Temporal Evolution of Signal Alterations in the Deep Gray Nuclei in term Neonates With Hypoxic-Ischemic Brain Injury: A Comprehensive Review.

The deep gray nuclei are paired interconnected gray nuclei comprising the basal ganglia and thalami. Injury to the deep gray nuclei secondary to hypoxic-ischemic injury is associated with poor short- and long-term clinical outcomes. The signal changes following hypoxic-ischemic injury are dynamic and evolve over a period of time from injury to resolution. Radiologically relevant events following hypoxic-ischemic injury include the onset of anaerobic metabolism immediately following hypoxic-ischemic injury, increase in cytotoxic edema followed by its resolution, and the onset and progression of neuronal necrosis and gliosis. Appearance of lactate peak on proton spectroscopy is the initial radiologic evidence of hypoxic-ischemic injury. Diffusion-weighted imaging has the highest prognostic value and pseudo-normalizes following 1 week of hypoxic-ischemic injury. Recommended timing for magnetic resonance imaging (MRI) is between 4 and 7 days. MR imaging performed between 1 and 6 months underestimates the extent of injury because radiologic changes are subtle. This review provides a detailed timeline of radiologic abnormalities in the deep gray nuclei following hypoxic-ischemic injury.

Ultrasound and computed tomography in the evaluation of mesenteric lesions: A pictorial review.

The mesentery is a broad fan-shaped fold of peritoneum that suspends the loops of small intestine from the posterior abdominal wall. Although primary neoplasms arising in the mesentery are rare, the mesentery is a major avenue for the dissemination of tumours, which can spread through hematogenous, lymphatic, direct or peritoneal seeding. Imaging helps in the diagnosis of these tumours and aids in directing appropriate treatment by assessing their size, extent and relationship with adjacent structures. The aim of this article is to describe the spectrum of imaging findings of the various mesenteric lesions using ultrasound and CT. Contribution: Evaluation of the mesentery is often neglected during routine ultrasound (US) because of inadequate training and unfamiliarity with the common US features encountered with mesenteric disease. CT plays an essential role in the diagnosis of mesenteric disease. Knowledge of imaging characteristics of various mesenteric lesions helps in timely diagnosis and management.

Spinal Chloroma - Herald of blast crisis in a patient with chronic myeloid leukaemia: A case report.

Myeloid sarcoma or chloroma is a localised tumour characterised by extramedullary proliferation of precursor myeloid cells. Commonly occurring in association with acute myeloid leukaemia, chloroma can occasionally be seen in myeloproliferative disorders with subsequent blastic transformation. Imaging plays an important role in the diagnosis and evaluation of this entity. A case of chloroma involving the dorso-lumbar vertebral region is presented in a patient with chronic myeloid leukaemia with subsequent blastic transformation.

Radiolucent Jaw Lesions: Imaging Approach.

Jaw lesions are a wide array of benign, malignant, and locally aggressive lesions. On radiography, they can appear radiolucent, mixed, or radioopaque. The imaging appearances of radiolucent jaw lesions are markedly overlapping. The role of the radiologist is to formulate a narrow differential diagnosis based on imaging characteristics and aid appropriate management decisions. The aim of this pictorial review is to familiarize the reader with the imaging approach to radiolucent jaw lesions, which form the bulk of jaw lesions in clinical practice.

Comparison of CECT and CT perfusion in differentiating benign from malignant neck nodes in oral cavity cancers.

AIM: The objective of the study was to assess the performance of CT Perfusion in comparison to CECT for preoperative detection of metastases to lymph nodes in squamous cell cancers of oral cavity. METHODS: Twenty-five patients with squamous cell cancers of oral cavity underwent CECT and CTP. Two radiologists evaluated CECT and CTP parameters independently. Surgery and post-operative histopathology was performed in all patients. RESULTS: Level wise analysis of the largest node was done. 102 lymph nodes on CECT and 82 lymph nodes on CTP were correlated with post-operative histopathological findings. CECT had a sensitivity, specificity and accuracy of 75 %, 98.6 % and 91.2 %(p-value <0.001) respectively in differentiating benign from metastatic nodes. Mean transit time[MTT] was significantly the most accurate CTP parameter and carried a sensitivity, specificity, accuracy and AUC of 90.5 %, 93.4 %, 92.7 % and 0.96 (p < 0.001). The sensitivity of MTT was higher than the sensitivity of overall CECT. CONCLUSIONS: CTP is a promising tool for detection of metastatic cervical nodes in squamous cell cancers of the oral cavity.

