Negative Magnetic Resonance Imaging Results Research Articles

Analysis of clinical characteristics and histopathological transcription in 40 patients afflicted by epilepsy stemming from focal cortical dysplasia.

This study aims to comprehensively analyze the clinical characteristics and identify the differentially expressed genes associated with drug-resistant epilepsy (DRE) in patients with focal cortical dysplasia (FCD). A retrospective investigation was conducted from July 2019 to June 2022, involving 40 pediatric cases of DRE linked to FCD. Subsequent follow-ups were done to assess post-surgical outcomes. Transcriptomic sequencing and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to examine differential gene expression between the FCD and control groups. Among the 40 patients included in the study, focal to bilateral tonic-clonic seizures (13/40, 32.50%) and epileptic spasms (9/40, 22.50%) were the predominant seizure types. Magnetic resonance imaging (MRI) showed frequent involvement of the frontal (22/40, 55%) and temporal lobes (12/40, 30%). In cases with negative MRI results (13/13, 100%), positron emission tomography/computed tomography (PET-CT) scans revealed hypometabolic lesions. Fused MRI/PET-CT images demonstrated lesion reduction in 40.74% (11/27) of cases compared with PET-CT alone, while 59.26% (16/27) yielded results consistent with PET-CT findings. FCD type II was identified in 26 cases, and FCD type I in 13 cases. At the last follow-up, 38 patients were prescribed an average of 1.27 ± 1.05 anti-seizure medications (ASMs), with two patients discontinuing treatment. After a postoperative follow-up period of 23.50 months, 75% (30/40) of patients achieved Engel class I outcome. Transcriptomic sequencing and qRT-PCR analysis identified several genes primarily associated with cilia, including CFAP47, CFAP126, JHY, RSPH4A, and SPAG1. This study highlights focal to bilateral tonic-clonic seizures as the most common seizure type in patients with DRE due to FCD. Surgical intervention primarily targeted lesions in the frontal and temporal lobes. Patients with FCD-related DRE showed a promising prognosis for seizure control post-surgery. The identified genes, including CFAP47, CFAP126, JHY, RSPH4A, and SPAG1, could serve as potential biomarkers for FCD. This study aimed to comprehensively evaluate the clinical data of individuals affected by focal cortical dysplasia and analyze transcriptomic data from brain tissues. We found that focal to bilateral tonic-clonic seizures were the most prevalent seizure type in patients with drug-resistant epilepsy. In cases treated surgically, the frontal and temporal lobes were the primary sites of the lesions. Moreover, patients with focal cortical dysplasia-induced drug-resistant epilepsy exhibited a favorable prognosis for seizure control after surgery. CFAP47, CFAP126, JHY, RSPH4A, and SPAG1 have emerged as potential pathogenic genes for the development of focal cortical dysplasia.

Repeated Prostate Cancer Screening Using Prostate-Specific Antigen Testing and Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) has been proposed to enhance the benefit-to-harm ratio of prostate cancer screening, but data on repeated screening outcomes are lacking. To describe outcomes of prostate-specific antigen (PSA)-based screening with MRI and prostate biopsies at repeat screening. This secondary analysis examined the population-based, screen-by-invitation STHLM3-MRI randomized clinical trial, which recruited Swedish men aged 50 to 74 years. Men were eligible for repeat screening at 2 to 3 years if they had PSA levels of 1.5 ng/mL or greater at trial inclusion, were randomized to the MRI-targeted group (including screening using biomarkers and MRI), and were not diagnosed with prostate cancer after the first screening round. Repeat screening was performed between November 10, 2021, and February 20, 2023. Data analysis was performed between May and August 2023. Participants underwent blood sampling, including PSA testing. A biparametric MRI scan was performed if PSA levels were 3 ng/mL or greater, and men with lesions with a Prostate Imaging-Reporting and Data System (PI-RADS) score of 3 or greater were referred for targeted and systematic biopsies. The primary outcome was clinically significant prostate cancer (Gleason score of ≥3 + 4). Secondary outcomes included the proportion of men with clinically insignificant cancer (Gleason score of 6), the number of elevated PSA tests, MRI scans, and biopsy procedures. Of 7609 men from the first screening round, 2078 (27.3%) were eligible for and were invited for rescreening. Among the invitees, 1500 (72.2%) participated. Their median age was 67 (IQR, 61-72) years. Of 1094 men with PSA levels between 1.5 and 2.9 ng/mL in the first screening round, 326 (29.8%) had levels of 3 ng/mL or greater in the second round. Overall, 667 men (44.5%) had PSA levels of 3 ng/mL or greater: 617 underwent MRI (92.5%), revealing 51 (7.6%) with equivocal lesions (PI-RADS score of 3) and 33 (4.9%) with suspicious lesions (PI-RADS score of ≥4). Only 10 of 383 men (2.6%) with a prior negative MRI result had a lesion with a PI-RADS score of 4 or greater. Among the 1500 rescreened men, 48 (3.2%) had a Gleason score of 3 + 4 or greater, including 19 (1.3%) with a score of 4 + 3 or greater and 11 (0.7%) with a score of 6. In this secondary analysis of the STHLM3-MRI randomized clinical trial, cancer detection during the second screening round in biennial PSA and MRI-based prostate cancer screening was limited, and the detection of low-grade tumors remained low. A substantial proportion of men exhibited elevated PSA levels during rescreening, and a considerable portion of MRI scans performed lacked lesions suggestive of cancer. Future studies should explore strategies to reduce MRI-related resource use. ClinicalTrials.gov Identifier: NCT03377881.

