Routine MR Sequences Research Articles

Visibility and Size of the Pancreatic Duct and Common Bile Duct on Routine 2D MRI Sequences in Children Without Pancreaticobiliary Disease.

BACKGROUND. Pancreatic duct (PD) or common bile duct (CBD) dilatation can indicate ductal pathology, but limited data describe normal pediatric duct measurements on routine 2D MRI sequences. OBJECTIVE. The purpose of this study was to characterize the visibility and diameter of the PD and CBD on 2D MR images in children without pancreaticobiliary disease. METHODS. This retrospective study included patients who underwent abdominal MRI using a rapid protocol (composed of noncontrast axial and coronal 2D SSFSE sequences) to assess for suspected appendicitis or ovarian torsion in the emergency department setting between January 23, 2023, and September 13, 2023, and excluded patients with a pancreatic or hepatobiliary abnormality on MRI or laboratory assessment. Four pediatric radiologists independently reviewed examinations. Reviewers recorded PD visibility in each of four segments (i.e., head, neck, body, and tail) and CBD visibility, and reviewers measured PD diameter in each segment and maximal CBD diameter. Duct measurements by age were characterized by linear regression analyses. RESULTS. The study included 177 patients (112 female patients, 65 male patients; mean age, 12.3 ± 3.4 [SD] years [age range, 5.1-17.7 years]). The observers reported PD visibility in the head in 35.6-94.9% of patients, neck in 18.6-72.3%, body in 22.6-89.8%, and tail in 7.3-26.0% and reported PD visibility in all four segments in 6.2-22.6% of patients. Maximum PD diameter in any segment, as a mean across observers, was 1.8 mm (range across observers, 0.7-3.5 mm). The expected maximal PD diameter in any segment, in terms of the 5th and 95th percentile values of observers' mean measurements, was 1.4-2.3 mm; the prediction interval's upper limit increased from age 5 to age 17 from 2.1 to 2.5 mm. All observers reported CBD visibility in all patients. The mean CBD diameter across observers was 3.1 mm (range across observers, 2.9-3.4 mm). The expected CBD diameter, in terms of the 5th and 95th percentile values of observers' mean measurements, was 2.3-4.9 mm; the prediction interval's upper limit increased from age 5 to age 17 from 3.9 to 5.0 mm. CONCLUSION. We report expected upper limits for PD and CBD measurements on 2D MR images in children without evidence of pancreaticobiliary disease. CLINICAL IMPACT. These findings may aid radiologists' identification of pancreaticobiliary duct abnormalities on routine abdominal MRI examinations.

Deep Learning Assisted Classification of T1ρ-MR Based Intervertebral Disc Degeneration Phases.

According to the T1ρ value of nucleus pulposus, our previous study has found that intervertebral disc degeneration (IDD) can be divided into three phases based on T1ρ-MR, which is helpful for the selection of biomaterial treatment timing. However, the routine MR sequences for patients with IDD are T1- and T2-MR, T1ρ-MR is not commonly used due to long scanning time and extra expenses, which limits the application of T1ρ-MR based IDD phases. To build a deep learning model to achieve the classification of T1ρ-MR based IDD phases from routine T1-MR images. Retrospective. Sixty (M/F: 35/25) patients with low back pain or lower limb radiculopathy are randomly divided into training (N = 50) and test (N = 10) sets. 1.5 T MR scanner; T1-, T2-, and T1ρ-MR sequence (spin echo). The T1ρ values of the nucleus pulposus in intervertebral discs (IVDs) were measured. IVDs were divided into three phases based on the mean T1ρ value: pre-degeneration phase (mean T1ρ value >110 msec), rapid degeneration phase (mean T1ρ value: 80-110 msec), and late degeneration phase (mean T1ρ value <80 msec). After measurement, the T1ρ values, phases, and levels of IVDs were input into the model as labels. Intraclass correlation coefficient, area under the receiver operating characteristic curve (AUC), F1-score, accuracy, precision, and recall (P < 0.05 was considered significant). In the test dataset, the model achieved a mean average precision of 0.996 for detecting IVD levels. The diagnostic accuracy of the T1ρ-MR based IDD phases was 0.840 and the AUC was 0.871, the average AUC of 5-folds cross validation was 0.843. The proposed deep learning model achieved the classification of T1ρ-MR based IDD phases from routine T1-MR images, which may provide a method to facilitate the application of T1ρ-MR in IDD. 4 TECHNICAL EFFICACY: Stage 2.

