MR Imaging Criteria Research Articles

Diagnostic Accuracy of Quantitative, Qualitative and Semi-Quantitative Delayed Post Gadolinium MR Imaging Criteria in Meniere's Disease

Abstract Clinical Relevance The recent detection of endolymphatic hydrops (EH); the pathological hallmark of MD; on the delayed post gadolinium MR hydropic sequences has resulted shift in the diagnostic paradigm. Researchers defined various MRI qualitative, quantitative, and semi-quantitative criteria and grading scales for endolymphatic hydrops however, the best performance and combination of MRI criteria in distinguish MD affected ears is little explored. Establishing the most reliable and highly performing MRI features will improve the ability of the radiologist to diagnose Meniere’s Disease. Objectives To evaluate the diagnostic performance of MRI criteria used for the detection of Menière’s Disease (MD) ears on delayed post-gadolinium MRI. To determine which combination of descriptors should be optimally applied to establish the diagnosis. Materials and Methods This retrospective case-control study evaluated consecutive delayed post-gadolinium MRI of patients with Menièriform symptoms. 7 quantitative and semi-quantitative MR criteria of MD and qualitative perilymphatic enhancement (PLE) in the cochlea were evaluated within the study cohort. Definite MD ears according to the 2015 Barany Society criteria were compared to control ears. Sensitivity and Specificty were calculated for each descriptor to determined which combination of MRI descriptors would best predict MD ears, and the area under the ROC curve for this model was measured. Results 50 patients (30 female, 20 males; age mean 50 ±13 years) with 30 definite MD and 15 control ears were evaluated. Of the defining MRI criteria, the grade 2 cochlear hydrops, the grade 2 vestibular hydrops, saccule as large as utricle and cochlear perilymphatic enhancement were associated with the presence of MD ears (p < 0.05). The highest sensitivity was achieved by severe vestibular hydrops and “saccule, as large as the utricle”. Conclusion The best predictors of MD are the quantitative detection of severe vestibular hydrops together with the Semiquantitative detection of enlarged or confluent saccules which add value to the diagnosis.

Matching proposed clinical and MRI criteria of aggressive multiple sclerosis to serum and cerebrospinal fluid markers of neuroaxonal and glial injury

BackgroundDefinitions of aggressive MS employ clinical and MR imaging criteria to identify highly active, rapidly progressing disease courses. However, the degree of overlap between clinical and radiological parameters and biochemical markers of CNS injury is not fully understood. Aim of this cross-sectional study was to match clinical and MR imaging hallmarks of aggressive MS to serum/CSF markers of neuroaxonal and astroglial injury (neurofilament light chain (sNfL, cNfL), and glial fibrillary acidic protein (sGFAP, cGFAP)).MethodsWe recruited 77 patients with relapsing–remitting MS (RRMS) and 22 patients with clinically isolated syndrome. NfL and GFAP levels in serum and CSF were assessed using a single-molecule-array HD-1-analyzer. A general linear model with each biomarker as a dependent variable was computed. Clinical and imaging criteria of aggressive MS, as recently proposed by the ECTRIMS Consensus Group, were modeled as independent variables. Other demographic, clinical or laboratory parameters, were modeled as covariates. Analyses were repeated in a homogenous subgroup, consisting only of newly diagnosed, treatment-naïve RRMS patients presenting with an acute relapse.ResultsAfter adjusting for covariates and multiplicity of testing, sNfL and cNfL concentrations were strongly associated with the presence of ≥2 gadolinium-enhancing lesions (psNfL = 0.00008; pcNfL = 0.004) as well as the presence of infratentorial lesions on MRI (psNfL = 0.0003; pcNfL < 0.004). No other clinical and imaging criteria of aggressive MS correlated significantly with NfL or GFAP in serum and CSF. In the more homogeneous subgroup, sNfL still was associated with the presence of ≥2 gadolinium-enhancing lesions (psNfL = 0.001), presence of more than 20 T2-lesions (psNfL = 0.049) as well as the presence of infratentorial lesions on MRI (psNfL = 0.034), while cNfL was associated with the presence of ≥2 gadolinium-enhancing lesions (psNfL = 0.011) and presence of more than 20 T2-lesions (psNfL = 0.029).ConclusionsAmong proposed risk factors for an aggressive disease course, MRI findings but not clinical characteristics correlated with sNfL and cNfL as a marker of neuroaxonal injury and should be given appropriate weight considering MS prognosis and therapy. No significant correlation was detected for GFAP alone.