The lateralization accuracy of inferior petrosal sinus sampling in Cushing's disease: experiences of a tertiary center.

The purpose of this study is to determine the accuracy of bilateral inferior petrosal sinus sampling (IPSS) in lateralization and to investigate variables associated with accurate IPSS lateralization prediction. Initially, data from 55 patients who underwent IPSS in our institution were reviewed retrospectively. IPSS lateralization and pituitary magnetic resonance imaging (MRI) results of these patients were compared with postoperative follow-up and immunohistochemical data to calculate the positive predictive values (PPVs) for IPSS and MRI. Variables likely to be associated with the accurate prediction of IPSS lateralization were analyzed. Twenty-seven patients (85.2% female, mean age of 38.5 ± 13.1 years) were enrolled in the study. With IPSS, interpetrosal ratios were found to be ≥ 1.4 in 26 (96.2%) cases, and this ratio correctly predicted adenoma localization for 18 patients (PPV: 69.2%). For 16 (59.2%) patients, right lateralization was detected, while left lateralization was detected for 10 (37%) patients. Right-sided IPSS lateralization was associated with enhanced accuracy (p = 0.026). No masses were detected in the MRI images of 10 (37%) patients, while microadenoma of ≤ 6 mm was detected for 17 (63%) patients. MRI results (when positive) correctly identified adenoma localization for 14 of the patients with lateralization accuracy higher than that of IPSS (PPV: 82.3% vs. 69.2%). IPSS is a valuable procedure in detecting tumor lateralization, especially in patients with Cushing's disease who have negative pituitary MRI results. However, since lateralization has a limited reliability, the pituitary gland should be comprehensively evaluated by taking into account the MRI findings (if positive) as well as data on the side of IPSS lateralization.

TP8.1.12 Diagnostic Utility of MRI in the Evaluation of Potential Malignancy in Patients Presented with Nipple Discharge

Abstract Aims Nipple discharge is a presentation commonly seen at breast clinics. It is conventionally evaluated with physical examination and sonography( or mammography). The aim of this study is to investigate the diagnostic value of magnetic resonance imaging (MRI) as an additional imaging tool in the evaluation of potential malignancy in patients presented with nipple discharge. Methods A retrospective evaluation of 85 patients with nipple discharge who underwent breast ultrasound (USS) and MRI between 04/06/2008 and 25/10/2019 was conducted. Clinical notes, radiographic reports and biopsy results were reviewed. Sensitivity, specificity, positive predictive value and negative predictive value of USS and MRI were calculated. Results Out of the 85 patients (all female; mean age 45.33 +/- 12.93 years old) with nipple discharge, 11 were found to have biopsy-proven malignancy (invasive ductal carcinoma/ ductal carcinoma in situ; 12.94% risk). USS failed to identify seven malignancies (27.27% sensitivity) while MRI missed three malignancies (72.72% sensitivity). USS falsely identified four malignancies from 74 patients with no malignancy (94.59% specificity) while MRI only falsely identified one case (98.65% specificity). For patients with negative USS results (U1/U2/U3) or negative MRI results (BI-RADS category 1,2 or 3), the negative predictive values of USS is 89.74% while that of MRI is 96.05%. The positive predictive values of USS and MRI are 42.86% and 88.88% respectively. Conclusion Compared to USS, MRI has a higher sensitivity, specificity, positive predictive value and predictive value. It will be a valuable addition to the standard nipple discharge evaluation workup to help rule out malignancy.

Development and validation of a predictive model for determining clinically significant prostate cancer in men with negative magnetic resonance imaging after transrectal ultrasound-guided prostate biopsy.

