Role of Diffusion-Weighted Imaging in the Evaluation of Perianal Fistulae.

Background Magnetic resonance imaging (MRI) is the imaging modality of choice for evaluating perianal fistulae, due to its ability to show the relationship of perianal fistulae with anal sphincters, fistula extensions, secondary ramifications and associated complications. Aim To evaluate the role of diffusion-weighted MRI in the evaluation of perianal fistulae. Settings and Design A hospital-based cross-sectional study. Materials and Methods The study group composed of 47 patients of perianal fistula. MRI with diffusion-weighted imaging (DWI) was performed with Philips 0.5 T Ingenia scanner. DWI with different b -values ( b = 50, b = 400, and b = 800 smm 2 ) were obtained. The MRI findings were correlated with local clinical examination and or surgical findings. Statistical Analysis Used Chi-square test, independent samples t -test, and receiver operating characteristic curve analysis. Result Fifty-nine perianal fistulas in 47 patients were included in the study sample. The visibility of perianal fistula on DWI was less than T2-weighted (T2W) and combined DWI-T2W images. Distinctly visualized (visibility score 2) perianal fistulas were observed in 47 fistulas (79.6%) on DWI, 54 (91.5%) on T2W, and 58 (98.3%) on DWI-T2W images. The mean of apparent diffusion coefficient (ADC) values of active fistula was 0.972 ± 0.127 [SD] 10 -3 mm 2 /s and inactive was 1.232 ± 0.185 [SD] 10 -3 mm 2 /s with a significant difference ( p -value < 0.0005). A cut-off mean ADC value of 1.105 × 10 -3 mm 2 /s was used to differentiate active from the inactive fistula with a sensitivity of 87.5% and specificity of 73.3%. Conclusion Combined DWI-T2W evaluation had a better performance in the detection of fistula than DWI or T2W alone. DWI with mean ADC calculation had a good performance in differentiating active from the inactive fistulas.

Normative magnetic resonance imaging measurements of orbital structures in pediatric population of North-Eastern India: A retrospective cross-sectional study.

Purpose: The people of Northeast India comprise mostly of Mongoloid descent with characteristic craniofacial features. The purpose of this study was to evaluate the normal orbital structures with MRI and determine normative data in the Northeast Indian pediatric population. Methods: MRI images of the 302 orbits of 151 pediatric patients below 16 years of age were retrospectively evaluated to measure the various orbital structures. Both axial and coronal MRI images were utilized for various orbital measurements. An independent sample t-test was done to compare various orbital data according to the sex and side. Linear regression was also done. Results: The mean age of the pediatric population was 9.64 ± 1.47 years with a male: Female ratio of 1.13:1. The mean interzygomatic line was 88.4 ± 9.09 mm and the interorbital line was 22.18 ± 3.62 mm. The mean thicknesses of medial, lateral, superior, and inferior recti muscles were 2.58 ± 0.46, 2.34 ± 0.42, 2.16 ± 0.40, and 2.53 ± 0.49 mm in males and 2.41 ± 0.41, 2.08 ± 0.34, 2.08 ± 0.46, and 2.46 ± 0.49 mm in females. The mean horizontal orbital, vertical orbital diameters, orbital index, mean volume of eyeball, and orbital cavity were 30.27 ± 2.97,3 7.06 ± 3.57, 122.58 ± 7.39, 4.63 ± 0.84, and 15.29 ± 3.52 in males, while 29.16 ± 3.23, 34.96 ± 3.99,119.96 ± 7.31, 4.49 ± 0.87, and 14.65 ± 3.47 in females, respectively. With an increase in age, the interzygomatic line (r = 0.883, r2 = 0.780; P < 0.0005), anterior medial interorbital line (r = 0.808, r2 = 0.652; P < 0.0005), mean volume of eyeball (r = 0.915, r2 = 0.838; P < 0.0005), orbital cavity (r = 0.924, r2 = 0.854; P < 0.0005), and distance between the optic nerve entry site (r = 0.829, r2 = 0.687; P < 0.0005) were increased. Conclusion: This study provides normative data of various orbital structures in a pediatric population and these data likely to be useful for diagnosing various pediatric orbital disorders and helps in the planning of various surgical procedures of orbits.

