Multi-parametric arterial spin labeling and diffusion-weighted imaging of paranasal sinuses masses.

PURPOSE: To evaluate arterial spin labeling (ASL) and diffusion-weighted imaging (DWI) in discrimination of benign from malignant paranasal sinus (PNS) tumors. MATERIAL AND METHODS: A prospective study was done upon 42 cases of PNS masses that underwent magnetic resonance ASL and DWI of the head. Tumor blood flow (TBF) and apparent diffusion coefficient (ADC) of the masses were calculated by two observers. The pathological diagnosis was malignant (n = 28) and benign (n = 14) cases. RESULTS: For both observers, the malignant PNS masses had significantly higher TBF (P < 0.001, 0.001) and lower ADC (P < 0.001, 0.001) than in benign masses. The ROC curve analysis of TBF, The threshed TBF was (121.45, 122.68 mL/100 g/min) used for differentiation between benign and malignant PNS masses, revealed sensitivity (92.9%, 89.3%), specificity (85.7%, 85.7%), accuracy (90.5%, 88.1%) and the AUC was 0.87 and 0.86 by both observers. the ROC curve analysis of ADC, The threshold ADC (1.215, 1.205 X10-3mm2/s) was used for differentiation between benign and malignant PNS masses, revealed sensitivity (96.4%, 89.3%), specificity (78.6%, 78.6%), accuracy of (90.5%, 85.7%) and the AUC was 0.93 and 0.92 by both observers. Combined analysis of TBF and ADC used for differentiation between benign and malignant PNS masses had revealed sensitivity (96.4%, 89.3%), specificity (92.9%, 85.7%) accuracy of (95.2%, 88.1%) and AUC. (0.995, 0.985) for both observers. CONCLUSION: Combined using of TBF and ADC have a role in differentiation malignant from benign PNS masses.

The value of the apparent diffusion coefficient value in the Liver Imaging Reporting and Data System (LI-RADS) version 2018.

PURPOSE: To assess role of the apparent diffusion coefficient (ADC) in the Liver Imaging Reporting and Data System (LI-RADS) version 2018 for the prediction of hepatocellular carcinoma (HCC). MATERIAL AND METHODS: Retrospective analysis of 137 hepatic focal lesions in 108 patients at risk of HCC, who underwent magnetic resonance imaging of the liver. Hepatic focal lesions were classified according to LI-RADS-v2018, and ADC of hepatic lesions was calculated by 2 independent blinded reviewers. RESULTS: The mean ADC of LR-1 and LR-2 were 2.11 ± 0.47 and 2.08 ± 0.47 × 10-3 mm2/s, LR-3 were 1.28 ± 0.12 and 1.36 ± 0.16 × 10-3 mm2/s, LR-4, LR-5 and LR-TIV were 1.07 ± 0.08 and 1.08 ± 0.12 × 10-3 mm2/s and LR-M were 1.02 ± 0.09 and 1.00 ± 0.09 × 10-3 mm2/s by both observers, respectively. There was excellent agreement of both readings for LR-1 and LR-2 (r = 0.988), LR-3 (r = 0.965), LR-4, LR-5 and LR-TIV (r = 0.889) and LR-M (r = 0.883). There was excellent correlation between ADC and LI-RADS-v2018 (r = -0.849 and -0.846). The cut-off ADC used to differentiate LR-3 from LR-4, LR-5, and LR-TIV were ≤ 1.21 and ≤ 1.23 × 10-3 mm2/s with AUC of 0.948 and 0.926. CONCLUSIONS: Inclusion of ADC to LI-RADS-v2018 improves differentiation variable LI-RADS categories and can helps in the prediction of HCC.

Effect of changes in optic nerve elasticity on central retinal artery blood flow in patients with idiopathic intracranial hypertension.

