P < 0.001). A total of 21 of the 31 tumors (67.7%) presented with similar configuration of the peritumoral focal fat-sparing area and temporal peritumoral enhancement area with respect to size and shape. The remaining 10 hemangiomas showed similar shape but slightly different size in these two imaging characteristics. CONCLUSION: Temporal peritumoral enhancement seen in hepatic hemangioma might be related to focal fatty sparing adjacent to the hemangiomas.

MRI of angiomatoid fibrous histiocytoma.

Angiomatoid fibrous histiocytoma is a rare soft tissue tumor of low-grade malignancy. We present the case of a 32-year-old man who complained of soreness and numbness over his left arm and hand over the previous 2 months and of having a palpable mass over his left upper back for 4 years. Magnetic resonance imaging (MRI) showed an intramuscular soft tissue mass in the left scapular region. The tumor mass was seen to have multiple cystic components with fluid-fluid levels. Histological examination showed multiple cystic spaces filled with blood lakes and hemosiderin deposits in the solid part of the tumor. After the initial surgery, the patient had local recurrences over 2.5 years. The immunohistochemical study at the second surgery showed that the recurrent tumor was strongly positive for the histiocytic marker CD68, and the myoid trait desmin. Histological diagnosis was compatible with angiomatoid fibrous histiocytoma.

Temporal peritumoral enhancement of hepatic cavernous hemangioma: findings at multiphase dynamic magnetic resonance imaging.

OBJECTIVE: To evaluate the occurrence rate of temporal peritumoral enhancement associated with hepatic cavernous hemangiomas and to correlate that with the speed of intratumoral contrast enhancement and tumor volume. METHODS: Dynamic magnetic resonance imaging (MRI) of 69 consecutive patients with 136 hemangiomas was reviewed for peritumoral enhancement. Tumor volume was estimated by the largest diameter on T2-weighted images. Speed of intratumoral contrast enhancement was determined by portal phase image and was categorized as rapid (>75% of tumor volume), intermediate (25%-75% of tumor volume), or slow (<25% of tumor volume). RESULTS: Temporal peritumoral enhancement was found in 37 (26.6%) of 136 hemangiomas. It was more common in hemangiomas with rapid enhancement (30 of 67 cases [44.8%]) than in those with intermediate (3 of 22 cases [13.6%]) and slow (4 of 47 cases [8.5%]) enhancement (P < 0.05). There was no statistically significant relation between lesion size and presence of temporal peritumoral enhancement (P > 0.05). CONCLUSIONS: Temporal peritumoral enhancement is not uncommonly seen in hepatic cavernous hemangiomas at dynamic MRI. It is most commonly encountered in rapidly enhancing small lesions. There is no statistically significant relation between temporal peritumoral enhancement and tumor volume, however.