Added Value of Three-Plane Multiecho Fast Field Echo MRI Sequence in the Evaluation of Acute Spinal Trauma Using Sensitivity: A Prospective Study.

Background Multiecho fast field echo (mFFE) MRI sequence provides added value to the conventional MR imaging in evaluation of acute spinal trauma, especially for detecting spinal cord hemorrhage which is a best predictor for patient prognosis. Objective This study aims to evaluate the diagnostic efficacies of three-plane mFFE MRI sequence along with the conventional MRI sequences in acute spinal trauma patients using sensitivity.  Materials and methods This prospective study comprised of 48 patients of acute spinal trauma. The neurological deficit of acute spinal trauma patients assessed according to the American Spine Injury Association (ASIA) scale. The correlation between the various MRI findings of acute spinal cord injury and neurological deficits were compared with the Chi-square test. Results Of 48 patients of acute spinal trauma, 36 males and 12 females with a mean age of 38.71±1.42 [SD] years. 22 (45.8%) patients had cord edema with a mean length of was 3.45±5.52 [SD] cm. The mean percentage of spinal canal compromisation was 39.47±25.47 [SD] and spinal cord compression 18.1±24.4 [SD]. There was statistical significance between the ASIA impairment scale and spinal canal compromisation and cord compression with a p-value of 0.0005. Cord hemorrhage observed in 13 (27%), non-hemorrhagic cord contusions in 3 (6.3%), cord transection in 5 (10.4%) and epidural hematoma in 10 (20.8%) patients with an initial high grade of ASIA scale. The visibility score of three-plane mFFE sequence was higher in comparison to the single plane sagittal mFFE and short tau inversion recovery (STIR) sequences. For detection of spinal cord hemorrhage with visibility score of 2, the three-plane mFFE had sensitivity of 77% followed by 38.5% with single plane sagittal mFFE and 7.7% with sagittal STIR images. 26 (54.2%) patients showed neurological improvement in their hospital stay/follow-up period and no improvement observed in 7 (14.6%) patients of acute spinal trauma. Conclusions Application of three-plane mFFE sequences detects more spinal cord hemorrhages and vertebral fractures with a better visibility score as compared to the single sagittal plane mFFE and STIR sequence.

Added Value of Diffusion-Weighted Magnetic Resonance Imaging in Differentiating Musculoskeletal Tumors Using Sensitivity and Specificity: A Retrospective Study and Review of Literature.

BACKGROUND: Diffusion-weighted imaging (DWI) provides added value to conventional MRI imaging in diagnosing and differentiating various benign and malignant musculoskeletal tumors. OBJECTIVE: The study aims to evaluate the diagnostic efficacies of diffusion-weighted imaging along with the conventional MRI sequences for differentiating benign and malignant musculoskeletal tumors using sensitivity and specificity. MATERIALS AND METHODS: This retrospective study was carried out on 73 histopathologically proven patients of various musculoskeletal tumors who presented to a tertiary care center between March 2017 to October 2018. Relevant clinical examinations and MRI scan of the requested body part of the musculoskeletal system were performed. Mean apparent diffusion coefficient (ADC) values were calculated in the bone as well as soft tissue tumors after placing uniform-sized region of interest (ROI) in the non-necrotic portion of the tumor. STATISTICAL ANALYSIS: Independent t-test and one-way analysis of variance (ANOVA) test were used to compare the mean ADC values of the various tumors with the histopathology. Receiver operating characteristic (ROC) curve analysis was done to determine the cut-off mean ADC values in the various bone and soft tissue tumors. RESULTS: Of 73 patients with musculoskeletal tumors (benign=20, malignant = 53), 47 patients were bone tumors (benign=12, malignant=35) and 26 patients were soft tissue tumors (benign=eight, malignant=18). Mean ADC value of benign bone tumor was 1.257±0.327[SD] x 10-3mm2/s and malignant was 0.951 ± 0.177[SD] x 10-3mm2/s. The mean ADC value of benign soft tissue tumor was 1.603±0.444[SD] x 10-3mm2/s and malignant was 1.036 ± 0.186[SD] x 10-3mm2/s. The cut-off mean ADC value was 1.058 x 10-3mm2/s for differentiating benign from malignant bone tumor with a sensitivity of 83.3%, specificity of 66.7% and accuracy of 78.7% while the cut-off mean ADC value of 1.198 x 10-3mm2/s for differentiating benign from malignant soft tissue tumors with a sensitivity of 83.3%, specificity of 87.5% and accuracy of 84.6%. CONCLUSIONS: DWI with ADC mapping can be used as an additional reliable tool along with conventional MRI sequences in discriminating benign and malignant musculoskeletal tumors.