PURPOSE: To assess changes in central retinal artery (CRA) blood flow by orbital color-coded Doppler ultrasonography in patients with idiopathic intracranial hypertension (IIH) and their relation with optic nerve (ON) elasticity assessed by shear wave elastography (SWE). METHODS: This study was carried out on 68 eyes of patients diagnosed with IIH and 32 eyes of healthy controls. The severity of papilledema in IIH patients was sub-classified into mild and moderate/severe groups. Color-coded Doppler was used to measure peak systolic velocity (PSV), end diastolic velocity (EDV), mean velocity (Vmean) and pulsatility index (PI) of the CRA. RESULTS: PSV, Vmean, and SWE were significantly higher in patients with IIH than in controls (p = 0.001). The optimal cut-off values of PSV and Vmean for differentiating IIH patients from controls were 11.25 and 6.75 cm/s with AUC 0.81 and 0.785 respectively. AUC was 0.92 and accuracy 91% for combined PSV, Vmean and SWE differentiation between IIH patients and controls. PSV, Vmean and SWE were significantly different between mild versus moderate/severe papilledema (p = 0.001). PSV and Vmean were correlated with papilledema (r = 0.790 and 0.722 respectively) and SWE (r = 0.818 and 0.761 respectively). CONCLUSION: IIH is associated with decreased ON elasticity and reduced CRA blood flow. Individual and combined color-coded Doppler of the CRA and SWE help in diagnosis of IIH. CRA hemodynamic changes are correlated with papilledema severity and with the extent of biomechanical changes in the ON represented by SWE.

The role of diffusion tensor imaging of the liver in children with autoimmune hepatitis.

PURPOSE: To evaluate the role of diffusion tensor imaging (DTI) of the liver in children with autoimmune hepatitis (AIH). MATERIAL AND METHODS: A prospective study was done on 42 children with AIH (30 girls and 12 boys, with a mean age of 13 years) and 20 age- and sex-matched healthy control children. They underwent DTI of the liver and laboratory tests. Liver biopsy was done for the patients. The mean diffusivity (MD) and fractional anisotropy (FA) of the liver were calculated and correlated with the pathological results. RESULTS: The mean MD and FA of the liver in children with AIH were 1.42 ± 0.06 × 10-3 mm2/s and 0.37 ± 0.11; and in the control children they were 1.55 ± 0.07 × 10-3 mm2/s and 0.25 ± 0.03, respectively. The MD and FA were significantly different in the children with AIH compared to the control children (p = 0.001). The cutoff MD and FA used to differentiate patients from controls were 1.50 × 10-3 mm2/s, 0.31 with AUC of 0.919 and 0.813, sensitivity of 97.6% and 66.7%, a specificity of 80% and 70%, an accuracy of 94.2% and 67.3%, PPV of 95.3 and 90.3, and NPV of 88.9 and 33.3, respectively. There was significantly lower MD and higher FA of the liver in children with AIH type I (n = 31) than type II (n = 11) (p = 0.001), and patients with (n = 9) and without (n = 33) overlap syndrome (p = 0.005). CONCLUSIONS: We concluded that DTI parameters can help to diagnose AIH, detect its phenotyping, and give clues as to the presence of associated overlap syndrome.

Diffusion tensor imaging of vertebral bone marrow in children with Gaucher's disease type I and III: Pre- and post-therapy.

PURPOSE: To assess diffusion tensor imaging (DTI) of the vertebral bone marrow (BM) in children with Gaucher's disease (GD) types I and III before and after therapy. METHODS: Prospective study was conducted upon 25 children with GD type I (n = 17) and III (n = 8) and 13 age and sex-matched controls underwent DTI of vertebral BM. Mean diffusivity (MD) and fractional anisotropy (FA) of vertebral BM was calculated and correlated with genotyping, chitotriosidase, hemoglobin (HB) and, platelet count. RESULTS: There was a statistically significant difference in MD and FA of BM between patients and controls (P = 0.001 and 0.02). The area under the curve (AUC) of MD and FA used to differentiate untreated patients from controls was 0.902 and 0.68 with sensitivity, specificity, and, accuracy 92%, 84.6%, and, 89.5% respectively. There was a significant difference in MD and FA of BM between untreated and treated patients (P = 0.001 and 0.02). AUC of MD and FA used to differentiate untreated from treated patients was 0.93 and 0.649 with sensitivity, specificity, and accuracy of 92%, 80%, and 86% respectively. There was a significant difference in MD and FA (P = 0.03, 0.001 respectively) of BM in GD with homozygous L444P mutation (n = 9) and other mutations (n = 14). Chiotriptase, HB and platelet count of patients was correlated with MD (r = -0.36, 0.42, -0.41) and FA (r = -0.47, -0.37, -0.46) respectively. CONCLUSION: DTI of vertebral BM can help in diagnosis and monitoring patients with GD after therapy and correlated with genotyping, and hematological biomarkers of GD.

