Thin Rim Enhancement Research Articles

Differentiating between adrenocortical carcinoma and lipid-poor cortical adenoma: A novel cross-sectional imaging-based score

BackgroundDiscrimination between adrenocortical carcinoma and lipid-poor cortical adenoma preoperatively is frequently difficult as these two entities have overlapping imaging characteristics. Differentiation will allow for the selection of the most appropriate operative approach and may help prevent over-treatment. We aimed to identify imaging features that could preoperatively differentiate adrenocortical carcinoma from lipid-poor cortical adenoma and use them in a novel imaging-based score. MethodsWe conducted a retrospective analysis of patients with pathologically proven adrenocortical carcinoma and lipid-poor cortical adenoma who underwent resection in a single tertiary referral center between March 1998 and August 2020. The inclusion criteria were diameter >1 cm, attenuation >10 Hounsfield units on nonenhanced computed tomography, and histopathologic diagnosis. Patients with metastatic or locally advanced adrenocortical carcinoma adenoma (stages 3–4) were excluded. We developed a score using binary logistic multivariate regression model in 5-fold derivation (∼70%) cohorts with stepwise backward conditional regression as feature selection. Standardized mean regression weight was used as variable score points. ResultsWe identified 232 adrenals resected across 211 patients. By comparing the imaging characteristics of adrenocortical carcinoma (n = 56) and lipid-poor cortical adenoma (n = 156), we revealed statistically significant differences between the groups in 9 parameters: size, attenuation, thin and thick rim enhancement patterns, heterogeneity, calcification, necrosis, fat infiltration, and lymph node prominence. The score mean performance was 100% sensitivity for the exclusion of adrenocortical carcinoma, 80% specificity (95% confidence interval, 68.3–91.5), 66% positive predictive value (95% confidence interval, 52.3–78.7), and 100% negative predictive value with area under the curve of 0.974. ConclusionWe defined and evaluated a novel 9-variable, imaging-based score. This score outperformed any single variable and could facilitate safe preoperative discrimination of adrenocortical carcinoma and lipid-poor cortical adenoma.

Adenoid Cystic Carcinoma of the Breast

Contrast-enhanced spectral mammogram (CESM) is a modern technique providing additional information to detect or diagnose breast cancers. We present a rare ACC of the breast on CESM. A 49-year-old woman with surgicopathological proved ACC was reported with tumor features on CESM, sonography and contrast-enhanced magnetic resonance imaging (CE-MRI). Sonography revealed a 1.4 cm × 1.2 cm × 1 cm circumscribe round mass in the upper outer quadrant of the left breast that was diagnosed with fibroadenoma. The mammogram did not show any discernible mass, however, the recombined subtracted images displayed a circumscribe mass with thin rim enhancement and enhanced internal patches that were resembling CE-MRI. Finally, the mass was proved to ACC. CESM facilitates the detection of isodense cancer and provides the enhanced features for differential diagnosis. Resembling CE-MRI, CESM displayed rim enhancement and internal enhanced patches as diagnostic clues for this case of ACC.

Role of Diffusion Weighted Imaging in Characterization of Intracranial Rim Enhancing Lesions

Introduction: The differentiation of rim enhancing abscess from high grade necrotic lesions is difficult in conventional imaging. Our purpose was to assess the role of diffusion weighted imaging of intracranial rim enhancing lesions to differentiate the etiologies.
 Methods: Fifty one patients, 32 male and 19 female with mean age of 48.47 years and with rim enhancing intracranial lesions in magnetic resonance imaging, who underwent surgery from January 2012 to December 2012, were studied for different characteristics of the lesions in DWI and pathologically correlated the observed findings.
 Results: Out of 58 rim enhancing lesions 21 were primary brain tumor, 18 abscess, 14 metastasis and 5 neurocysticercosis. Twenty lesions had restricted diffusion in center, 22 lesions had thin smooth enhancing rim and 23 lesions were with low T2 complete rim. Diffusion restriction at non enhancing center of the lesion and thin smooth enhancing rim have sensitivity and specificity of 88.89% and 90.24% (p <0.0001) for brain abscess and 83.33% and 80.49% (p <0.0001) for other lesions. ADC ratio of center to that of normal white matter showed sensitivity and specificity of 88.9% and 90% respectively (p <0.0001) at cut off point of 1.09. Lesions with thin smooth rim enhancement with diffusion restriction in nonenhancing center are 100% specific for brain abscess.
 Conclusions: On studying the different MRI characteristics of rim enhancing lesions, combining enhancement characteristic with DWI is more helpful in coming to the proper diagnosis.

