ABSTRACT
BACKGROUND AND PURPOSE: Differentiating between treatment-related lesions and tumor progression remains one of the greatest dilemmas in neuro-oncology. Diffusion MR imaging characteristics may provide useful information to help make this distinction. The aim of the study was to assess the diagnostic accuracy of the centrally reduced diffusion sign for differentiation of treatment-related lesions and true tumor progression in patients with suspected glioma recurrence. MATERIALS AND METHODS: The images of 231 patients who underwent an operation for suspected glioma recurrence were reviewed. Patients with susceptibility artifacts or without central necrosis were excluded. The final diagnosis was established according to histopathology reports. Two neuroradiologists classified the diffusion patterns on preoperative MR imaging as the following: 1) reduced diffusion in the solid component only, 2) reduced diffusion mainly in the solid component, 3) no reduced diffusion, 4) reduced diffusion mainly in the central necrosis, and 5) reduced diffusion in the central necrosis only. Diagnostic accuracy metrics and the area under the receiver operating characteristic curve were estimated for the diffusion patterns. RESULTS: One hundred three patients were included (22 with treatment-related lesions and 81 with tumor progression). The diagnostic accuracy results for the centrally reduced diffusion pattern as a predictor of treatment-related lesions ("mainly central" and "exclusively central" patterns versus all other patterns) were as follows: 64% sensitivity (95% CI, 41%-83%), 84% specificity (95% CI, 74%-91%), 52% positive predictive value (95% CI, 37%-66%), and 89% negative predictive value (95% CI, 83%-94%). CONCLUSIONS: The centrally reduced diffusion sign is associated with the presence of treatment effect. The probability of a histologic diagnosis of a treatment-related lesion is low (11%) in the absence of centrally reduced diffusion.
Subject(s)
Brain Neoplasms/diagnostic imaging , Brain/diagnostic imaging , Diffusion Magnetic Resonance Imaging/methods , Glioma/diagnostic imaging , Neoplasm Recurrence, Local/diagnostic imaging , Adult , Aged , Aged, 80 and over , Brain/pathology , Brain Neoplasms/pathology , Combined Modality Therapy/adverse effects , Disease Progression , Female , Glioma/pathology , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Necrosis/diagnostic imaging , ROC Curve , Sensitivity and SpecificityABSTRACT
BACKGROUND AND PURPOSE: Accurate preoperative differentiation of primary central nervous system lymphoma and enhancing glioma is essential to avoid unnecessary neurosurgical resection in patients with primary central nervous system lymphoma. The purpose of the study was to evaluate the diagnostic performance of a machine-learning algorithm by using texture analysis of contrast-enhanced T1-weighted images for differentiation of primary central nervous system lymphoma and enhancing glioma. MATERIALS AND METHODS: Seventy-one adult patients with enhancing gliomas and 35 adult patients with primary central nervous system lymphomas were included. The tumors were manually contoured on contrast-enhanced T1WI, and the resulting volumes of interest were mined for textural features and subjected to a support vector machine-based machine-learning protocol. Three readers classified the tumors independently on contrast-enhanced T1WI. Areas under the receiver operating characteristic curves were estimated for each reader and for the support vector machine classifier. A noninferiority test for diagnostic accuracy based on paired areas under the receiver operating characteristic curve was performed with a noninferiority margin of 0.15. RESULTS: The mean areas under the receiver operating characteristic curve were 0.877 (95% CI, 0.798-0.955) for the support vector machine classifier; 0.878 (95% CI, 0.807-0.949) for reader 1; 0.899 (95% CI, 0.833-0.966) for reader 2; and 0.845 (95% CI, 0.757-0.933) for reader 3. The mean area under the receiver operating characteristic curve of the support vector machine classifier was significantly noninferior to the mean area under the curve of reader 1 (P = .021), reader 2 (P = .035), and reader 3 (P = .007). CONCLUSIONS: Support vector machine classification based on textural features of contrast-enhanced T1WI is noninferior to expert human evaluation in the differentiation of primary central nervous system lymphoma and enhancing glioma.