Prostate Imaging Reporting and Data System (PI-RADS): What the radiologists need to know?

We aim to review the new modifications in MR imaging technique, image interpretation, lexicon, and scoring system of the last version of Prostate Imaging Reporting and Data System version 2.1 (PI-RADS v2.1) in a simple and practical way. This last version of PI-RADS v2.1 describes the new technical modifications in the protocol of Multiparametric MRI (MpMRI) including T2, diffusion-weighted imaging (DWI), and dynamic contrast enhancement (DCE) parameters. It includes also; new guidelines in the image interpretation specifications in new locations (lesions located in the central zone and anterior fibromuscular stroma), clarification of T2 scoring of lesions of the transition zone, the distinction between DWI score 2 and 3 lesions in the transition zone and peripheral zone, as well as between positive and negative enhancement in DCE. Biparametric MRI (BpMRI) along with simplified PI-RADS is gaining more acceptances in the assessment of clinically significant prostatic cancer.

Multi-parametric arterial spin labeling and diffusion-weighted imaging in differentiation of metastatic from reactive lymph nodes in head and neck squamous cell carcinoma.

PURPOSE: To assess arterial spin labeling (ASL) and diffusion-weighted imaging (DWI) in the differentiation of metastatic from reactive lymph nodes (LNs) in head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS: Retrospective analysis of 113 LNs in 43 patients with HNSCC underwent ASL and DWI of the neck. The tumor blood flow (TBF) and apparent diffusion coefficient (ADC) of the cervical LNs were calculated. The final diagnosis of metastatic (n = 82) and reactive (n = 31) was proved with the pathological examination. RESULTS: The TBF of metastatic LNs (58.8 ± 10.2, 58.6 ± 8.5 mL/100 g/min) was significantly higher (p = 0.001) than the reactive LNs (23.2 ± 10.3, 28.2 ± 16.7 mL/100 g/min) for both observers, respectively. The ADC of metastatic LN (1.12 ± 0.07, 1.21 ± 0.07 × 10-3mm2/s) was significantly lower (p = 0.001) than reactive LN (1.41 ± 0.09, 1.44 ± 0.14 × 10-3mm2/s) for both observers, respectively. The threshold of TBF (> 39.5, 40.5 mL/100 g/min), ADC (≥ 1.31, 1.30 X10-3mm2/s) and combined parameters for both observers, respectively, used for differentiating metastatic from reactive LNs revealed an area under the curve of (0.94, 0.945), (0.90, 0.931), and (0.98, 0.989), an accuracy of (88.6%, 80.5%), (80.0%, 88.5%), and (94.3%, 98.2), respectively. CONCLUSION: Combined TBF and ADC are non-invasive imaging parameters that can play a role in differentiation metastatic from reactive LNs in patients with HNSCC.

Role of diffusion-weighted imaging in prediction of nipple-areolar complex invasion by breast cancer.