CT features for diagnosing acute torsion of uterine subserosal leiomyoma.

To evaluate the usefulness of computed tomographic (CT) features for identifying acute torsion of uterine subserosal leiomyoma (USL). We analyzed contrast-enhanced CT examinations of 7 USLs with torsion and 44 USLs without torsion. Two radiologists evaluated the CT features, which consisted of poor contrast enhancement inside the USL, thin rim enhancement around the USL, calcification within the USL, a beak sign between the uterus and USL, fan-shaped poor contrast enhancement in the uterus area adjacent to the USL (dark fan sign), and ascites. We analyzed the frequencies of these CT features in the USLs with versus without torsion using Fisher's exact test. The respective frequencies of CT features in USLs with and without torsion were as follows: poor contrast enhancement, 86 and 5% (P=0.001); thin rim enhancement, 71 and 9% (P=0.001); calcification, 29 and 18% (P=0.61); beak sign, 57 and 86% (P=0.10); dark fan sign, 57 and 0% (P=0.001); and ascites, 100 and 20% (P=0.01). The CT features of poor contrast enhancement, thin rim enhancement, and dark fan sign are valuable for identifying acute torsion of USL.

Osteomyelitis of the lower extremity: pathophysiology, imaging, and classification, with an emphasis on diabetic foot infection.

Osteomyelitis is inflammation of the bone caused by an infectious organism, and is a difficult clinical problem. The pathophysiology, imaging, and classification of osteomyelitis are challenging, varying with the age of the patient (child versus adult), the chronicity of the infection (acute versus chronic), and the route of spread (hematogenous versus contiguous focus), as well as the immune and vascular status of the patient and affected region. The two most common classification schemes are those of Lew and Waldvogel, and Cierny and Mader. Brodie's abscess is seen in subacute osteomyelitis, while sequestrum, involucrum, and cloaca are inter-related entities of chronic osteomyelitis. Imaging workup of suspected osteomyelitis should begin with radiographs, although MRI is the most accurate imaging test. Three patterns of T1 signal change have been described in the setting of suspected osteomyelitis including confluent intramedullary, hazy reticular, and subcortical. The confluent intramedullary pattern is most associated with osteomyelitis, while hazy reticular is rarely associated with hematogenous osteomyelitis, and subcortical is not associated with osteomyelitis. It can be challenging to differentiate neuropathic arthropathy from osteomyelitis. Osteomyelitis tends to involve a single bone subjacent to an ulcer or sinus tract. In contrast, neuropathic arthropathy tends to involve multiple bones of the midfoot. Subchondral cystic change, thin rim enhancement of a joint effusion, and the presence of intra-articular bodies are more indicative of a neuropathic joint without infection. Biopsy can play an important role in diagnosis and treatment of osteomyelitis.

Value of breast MRI for patients with a biopsy showing atypical ductal hyperplasia (ADH).

To evaluate the diagnostic value of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) for patients with atypical ductal hyperplasia (ADH) in predicting malignant upgrade. 3T DCE-MRI was performed for 17 patients with ADH (median age 52, range 42-76) proven by stereotactic biopsy (n = 15), and ultrasound-guided biopsy (n = 2) from January 2011 to April 2015. All patients underwent surgical excision after the MRI. Two radiologists prospectively reviewed the MRI to determine the presence or absence of suspicious findings at the site of biopsy, and evaluated the MR features of any lesion present according to the Breast Imaging Reporting and Data System (BI-RADS) lexicon. MRI findings and clinical information were correlated with the final surgical pathology by multivariate analysis. Nine of 17 lesions were upgraded to malignancy. MRI demonstrated suspicious nonmass enhancement (NME) at the site of biopsy in all upgraded patients. The median size was 19.5 mm (range, 9-44 mm). In the eight patients without upgrade, no enhancement (n = 2), linear enhancement along the biopsy track (n = 4), thin rim enhancement around hematoma (n = 1), and a focal NME (n = 1) were seen. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MRI findings were 100, 87.5, 90, and 100%, respectively. Multivariate analysis revealed that the presence of suspicious enhancement on MRI was the most significant predictor of upgrade to malignancy (P = 0.0006) CONCLUSION: Our study revealed a high NPV of DCE-MRI for patients with ADH in terms of malignant upgrade at subsequent surgery. This suggests that patients with ADH without suspicious enhancement on DCE-MRI might be followed with DCE-MRI rather than undergoing surgical excision. 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1738-1747.