Dark Rims: Novel Sequence Enhances Diagnostic Specificity in Multiple Sclerosis.

The 2010 McDonald criteria are designed to sensitively detect MS; however, the low specificity of these criteria can occasionally lead to the misdiagnosis of MS. The purpose of this study was to determine whether a novel double inversion recovery MR imaging technique has the potential to increase the specificity of diagnostic criteria distinguishing MS from non-MS white matter lesions. This was a cross-sectional observational study. MR imaging data were acquired between 2011 and 2016. A novel double inversion recovery sequence that suppresses CSF and GM signal was used (GM-double inversion recovery). We compared WM lesions in a group of patients with multiple sclerosis and in a second group of positive controls with white matter lesions who did not have a diagnosis of MS. The presence of a rim on the GM-double inversion recovery MR imaging sequence was combined with the 2001 and 2010 McDonald disseminated-in-space criteria. Multiple MR imaging markers, including lesion location, size, and the presence of a rim, were compared between groups as well as a quantitative measure of lesion T1 hypointensity. MR images from 107 patients with relapsing-remitting MS (median age, 32 years) and 36 positive control (median age, 39 years) subjects were analyzed. No significant differences were found in age and sex. In patients with MS, 1120/3211 lesions (35%) had a rim on GM-double inversion recovery; the positive control group had only 9/893 rim lesions (1%). Rims were associated with a decrease in the lesion T1 ratio. Using the 2010 MR imaging criteria plus the presence of rims on GM-double inversion recovery, we achieved 78% and 97% specificity in subjects with ≥1 and ≥2 rim lesions, respectively. The addition of a novel GM-double inversion recovery technique enhanced specificity for diagnosing MS compared with established MR imaging criteria.

MR Imaging Criteria for the Detection of Nasopharyngeal Carcinoma: Discrimination of Early-Stage Primary Tumors from Benign Hyperplasia.

MR imaging can detect nasopharyngeal carcinoma that is hidden from endoscopic view, but for accurate detection carcinoma confined within the nasopharynx (stage T1) must be distinguished from benign hyperplasia of the nasopharynx. This study aimed to document the MR imaging features of stage T1 nasopharyngeal carcinoma and to attempt to identify features distinguishing it from benign hyperplasia. MR images of 189 patients with nasopharyngeal carcinoma confined to the nasopharynx and those of 144 patients with benign hyperplasia were reviewed and compared in this retrospective study. The center, volume, size asymmetry (maximum percentage difference in area between the right and left nasopharyngeal halves), signal intensity asymmetry, deep mucosal white line (greater contrast enhancement along the deep tumor margin), and absence/distortion of the adenoidal septa were evaluated. Differences were assessed with logistic regression and the χ2 test. The nasopharyngeal carcinoma center was lateral, central, or diffuse in 134/189 (70.9%), 25/189 (13.2%), and 30/189 (15.9%) cases, respectively. Nasopharyngeal carcinomas involving the walls showed that a deep mucosal white line was present in 180/183 (98.4%), with a focal loss of this line in 153/180 (85%) cases. Adenoidal septa were absent or distorted in 111/111 (100%) nasopharyngeal carcinomas involving the adenoid. Compared with benign hyperplasia, nasopharyngeal carcinoma had a significantly greater volume, size asymmetry, signal asymmetry, focal loss of the deep mucosal white line, and absence/distortion of the adenoidal septa (P < .001). Although size asymmetry was the most accurate criterion (89.5%) for nasopharyngeal carcinoma detection, use of this parameter alone would have missed 11.9% of early-stage T1 nasopharyngeal carcinomas. MR imaging features can help distinguish stage T1 nasopharyngeal carcinoma from benign hyperplasia in most cases.

Vasogenic edema characterizes pediatric acute disseminated encephalomyelitis.