THE AIM OF THIS WORK: The aim of this work was to estimate the role of diffusion-weighted imaging (DWI) in predicting malignant invasion of the nipple-areolar complex (NAC) by underlying breast cancer. MATERIAL AND METHODS: This prospective study included 70 female patients with breast cancer with a mean age of 45.8 years (range: 28-68). DWI of the breast was done for all patients. Apparent diffusion coefficient (ADC) maps were automatically constructed. The mean ADC values of NAC were independently measured by two observers who are experts in breast imaging and correlated with the results of histopathological examinations. RESULTS: Both observers found a significantly lower ADC value of malignant NAC invasion (n = 18) when compared with free NAC (n = 52), with mean ADC value for malignant NAC invasion was 0.86 ± 0.35 × 10-3 mm2/s and 0.84 ± 0.08 × 10-3 mm2/s for observer one and two respectively versus mean ADC value of 1.34 ± 0.25 × 10-3 mm2/s and 1.4 ± 0.26 × 10-3 mm2/s for free NAC by observer one and two respectively (P-value =0.001). Observer one found that a cutoff ADC value of 1.05 × 0-3 mm2/s can predict malignant NAC invasion with 0.975 AUC, 92.8% accuracy, 94.4% sensitivity, and 92.3% specificity. Observer two found that a cutoff ADC value of 0.95 × 10-3 mm2/s can predict malignant NAC invasion with 0.992 AUC, 95.7% accuracy, 88.9% sensitivity, and 98.1% specificity. CONCLUSION: DWI can predict malignant NAC invasion in patients with breast cancer.

Imaging of congenital cranial dysinnervation disorders: What radiologist wants to know?

We aim to review the imaging features of congenital cranial dysinnervation disorders. Characteristic imaging findings can define subtypes of these disorders through assessment of cranial nerves, extraocular muscles, orbital, and brain abnormalities. Duane retraction syndrome shows absent or hypoplasic 6th cranial nerve and preserved extraocular muscles (EOM). Mobius syndrome shows absent 7th and 6th cranial nerves, absence of facial colliculus, flattening of the dorsal aspect of the pons, hypoplasia of the pons and medulla, and flattening of the 4th ventricular floor. Congenital fibrosis of the extraocular muscles reveals unilateral or bilateral hypoplasia or aplasia of the 3rd cranial nerve, atrophy of superior rectus and levator palpebrae superioris muscles, and atrophy of the brainstem and cerebellar hemispheres. Horizontal gaze palsy and progressive scoliosis show characteristic split pons sign, butterfly medulla, absent facial colliculi, and spinal scoliosis. HOXA1 Mutations show a bilateral absence of 6th cranial nerves with the underdeveloped inner ear. Pontine Cap Tegmental Dysplasia shows ventral pontine hypoplasia, dorsal tegmental projection into the 4th ventricle, and variable cranial nerve deficits.

Interstitial Lung Fibrosis Imaging Reporting and Data System: What Radiologist Wants to Know?

The aim of this work is to review interstitial lung fibrosis Imaging Reporting and Data System (ILF-RADS) that was designed for reporting of interstitial lung fibrosis (ILF). Findings include pulmonary and extrapulmonary findings and is subsequently designed into 4 categories. Pulmonary findings included lung volume, reticulations, traction bronchiectasis, honeycomb, nodules, cysts, ground glass, consolidation, mosaic attenuation and emphysema, and distribution of pulmonary lesions; axial (central, peripheral and diffuse), and zonal distribution (upper, middle, and lower zones). Complications in the form of acute infection, acute exacerbation, and malignancy were also assessed. Extrapulmonary findings included mediastinal, pleural, tracheal, and bone or soft tissue lesions. The lexicon of usual interstitial pneumonia (UIP) was classified into 4 categories designated as belonging in 1 of 4 categories. Lexicon of ILF-RADS-1 (typical UIP), ILF-RADS-2 (possible UIP), ILF-RADS-3 (indeterminate for UIP), and ILF-RADS-4 (inconsistent with UIP).

Multi-parametric arterial spin labelling and diffusion-weighted magnetic resonance imaging in differentiation of grade II and grade III gliomas.