Fractional anisotropy within zone of destruction, tremor evaluation and MRI manifestation follow up after focused ultrasound thalamotomy for patients with Parkinson’s disease

Purpose. Assessment of MRI manifestation including fractional anisotropy within nucleus of destruction after focused ultrasound thalamotomy and estimation of its correlation with tremor severity.Material and methods. 7 patients with clinically approved Parkinson's disease were included. MRI examinations of the brain were performed before FUS-thalamotomy, within 3 hours, after 24 hours, after 3 and 6 months after the operation. The study protocol included routine MR sequences; fractional anisotropy maps were generated. Before surgery, after a day, 3 and 6 months, the severity of tremor was assessed by the CRST scale; CRST values correlation with the values of fractional anisotropy, as well as the correlation of the coordinates of the destruction focus with the residual therapeutic effect of the operation was estimated using a linear regression model.Results. The general patterns of the MRI manifestation were revealed: the appearance after the operation of the nucleus of destruction with the accumulation of paramagnetic substances in the structure and perifocal edema. The severity of the MRI-changes reached a maximum one day after the operation, regressed and were practically not visualized after 3 and 6 months. There was a high correlation between the volumes of the nucleus of destruction and perifocal edema, no correlation between the severity of tremor and the values of fractional anisotropy in the nucleus of destruction, a weak correlation between the localization of the nucleus of destruction and the value of the residual therapeutic effect of FUS-thalamotomy 6 months after surgery.Conclusions. The MRI manifestation during 6 months after FUS-thalamotomy had a similar character in all patients, reached a maximum severity one day after the operation and had gradual regression. Fractional anisotropy values did not correlate with tremor severity. For a prolonged therapeutic effect the contribution of the localization of the focus along the sagittal axis is possible.

A study of the diagnostic efficacy of diffusion-weighted magnetic resonance imaging in the diagnosis of perianal fistula and its complications.

To determine the diagnostic efficacy of diffusion-weighted magnetic resonance imaging (DWI) in the diagnosis of perianal fistula and its complications. This is a retrospective study based on the data of 47 patients with a clinical diagnosis of perianal fistula, who had an MRI study performed on a 1.5-T GE Signa MR scanner. DWI sequences were done using 3 different b-values. Other routine MR sequences were included. The MR images were studied to compare the diagnostic efficacy of the DW MRI sequence and other sequences in diagnosing perianal fistula and its complications. Apparent diffusion coefficient (ADC) values of abscesses and inflammatory soft tissue lesions were measured using ADC maps. The standard reference to obtain diagnostic efficacy was post-surgical data. Seventy-nine perianal fistulas were diagnosed in 47 patients who had undergone an MRI study. The sensitivity and specificity of different MR sequences in diagnosing perianal fistulas are T2 FSFSE: 92% sensitivity; DWI: 96% sensitivity; combined T2+DWI: 100% sensitivity; and post-gadolinium T1 FS has 100% sensitivity in diagnosing perianal fistulas. The mean apparent diffusion coefficient for the abscess in our study was 0.990 ± 0.05 × 10-3, and the mean apparent diffusion coefficient for an inflammatory soft tissue lesion was 1.440 ± 0.05 × 10-3. The optimal ADC cut-off for the abscess was 1.098 × 10-3 mm2/s showing 100% sensitivity and 93.8% specificity. DW imaging is a reliable sequence to diagnose perianal fistula and its complications. Measurement of ADC values is reliable in diagnosing perianal abscess collection. DWI sequence helps patients with renal impairment in whom IV gadolinium is contraindicated.

Technical Update on MR Neurography.