MR imaging criteria for diagnosing acute disseminated encephalomyelitis (ADEM) have not been clearly established. Due to the wide spectrum of differential considerations, new imaging features allowing early and accurate diagnosis for ADEM are needed. We hypothesized that ADEM lesions would be characterized by vasogenic edema due to the potential reversibility of the disease. Sixteen patients who met the diagnostic criteria for ADEM proposed by the International Pediatric Multiple Sclerosis Study Group (IPMSSG) and had complete MR imaging studies performed at our institution during the acute phase of the disease were identified retrospectively and evaluated by experienced pediatric neuroradiologists. Vasogenic edema was demonstrated on diffusion-weighted imaging (DWI) and corresponding apparent diffusion coefficient (ADC) maps in 12 out of 16 patients; cytotoxic edema was identified in two patients while the other two patients displayed no changes on DWI/ADC. ADC values for lesions and normal-appearing brain tissue were 1.39 ± 0.45 × 10(-3) and 0.81 ± 0.09 × 10(-3) mm/s(2), respectively (p=0.002). When considering a cutoff of 5 days between acute and subacute disease, no difference between ADC values in acute vs. subacute phase was depicted. However, we found a significant correlation and an inverse and significant relationship between time and ADC value. We propose that vasogenic edema is a reliable diagnostic sign of acute neuroinflammation in ADEM.

MR imaging features and contrast enhancement characteristics in benign and malignant breast lesions

Introduction: Breast cancer is the commonest female malignancy in Malaysia and other countries the world. All races are affected in Malaysia and breast cancer comprised 30.4% of all newly diagnosed cancer cases. A women in Malaysia has a 1 in 19 chances of getting breast cancer in her lifetime. The Age Standardized Rate (ASR) of female breast cancer in Malaysia is 52.8 per 100,000 people and is higher than that in Singapore, Hong Kong and Shanghai, but it is lower than that in Australia and the UK. Out of the 4,337 new cases of female breast cancer cases reported to the National Cancer Registry of Malaysia in 2002, 52.3% were for women less than 50 years old. Genetic risk factors have not been studies thoroughly in Malaysia. Methods: We prospectively studied 55 patients with breast lumps in whom MR imaging was performed. The T1- and T2-weighted, axial STIR, fat-suppression contrast enhanced fast spin echo and two dimensional dynamic enhanced fast spoiled gradient-echo images were obtained. The tumour margins and shape, enhancement pattern and time-signal intensity curves were analysed. Results: A total of 37 patients fulfilled the study criteria with the mean age of 43.46 &plusmn;11.99 years (age ranged 21-70). There were 23 benign and 14 malignant lesions. The MR imaging criteria suggestive of malignancy were poorly defined and spiculated margins, irregular shape, heterogeneous and rim enhancement as well as type II and III curves. On the other hand, the criteria for a benign breast lesions were well-defined margin, regular and lobulated shape, none or homogeneous enhancement and type I curve. Only the malignant lesions are characterised by skin, retroareolar, nipple and pectoralis muscle involvement. Conclusion: MR imaging is a valuable complementary breast imaging tool to further evaluate equivocal findings on conventional x-ray mammography. A combination of lesion morphology and enhancement characteristics is useful in distinguishing benign from malignant lesions. DOI: http://dx.doi.org/10.3126/joim.v34i2.9052 &nbsp; Journal of Institute of Medicine August, 2012; 34:2 28-34

MR imaging features and contrast enhancement characteristics in benign and malignant breast lesions

Introduction: Breast cancer is the commonest female malignancy in Malaysia and other countries the world. All races are affected in Malaysia and breast cancer comprised 30.4% of all newly diagnosed cancer cases. A women in Malaysia has a 1 in 19 chances of getting breast cancer in her lifetime. The Age Standardized Rate (ASR) of female breast cancer in Malaysia is 52.8 per 100,000 people and is higher than that in Singapore, Hong Kong and Shanghai, but it is lower than that in Australia and the UK. Out of the 4,337 new cases of female breast cancer cases reported to the National Cancer Registry of Malaysia in 2002, 52.3% were for women less than 50 years old. Genetic risk factors have not been studies thoroughly in Malaysia. Methods: We prospectively studied 55 patients with breast lumps in whom MR imaging was performed. The T1- and T2-weighted, axial STIR, fat-suppression contrast enhanced fast spin echo and two dimensional dynamic enhanced fast spoiled gradient-echo images were obtained. The tumour margins and shape, enhancement pattern and time-signal intensity curves were analysed. Results: A total of 37 patients fulfilled the study criteria with the mean age of 43.46 ±11.99 years (age ranged 21-70). There were 23 benign and 14 malignant lesions. The MR imaging criteria suggestive of malignancy were poorly defined and spiculated margins, irregular shape, heterogeneous and rim enhancement as well as type II and III curves. On the other hand, the criteria for a benign breast lesions were well-defined margin, regular and lobulated shape, none or homogeneous enhancement and type I curve. Only the malignant lesions are characterised by skin, retroareolar, nipple and pectoralis muscle involvement. Conclusion: MR imaging is a valuable complementary breast imaging tool to further evaluate equivocal findings on conventional x-ray mammography. A combination of lesion morphology and enhancement characteristics is useful in distinguishing benign from malignant lesions. DOI: http://dx.doi.org/10.3126/joim.v34i2.9052 Journal of Institute of Medicine August, 2012; 34:2 28-34