Subject(s)
Algorithms , Central Nervous System Neoplasms/diagnosis , Glioma/diagnosis , Lymphoma/diagnosis , Support Vector Machine , Adult , Diagnosis, Differential , Female , Glioma/pathology , Humans , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Male , Middle Aged , ROC Curve , Sensitivity and SpecificityABSTRACT
OBJECTIVES: To compare the sensitivity of enhancing multiple sclerosis (MS) lesions in gadolinium-enhanced 2D T1-weighted gradient-echo (GRE) and spin-echo (SE) sequences, and to assess the influence of visual conspicuity and laterality on detection of these lesions. METHODS: One hundred MS patients underwent 3.0T brain MRI including gadolinium-enhanced 2D T1-weighted GRE and SE sequences. The two sets of contrast-enhanced scans were evaluated in random fashion by three experienced readers. Lesion conspicuity was assessed by the image contrast ratio (CR) and contrast-to-noise ratio (CNR). The intracranial region was divided into four quadrants and the impact of lesion location on detection was assessed in each slice. RESULTS: Six hundred and seven gadolinium-enhancing MS lesions were identified. GRE images were more sensitive for lesion detection (0.828) than SE images (0.767). Lesions showed a higher CR in SE than in GRE images, whereas the CNR was higher in GRE than SE. Most misclassifications occurred in the right posterior quadrant. CONCLUSIONS: The gadolinium-enhanced 2D T1-weighted GRE sequence at 3.0T MRI enables detection of enhancing MS lesions with higher sensitivity and better lesion conspicuity than 2D T1-weighted SE. Hence, we propose the use of gadolinium-enhanced GRE sequences rather than SE sequences for routine scanning of MS patients at 3.0T. KEY POINTS: ⢠2D SE and GRE sequences are useful for detecting active MS lesions. ⢠Which of these sequences is more sensitive at high field remains uncertain. ⢠GRE sequence showed better sensitivity for detecting active MS lesions than SE. ⢠We propose GRE sequence for detecting active MS lesions at 3.0T.
Subject(s)
Contrast Media , Image Enhancement/methods , Magnetic Resonance Imaging/methods , Multiple Sclerosis/diagnostic imaging , Organometallic Compounds , Adolescent , Adult , Brain/diagnostic imaging , Brain/pathology , Female , Humans , Male , Middle Aged , Multiple Sclerosis/pathology , Reproducibility of Results , Sensitivity and Specificity , Young AdultABSTRACT
BACKGROUND AND PURPOSE: Determining the diagnostic accuracy of different MR sequences is essential to design MR imaging protocols. The purpose of the study was to compare 3T sagittal FSE T2, STIR, and T1-weighted phase-sensitive inversion recovery in the detection of spinal cord lesions in patients with suspected or definite MS. MATERIALS AND METHODS: We performed a retrospective analysis of 38 patients with suspected or definite MS. Involvement of the cervical and thoracic cord segments was recorded on sagittal FSE T2, STIR, and T1-weighted phase-sensitive inversion recovery sequences independently by 2 readers. A consensus criterion standard read was performed with all sequences available. Sensitivity, specificity, and interobserver agreement were calculated for each sequence. RESULTS: In the cervical cord, the sensitivity of T1-weighted phase-sensitive inversion recovery (96.2%) and STIR (89.6%) was significantly higher (P < .05) than that of FSE T2 (50.9%), but no significant difference was found between T1-weighted phase-sensitive inversion recovery and STIR. In the thoracic cord, sensitivity values were 93.8% for STIR, 71.9% for FSE T2, and 50.8% for T1-weighted phase-sensitive inversion recovery. Significant differences were found for all comparisons (P < .05). No differences were detected in specificity. Poor image quality and lower sensitivity of thoracic T1-weighted phase-sensitive inversion recovery compared with the other 2 sequences were associated with a thicker back fat pad. CONCLUSIONS: The use of an additional sagittal sequence other than FSE T2 significantly increases the detection of cervical and thoracic spinal cord lesions in patients with MS at 3T. In the cervical segment, both STIR and T1-weighted phase-sensitive inversion recovery offer high sensitivity and specificity, whereas in the thoracic spine, STIR performs better than T1-weighted phase-sensitive inversion recovery, particularly in patients with a thick dorsal fat pad.