Imaging features of hepatic sarcomatous carcinoma on computed tomography and gadoxetic acid-enhanced magnetic resonance imaging.

To determine the imaging features of hepatic sarcomatous carcinoma including sarcomatous intrahepatic cholangiocarcinoma (S-ICC) and sarcomatous hepatocellular carcinoma (S-HCC) on computed tomography (CT) and gadoxetic acid-enhanced magnetic resonance imaging (MRI). Twenty-four patients with pathologically confirmed S-ICCs (n=13), S-HCCs (n=7), sarcomatous carcinoma (n=2), carcinosarcoma (n=1), and sarcomatous combined HCC-CC (n=1) (size range 2.1-23 cm, mean 8.3 cm) underwent gadoxetic acid-enhanced MRI (n=20) and/or dynamic CT (N=24). Underlying chronic hepatitis or cirrhosis was found in 17 patients. Two reviewers evaluated morphology, signal intensity, and enhancement features of tumors based on a consensus. Lobulated contour was observed in 15 tumors (62.5%); the rest were round or oval masses. During dynamic imaging, S-ICCs showed poor enhancement (n=10 on CT; n=7 on MRI) or initial thin-rim enhancement with/without progressive enhancement (n=3 on CT; n=6 on MRI). S-HCCs and the other four tumors showed a thin or thick enhancement pattern on both CT and MRI. T2 bright signal intensity similar to fluid was found in 10 tumors. Target appearance on hepatobiliary phase and diffusion-weighted imaging was seen in two S-ICCs and two S-HCCs. Of 18 surgically resected tumors, 17 showed vascular invasion and/or thrombosis in histology and 12 in CT and MRI. Ten tumors were accompanied by intrahepatic metastasis or tumor seeding and 19 patients had recurrence or progression of tumors during follow-up. Hepatic sarcomatous carcinoma including S-HCC and S-ICC generally presents minimal rim-like arterial enhancement or extreme hypovascularity on CT and gadoxetic acid-enhanced MRI with a high frequency of T2 bright area due to extensive necrosis and vascular invasion.

Dermoid Cyst Excision under Müller Muscle in a Patient with Blepharoptosis.

Dermoid Cyst Excision under Müller Muscle in a Patient with Blepharoptosis.

Benign mural nodules within fluid collections at MRI after soft-tissue sarcoma resection.

The purpose of this study was to determine the prevalence and clinical significance of nodules within fluid collections on MRI after surgical resection of soft-tissue sarcoma. This retrospective study included 175 patients who underwent resection of primary soft-tissue sarcoma and whose postoperative MRI reports mentioned fluid. Images were reviewed to determine the presence of fluid collections of 1 cm or greater in diameter in the surgical bed and any nodule (measuring ≥ 0.7 cm) within the collection. Signal intensity and characteristics of each collection and rim and presence of septa or blood products were recorded. Size, signal intensity, and contrast enhancement of nodules were reviewed. Nodules were classified as benign or malignant on the basis of histologic results or clinical or MRI follow-up. Fluid collections were present in 75 patients. Of those, 45 collections (60%) showed homogeneous fluid signal intensity and 30 (40%) were heterogeneous; septa were present in 45 (60%) and blood products in 12 (16%). Most collections showed a thin rim (59%) and rim enhancement (88%). Nodules were present along the inner wall of six (8%) collections. Four (66%) nodules enhanced and two (33%) were T1 hyperintense. At follow-up MRI, two nodules were stable in size, one decreased, and three resolved. Nodules in three patients were biopsied; all were benign. Two other patients had no recurrence at follow-up, and another died at 3 months. A nodule within a postoperative fluid collection at MRI after soft-tissue sarcoma resection generally does not represent tumor recurrence; short-interval follow-up MRI is recommended rather than immediate biopsy.