PURPOSE: To assess arterial spin labelling (ASL) perfusion and diffusion MR imaging (DWI) in the differentiation of grade II from grade III gliomas. MATERIAL AND METHODS: A prospective cohort study was done on 36 patients (20 male and 16 female) with diffuse gliomas, who underwent ASL and DWI. Diffuse gliomas were classified into grade II and grade III. Calculation of tumoural blood flow (TBF) and apparent diffusion coefficient (ADC) of the tumoral and peritumoural regions was made. The ROC curve was drawn to differentiate grade II from grade III gliomas. RESULTS: There was a significant difference in TBF of tumoural and peritumoural regions of grade II and III gliomas (p = 0.02 and p =0.001, respectively). Selection of 26.1 and 14.8 ml/100 g/min as the cut-off for TBF of tumoural and peritumoural regions differentiated between both groups with area under curve (AUC) of 0.69 and 0.957, and accuracy of 77.8% and 88.9%, respectively. There was small but significant difference in the ADC of tumoural and peritumoural regions between grade II and III gliomas (p = 0.02 for both). The selection of 1.06 and 1.36 × 10-3 mm2/s as the cut-off of ADC of tumoural and peritumoural regions was made, to differentiate grade II from III with AUC of 0.701 and 0.748, and accuracy of 80.6% and 80.6%, respectively. Combined TBF and ADC of tumoural regions revealed an AUC of 0.808 and accuracy of 72.7%. Combined TBF and ADC for peritumoural regions revealed an AUC of 0.96 and accuracy of 94.4%. CONCLUSION: TBF and ADC of tumoural and peritumoural regions are accurate non-invasive methods of differentiation of grade II from grade III gliomas.

Role of susceptibility-weighted imaging in patients with idiopathic intracranial hypertension.

PURPOSE: To evaluate the role of susceptibility-weighted imaging (SWI) in patients with idiopathic intracranial hypertension (IIH). MATERIALS AND METHODS: A prospective study was done on 55 patients with IIH who underwent SWI of the brain. The images were evaluated by two independent readers for cerebral microbleeds (CMBs) and the interobserver agreement between both readers was calculated. The graphic rating scale (GRS) for headache was calculated. RESULTS: CMBs were found in 16 (29%) of patients with IIH for both readers with excellent interobserver agreement (K = 0.8, p = 0.001). There was excellent interobserver agreement for location (K = 0.8, p = 0.001) and side of CMBs (K = 0.8, p = 0.001). There was good interobserver agreement for size of CMBs (K = 0.75, p = 0.002) and number (K = 0.6, p = 0.006). The mean GRS for headache in patients with CMBs (5.61 ± 1.3) was significantly higher (p = 0.02) than that of patients without CMBs (4.9 ± 0.8). CONCLUSION: We concluded that SWI can detect CMBs in patients with IIH especially in  patients with higher GRS for headache.

Imaging of Fulminant Demyelinating Disorders of the Central Nervous System.

We aim to review the imaging appearance of fulminant demyelinating disorders of central nervous system that have different pathological features, clinical course, clinical features, and imaging findings different from classic multiple sclerosis. Routine magnetic resonance imaging (MRI) can help in accurate localization of the lesions, detection of associated lesions, and monitoring of these patients. Advanced MRI combined with routine MRI can aid in differentiation fulminant demyelinating lesions from simulating malignancy. Tumefactive demyelination lesions are located in supratentorial white matter mainly frontal and parietal regions with incomplete rim enhancement. Baló concentric sclerosis shows characteristic concentric onion skin appearance. Schilder disease is subacute or acute demyelinating disorders with one or more lesions commonly involving the centrum semiovale. Marburg disease is the most severe demyelinating disorder with diffuse infiltrative lesions and massive edema involving both the cerebral hemisphere and brain stem.

Diagnostic accuracy of diffusion tensor imaging in differentiating malignant from benign compressed vertebrae.