Imaging evaluation of peripheral nerves (PNs) is challenging. Magnetic resonance imaging (MRI) and ultrasonography are the modalities of choice in the imaging assessment of PNs. Both conventional MRI pulse sequences and advanced techniques have important roles. Routine MR sequences are the workhorse, with the main goal to provide superb anatomical definition and identify focal or diffuse nerve T2 signal abnormalities. Selective techniques, such as three-dimensional (3D) cranial nerve imaging (CRANI) or 3D NerveVIEW, allow for a more detailed evaluation of normal and pathologic states. These conventional pulse sequences have a limited role in the comprehensive assessment of pathophysiologic and ultrastructural abnormalities of PNs. Advanced functional MR neurography sequences, such as diffusion tensor imaging tractography or T2 mapping, provide useful and robust quantitative parameters that can be useful in the assessment of PNs on a microscopic level. This article offers an overview of various technical parameters, pulse sequences, and protocols available in the imaging of PNs and provides tips on avoiding potential pitfalls.

Evaluation of the degenerative lumbar osseous morphology using zero echo time magnetic resonance imaging (ZTE-MRI)

To determine and compare the performance of zero echo imaging (ZTE) with conventional MRI sequences on lumbar osseous morphology in patients suspected with lumbar degeneration with multi-slice computed tomography (MSCT) as standard reference. 22 subjects with concerned lumbar degeneration were recruited. All subjects were scanned with ZTE sequence after routine conventional MR sequences on a 3.0T system and also received MSCT examination. Image quality was assessed. The quantitative and qualitative parameters of lumbar osseous morphology on MSCT, ZTE and MRI images were evaluated by three musculoskeletal radiologists independently. Inter-reader and inter-modality reliability and the difference between the modalities were calculated. There was no difference for the osseous parameters between modalities, including axial orientation (p = 0.444), IAD (p = 0.381), lateral recess (p = 0.370), pedicle width (p = 0.067), pedicle height (p = 0.056), and osteophyte grade (p = 0.052). The measurement of the foramina diameter was statistically different between conventional MRI and MSCT (p < 0.05) but not between the MSCT and ZTE (p = 0.660). Conventional MRI was more likely to miss cortical bone abnormalities. ZTE appeared blurrier in cortical bone than MSCT, especially in cases with severe lumbar degeneration. The inter-reader agreement between MSCT and ZTE-MRI was higher than between MSCT and conventional MRI. ZTE-MRI could offer more cortical bone details than conventional MRI images and might be a valid alternative to CT for lumbar osseous morphology assessment to some extent.

Использование симптома центральной вены для дифференциальной диагностики демиелинизирующих заболеваний центральной нервной системы

The search for highly sensitive and highly specific biomarkers of MS, including neuroimaging biomarkers, continues. One of such biomarkers is the central vein sign detectable on SW and T2-weighted MR images. The sensitivity and specificity of methods used for central vein sign detection vary. This article describes two clinical cases of patients with similar neurological symptoms which required making differential diagnosis between multiple sclerosis and secondary demyelination in the presence of a systemic disorder (systemic lupus erythematosus). In addition to routine MR sequences, we used SWI generated by a 3T scanner. The lesions with the central vein sign were counted; the proportion of perivenular lesions was determined. In the multiple sclerosis case, all the lesions were perivenular; the proportion of lesions with the central vein sign in the patient with secondary demyelination in the presence of systemic lupus erythematosus was 16.7%. The use of SW images improved the informative value of the analysis.

DOES QUANTIFICATION OF DIFFUSION (ADC VALUE) AID IN IDENTIFYING MALIGNANT VERTEBRAL LESIONS? A CROSS SECTIONAL OBSERVATIONAL STUDY.