Long-Term MRI Findings of Muslin-Induced Foreign Body Granulomas after Aneurysm Wrapping

Muslin-induced foreign body granulomas are rare delayed complications after wrapping of intracranial aneurysms. Few small case series have been reported, with a paucity of documented MRI findings. In addition, there are no reports on long-term radiological appearances or temporal evolution of conservatively managed patients. We thus report on the long-term radiological and clinical follow-up of two patients with asymptomatic muslin-induced foreign body granulomas after wrapping of recurrent middle cerebral arterial aneurysms. Both patients were successfully managed conservatively and remain asymptomatic three and six years after diagnosis of their granulomas. A literature review confirms that MRI features of muslin-induced foreign body granuloma are typical. Features include focal areas of elevated T2 signal with increased diffusion-weighted signal and thin rim enhancement. To the best of our knowledge, this is the first report to confirm that there is a corresponding reduction in apparent diffusion coefficient, as typical in an intracranial abscess. Thus a history of aneurysm wrapping is critical for diagnosis. Accurate clinical recognition of this exuberant inflammatory response will avoid misdiagnosis as pyogenic abscess or tumor and prevent unnecessary or invasive treatment.

Giant Epidermal Cyst on Posterior Scalp

Giant Epidermal Cyst on Posterior Scalp

The potential role of dynamic MRI in assessing the effectiveness of high-intensity focused ultrasound ablation of breast cancer

Purpose: To retrospectively evaluate magnetic resonance imaging (MRI) features of breast cancer after high-intensity focused ultrasound (HIFU) ablation.Materials and methods: Six patients with invasive ductal carcinomas underwent HIFU ablation. In all patients, dynamic MRI was performed prior to and two weeks after HIFU. Serial follow-up studies were performed. Changes in signal intensity and size of the index tumour in addition to peripheral enhancement patterns were evaluated. Histopathological results were compared with MRI findings.Results: All patients had a single index tumour with a mean size 25.6 mm (range 12 to 37 mm) at the ablation time. In three of six patients, thin rim enhancement around the ablation zone was seen on the subtraction image after first ablation, which showed no change on follow-up MRI. Complete ablation was confirmed by the histopathology (biopsy in two and surgery in one). In the remaining three patients, nodular or irregular thick enhancement was shown on the subtraction image and viable tumour was confirmed by surgery and biopsy in two patients.Conclusion: The MR characteristics of successfully ablated breast cancers included central dark signal intensities with thin rim enhancement on subtraction images. Nodular or irregular thick enhancements should raise concern of partial ablation. We propose MRI plays a critical role in assessing the effectiveness of HIFU treatment.

Postexcisional Breast Magnetic Resonance Imaging in Patients With Breast Cancer

The purposes of this study were to present magnetic resonance imaging (MRI) findings in patients with breast cancer soon after the excisional biopsy and before definitive surgery and to assess the diagnostic accuracy of MRI for prediction of residual cancer. Breast MRI was performed on 51 patients with breast cancer diagnosed by excisional biopsy. The morphologic type of postexcisional site was categorized into regular thin rim enhancement (P1), peripheral nodular enhancement (P2), satellite nodule within 2 mm from the cavity margin (P3), and irregularly thickened wall enhancement (P4). Enhancement pattern was categorized into "washout," "plateau," and "progressive" enhancement. All patients underwent definitive surgery after MRI. Magnetic resonance imaging findings were correlated with the pathologic findings. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of MRI for prediction of residual cancer were 92.1%, 69.2%, 78.4%, 88.6%, 56.3%, respectively. MRI is a sensitive method for prediction of residual cancer after excisional biopsy.