Comparison of MR Imaging Findings between Extraligamentous and Subligamentous Disk Herniations in the Lumbar Spine

The method of treating an HIVD in the lumbar spine may depend on the integrity of the PLL. The purpose of this study was to analyze and compare the MR imaging findings of extraligamentous and subligamentous HIVDs in the lumbar spine. One hundred seventeen patients (M/F = 71:46; mean age, 47 years; age range, 15-79 years) underwent lumbar spine MR imaging and disk surgery (extraligamentous/subligamentous = 66:51) from May 2003 to November 2006. Two radiologists in consensus retrospectively reviewed all MR images, focusing on 10 criteria. The following 5 criteria are suggestive of extraligamentous HIVD in the lumbar spine: 1) spinal canal compromised for more than half its dimension, 2) internal signal difference in the HIVD, 3) an ill-defined margin of the HIVD, 4) disruption of the continuous low-signal-intensity line covering the HIVD, and 5) the presence of an internal dark line in the HIVD (P < .05). When we combined these 5 MR imaging criteria, the sensitivity, specificity, accuracy, and odds ratio were 77.3%, 74.5%, 76.1%, and 9.93 (P < .0001). Our proposed 5 MR imaging criteria will be helpful in differentiating extraligamentous and subligamentous HIVDs in the lumbar spine.

Optimizing MR Imaging Detection of Type 2 Focal Cortical Dysplasia: Best Criteria for Clinical Practice

Type 2 FCD is one of the main causes of drug-resistant partial epilepsy. Its detection by MR imaging has greatly improved surgical outcomes, but it often remains overlooked. Our objective was to determine the prevalence of typical MR imaging criteria for type 2 FCD, to provide a precise MR imaging pattern, and to optimize its detection. We retrospectively reviewed 1.5T MR imaging of 71 consecutive patients with histologically proved type 2 FCD. The protocol included millimetric 3D T1-weighted, 2D coronal and axial T2-weighted, and 2D or 3D FLAIR images. Two experienced neuroradiologists looked for 6 criteria: cortex thickening, cortical and subcortical signal changes, blurring of the GWM interface, the "transmantle" sign, and gyral abnormalities. The frequency of each sign and their combination were assessed. We compared the delay between epilepsy onset and surgery, taking into account the time of type 2 FCD detection by MR imaging. Only 42 patients (59%) had positive MR imaging findings. In this group, a combination of at least 3 criteria was always found. Subcortical signal changes were constant. Three characteristic signs (cortical thickening, GWM blurring, and transmantle sign) were combined in 64% of patients, indicating that MR imaging can be highly suggestive. However, typical features of type 2 FCD were overlooked on initial imaging in 40% of patients, contributing to a delay in referral for surgical consideration (17 versus 11.5 years when initial MR imaging findings were positive). A combination of 3 major MR imaging signs allows type 2 FCD to be recognized in clinical practice, thereby enabling early identification of candidates for surgery.

Recommendations from Gynaecological (GYN) GEC-ESTRO Working Group (IV): Basic principles and parameters for MR imaging within the frame of image based adaptive cervix cancer brachytherapy