PURPOSE: To study diagnostic accuracy of diffusion tensor imaging (DTI) in differentiating malignant from benign compressed vertebrae. METHODS: This study was done on 43 patients with compressed vertebrae on conventional magnetic resonance study that underwent DTI. The mean diffusivity (MD) and fractional anisotropy (FA) of malignant (n = 24) and benign (n = 19) compressed vertebrae were calculated by two readers. RESULTS: There was a significantly lower (P = 0.001) MD of both readers between malignant (0.74 ± 0.2 and 0.78 ± 0.2 × 10-3 mm2/s) and benign (1.67 + 0.3 and 1.63 ± 0.3 × 10-3 mm2/s) compressed vertebrae. The FA of malignant compressed vertebrae of both readers (0.55 ± 0.2 and 0.52 ± 0.1) was significantly higher (P = 0.001) than that of benign (0.26 ± 0.1 and 0.28 ± 0.1) compressed vertebrae. There was excellent inter-reader agreement between both readers using MD (K = 0.91) and FA (K = 0.86). The thresholds of MD and FA used for differentiating malignant from benign compressed vertebrae of both readers were 1.15 and 1.16 × 10-3 mm2/s and 0.37 and 0.34 with area under the curve (AUC) of 0.98, 0.96, 0.93, and 0.92 and diagnostic accuracy of 95.3%, 88.4%, 90.1%, and 86.0% respectively. Combined MD and FA revealed AUC of 0.99 and 0.97 and diagnostic accuracy of 95.3% and 93.0% by both readers respectively. CONCLUSION: DTI is a non-invasive technique providing accurate imaging parameters that can be used for differentiating malignant from benign compressed vertebrae.

Multi-parametric MR imaging using pseudo-continuous arterial-spin labeling and diffusion-weighted MR imaging in differentiating subtypes of parotid tumors.

PURPOSE: To evaluate multi-parametric MR imaging using pseudo-continuous arterial-spin labeling (pCASL) and diffusion-weighted imaging (DWI) in differentiating subtypes of parotid tumors. MATERIAL AND METHODS: This study was done on 61 consecutive patients (27 M, 34 F aged 15-75 ys: mean 42 ys) with parotid tumors that underwent pCASL and DWI with the calculation of tumor blood flow (TBF) and apparent diffusion coefficient (ADC). RESULTS: The mean TBF and ADC of parotid malignancy (n = 20) (53.1 ±â€¯6.9 mL/100 g/min and 0.66 ±â€¯0.1 × 10-3 mm2/s) was a significant different (P = 0.001) than benign tumors (n = 41) (22.7 ±â€¯2.7 mL/100 g/min and 1.28 ±â€¯0.4 × 10-3 mm2/s) respectively. Multi-parametric TBF and ADC were used to differentiate malignant from benign tumors has an AUC (AUC) of 0.97, and the accuracy of 90%. There was a significant difference (P = 0.001) TBF between Warthin tumors (WT) (26.7 ±â€¯9.7 mL/100 g/min) and malignancy. Selection of TBF of 30.5 mL/100 g/min to differentiate malignancy from WT revealed an AUC of 0.95 and the accuracy of 87%. There was a significant difference in TBF and ADC of pleomorphic adenomas (PA) from malignancy (P = 0.001). Multi-parametric TBF and ADC were used to differentiate PA from parotid malignancy revealed an AUC of 1.00. There was a significant difference in TBF and ADC of PA and WT (P = 0.001). Multi-parametric MRI using TBF and ADC used to differentiate PA from WT have an AUC of 0.99, and the accuracy of 92%. CONCLUSION: Multi-parametric MR imaging using pCASL and DWI is useful for differentiating benign parotid tumors from parotid malignancy and PA from WT and TBF helps in discrimination of WT from parotid malignancy.

Multimodal imaging of fibrosing mesenteric tuberculosis.

This article presents fibrosing mesenteric tuberculosis in a 19-year-old Arab boy who presented with weight loss, fever, abdominal pain, and distension. Abdominal contrast enhanced computed tomography (CECT) was performed which showed large infiltrative ill-defined mesenteric-based enhancing soft tissue phlegmonous mass with surrounding desmoplastic reaction causing retraction-kinking of small bowel loops associated with central necrotic mesenteric lymph nodes, multifocal small bowel wall thickening, and ascites. Abdominal tuberculosis is a diagnostic challenge particularly if pulmonary tuberculosis is absent as in this case. CT appears to be the modality of choice if clinical and epidemiological suspicion is high in order to ensure early treatment for a favorable outcome.

Prediction of malignancy of submandibular gland tumors with apparent diffusion coefficient.