Subject(s)
Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Multiple Sclerosis/diagnostic imaging , Spinal Cord/diagnostic imaging , Adult , Aged , Female , Humans , Male , Middle Aged , Multiple Sclerosis/pathology , Retrospective Studies , Sensitivity and Specificity , Spinal Cord/pathologyABSTRACT
BACKGROUND AND PURPOSE: Estimates of blood volume and volume transfer constant are parameters commonly used to characterize hemodynamic properties of brain lesions. The purposes of this study were to compare values of volume transfer constant and estimates of blood volume in high-grade gliomas on a pixel-by-pixel basis to comprehend whether they provide different information and to compare estimates of blood volume obtained by dynamic contrast-enhanced MR imaging and dynamic susceptibility contrast-enhanced MR imaging. MATERIALS AND METHODS: Thirty-two patients with biopsy-proved grade IV gliomas underwent dynamic contrast-enhanced MR imaging and dynamic susceptibility contrast-enhanced MR imaging, and parametric maps of volume transfer constant, plasma volume, and CBV maps were calculated. The Spearman rank correlation coefficients among matching values of CBV, volume transfer constant, and plasma volume were calculated on a pixel-by-pixel basis. Comparison of median values of normalized CBV and plasma volume was performed. RESULTS: Weak-but-significant correlation (P < .001) was noted for all comparisons. Spearman rank correlation coefficients were as follows: volume transfer constant versus CBV, ρ = 0.113; volume transfer constant versus plasma volume, ρ = 0.256; CBV versus plasma volume, ρ = 0.382. We found a statistically significant difference (P < .001) for the estimates of blood volume obtained by using dynamic contrast-enhanced MR imaging (mean normalized plasma volume, 13.89 ± 11.25) and dynamic susceptibility contrast-enhanced MR imaging (mean normalized CBV, 4.37 ± 4.04). CONCLUSIONS: The finding of a very weak correlation between estimates of microvascular density and volume transfer constant suggests that they provide different information. Estimates of blood volume obtained by using dynamic contrast-enhanced MR imaging are significantly higher than those obtained by dynamic susceptibility contrast-enhanced MR imaging in human gliomas, most likely due to the effect of contrast leakage.
Subject(s)
Brain Neoplasms/physiopathology , Cerebrovascular Circulation/physiology , Glioma/physiopathology , Magnetic Resonance Imaging/methods , Adult , Aged , Blood Volume , Brain Neoplasms/pathology , Contrast Media , Female , Glioma/pathology , Humans , Male , Middle Aged , Neoplasm GradingABSTRACT
Los procesos que cursan con necrosis grasa intraabdominal se manifiestan frecuentemente por dolor abdominal agudo/subagudo, hallazgos clínicos que pueden ser originados por afecciones tan variadas como la apendicitis epiploica, el infarto omental, la necrosis grasa encapsulada, la paniculitis mesentérica, la apendicitis, la diverticulitis y ciertas neoplasias. En este contexto, y a pesar de que la localización anatómica del dolor y la sintomatología acompañante pueden ayudar a la orientación diagnóstica, ésta puede ser equívoca llevando a una cirugía innecesaria. Para el diagnóstico van a resultar imprescindibles pruebas de imagen como la ecografía y, sobre todo la tomografía computarizada, debiendo el radiólogo reconocer los hallazgos característicos de cada una de ellas, lo que permitirá el adecuado manejo del dolor abdominal y prevenir una cirugía innecesaria (AU)
The processes that course with intraabdominal fat necrosis often manifest with acute or subacute abdominal pain; these clinical findings can be caused by various conditions, including epiploic appendagitis, omental infarction, encapsulated fat necrosis, mesenteric panniculitis, appendicitis, diverticulitis, and certain neoplasms. In this context, although the anatomic location of the pain and accompanying symptomatology can help orient the diagnosis, there is a risk of unnecessary surgery. Imaging tests like ultrasonography and especially computed tomography are essential for diagnosing intraabdominal fat necrosis. Radiologists must be familiar with the characteristic findings for all the conditions that can cause acute or subacute abdominal pain to ensure appropriate management and prevent unnecessary surgery (AU)
Subject(s)
Humans , Male , Female , Abdominal Fat/pathology , Abdominal Fat , Abdominal Pain/complications , Abdominal Pain/etiology , Abdominal Pain , Diagnosis, Differential , /methods , Fat Necrosis/complications , Fat Necrosis , Peritoneal Cavity/pathology , Peritoneal Cavity , Omentum/pathology , Omentum , Appendicitis/pathology , Appendicitis , Diverticulitis/pathology , DiverticulitisABSTRACT
The processes that course with intraabdominal fat necrosis often manifest with acute or subacute abdominal pain; these clinical findings can be caused by various conditions, including epiploic appendagitis, omental infarction, encapsulated fat necrosis, mesenteric panniculitis, appendicitis, diverticulitis, and certain neoplasms. In this context, although the anatomic location of the pain and accompanying symptomatology can help orient the diagnosis, there is a risk of unnecessary surgery. Imaging tests like ultrasonography and especially computed tomography are essential for diagnosing intraabdominal fat necrosis. Radiologists must be familiar with the characteristic findings for all the conditions that can cause acute or subacute abdominal pain to ensure appropriate management and prevent unnecessary surgery.