Background: Characterization of vertebral pathologies as benign or malignant is a frequent dilemma that often requires invasive procedures for diagnosis. Today, imaging is sufcient for diagnosis of most benign vertebral pathologies with further conrmation on response to therapy. With better understanding of diffusion characteristics of tissues, attempt is being made to assess various imaging characteristics to make a denite diagnosis of malignant lesions as well. In this study we quantied apparent diffusion coefcient (ADC) of lesions in an effort to determine whether ADC values are different for benign or malignant vertebral body lesions. Consecutive patients that reported to the department of Radiodiagnosis, during 1st November 2017 to 31st March 2019, were included in the study. In this cross sectional observational study, for 32, that is, 22 benign and ten malignant vertebral lesions, diffusion weighted (DW) MRI sequence was done and ADC values were recorded. Conrmation was done with post treatment follow up or wherever feasible, tissue diagnosis. All malignant cases had histopathology conrmation from the site of primary lesion. Quantitative variables using independent t-test were used for comparison of ADC values between two groups. Results: The difference in mean ADC values of benign and malignant lesions were statistically signicant (P&lt;0.0001). The optimal cutoff of ADC -3 2 value for differentiating benign from malignant vertebral body lesion was 0.950 x 10 mm /s with sensitivity of 80% and specicity of 95.45%. Conclusion:In all cases, DWI/ ADC, along with routine MR sequences, were able to characterize the lesion either as benign or malignant except in two cases of tubercular infection of spine and one each of spindle cell sarcoma &amp; metastasis from cancer lung where there was overlap of ADC values.

Diffusion-Weighted Imaging: An Exciting and Problem-Solving Tool in Patients with Hepatic Metastases.

Background The diffusion-weighted imaging (DWI) is based on the random Brownian motion of water molecules that influences image contrast depending on different pathological conditions. Objective The purpose of this study was to evaluate the efficacy of various magnetic resonance imaging (MRI) sequences including diffusion-weighted and gadobenate-enhanced MRI in the detection and characterization of liver lesions in a patient of known primary malignancy and to compare MRI with contrast-enhanced computed tomography (CECT) and ultrasonography (USG) in the detection of liver metastases. Methods All patients underwent a multiphase MRI. The final diagnosis was established by histopathological examination. Results A total of 43 patients of known primary malignancy were enrolled. MRI gave a provisional diagnosis of liver metastases in 21 patients and benign disease in 22 patients with histopathological correlation revealing two false-negative and one false-positive result. In the detection of lesions, DWI outscored other sequences (92.9 vs. 83.5% in hepatobiliary phase vs. 55.0% in T 2 -weighted sequences) with a statistically significant difference noted only in comparison with T 2 -weighted sequences ( p < 0.001). In 16 patients, MRI added new lesions that were not detected by CECT/USG. The sensitivity and specificity of MRI for detecting metastases were 90.9%/95.2% and 97.9%/96.8% for per-patient and per-lesion basis, respectively. Conclusion Multiphase MRI improved both the detection and characterization of liver metastases. Adding DWI to the routine MR sequences helped in detecting small liver metastases (<10 mm) not detected by other sequences.

Experience of application of T2-mapping MRI assessment of inflammatory myopathies

Specialized quantitative MRI techniques allow identifying structural changes in individual muscles in inflammatory myopathies.Aim. To evaluate the role of T2 mapping MRI and to evaluate specific changes in T2 relaxation time in patients with inflammatory myopathies at different stages of the disease process.Methods. T2 mapping technique for assessing structural changes in muscle tissues was optimized for the Philips “Ingenia” 3.0T MR scanner. T2 relaxation (T2rt) time of the thigh and lower leg muscles (muscule rectus femoris, m. vastus lateralis, m. adductor magnus, m. soleus, m. tibialis anterior, medial and lateral head of m. gastrocnemius) was assessed in the control group (n = 9) and the study group (n = 6). Patients recruited in the study group suffered from dermatomyositis and polymyositis of various severity.Results. The following values of T2rt were obtained in the control group: m.rectus femoris – 78.2±6.9 ms, m.vastus lateralis – 79.5±4.8 ms, m.adductor magnus – 77.1±4.4 ms, m. soleus – 92.9±4.3 ms, m. tibialis anterior – 89.4±1.3 ms, m.gastrocnemius medial head – 93.7±2.4 ms, m.gastrocnemius lateral head – 92.9±3.5 ms. Patients with polymyositis and dermatomyositis showed an increase in the signal intensity on STIR and PD-SPAIR in the structure of m.soleus, m. gastrocmenius, m.rectus femoris, as well as a significant increase in T2rt of 40–49% (p&lt;0.01). T2rt values did not differ in patients with polymyositis who received drug therapy and had clinical remission. Patients with dermatomyositis who had laboratory remission along with the deterioration reported an increase in T2rt in the structure of long spine muscles, m. rectus femoris and m. vastus lateralis equal to 15–25% (p&lt;0.05). However, none significant changes in the signal characteristics on STIR and PDSPAIR were reported.Conclusion. The sensitivity of the reported technique in the detection of sub-acute swelling of muscle tissue in the absence of significant changes in signal characteristics on routine MR sequences had been shown.

