Utility of Non-EPI DWI MRI Imaging in Cholesteatoma: The Indian Perspective.

The purpose of this prospective observational study was to evaluate the diagnostic performance of non-EPI-based techniques, in detecting both primary and residual/recurrent cholesteatoma in a tertiary care center. 56 patients (25 female and 31 male) aged between 6 and 59 years were prospectively evaluated for the presence or absence of cholesteatoma. This included both primary and postoperative recurrent cholesteatoma (16). All the patients underwent sequential CT scans of temporal bones and non-EPI DWI (Non-Echo Planar Diffusion-Weighted Imaging) MRI techniques. The findings were correlated with surgical findings regarding the presence or absence of cholesteatoma. The size of cholesteatoma that was diagnosed on non-EPI DWI MRI was measured. The smallest size was 6 mm and the largest one was 21 mm. The accuracy of non-EPI DWI MRI in diagnosing cholesteatoma (primary and recurrent) was 97.5%. Whereas in diagnosing recurrent cholesteatoma accuracy was 100%. Accuracy of non-EPI DWI MRI is very high in diagnosing cholesteatoma especially in recurrent cholesteatoma and can potentially replace second look surgery when intact canal wall techniques are used. The technique is best used with a CT Scan of the temporal bone to depict bony changes, anatomical variants, or complications. The combination of HRCT and non-EPI DWI needs to be employed in diagnosing primary and recurrent cholesteatoma to maximize the diagnostic benefit as they are complimentary.

Percentage signal intensity recovery: A step ahead of rCBV in DSC MR perfusion imaging for the differentiation of common neoplasms of brain.

CONTEXT: Relative cerebral blood volume (rCBV) and percentage signal recovery (PSR) obtained from T2* dynamic susceptibility contrast magnetic resonance imaging are important parameters for brain tumor assessment. AIM: To study the accuracy of PSR in the differentiation of low-grade glioma, high-grade glioma, lymphoma, and metastases particularly in comparison to rCBV. SETTINGS AND DESIGN: Retrospective observational study. SUBJECTS AND METHODS: Study included pathologically confirmed cases of 10 low-grade glioma, 22 high-grade glioma, 6 lymphoma, and 12 metastases (Total 50). PSR, relative PSR (rPSR), and rCBV were calculated. STATISTICAL ANALYSIS USED: Accuracy of these parameters studied statistically using analysis of variance and ROC (Receiver operating characteristic) curves. RESULTS: rCBV was higher in metastases (3.45 ± 2.82) and high-grade glioma (3.47 ± 1.62), whereas was low in lymphoma (1.03 ± 0.74) and low-grade glioma (1.43 ± 0.47) with P value of 0.030. PSR was low in metastases (48 ± 16.18), intermediate in glioma (73.24 ± 6.39 and 88.26 ± 6.05, high and low grade), and high in lymphoma (112.16 ± 10.57) with P value < 0.000. rPSR was higher for lymphoma (1.73 ± 0.57) than high-grade glioma (0.85 ± 0.11) and metastasis (0.69 ± 0.19) with P value <.000. Area under ROC for PSR was greater than rCBV in differentiating metastases from lymphoma (1.00 vs 0.13), high-grade glioma from lymphoma (1.00 vs 0.38), high-grade glioma from metastases (0.89 vs 0.58), and high-grade glioma from low-grade glioma (0.96 vs 0.03) with excellent curve characteristics. F values for PSR and rPSR from ANOVA analysis were 71.47 and 36.77, was better than rCBV (3.84) in differentiating these groups. CONCLUSIONS: Percentage of signal recovery shows low recovery values in metastases, intermediate recovery values in glioma, and overshoot in lymphoma. PSR values show lower overlap than rCBV between lymphoma and metastases; and between high grade glioma and metastases. PSR difference is also higher than rCBV between low- and high-grade gliomas. Hence, PSR can potentially help as an additional perfusion parameter in the preoperative differentiation of these tumors.

Magnetic resonance imaging of common, uncommon, and rare implantation sites in ectopic pregnancy.

OBJECTIVE: To review the MRI appearances of tubal and non-tubal implantation sites in ectopic pregnancy. CONCLUSION: Transvaginal ultrasound is the primary imaging modality in ectopic pregnancy and MRI is used as a problem-solving tool in selected indications as detailed in the article. MRI features of tubal, interstitial, cervical, cesarean scar, cornual, ovarian, abdominal, and heterotopic pregnancies are provided to familiarize the radiologists with their appearances thereby assisting them in making early and accurate diagnosis.

Anhidrotic ectodermal dysplasia presenting as atrophic rhinitis.

Atrophic rhinitis is a chronic inflammatory disease of the nose. The aetiology of primary atrophic rhinitis is not yet known, although secondary atrophic rhinitis is known to be associated with chronic granulomatous diseases such as tuberculosis and leprosy. The authors report a case of atrophic rhinitis, which was a presenting feature of a rare genetic disorder known as Christ-Siemens-Touraine syndrome, also known as anhidrotic ectodermal dysplasia.