The GYN GEC-ESTRO working group issued three parts of recommendations and highlighted the pivotal role of MRI for the successful implementation of 3D image-based cervical cancer brachytherapy (BT). The main advantage of MRI as an imaging modality is its superior soft tissue depiction quality. To exploit the full potential of MRI for the better ability of the radiation oncologist to make the appropriate choice for the BT application technique and to accurately define the target volumes and the organs at risk, certain MR imaging criteria have to be fulfilled. Technical requirements, patient preparation, as well as image acquisition protocols have to be tailored to the needs of 3D image-based BT. The present recommendation is focused on the general principles of MR imaging for 3D image-based BT.Methods and parameters have been developed and progressively validated from clinical experience from different institutions (IGR, Universities of Vienna, Leuven, Aarhus and Ljubljana) and successfully applied during expert meetings, contouring workshops, as well as within clinical and interobserver studies.It is useful to perform pelvic MRI scanning prior to radiotherapy (“Pre-RT-MRI examination”) and at the time of BT (“BT MRI examination”) with one MR imager. Both low and high-field imagers, as well as both open and close magnet configurations conform to the requirements of 3D image-based cervical cancer BT. Multiplanar (transversal, sagittal, coronal and oblique image orientation) T2-weighted images obtained with pelvic surface coils are considered as the golden standard for visualisation of the tumour and the critical organs. The use of complementary MRI sequences (e.g. contrast-enhanced T1-weighted or 3D isotropic MRI sequences) is optional. Patient preparation has to be adapted to the needs of BT intervention and MR imaging. It is recommended to visualise and interpret the MR images on dedicated DICOM-viewer workstations, which should also assist the contouring procedure. Choice of imaging parameters and BT equipment is made after taking into account aspects of interaction between imaging and applicator reconstruction, as well as those between imaging, geometry and dose calculation.In a prospective clinical context, to implement 3D image-based cervical cancer brachytherapy and to take advantage of its full potential, it is essential to successfully meet the MR imaging criteria described in the present recommendations of the GYN GEC-ESTRO working group.

Benign and Suspicious Ovarian Masses—MR Imaging Criteria for Characterization: Pictorial Review

Ovarian masses present a special diagnostic challenge when imaging findings cannot be categorized into benign or malignant pathology. Ultrasonography (US), Computed Tomography (CT), and Magnetic Resonance Imaging (MRI) are currently used to evaluate ovarian tumors. US is the first-line imaging investigation for suspected adnexal masses. Color Doppler US helps the diagnosis identifying vascularized components within the mass. CT is commonly performed in preoperative evaluation of a suspected ovarian malignancy, but it exposes patients to radiation. When US findings are nondiagnostic or equivocal, MRI can be a valuable problem solving tool, useful to give also surgical planning information. MRI is well known to provide accurate information about hemorrhage, fat, and collagen. It is able to identify different types of tissue contained in pelvic masses, distinguishing benign from malignant ovarian tumors. The knowledge of clinical syndromes and MRI features of these conditions is crucial in establishing an accurate diagnosis and determining appropriate treatment. The purpose of this paper is to illustrate MRI findings in neoplastic and non-neoplastic ovarian masses, which were assessed into three groups: cystic, solid, and solid/cystic lesions. MRI criteria for the correct diagnosis and characteristics for differentiating benign from malignant conditions are shown in this paper.

Treatment of unresectable skull base meningiomas with somatostatin analogs

The standard surgical treatment for meningiomas is total resection, but the complete removal of skull base meningiomas can be difficult for several reasons. Thus, the management of certain meningiomas of the skull base--for example, those involving basal vessels and cranial nerves--remains a challenge. In recent reports it has been suggested that somatostatin (SST) administration can cause growth inhibition of unresectable and recurrent meningiomas. The application of SST and its analogs is not routinely integrated into standard treatment strategies for meningiomas, and clinical studies proving growth-inhibiting effects do not exist. The authors report on their experience using octreotide in patients with recurrent or unresectable meningiomas of the skull base. Between January 1996 and December 2010, 13 patients harboring a progressive residual meningioma (as indicated by MR imaging criteria) following operative therapy were treated with a monthly injection of the SST analog octreotide (Sandostatin LAR [long-acting repeatable] 30 mg, Novartis). Eight of 13 patients had a meningioma of the skull base and were analyzed in the present study. Postoperative tumor enlargement was documented in all patients on MR images obtained before the initiation of SST therapy. All tumors were benign. No patient received radiation or chemotherapy before treatment with SST. The growth of residual tumor was monitored by MR imaging every 12 months. Three of the 8 patients had undergone surgical treatment once; 3, 2 times; and 2, 3 times. The mean time after the last meningioma operation (before starting SST treatment) and tumor enlargement as indicated by MR imaging criteria was 24 months. A total of 643 monthly cycles of Sandostatin LAR were administered. Five of the 8 patients were on SST continuously and stabilized disease was documented on MR images obtained in these patients during treatment (median 115 months, range 48-180 months). Three of the 8 patients interrupted treatment: after 60 months in 1 case because of tumor progression, after 36 months in 1 case because of side effects, and after 36 months in 1 case because the health insurance company denied cost absorption. Although no case of tumor regression was detected on MR imaging, the study results indicated that SST analogs can arrest the progression of unresectable or recurrent benign meningiomas of the skull base in some patients. It remains to be determined whether a controlled prospective clinical trial would be useful.