Comparison of Volumetric Fat Suppressed Proton Density and Standard Routine MR Sequences in the Evaluation of Meniscal Tears

Abstract Background: The knee joint is the most common joint liable for injuries with knee MRI being the most preferred imaging modality for the assessment of knee pain. The com-monest indications are the evaluation of the meniscal lesions, and ligamentous injuries. Arthroscopy is considered the gold standard tool for the assessment of knee derangement, although knee MR exami-nation has shown significant influence upon the clinicians' management decisions. Current standard two dimensional MR protocol is time consuming with limitations of these sequences that have to be considered. Volumetric fat suppressed proton density sequence is used with the advantage of faster acquisition in comparison with standard routine sequences. The volumetric PD FS sequence can demonstrate similar diagnostic results to that of the standard three planes sequences in the assessment of internal knee derangement especially as regards meniscal injuries. Aim of Study: To assess the diagnostic accuracy of volu-metric fat suppressed proton density sequence versus standard two dimensional (2D) sequences at 1.5T MR in the evaluation of meniscal tears. Patients and Methods: The study included 81 patients presenting with suspected post traumatic meniscal injury. Patients were referred to the Kasr Al-Aini Hospital Radiology Department between February 2018 and January 2019 after full clinical examination to evaluate their knee joints using MRI. Results: In our study the results showed typical concord-ance between standard two dimensional (2D) three planes sequences and volumetric fat suppressed proton density sequence in the detection of medial and lateral meniscal tears after using arthroscopy as the gold standard. Both sequences showed sensitivity=95.92%, specificity=100%, Positive Pre-dictive Value (PPV)=100%, Negative Predictive Value (NPV) =94.12% and accuracy=97.53% for Medial Meniscal (MM) tears as well as sensitivity=75%, specificity=100% PPV=100%, NPV=94.2% and accuracy=95.06% for Lateral Meniscal (LM) tears. Conclusion: The volumetric fat suppressed proton density sequence had shorter acquisition time and delivered similar high diagnostic accuracy to the standard 2D sequences in diagnosing meniscal tears.

Evaluation of 3 T lung magnetic resonance imaging in children with allergic bronchopulmonary aspergillosis: Pilot study

ObjectiveTo evaluate the diagnostic performance of 3 T lung magnetic resonance imaging (MRI) in children with allergic bronchopulmonary aspergillosis (ABPA). Materials and methodsThis study protocol was approved by the institutional ethics committee. From October 2015 to January 2018, we prospectively evaluated twenty-seven consecutive children with ABPA. The diagnosis of ABPA was made on the ISHAM-ABPA working group criteria. High resolution computed tomography (HRCT) and 3 T MRI of the chest was performed on the same day. Bronchiectasis, consolidation, nodules, and mucus impaction were assessed in all segments. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of MRI were calculated using HRCT findings as the reference standard. Interobserver agreement was calculated using the kappa statistic. ResultsThe mean age of the patients was 9.89 years (range: 5–16 years). There were 20 males and 7 females. The sensitivity, specificity, PPV, and NPV for bronchiectasis was 68%, 100%, 100% and 71.43% respectively. The sensitivity, specificity, PPV, and NPV for consolidation was 80%, 100%, 100% and 96% respectively. For detection of nodules, the sensitivity, specificity, PPV, and NPV was 75%, 100%, 100% and 88.46% respectively. There was 100% sensitivity, specificity, PPV and NPV for mucus impaction. There was a high degree of interobserver agreement for MRI findings (k = 0.9–1) as well as agreement (k = 0.7–1) between CT and MRI for all the four findings. ConclusionWith the currently available routine MR sequences, MRI demonstrates high specificity but less sensitivity and negative predictive value to HRCT scan in children with ABPA. Newer MR sequences need to be explored and validated to enhance the potential of lung MRI in ABPA.