The interpretation of negative magnetic resonance imaging (MRI) screening results for clinically significant prostate cancer (csPCa) (International Society of Urological Pathology grade ≥group 2) is debatable and poses a clinical dilemma for urologists. No nomograms have been developed to predict csPCa in such populations. In this study, we aimed to develop and validate a model for predicting the probability of csPCa in men with negative MRI (PI-RADS score 1-2) results after transrectal ultrasound-guided systematic prostate biopsy. The development cohort consisted of 728 patients with negative MRI results who underwent subsequent prostate biopsy at our center between January 1, 2014 and December 31, 2017. The patients' clinicopathologic data were recorded. The Lasso regression was used for data dimension reduction and feature selection, then multivariable binary logistic regression was used to build a predictive model with regression coefficients. The model was validated in an independent cohort of 334 consecutive patients from January 1, 2018 and June 30, 2020. The performance of the predictive model was assessed with respect to discrimination, calibration, and decision curve analysis. The predictors incorporated in this model included age, history of previous negative prostate biopsy, prostate specific antigen density (PSAD), and lower urinary tract symptoms, with PSAD being the strongest predictor. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.875 (95% confidence interval, 0.816-0.933) and good calibration (unreliability test, p = .540). Decision curve analysis demonstrated that the model was clinically useful. This study presents a good nomogram that can aid pre-biopsy risk stratification for the detection of csPCa, and that may help inform biopsy decisions in patients with negative MRI results.

Comparison of Multiparametric Magnetic Resonance Imaging–Targeted Biopsy With Systematic Transrectal Ultrasonography Biopsy for Biopsy-Naive Men at Risk for Prostate Cancer

Magnetic resonance imaging (MRI) with targeted biopsy is an appealing alternative to systematic 12-core transrectal ultrasonography (TRUS) biopsy for prostate cancer diagnosis, but has yet to be widely adopted. To determine whether MRI with only targeted biopsy was noninferior to systematic TRUS biopsies in the detection of International Society of Urological Pathology grade group (GG) 2 or greater prostate cancer. This multicenter, prospective randomized clinical trial was conducted in 5 Canadian academic health sciences centers between January 2017 and November 2019, and data were analyzed between January and March 2020. Participants included biopsy-naive men with a clinical suspicion of prostate cancer who were advised to undergo a prostate biopsy. Clinical suspicion was defined as a 5% or greater chance of GG2 or greater prostate cancer using the Prostate Cancer Prevention Trial Risk Calculator, version 2. Additional criteria were serum prostate-specific antigen levels of 20 ng/mL or less (to convert to micrograms per liter, multiply by 1) and no contraindication to MRI. Magnetic resonance imaging-targeted biopsy (MRI-TB) only if a lesion with a Prostate Imaging Reporting and Data System (PI-RADS), v 2.0, score of 3 or greater was identified vs 12-core systematic TRUS biopsy. The proportion of men with a diagnosis of GG2 or greater cancer. Secondary outcomes included the proportion who received a diagnosis of GG1 prostate cancer; GG3 or greater cancer; no significant cancer but subsequent positive MRI results and/or GG2 or greater cancer detected on a repeated biopsy by 2 years; and adverse events. The intention-to-treat population comprised 453 patients (367 [81.0%] White, 19 [4.2%] African Canadian, 32 [7.1%] Asian, and 10 [2.2%] Hispanic) who were randomized to undergo TRUS biopsy (226 [49.9%]) or MRI-TB (227 [51.1%]), of which 421 (93.0%) were evaluable per protocol. A lesion with a PI-RADS score of 3 or greater was detected in 138 of 221 men (62.4%) who underwent MRI, with 26 (12.1%), 82 (38.1%), and 30 (14.0%) having maximum PI-RADS scores of 3, 4, and 5, respectively. Eighty-three of 221 men who underwent MRI-TB (37%) had a negative MRI result and avoided biopsy. Cancers GG2 and greater were identified in 67 of 225 men (30%) who underwent TRUS biopsy vs 79 of 227 (35%) allocated to MRI-TB (absolute difference, 5%, 97.5% 1-sided CI, -3.4% to ∞; noninferiority margin, -5%). Adverse events were less common in the MRI-TB arm. Grade group 1 cancer detection was reduced by more than half in the MRI arm (from 22% to 10%; risk difference, -11.6%; 95% CI, -18.2% to -4.9%). Magnetic resonance imaging followed by selected targeted biopsy is noninferior to initial systematic biopsy in men at risk for prostate cancer in detecting GG2 or greater cancers. ClinicalTrials.gov Identifier: NCT02936258.