MR imaging findings and MR criteria for instability in osteochondritis dissecans of the elbow in children

Osteochondritis dissecans (OCD) of the elbow is an uncommon cause of elbow pain in adolescents and occurs at different locations in the elbow joint. Early diagnosis and treatment may prevent surgery. The aim of the study is to describe the MR imaging features of OCD at initial imaging, and to correlate these findings with surgical findings of stability and instability with arthroscopic findings as the reference standard. Patients were identified through a keyword search of the radiology information system from 2000 to 2009. Twenty-five patients (26 elbows) with OCD of the elbow were identified (age 10.4-18 years, mean age 14 years). MR studies were retrospectively reviewed by two radiologists in consensus to define MR imaging findings and to determine the presence of previously described MR imaging criteria for OCD instability (i.e., high T2 signal rim, surrounding cysts, high T2 signal fracture line, fluid-filled osteochondral defect). Sensitivity of the individual and combined criteria was calculated. OCD occurred in the capitellum in 24 patients (92%), in the trochlea in 2 patients (8%) and radial head in 1 patient (4%). Loose bodies were identified in 11 (42%) patients. Eighteen patients demonstrated MRI findings in keeping with unstable lesions. In all 11 patients who had surgery the surgical findings of instability correlated with the MRI findings. When combined, the MR criteria were 100% sensitive for instability of OCD lesions of the elbow. The vast majority of OCD of the elbow occurs in the capitellum. When used together, the MR criteria for instability were 100% sensitive for evaluation OCD lesions of the elbow.

MR Imaging-Guided Intravenous Thrombolysis in Posterior Cerebral Artery Stroke

PCA stroke was under-represented in or excluded from the clinical trials examining thrombolysis based on the PWI-DWI mismatch concept. We present 6 patients with PCA stroke treated with thrombolysis in an extended time window by using MR imaging criteria. Symptoms included aphasia, sensorimotor hemiparesis, hemineglect, and homonymous hemianopia. Initial MR imaging demonstrated circumscribed ischemic lesions in the thalamus or hippocampus; MR angiography showed PCA occlusion with corresponding hypoperfusion. Follow-up MR imaging showed partial/complete recanalization in 4 patients with minor infarction growth, while in 1 patient, PCA occlusion persisted, resulting in a large PCA infarction. Three patients improved within 2 hours; at discharge, homonymous hemianopia had resolved in 3 patients. At 3-month follow-up, 4 patients had an mRS score of 0 or 1. These results support the approach to treat patients with PCA stroke with thrombolysis based on the mismatch concept. Because rehabilitation options for hemianopia are limited, thrombolysis may enhance the chance of a favorable outcome.

New MR imaging criteria with a diffusion-weighted sequence for the diagnosis of hepatocellular carcinoma in chronic liver diseases

To propose MRI criteria with a diffusion-weighted imaging (DWI) sequence for the diagnosis of hepatocellular carcinoma (HCC). Patients, who underwent liver MRI with contrast-enhanced sequences and DWI between 2004 and 2008 and who had at least one confirmed HCC of at least 10mm, were included. Index diagnostic criteria were: (1) enhancement in the arterial-dominant phase and washout in the portal venous and/or equilibrium phases; (2) enhancement in the arterial-dominant phase and hyperintensity on DWI; (3) enhancement in the arterial-dominant phase and washout in the portal venous and/or equilibrium phases or hyperintensity on DWI. Two radiologists independently reviewed the corresponding sets of sequences (DWI alone; T1-weighted sequence before and after dynamic injection of gadolinium chelates; combined DWI-T1-weighted sequence). Inter-observer agreement and sensitivity were determined per nodule. Ninety-one patients were included (109 HCCs). The sensitivity of conventional MRI criteria for the diagnosis of HCC was 59.6% for both radiologists. The sensitivity of enhancement in the arterial-dominant phase and hyperintensity on DWI was 77.1% or 76.1%, depending on the radiologist. The sensitivity of enhancement in the arterial-dominant phase and washout in the portal venous and/or equilibrium phases or hyperintensity on DWI was 84.4% or 85.3%, depending on the radiologist. The inter-observer agreement for the latter was very good (kappa coefficient 0.82). These results were consistent in HCCs smaller than 20mm. The proposed criteria, based on the characteristics of lesions after gadolinium chelate administration and hyperintensity on DWI, significantly increased the sensitivity for the diagnosis of HCC compared to conventional criteria, regardless of tumor size.