Independent association of extent of resection with survival in patients with malignant brain astrocytoma

With recent advances in the adjuvant treatment of malignant brain astrocytomas, it is increasingly debated whether extent of resection affects survival. In this study, the authors investigate this issue after primary and revision resection of these lesions. The authors retrospectively reviewed the cases of 1215 patients who underwent surgery for malignant brain astrocytomas (World Health Organization [WHO] Grade III or IV) at a single institution from 1996 to 2006. Patients with deep-seated or unresectable lesions were excluded. Based on MR imaging results obtained < 48 hours after surgery, gross-total resection (GTR) was defined as no residual enhancement, near-total resection (NTR) as having thin rim enhancement of the resection cavity only, and subtotal resection (STR) as having residual nodular enhancement. The independent association of extent of resection and subsequent survival was assessed via a multivariate proportional hazards regression analysis. Magnetic resonance imaging studies were available for review in 949 cases. The mean age and mean Karnofsky Performance Scale (KPS) score at time of surgery were 51 +/- 16 years and 80 +/- 10, respectively. Surgery consisted of primary resection in 549 patients (58%) and revision resection for tumor recurrence in 400 patients (42%). The lesion was WHO Grade IV in 700 patients (74%) and Grade III in 249 (26%); there were 167 astrocytomas and 82 mixed oligoastrocytoma. Among patients who underwent resection, GTR, NTR, and STR were achieved in 330 (35%), 388 (41%), and 231 cases (24%), respectively. Adjusting for factors associated with survival (for example, age, KPS score, Gliadel and/or temozolomide use, and subsequent resection), GTR versus NTR (p < 0.05) and NTR versus STR (p < 0.05) were independently associated with improved survival after both primary and revision resection of glioblastoma multiforme (GBM). For primary GBM resection, the median survival after GTR, NTR, and STR was 13, 11, and 8 months, respectively. After revision resection, the median survival after GTR, NTR, and STR was 11, 9, and 5 months, respectively. Adjusting for factors associated with survival for WHO Grade III astrocytoma (age, KPS score, and revision resection), GTR versus STR (p < 0.05) was associated with improved survival. Gross-total resection versus NTR was not associated with an independent survival benefit in patients with WHO Grade III astrocytomas. The median survival after primary resection of WHO Grade III (mixed oligoastrocytomas excluded) for GTR, NTR, and STR was 58, 46, and 34 months, respectively. In the authors' experience with both primary and secondary resection of malignant brain astrocytomas, increasing extent of resection was associated with improved survival independent of age, degree of disability, WHO grade, or subsequent treatment modalities used. The maximum extent of resection should be safely attempted while minimizing the risk of surgically induced neurological injury.

Radiologic–pathologic correlation of hepatocellular carcinoma treated with internal radiation using yttrium-90 microspheres #

We present the correlation between radiologic and pathologic findings in HCC patients who underwent radioembolization with yttrium-90 ((90)Y) microspheres prior to resection or transplantation. Thirty-five patients with a total of 38 lesions who underwent liver explantation after (90)Y radioembolization were studied. Imaging surrogates following treatment were evaluated; the explants were examined for assessment of necrosis by pathology. The correlation between radiologic and histologic findings of the treated lesions was analyzed. Twenty-three of 38 (61%) target lesions showed complete pathologic necrosis. All target lesions demonstrated some degree of histologic necrosis at explant. Complete histologic necrosis was seen in 89% of lesions with pretreatment size <3 cm. Complete pathologic necrosis was seen in 100%, 78%, and 93% of the lesions that were shown to have complete response by European Association for the Study of the Liver (EASL) necrosis criteria, partial response by World Health Organizaton (WHO) criteria, or thin rim enhancement on posttreatment imaging, respectively. In contrast, complete pathologic necrosis was seen in only 52% and 38% of the lesions that showed partial response by EASL criteria and peripheral nodular enhancement, respectively. Post-radioembolization imaging findings of response by EASL and WHO criteria are predictive of the degree of pathologic necrosis. Rim enhancement was an imaging characteristic that correlated well with histologic necrosis.