The role of magnetic resonance imaging in active surveillance of prostate cancer.

Active surveillance (AS) is an important strategy to avoid overtreatment of prostate cancer (PCa) and has become the standard of care for low-risk patients. The role of magnetic resonance imaging (MRI) in AS has expanded due to its ability to risk stratify patients with suspected or known PCa, and MRI has become an integral part of the AS protocols at various institutions. A negative pre-biopsy MRI result is associated with a very high negative predictive value for a Gleason score ≥ 3+4. A positive MRI result in men who are otherwise eligible for AS has been shown to be associated with the presence of high-grade PCa and therefore with ineligibility. In addition, MRI can be used to guide and determine the timing of per-protocol biopsy during AS. However, there are several MRI-related issues that remain unresolved, including the lack of a consensus and guidelines; concerns about gadolinium deposition in various tissues; and increased demand for higher efficiency and productivity. Similarly, the need for the combined use of targeted and systematic sampling is still a matter of debate when lesions are visible on MRI. Here, we review the current AS guidelines, as well as the accepted roles of MRI in patient selection and monitoring, the potential uses of MRI that are still in question, and the limitations of the method.

Active surveillance in intermediate-risk prostate cancer.

Active surveillance (AS), now the standard of care for most men with favourable-risk prostate cancer, is appealing for selected men with 'favourable' intermediate-risk prostate cancer. This is a review of the indications for conservative management in this population, the outcomes reported in prospective series, and the use of molecular biomarkers and imaging to identify optimal candidates. Candidates are those patients who are categorized as having intermediate-risk disease either because of a prostate-specific antigen level between 10 and 20 ng/mL, or by virtue of having Grade Group 2 disease, with a small percentage of Gleason 4 pattern, and a negative magnetic resonance imaging result or negative targeted biopsy of a region of interest. Confirmation with a favourable score on a tissue-based genetic assay can provide further reassurance. A subset of patients with intermediate-risk disease has indolent disease that may benefit from AS; at the same time, some patients with intermediate-risk disease have an aggressive clinical course that requires early definitive therapy. This heterogeneity is not adequately captured with traditional histopathological staging. Clinical, genomic and radiological biomarkers are the key to appropriate risk stratification and patient selection. The benefits of AS make it an appealing option for selected patients with intermediate-risk disease.

Utility of stereo-electroencephalography recording guided by magnetoencephalography in the surgical treatment of epilepsy patients with negative magnetic resonance imaging results

Objective: It is challenging for neurosurgeons to perform surgeries on patients without detectable structural lesions. Therefore, this retrospective study aimed to explore the outcome of stereo-electroencephalography (SEEG) in suspicious areas guided by magnetoencephalography (MEG)-magnetic resonance imaging (MRI) reconstruction in MRI-negative epilepsy patients.Methods: This study included 47 patients with negative-MRI epilepsy. Seizure outcome at 24 months was assessed using a modified Engel’s classification. Accordingly, class I and II were considered favorable outcomes, whereas classes III and IV were unfavorable. Furthermore, patients were classified into a consistent group if the results of MEG and SEEG indicated the same area of the brain. The relationship between surgical outcome and the concordance of MEG and SEEG was analyzed.Results: A complete seizure-free condition was achieved in 22 (47%) patients. Sex, handedness, age and duration of illness were not significantly associated with seizure-free outcome (p = .187 [Pearson chi-squared test]). The number of patients with favorable outcome (Engle I and II) was as high as 68% at the time of follow-up. Furthermore, more seizure-free patients were found in the SEEG and MEG consistent group.Conclusions: SEEG is a valuable tool in the pre-evaluation for resective epilepsy surgery, particularly in negative-MRI epilepsy patients; MEG greatly facilitates localization for SEEG electrode implantation. However, none of these tools are absolutely sensitive and reliable; therefore, collecting as much information as possible is necessary to achieve satisfactory results in epilepsy surgery.

Primary diagnosis of pulmonary embolism with unenhanced MRI for patients not eligible for CTPA: Clinical outcome