T2 mapping in the quantitative evaluation of articular cartilage changes in children with hemophilia: A pilot study.

ABSTRACTImportanceJoint disease affects more than 90% of severe hemophiliacs. Early diagnosis is critical in preventing hemophilic arthritis. Magnetic resonance imaging (MRI) enables visualization of early arthropathic changes and plays an important role in treatment.ObjectiveTo evaluate the role of T2 mapping in detecting early cartilage lesions in the knee and ankle joints of children with hemophilic arthropathy.MethodsTarget joints of 15 male patients with clinically confirmed moderate or severe hemophilia were evaluated with MRI. In addition to routine MRI protocols (T1WI, T2_FFE, T2_SPAIR, PDW_TSE), T2 mapping was used to evaluate the articular cartilage of target joints.ResultsThe mean T2 value of the distal femoral cartilage was 46.72 ± 10.94 ms, which is higher than the reported age‐matched normal value (40.27 ± 3.50 ms). The mean T2 value of the proximal tibial cartilage was 45.60 ± 8.82 ms, which is higher than the reported normal value (31.15 ± 1.86 ms). Four examined joints (two ankles, two knees) showed normal morphology with no abnormal signal on routine MR sequences. However, T2 mapping showed locally increased T2 values in the cartilage, along with uneven color scales.InterpretationThe quantitative assessment method of T2 mapping might be helpful to early diagnosis for articular cartilage lesions. It might be a potential tool for early assessment of cartilage changes and quantification of lesion's severity for hemophilia joint.

Preliminary Study of MR Diffusion Tensor Imaging of Pancreas for the Diagnosis of Acute Pancreatitis.

ObjectivesTo evaluate the feasibility of differentiating between acute pancreatitis (AP) and healthy pancreas using diffusion tensor imaging (DTI) and correlate apparent diffusion coefficient (ADC) /fractional anisotropy (FA) values with the severity of AP.Material and Methods66 patients diagnosed with AP and 20 normal controls (NC) underwent DTI sequences and routine pancreatic MR sequences on a 3.0T MRI scanner. Average ADC and FA values of the pancreatic were measured. Differences of FA and ADC values between the AP group and the NC group with AP and healthy pancreas were compared by two-sample independent t-test. The severity of AP on MRI was classified into subgroups using MR severity index (MRSI), where the mean FA and ADC values were calculated. Relationship among the FA values, ADC values and MRSI were analyzed using Spearman's rank correlation coefficients.ResultsThe pancreatic mean ADC value in the AP group (1.68 ± 0.45×10−3mm2/s) was significantly lower than in the NC group (2.09 ± 0.55×10−3mm2/s) (P = 0.02); the same as mean FA value (0.39 ± 0.23 vs 0.54 ± 0.12, P = 0.00). In the subgroup analysis, the pancreatic ADC and FA value of edema AP patients was significantly higher than necrosis AP patients with P = 0.000 and P = 0.001respectively. In addition, as severity of pancreatitis increased according to MRSI, lower pancreatic ADC (r = -0.635) and FA value (r = -0.654) were noted.ConclusionBoth FA and ADC value from DTI can be used to differentiate AP patients from NC. Both ADC and FA value of pancreas have a negative correlation with the severity of AP.

Diagnostic Performance of Routine Brain MRI Sequences for Dural Venous Sinus Thrombosis.