Added value of 3D-DRIVE and SWI Magnetic Resonance Imaging Sequences in Intraventricular Neurocysticercosis (IVNCC): An Institutional Experience from Northeast India.

Background: Prompt diagnosis and early treatment institution are important in intraventricular neurocysticercosis (IVNCC) as compared to the parenchymal or racemose form because it is associated with a poorer patient prognosis. Intraventricular neurocysticercosis is often missed on CT scan or conventional cranial magnetic resonance imaging because of similar density or signal intensity of cysticercus lesion with cerebrospinal fluid.Thestudy aims to evaluate the added value of 3D-DRIVE and SWI MRI sequences in isolated intraventricular cysticercosis with acute neurological presentation. Methods and Materials: This retrospective study was carried out on diagnosed 10 patients with isolated intraventricular neurocysticercosis (IVNCC) presented to a tertiary care hospital with an acute onset of symptoms or acute neurological deficit between June 2019 to May 2021. Relevant neurological examination, CSF analysis, a serological test of neurocysticercosis and MRI scan of the brain were performed. Result: Tenpatients of isolated intraventricular neurocysticercosis (3 males and 7 females) having 3 pediatric and 7 adults were included in this study sample.The common neurological complications of the isolated intraventricular neurocysticercosis in this study are observed as obstructive hydrocephalus in 8(80%) patients and ependymitis in 7(70%) patients. IVNCC with distinctly visualized scolex (visibility score 2) identified in 2(20%) patients in T2WI, 8 (80%) patients in 3D-DRIVE and 3(30%) patients in SWI sequences. The cyst wall of IVNCC was distinctly visualized (visibility score 2) in 1(10%) patient in T2WI, 8(80%) patients in 3D-DRIVE and 6(60%) patients in SWI sequence. Conclusion: Heavily T2-weighted steady-state and SWI sequences should be added to routine MRI sequences that helps to identify IVNCC and should be used in patients with unexplained hydrocephalus, especially in endemic regions of Neurocysticercosis.

Magnetic resonance imaging evaluation of posterior spinal tuberculosis: a cross-sectional study.

BACKGROUND: Isolated posterior spinal (element) tuberculosis (TB) is uncommon compared to classical anterior spinal or para-discal TB. Here, we report magnetic resonance imaging (MRI) findings of posterior spinal TB in 19 patients without involvement of the vertebral body and intervertebral disc. PURPOSE: To evaluate the MRI findings in isolated posterior spinal (element) TB. MATERIAL AND METHODS: Clinical and MRI data of 19 patients of isolated posterior spinal TB were retrospectively evaluated. RESULTS: Of the 19 patients, group A comprised 4 (21%) patients with rapid onset lower limb weakness and pyramidal signs while group B comprised 15 (79%) patients without any neurological deficit. Lumbar vertebrae commonly affected 9 (47.4%) patients followed by dorsal vertebrae in 8 (42.1%) patients and cervical vertebrae in 2 (10.5%) patients. The pedicle was most commonly involved in 12 (63.2%) patients followed by the lamina in 11 (58%) patients, and spinous process and facet joint in 6 (31.6%) patients each. Extra-spinal inflammation/pyomyositis/paraspinal abscess was found in 13 (68.4%) patients followed by epidural abscess 3 (15.8%) patients and both extra spinal inflammation and epidural abscess in 3 (15.8%) patients (15.8%). Compressive cord myelopathy was observed in 4 (21%) patients, where three patients underwent emergency decompression laminectomy and the remaining 16 patients were treated conservatively with anti-tubercular therapy. CONCLUSION: Initial diagnosis of isolated posterior element TB is challenging and requires a high index of suspicion. Early diagnosis of isolated posterior spinal TB is important as early treatment may be beneficial and decreases patient morbidity.