PurposeTo follow up the clinical outcome of patients with suspected pulmonary embolism (PE), in those only imaged using unenhanced, free-breathing magnetic resonance imaging (MRI). Methods and materialsFifty-seven patients aged 29–99 years (mean 70, SD 18) that could not undergo Computed Tomography Pulmonary Angiography (CTPA) were offered alternative imaging diagnostics in parallel with ongoing methodological studies validating MRI vs CTPA. Contraindications included renal failure (n = 44), severe iodine contrast allergy (n = 10), pregnancy (n = 2) and radioactive iodine therapy (n = 1). The unenhanced MRI protocol was based on free-breathing, steady-state free precession with no cardiac or respiratory gating. Retrospective review of the electronic medical record (EMR) was made of 0–12 months post-imaging and was collected during 2012–2018. ResultsAll 57 MRIs were of diagnostic quality and 12 pulmonary embolisms were diagnosed. Of the 57 patients, 44 were already on, or had started anticoagulation therapy due to clinical suspicion of PE. Four of the patients were put on anticoagulation after the positive MRI and 13 were taken off anticoagulation after a negative MRI report. Other diagnoses reported (considering dyspnea) were pleural effusion (n = 24), consolidation (n = 12) and pericardial effusion (n = 2). One patient had a deep vein thrombosis (DVT) within three months of our negative MRI result and then had a stroke within one year. Another patient suffered a stroke within three months of being diagnosed (by MRI) with PE and given anticoagulation as treatment. ConclusionsOur method supported or altered clinical decision-making and treatment in this cohort. A diagnostic tool for PE without intravenous contrast agent or radiation is of great benefit for certain patients.

Cranial ultrasound and neurophysiological testing to predict neurological outcome in infants born very preterm.

Infants born preterm are at risk of cerebral palsy (CP) and motor or cognitive developmental delay. For clinicians, it is essential to know the relative predictive accuracy of the most commonly used neuroimaging and neurophysiological tests for the early prediction of adverse neurodevelopmental outcome. The aim of this study was to compare the accuracy of these tests in survivors of a population of infants born very preterm. A retrospective cohort study was performed in 163 children born before 32 weeks gestational age. We compared the accuracy in predicting adverse neurodevelopmental outcome at the age of 2 years 6 months of early and late cranial ultrasound (CUS), magnetic resonance imaging, somatosensory evoked potentials after stimulation of the posterior tibial nerve, and electroencephalography by calculating positive and negative likelihood ratios. An abnormal early CUS is the best predictor of the presence of CP (positive likelihood ratio 6.09), motor developmental delay (positive likelihood ratio 3.11), and cognitive developmental delay (positive likelihood ratio 5.66). Overall, negative likelihood ratios were poor, ranging between 0.49 and 0.98, meaning that a normal test result had only minimal influence on the probability of adverse neurological outcome. None of the diagnostic tests had a good performance in predicting future neurodevelopmental problems in infants born preterm. A normal test result provided very little clinically useful information. An abnormal early cranial ultrasound (positive test result) is the best predictor of adverse neurodevelopmental outcome. All negative results have poor predictive value of future neurodevelopmental problems.

Hip pathology: the diagnostic accuracy of magnetic resonance imaging

BackgroundHip arthroscopy has led to a greater understanding of intra-articular hip pathology. Non-contrast magnetic resonance imaging (MRI) is currently the gold standard in non-invasive imaging diagnosis, with high sensitivity in identifying labral pathology but equivocal results for ligamentum teres damage and chondral defects.The aim of this study is to determine the accuracy of non-contrast MRI for diagnosis of intra-articular hip derangements and identify radiological features that could increase the accuracy of the diagnosis.MethodsA prospective study of 71 hips on 68 patients undergoing hip arthroscopy was conducted comparing pre-operative analysis of MRI imaging versus an arthroscopic examination. Two musculoskeletal radiologists reported the data independently. All hip arthroscopies were performed by a single surgeon. Patients with MRIs performed within 6 months before hip arthroscopy were included.Outcome measures included observer accuracy identifying ligamentum teres tears, labral lesions, and chondral rim damage. Secondary outcome measures included inter-observer variability and correctly staged ligamentum teres tears.ResultsThe accuracy of radiology reporting for ligamentum teres tears, labral damage, and chondral rim lesions was 85.92% for each instance. The MRI findings most consistent with labral tears include the presence of linear high signal traversing the articular surface into the labrum, presence of intra-labral fluid signal, and loss of homogenous low signal triangular morphology. Chondral rim damage was difficult to diagnose, but abnormal signal at the chondrolabral junction with partial thickness defects would suggest damage. Ligamentum teres tears are commonly found but poorly graded. Thickening and increased signal suggests synovitis while discontinuity and fraying suggests partial tearing.ConclusionConventional non-arthrographic MRI offers an accurate non-invasive method to screen patients with symptoms referable to the hip by revealing the presence of labral tears, chondral defects, and ligamentum teres tears/synovitis. This study demonstrates that tears and synovitis of the ligamentum teres as potential sources of hip pain can be accurately identified on conventional non-arthrographic MRI. However, MRI has poor specificity and negative predictive value, and thus, a negative MRI result may warrant further investigation.