Abstract No. 122: Radiologic-Pathologic Correlation of Treated HCC Tumors with Y90 Microspheres

Abstract No. 122: Radiologic-Pathologic Correlation of Treated HCC Tumors with Y90 Microspheres

Imaging Characteristics of Dacryocystocele Diagnosed after Surgery for Sinonasal Cancer

A dacryocystocele forms when tears accumulate within the lacrimal sac as a result of an obstruction more distally in the lacrimal drainage apparatus, which may occur as a complication of sinonasal surgery. The purpose of this study was to define the imaging characteristics of a postoperative dacryocystocele occurring after surgery for sinonasal cancer and to review the anatomy of the nasolacrimal drainage apparatus. We reviewed the clinical records and imaging findings of 8 patients who underwent surgery for sinonasal cancer and were diagnosed with a postoperative dacryocystocele between August 2001 and November 2005. The imaging studies performed at the time of diagnosis of dacryocystocele were CT in 6 patients and MR imaging in 2 patients. On both CT and MR imaging, dacryocystoceles had a characteristic appearance of a fluid collection with thin rim enhancement along the course of the affected nasolacrimal duct, with no adjacent solid components. In none of the patients was the dacryocystocele confused with a recurrent tumor. Dacryocystocele after surgery for sinonasal cancer has a characteristic appearance on CT and MR imaging. Familiarity with this complication of sinonasal surgery and its appearance on imaging will enable radiologists to avoid misinterpreting dacryocystocele as a recurrent tumor or another process.

Nasal Septal Abscess in Patients with Immunosuppression

The purpose of this study was to review the imaging findings of nasal septal abscess in 2 patients with immunosuppression. Two patients with immunosuppression were identified as having a nasal septal abscess, and correlative CT imaging in both patients was evaluated. The characteristic radiographic appearance of a nasal septal abscess included a fluid collection with thin rim enhancement, located within the cartilaginous nasal septum. After CT examination, incision and drainage was performed in both patients, and appropriate antibiotic coverage was initiated. Clinical and imaging follow-up demonstrated no signs of residual infection. Nasal septal abscess has a characteristic appearance on CT examination. Prompt diagnosis and treatment, including incision and drainage and appropriate antibiotic coverage, are necessary to avoid serious complications.

Subungual keratoacanthoma: ultrasound and magnetic resonance imaging findings

Subungual keratoacanthoma is a rare, squamoproliferative neoplasm arising at the nail bed. It may cause erosion of the underlying bone. We report a case of subungual keratoacanthoma of the right thumb in a 63-year-old man. Radiographs showed cortical erosion of the distal phalanx of the right thumb. Ultrasonography showed a mixed echoic tumor. On magnetic resonance imaging (MRI), the tumor showed intermediate signal intensity on T1-weighted images and mixed intermediate and high signal intensity on T2-weighted images with peripheral thin rim enhancement.

Imaging of Hepatocellular Carcinoma After Treatment with Yttrium-90 Microspheres

Yttrium-90 radioembolization is an emerging therapy for unresectable hepatocellular carcinoma (HCC). Although therapeutic response based on size has been evaluated in numerous studies, necrosis has been used as a criterion of response in only a few studies. The purpose of our study was to describe the imaging features of HCC after 90Y treatment and to compare size criteria (World Health Organization [WHO] and Response Evaluation Criteria in Solid Tumors [RECIST]) with necrosis criteria and combined criteria (RECIST and necrosis) for assessment of response. CT images of 42 patients with 76 90Y-treated HCC lesions were analyzed. We used four response criteria: WHO size, RECIST size, necrosis, and combined criteria (RECIST and necrosis). Imaging features of treated lesions included both nodular and peripheral rim enhancement. Survival was assessed with the Kaplan-Meier method. The response rate was 23% according to RECIST criteria, 26% according to WHO criteria, 57% according to necrosis criteria, and 59% according to combined criteria. Response according to necrosis and combined criteria was detected earlier than response according to size criteria alone. Ten responding lesions initially increased in size. After therapy, enhancing peripheral nodules increased in size in 10 lesions, decreased in size in two lesions, and disappeared in two lesions. Twenty-one of 25 lesions with thin rim enhancement after 90Y administration responded to treatment. The median survival times were 660 and 236 days for Okuda stage I and Okuda stage II disease, respectively. Use of combined size and necrosis criteria may lead to more accurate assessment of response to 90Y therapy than use of size criteria alone. Imaging features after 90Y treatment, including size, necrosis, peripheral enhancing nodules, and thin rim enhancement, are described.