Bevacizumab/irinotecan in recurrent malignant glioma: A retrospective analysis of MRI, FET-PET, and clinical performance.

e12545 Background: Treatment of recurrent malignant glioma with bevacizumab (Avastin)/irinotecan yields high radiologic response rates. Avastin rapidly reduces contrast enhancement in MRI by restoring the blood-brain barrier. Therefore tumor evaluation using classical MacDonald's response criteria may be insufficient. In this retrospective study we aim to complement classical MR imaging criteria with T2 volumetry and FET-PET data to evaluate patients with recurrent malignant glioma treated with Avastin/irinotecan and to compare these imaging data to the patient's clinical performance status (CPS). Methods: 13 patients were treated with 10 mg/kg Avastin and 125 mg/kg irinotecan. MRI and FET-PET scans were performed in 8 weeks intervals, clinical examination was done biweekly. MR scanning included T1/T2 sequences with/without contrast application. Tumor volume was assessed using T2 and T1 post contrast volumetry applying standard MacDonald's response criteria. FET-PET was done applying a standard dose of 18F-fluoroethyltyrosine (18F-FET) using a standardized uptake threshold value of 1.6. CPS was assessed using a scoring system including Karnofsky performance index and clinical examination. Results: In the first follow-up PET results matched with T1 post contrast volumetry, T2 volumetry and CPS out of 13 patients in 9 (69%), 5 (38%) and 6 (46%) cases, respectively. 2 patients died before the second follow-up. Out of 11 patients PET results matched with T1 post contrast volumetry, T2 volumetry and CPS in 6 (55%), 5 (45%) and 6 (55%) cases, respectively. 4 nonresponsive patients with rapid clinical deterioration demonstrated early progress in PET-imaging which was not predictable on anatomic imaging. Conclusions: During the course of Avastin/irinotecan therapy PET-scan and MR imaging results are highly variable due to changes of tumor growth pattern (i.e., transformation to gliomatosis cerebri). PET scans predicted early tumor progression in nonresponding patients in this study group. No significant financial relationships to disclose.

Magnetic resonance imaging–graded hypothalamic compression in surgically treated adult craniopharyngiomas determining postoperative obesity

Obesity as a consequence of management of pediatric craniopharyngioma is a well-described phenomenon related to the degree of hypothalamic involvement. However, weight change and obesity have not been analyzed in adult patients. Therefore, the purpose of this study was 1) to evaluate the pattern of postoperative weight gain related to preoperative body mass index (BMI), 2) determine if postoperative weight gain is an issue in adult patients, and 3) develop an objective MR imaging grading system to predict risk of postoperative weight gain and obesity in adults treated for craniopharyngioma. The authors retrospectively screened 296 patients with known craniopharyngioma for the following inclusion criteria: pathologically confirmed craniopharyngioma, index surgery at the authors' institution, and operative weight and height recorded with at least 3 months of follow-up including body weight measurement. Patients aged 18 years or younger were excluded, yielding 28 cases for analysis. Cases of craniopharyngiomas were compared with age- and sex-matched controls (pituitary adenoma patients) to evaluate the pattern and significance of perioperative weight changes. Mean age was 46 +/- 17 years at surgery, and 64% of the patients were male. Complete resection was achieved in 71% of cases. There was no correlation of preoperative BMI and postoperative weight gain testing in a linear model. Sixty-one percent and 46% of patients had postoperative weight gains greater than 4 and 9%, respectively. Comparing craniopharyngioma patients (cases) to age- and sex-matched controls, the preoperative BMIs were similar (p = 0.93) between cases (mean 28.9 [95% CI 30.9-26.9]) and controls (mean 29.3 [95% CI 31.9-26.7]). However, there was a trend to a greater mean postoperative weight change (percentage) in cases (10.1%) than in controls (5.6%) (p = 0.24). Hypothalamic T2 signal change and irregular contrast enhancement correlated and predicted higher-grade hypothalamic involvement. Furthermore, they can be used to objectively grade hypothalamic involvement as the authors propose. Progressive hypothalamic involvement correlated with larger postoperative weight gains (p = 0.022); however, hypothalamic involvement did not correlate with preoperative BMI (p = 0.5). Postoperative weight gain in adult patients undergoing surgery for craniopharyngioma is a significant problem and correlates with hypothalamic involvement, as it does in pediatric patients. Finally, objective MR imaging criteria can be used to predict risk of postoperative weight gain and aid in grading of hypothalamic involvement.