Is Liver-Specific Gadoxetic Acid-Enhanced Magnetic Resonance Imaging a Reliable Tool for Detection of Hepatocellular Carcinoma in Patients with Chronic Liver Disease?

Gadoxetic acid is a recently developed hepatobiliary-specific contrast material used for magnetic resonance imaging (MRI) which enables highly sensitive detection of hepatocellular carcinoma (HCC). We performed a meta-analysis of all available studies of the diagnostic performance of gadoxetic acid-enhanced MRI (Gd-EOB-MRI) for detection of HCC in patients with chronic liver disease. Databases including MEDLINE and EMBASE were searched for relevant original articles published from January 2000 to April 2012. Pooled estimation and subgroup analysis data were obtained by statistical analysis. Across 10 studies of 570 patients, Gd-EOB-MRI sensitivity was 0.91 (95 % CI 0.77, 0.97) and specificity was 0.93 (95 % CI 0.85, 0.97). Overall, LR+ was 13.6 (95 % CI 5.6, 33.2), LR- was 0.10 (95 % CI 0.04, 0.27), and DOR was 140.36 (95 % CI 28, 696). Among patients with high pre-test probabilities, MRI enabled confirmation of HCC; among patients with low pre-test probabilities, MRI enabled exclusion of HCC. Worst-case-scenario (pre-test probability, 50 %) post-test probabilities were 93 and 9 % for positive and negative MRI results, respectively. In studies in which both Gd-EOB-MRI and contrast enhanced computed tomography (CE-CT) were performed, Gd-EOB-MRI was more sensitive than CE-CT (0.93 vs. 0.78; p < 0.05). Subgroup analysis suggested average lesion size (<2 vs. >2 cm) did not affect the diagnostic accuracy of the test (p > 0.05). A limited number of small studies suggest Gd-EOB-MRI has good diagnostic performance in the detection of HCC among patients with chronic liver disease. It is also confirmed to be a reliable tool for evaluation of small early-stage HCC.

Is Magnetic Resonance Imaging a Reliable Diagnostic Tool in the Evaluation of Active Crohn’s Disease in the Small Bowel?

To evaluate the overall diagnostic accuracy of magnetic resonance imaging (MRI) in assessing the activity of Crohn's disease (CD) in the small bowel. Cross-sectional imaging techniques are playing an increasing role in the evaluation of suspected CD. Advantages of MRI include a lack of ionizing radiation, the ability to provide dynamic information regarding bowel distention and motility, improved soft-tissue contrast, and a relatively safe intravenous contrast agent profile. Two reviewers searched MEDLINE, EMBASE, and other electronic databases to identify studies in which MRI imaging was evaluated for assessing the activity of CD in the small bowel from January 2001 to September 2011. Bivariate random-effects meta-analytic methods were used to estimate summary, sensitivity, specificity, and receiver operating characteristic curves. MRI had a pooled sensitivity of 0.87 [95% confidence interval (CI): 0.77, 0.93] and a pooled specificity of 0.91 (95% CI: 0.81, 0.96). Overall, likelihood ratio (LR)+ was 9.5 (95% CI: 4.4, 20.6) and LR- was 0.14 (95% CI: 0.08, 0.26). In patients with high pretest probabilities, MRI enabled confirmation of active CD; in patients with low pretest probabilities, MRI enabled exclusion of active CD. Worst-case-scenario (pretest probability, 50%) posttest probabilities were 90% and 13% for positive and negative MRI results, respectively. A limited number of small studies suggest that MRI has high sensitivity and specificity for diagnosis of active CD in the small bowel; MRI will likely also prove to be suitable as the primary modality for active CD imaging surveillance.

A pooled analysis of MRI in the detection of bone marrow infiltration in patients with malignant lymphoma