Signs suggestive of unexpected dural venous sinus thrombosis are detectable on routine MR imaging studies without MRV. We assessed performance characteristics and interrater reliability of routine MR imaging for the diagnosis of dural venous sinus thrombosis, focusing on the superior sagittal, transverse, and sigmoid sinuses. This case series included 350 patients with MRIs performed with contrast-enhanced MRV and 79 patients with routine MRIs performed within 48 hours of a CTV from 2008 to 2014 (total, n = 429). Routine MR images were separated from the contrast-enhanced MRVs and CTVs. Three neuroradiologists, blinded to clinical data, independently reviewed the MRIs for signs of dural venous sinus thrombosis, including high signal on sagittal T1, loss of flow void on axial T2, high signal on FLAIR, high signal on DWI, increased susceptibility effects on T2*-weighted gradient recalled-echo imaging, and filling defects on axial contrast-enhanced spin-echo T1WI and/or volumetric gradient-echo T1WI. Two neuroradiologists independently reviewed contrast-enhanced MRVs and CTVs to determine the consensus gold standard. Interrater reliability was calculated by using the κ coefficient. Contrast-enhanced MRV and CTV confirmed that dural venous sinus thrombosis was present in 72 of 429 cases (16.8%). The combination of routine MR sequences had an overall sensitivity of 79.2%, specificity of 89.9%, and moderate interrater reliability (κ = 0.50). The 3 readers did not have similar performance characteristics. 69.4% of positive cases had clinical suspicion of dural venous sinus thrombosis indicated on imaging requisition. Routine MR images can suggest dural venous sinus thrombosis with high specificity in high-risk patients, even in cases without clinical suspicion.

DWI/ADC in Differentiation of Benign from Malignant Focal Liver Lesion.

Material and methods:The study was of prospective-retrospective character. It was carried out at the AKH in Vienna (Austria), where 100 patients with focal liver lesions were included in the study. All patients underwent the routine MR sequences on appliances 1,5 and 3T (Siemens, Germany): T1, T2, HASTE, VIBE, and a DWI with three b values (b 50, b 300 b 600 s / mm2) and ADC map with ROI (regions of interest). The numerical value of ADC map was calculated, where n = 100 liver lesions, by two independent radiologists.Results:On the basis of matching the PH finding statistically we get DWI accuracy of 96.8% for the assessment of liver lesions. The average numerical value of ADC in benign hepatic lesions (FNH, Hemangiomas) in our study amounted to 1.88 (1.326 to 2.48) x103 mm2 /s, while the value of malignant liver lesions (HCC, CCC, CRCLM) were significantly lower and amounted to 1.15 (1.024 to 1.343) x10-3 mm2 /s (Figure 2). Differences between the mean ADC of benign and malignant lesions showed a statistically significant difference with p <0.0005. In our research, we get cut-off for the ADC value of 1,341x10-3 mm2 /s, which proved to be the optimal parameter for differentiation between benign and malignant lesions.Conclusion:Measuring ADC values with DWI as an additional MRI tool can help in oncological practice by distinguishing normal liver parenchyma from focal lesions, and in differentiating benign from malignant liver lesions, particularly in cases where administration of contrast is not possible.

MR imaging of children and young adults with classic findings of osteonecrosis on unenhanced MR images: do contrast-enhanced sequences help?

The added value of routine contrast-enhanced MR imaging in children with classic findings of osteonecrosis on unenhanced MR images has not been determined. Our purpose was to determine the added value of routine contrast-enhanced MR sequences for identifying complications of osteonecrosis. Sixty-four patients who underwent 139 contrast-enhanced MR examinations were retrospectively identified. Unenhanced images and subsequently both unenhanced and enhanced images were reviewed in consensus. The location of osteonecrosis and the presence of complicating features (epiphyseal collapse, marrow edema, joint effusion, soft tissue edema) were recorded. Cohen's kappa coefficients (κ) were calculated to assess agreement. A diagnosis of classic osteonecrosis was made in 22.3% of unenhanced examinations and 28.1% of enhanced examinations (κ = 0.734, P < 0.001). Among patients with complicated osteonecrosis, unenhanced images interpreted without and with contrast-enhanced images showed epiphyseal collapse in 51.2% and 42.5% (κ = 0.796, P < 0.001), marrow edema in 50.4% and 46.8% (κ = 0.727, P < 0.001), joint effusion in 44.9% and 51.2% (κ = 0.686, P < 0.001), and soft tissue edema in 12.2% and 10.1% (κ = 0.674, P < 0.001). The high observed agreement between the unenhanced MR images interpreted without and with contrast-enhanced images shows little marginal benefit from the use of routine contrast-enhanced imaging in children and young adults with classic findings of osteonecrosis on unenhanced MR images.