OBJECTIVE: This study was performed to predict malignancy of submandibular gland tumors using the apparent diffusion coefficient (ADC). METHODS: In total, 31 patients (19 male, 12 female; age, 16-71 years) with solid submandibular gland tumors were retrospectively analyzed. All patients underwent single-shot echo-planar diffusion-weighted magnetic resonance imaging of the submandibular gland region. ADC maps of the submandibular gland were reconstructed. The ADC value of the submandibular gland tumors was calculated. A freehand region of interest encompassing the homogenous tumor and solid part of the heterogeneous tumor was established. RESULTS: The mean ADC for submandibular gland malignancy (1.15 ± 0.09 × 10-3 mm2/s) was significantly lower than that for benignancy (1.55 ± 0.25 × 10-3 mm2/s, P = 0.001). An ADC of 1.26 × 10-3 mm2/s could predict malignancy of submandibular gland tumors with an area under the curve of 0.869, accuracy of 84%, sensitivity of 88%, and specificity of 81%. CONCLUSION: The ADC is a noninvasive imaging parameter that can be used for prediction of malignancy of submandibular gland tumors.

Diffusion tensor imaging of the optic disc in idiopathic intracranial hypertension.

PURPOSE: To study optic disc in idiopathic intracranial hypertension (IIH) with diffusion tensor imaging. METHODS: Prospective study was carried out on 31 consecutive patients with IIH and 17 age and sex-matched controls that underwent diffusion tensor imaging of optic nerve. Fractional anisotropy (FA) and mean diffusivity (MD) of optic disc were measured by two readers. Grades of papilledema and visual field defects were evaluated by ophthalmologist. RESULTS: FA of optic disc was significantly lower in IIH than controls (p = 0.001) with excellent inter-observer agreement (K = 0.93) of both readers. The cutoff FA used to differentiating IIH from controls were 0.28 and 0.29 with area under curve (AUC) of 0.921 and 0.914, accuracy 92% and 91%, and sensitivity 97% and 96%. MD of optic disc were significantly higher in IIH than in controls (p = 0.001) with excellent inter-observer agreement (K = 0.91) of both readers. The cutoff MD used to differentiating IIH from controls was 1.51 and 1.22 × 10-3 mm2/s with AUC 0.943 and 0.922, and accuracy 94% and 92% respectively. FA of optic disc was significantly lower in early than advanced papilledema and visual field defects (p = 0.001, 0.001) respectively. The MD of optic disc was significantly higher in early than advanced papilledema and visual field defects (p = 0.001, 0.001) respectively. CONCLUSION: Diffusion tensor imaging parameters of optic disc are non-invasive reliable imaging parameters that can be used for diagnosis of IIH and well correlated with papilledema and visual field defects.

Multi-parametric MR imaging using apparent diffusion coefficient and fat fraction in quantification of bone marrow in pediatrics with Gaucher disease.

PURPOSE: To assess multi-parametric MR imaging with apparent diffusion coefficient (ADC) and fat fraction (FF) in detection and quantification of bone marrow involvement in pediatric patients with Gaucher disease. MATERIAL AND METHODS: This study was conducted upon 29 pediatric patients with Gaucher disease and 13 age and sex matched controls that underwent diffusion-weighted MR imaging and dual-echo gradient recalled echo imaging. The ADC and FF of the bone marrow were calculated. RESULTS: There was significant difference in ADC (P = 0.001) and FF (P = 0.001) of bone marrow between patients and controls. The cutoff ADC and FF differentiate patients from controls were 0.47 × 10-3 mm2/s and 0.36 with area under the curve of 0.947 and 0.885 and accuracy of 86.5% and 83.8% respectively. There was significant difference in ADC (P = 0.001) and FF (P = 0.001) between untreated (n = 17) and treated (n = 12) patients. The cutoff ADC and FF differentiate untreated from treated patients were 0.39 × 10-3 mm2/s and 0.27 with area under curve of 0.886 and 0.851 and accuracy of 88% and 84% respectively. CONCLUSION: Multi-parametric MR imaging using ADC and FF are quantitative imaging parameters that can be used for detection and quantification of vertebral bone marrow involvement in pediatric patients with Gaucher disease.