To explore the role of magnetic resonance imaging (MRI) in detecting bone marrow infiltration of malignant lymphoma through a systematic review and meta-analysis. Studies that evaluated the diagnostic performance of MRI in detecting bone marrow infiltration of malignant lymphoma were acquired from the MEDLINE, EMBASE, Cancerlit, and Cochrane Library database, from February 1987 to May 2012. Pooled estimation and subgroup analysis data were obtained by statistical analysis. A total of 13 studies involving 634 patients who fulfilled all of the inclusion criteria were considered for the analysis. No publication bias was found (p = 0.70). The pooled sensitivity of MRI was 0.82 [95% confidence intervals (CI): 0.70-0.90] and the pooled specificity was 0.79 (95% CI: 0.72-0.84). Overall, positive likelihood ratios (LR+) was 3.9 (95% CI: 2.8-5.4) and negative likelihood ratios (LR-) was 0.23 (95% CI: 0.13-0.41). In patients with high pre-test probabilities, MRI enabled confirmation of bone marrow involvement; in patients with low pre-test probabilities, MRI enabled exclusion of bone marrow involvement. Worst-case-scenario (pre-test probability, 50%) post-test probabilities were 80% and 18% for positive and negative MRI results, respectively. In subgroup analysis, MRI performed with 1.5 T devices had higher pooled specificity (0.80, 95% CI: 0.71-0.88) than the MRI with ≤1 T (0.78, 95% CI: 0.71-0.85; p < 0.05). The pooled sensitivity of MRI with diffusion-weighted imaging (DWI) was 0.65 (95% CI: 0.39-0.92) and the pooled specificity was 0.83 (95% CI: 0.69-0.97). The sensitivity and specificity of MRI without DWI was 0.85 (95% CI: 0.76-0.94) and 0.79 (95% CI: 0.72-0.85), respectively. A limited number of small studies indicate that MRI can serve as a valuable tool for detecting bone marrow infiltration of malignant lymphoma. Results were most promising when performing MRI using high field strength devices. MRI with DWI is shown to be more specific than conventional MRI techniques. This deserves further investigation in future studies.

Is There a Role for Magnetic Resonance Imaging in Diagnosing Palpable Breast Masses When Mammogram and Ultrasound Are Negative?

The use of breast magnetic resonance imaging (MRI) for screening high-risk patients is well established. However, the role of MRI as a diagnostic problem-solving tool is less well studied. With the increasing availability of MRI, its use for problem solving has increased. This small retrospective study examines the use and utility of breast MRI in evaluating palpable breast masses with negative diagnostic mammogram and ultrasound studies. We reviewed our breast MRI database, selecting breast MRI studies performed to assess palpable abnormalities with negative mammogram and ultrasound findings. Evidence of cancer was determined by biopsy. Seventy-seven studies were included, comprising 1.3% of all breast MRI studies performed at our institution during the study period (2005-2011). Twenty-two patients underwent biopsy, and 55 were followed clinically without biopsy. Approximately half (27 of 55) of the patients without biopsy were lost to follow-up after negative MRI, and the rest had no evidence of cancer on imaging or clinical examination at 1 year. Of the 22 patients who underwent biopsy, 2 were diagnosed with cancer, both with positive MRI studies. Sensitivity of MRI when compared to tissue diagnosis was 100%, and specificity was 70%. Positive and negative predictive values were 25% and 100%, respectively. When used for evaluation of a palpable breast mass with negative traditional imaging, breast MRI likely offers low yield of cancer diagnosis and low specificity. Negative MRI results may cause a low compliance rate for recommended follow-up. Because a biopsy is indicated for persistent palpable masses, the addition of diagnostic MRI only adds another step, with associated costs and burdens.

Comparison of PET/CT and MRI for the detection of bone marrow invasion in patients with squamous cell carcinoma of the oral cavity

Our aim was to retrospectively assess the diagnostic performance from combined positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) for the detection of bone marrow invasion of the mandible or maxilla in patients with oral cavity squamous cell carcinoma (OCSCC). A total of 114 patients with OCSCC, arising from or abutting the upper or lower alveolar ridge, underwent staging PET/CT and MRI studies before surgery. The possibility of bone marrow invasion on PET/CT and MRI was graded retrospectively on a 5-point score. Histopathology was taken as the reference standard. Sensitivity, specificity, predictive values and likelihood ratios were calculated. Clinical factors affecting the performance, like tumor origin and dentate status were also explored. PET/CT was found to be more specific than MRI (83% vs. 61%, respectively, p=0.0015) but less sensitive (78% vs. 97%, respectively, p=0.0391). Dentate status and tumor origin affected the diagnostic performance of PET/CT. In patients with positive MRI, sensitivity and specificity of PET/CT were 78% and 100% in dentate patients with alveolar ridge tumors, 75% and 80% in dentate patient with buccal tumors, 90% and 33% in edentulous patients with alveolar ridge tumors and 0% and 63% for edentulous patients with buccal tumors, respectively. PET/CT is more specific than MRI and can be used to complement the role of MRI. A negative MRI result can confidently exclude the presence of bone marrow invasion, while in patients with positive MRI findings, a negative PET/CT may be useful to rule out bone marrow invasion in dentate patients.