Diffusion-weighted imaging using ADC mapping as an imaging biomarker for breast cancer invasiveness.

11093 Background: Recently, functional imaging techniques such as diffusion weighted imaging (DWI) have been added to routine MR and have shown great potential for improving breast cancer diagnosis. DWI depicts cellular diffusivity on a molecular level and can be quantified using the apparent diffusion coefficient (ADC). In malignant tumors diffusivity is restricted, leading to lower ADC values than benign tumors. The aim of this study was to proof, that DWI can be used to differentiate benign from malignant tumors and to elucidate if ADC can serve as an imaging biomarker for breast cancer invasiveness. Methods: In this IRB-approved study 250 patients with 267 suspicious breast lesions (BI-RADS IV-V) were included. All patients underwent routine MR at 3T. A DWI-sequence was added to a standard imaging protocol, increasing measurement time by 2:30 min. The lesions were identified in routine MR and DWI sequences and ADC values of the lesions were calculated. Histopathology was used as the standard of reference for all lesions. Appropriate statistical tests were used to compare the ADC values of benign and malignant tumors (cut-off value 1.25×10-3mm²/s), of invasive and non-invasive disease and between different invasive tumor subtypes. Results: There were 91 benign (mean ADC 1.58×10-3mm²/s) and 176 malignant (.94×10-3mm²/s) lesions, sensitivity and specificity were 94.3% (PPV 95.4%, CI 0.91-0.98) and 91.2% (NPV 89.2%, CI 0.81-0.94). 155 lesions were invasive cancers (median ADC .90×10-3mm²/s), while 21 were non-invasive ductal carcinoma in situ (1.22×10-3mm²/s). The invasive cancers were 130 invasive ductal (median ADC .91×10-3mm²/s) and 25 invasive lobular cancers (.83×10-3mm²/s). ADC was significantly different between benign and malignant lesions (p&lt;.001) and between invasive and non-invasive cancers (p&lt;.001), while no significant difference could be found between the invasive cancer subtypes (p=.163). Conclusions: Diffusion-weighted imaging reliably allows differentiation of benign and malignant breast tumors. The data suggest that ADC can be used as a non-invasive imaging biomarker for breast cancer invasiveness and may be of importance to treatment planning and outcome in breast cancer patients.

A differential diagnosis to “growing lipoma”

Dear Editor:We read with interest the article by Kim et al. [1]onregrowing lipoma in lipomyelomeningocele (LMMC). It isindeed a very interesting clinical phenomenon.We would like to make some pertinent observations.LMMC with a growing lipoma may represent a relativelybenignsituationunlessthepatientbecomessymptomaticagain.We illustrate a differential diagnosis to this condition thatwe have recently encountered in our experience.A 7-year-old boy with a history of detethering surgery at2 years of age at a hospital abroad for LMMC presented to uswith worsening neurological symptoms and signs. Hispathological diagnosis documented then was “fibrolipoma.”Magnetic resonance imaging revealed a low-lying cord with aconus medullaris lesion with hypointense cystic area andlipoma (Fig. 1). With a provisional diagnosis of retethering, anexploration was performed. The exploration revealed adermoidoftheconus,withallitsclassicalpathologicalfeatures.In the event of patient operated for LMMC becomingsymptomatic, undoubtedly, retethering would remain theprimary diagnosis. Along with a growing lipoma, adiagnosis of a dermoid at the location should also beconsidered. A predominantly lipid containing dermoid dueto its content may mimic a LMMC on routine MRsequences [2]. In addition, there have also been casereports of a co-existence of these two pathologies [3].Hence, caution should be exercised before a radiologicaldiagnosis of a growing lipoma is made. The possibility ofdermoid adds a dimension to patient counseling, surgicalplanning, and to the long-term prognosis.References

Guidelines for the macroscopic processing of radical prostatectomy and pelvic lymphadenectomy specimens

<h3>BACKGROUND AND PURPOSE:</h3> Signs suggestive of unexpected dural venous sinus thrombosis are detectable on routine MR imaging studies without MRV. We assessed performance characteristics and interrater reliability of routine MR...