MRT des Kniegelenks nach Kreuzband- und Meniskusoperationen

Durch die steigende Anzahl kniechirurgischer Eingriffe nimmt die postoperative Diagnostik in der MRT des Kniegelenks einen immer breiteren Raum ein. Für die Beurteilung von vorderen Kreuzbandtransplantaten und voroperierten Menisci sind grundlegende Kenntnisse der Operationstechnik essenziell, um postoperative Normalbefunde von Transplantatversagen, Rerupturen und Komplikationen abgrenzen zu können.

Contribution of diffusion-weighted MR imaging for predicting benignity of complex adnexal masses

The purpose of this study was to prospectively assess the contribution of diffusion-weighted MR imaging (DWI) for characterizing complex adnexal masses. Seventy-seven women (22-87 years old) with complex adnexal masses (30 benign and 47 malignant) underwent MR imaging including DWI before surgery. Conventional morphological MR imaging criteria were recorded in addition to b(1,000) signal intensity and apparent diffusion coefficient (ADC) measurements of cystic and solid components. Positive likelihood ratios (PLR) were calculated for predicting benignity and malignancy. The most significant criteria for predicting benignity were low b(1,000) signal intensity within the solid component (PLR = 10.9), low T2 signal intensity within the solid component (PLR = 5.7), absence of solid portion (PLR = 3.1), absence of ascites or peritoneal implants (PLR = 2.3) and absence of papillary projections (PLR = 2.3). ADC measurements did not contribute to differentiating benign from malignant adnexal masses. All masses that displayed simultaneously low signal intensity within the solid component on T2-weighted and on b(1,000) diffusion-weighted images were benign. Alternatively, the presence of a solid component with intermediate T2 signal and high b(1,000) signal intensity was associated with a PLR of 4.5 for a malignant adnexal tumour. DWI signal intensity is an accurate tool for predicting benignity of complex adnexal masses.

MR Imaging Criteria for the Prediction of Extranodal Spread of Metastatic Cancer in the Neck

The presence of extranodal spread in metastatic nodes significantly affects treatment planning and prognosis of the patient with head and neck cancer. We attempted to evaluate the predictive capability of MR imaging for the extranodal spread in the neck. We retrospectively studied MR images from 109 patients with histologically proved metastatic nodes, of which 39 were positive for extranodal spread. We assessed 47 extranodal spread-positive and 130 extranodal spread-negative metastatic nodes by using the following MR imaging findings as the possible criteria for extranodal spread: 1) nodal size (short-axis diameter); 2) obliterated fat spaces between the metastatic node and adjacent tissues, such as the muscles and skin on T1-weighted images ("vanishing border" sign); 3) the presence of high-intensity signals in the interstitial tissues around and extending from a metastatic node on fat-suppressed T2-weighted images ("flare" sign); and 4) an irregular nodal margin on gadolinium-enhanced T1-weighted images ("shaggy margin"). Multivariate logistic regression analysis was conducted to identify independent predictive criteria for extranodal spread. Nodal size, shaggy margin, and flare sign criteria were independent and significant MR imaging findings suggestive of extranodal spread in the metastatic nodes. We obtained 77% sensitivity and 93% specificity with the flare sign, 65% sensitivity and 99% specificity with the shaggy margin, and 80% sensitivity and 85% specificity with the size criterion (cutoff point = 16 mm). Fat-suppressed T2-weighted and gadolinium-enhanced T1-weighted images are useful for the detection of extranodal spread in metastatic nodes in the neck.