The role of 6-[18F]fluorodopamine positron emission tomography in the localization of adrenal pheochromocytoma associated with von Hippel–Lindau syndrome

[(123/131)I]metaiodobenzylguanidine (MIBG) scintigraphy is considered as the gold standard in the localization of pheochromocytoma. However, this method has less optimal sensitivity for the detection of pheochromocytoma associated with von Hippel-Lindau (VHL). Our preliminary results suggest that this is partially due to the low expression of cell membrane norepinephrine transporter system in VHL-related pheochromocytoma cells. Another probable cause may be the low affinity that [(123/131)I]MIBG has for these cells. Recently, 6-[(18)F]fluorodopamine ([(18)F]DA) positron emission tomography (PET) has been introduced as a novel functional imaging modality with high sensitivity for pheochromocytoma. Therefore, we investigated whether [(18)F]DA PET is more effective than [(123/131)I]MIBG scintigraphy in the diagnostic localization of VHL-related adrenal pheochromocytoma. In this study, we evaluated seven VHL patients in whom adrenal pheochromocytomas were confirmed by histopathology results. Adrenal pheochromocytomas were localized using computed tomography (CT), magnetic resonance imaging (MRI), [(123/131)I]MIBG scintigraphy and [(18)F]DA PET. [(18)F]DA PET localized pheochromocytoma in all the seven patients, as did in CT. In contrast, three out of the seven had negative results utilizing [(123/131)I]MIBG scintigraphy and one out of the six patients had negative MRI results. [(18)F]DA PET was found to show more promising results when compared with [(123/131)I]MIBG scintigraphy in the diagnostic localization of VHL-related adrenal pheochromocytoma, with a 100% rate of localization. Thus, [(18)F]DA PET in conjunction with CT/MRI should be considered as an effective method for the proper localization of VHL-related adrenal pheochromocytoma.

Fluorine-18-l-Dihydroxyphenylalanine (18F-DOPA) Positron Emission Tomography as a Tool to Localize an Insulinoma or β-Cell Hyperplasia in Adult Patients

Fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) positron emission tomography (PET) is a promising method in localizing neuroendocrine tumors. Recently, it has been shown to differentiate focal forms of congenital hyperinsulinism of infancy. The current study was set up to determine the potential of 18F-DOPA PET in identifying the insulin-secreting tumors or beta-cell hyperplasia of the pancreas in adults. We prospectively studied 10 patients with confirmed hyperinsulinemic hypoglycemia and presumed insulin-secreting tumor using 18F-DOPA PET. Anatomical imaging was performed with computed tomography (CT) and magnetic resonance imaging (MRI). All patients were operated on, and histological verification was available in each case. Semiquantitative PET findings in the pancreas using standardized uptake values were compared to standardized uptake values of seven consecutive patients with nonpancreatic neuroendocrine tumors. By visual inspection of 18F-DOPA PET images, it was possible in nine of 10 patients to localize the pancreatic lesion, subsequently confirmed by histological analysis. 18F-DOPA uptake was enhanced in six of seven solid insulinomas and in the malignant insulinoma and its hepatic metastasis. Two patients with beta-cell hyperplasia showed increased focal uptake of 18F-DOPA in the affected areas. As compared to CT or MRI, 18F-DOPA PET was more sensitive in localizing diseased pancreatic tissue. 18F-DOPA PET was useful in most patients with insulinoma and negative CT, MRI, and ultrasound results. In agreement with previous findings in infants, preoperative 18F-DOPA imaging seems to be a method of choice for the detection of beta-cell hyperplasia in adults. It should be considered for the detection of insulinoma or beta-cell hyperplasia in patients with confirmed hyperinsulinemic hypoglycemias when other diagnostic work-up is negative.

False Negative Magnetic Resonance Imaging Results: A Report of 2 Cases

Objectives The purpose of this study is to present 2 clinical case studies in which large herniated disks were not detected on magnetic resonance imaging (MRI), leading to false negative results, and discuss some issues regarding potential shortcomings of MRI. Clinical Features Cases of cervical and lumbar herniated nucleus pulposus (HNP) are presented. Each patient had severe pain and neurological deficit. The patients had positive physical examination findings suggestive of HNP despite the negative MRI scans. Both subsequently underwent myelography and computed tomography to arrive at the final and definitive diagnosis of HNP. Intervention and Outcome Both patients failed a course of conservative care that included manual and mechanical traction, manual mobilization, myofascial release techniques, epidural steroid injections, oral steroid and narcotic medications, and rehabilitative exercises. Both patients eventually required surgical decompression. Conclusion False negative MRI results in these cases of large HNPs emphasize the importance of case history and physical examination findings as the basis for ordering diagnostic tests. The conclusion of this article is simple; no single diagnostic test should be considered as 100% accurate, as false negative studies may occur that may mislead the patient and clinician.