Alveolar soft part sarcoma of the retroperitoneum: A case report.

Alveolar soft part sarcoma is a rare soft tissue tumor with uncertain histogenesis. It is a slow growing tumor with a high rate of metastasis. The tumor is not easily identified as clinical symptoms are not pronounced. The retroperitoneum is a rare location of tumor, with a few cases published in literature. Surgical excision is the mainstay of treatment. Here we describe a rare case of a large retroperitoneal Alveolar soft part sarcoma in a young female with radiological and histopathological findings.

Diffusion-weighted magnetic resonance imaging in the characterization of odontogenic cysts and tumors.

OBJECTIVES: The aim of this study was to evaluate diffusion-weighted imaging (DWI) in comparison with morphologic magnetic resonance imaging (MRI) in differentiating among odontogenic keratocyst (OKC), unicystic ameloblastoma (UAB), and dentigerous cyst (DC). STUDY DESIGN: Contrast-enhanced MRI, including DWI, was performed on 27 patients with the 3 lesions. Signal intensity characteristics were evaluated on T1- and T2-weighted MRI. The apparent diffusion coefficient (ADC) cutoff value to most effectively differentiate among the 3 lesions was calculated with receiver operating characteristic analysis. RESULTS: In total, 17 OKCs, 5 UABs, and 5 DCs were diagnosed histologically. There were no significant differences among them in signal intensity on T1- or T2-weighted images (P ≥ .13). On DWI, 14 of 17 OKCs showed restricted diffusion with a mean ADC value of 0.954 × 10-3 mm2/s. All 5 UABs and all 5 DCs exhibited facilitated diffusion with ADC values ≥ 2.150 × 10-3 mm2/s. The ADC cutoff to differentiate OKCs from UABs was 2.137 × 10-3 mm2/s (P = .01); UABs from DCs was 2.422 × 10-3 mm2/s (P = .03); and OKCs from DCs was 2.347 × 10-3 mm2/s (P = .01). CONCLUSIONS: Addition of diffusion-weighted sequences to MRI jaw protocols can assist in the characterization of OKCs, UABs, and DCs.

Painful clicking jaw: a pictorial review of internal derangement of the temporomandibular joint.

Temporomandibular joint disorders are a common cause of chronic musculoskeletal pain worldwide. Among these, internal disc derangement is the most frequent type of disorder. Internal derangement is defined as an abnormal positional and functional relationship between the disc and articulating surfaces. Common clinical symptoms include pain and clicking. Imaging plays a key role in diagnosing temporomandibular joint disorders. It is important for the radiologist to detect early imaging signs of internal derangement, thereby avoiding the evolution of this condition to degenerative joint disease. The aim of this article is to familiarise the reader with the spectrum of imaging findings that are encountered at different stages of the disease.

Diagnostic Value of Acoustic Radiation Force Impulse Quantification in the Differentiation of Benign and Malignant Thyroid Nodules.

The objective of this study was to evaluate the role of ultrasound elastography using acoustic radiation force impulse (ARFI) quantification in characterizing and differentiating malignant versus benign thyroid nodules. A total of 40 thyroid nodules were evaluated with conventional sonography and ultrasound elastography using ARFI quantification. The final diagnosis was obtained from histologic findings. A total of 14 malignant and 26 benign nodules were diagnosed on the basis of histologic examination. Majority of the malignant thyroid nodules demonstrated presence of intranodular vascular flow, hypoechoic echotexture, absent halo, irregular margins and microcalcifications. However, a considerable overlap was noted in the sonographic features of malignant and benign thyroid nodules. On ARFI quantification, the mean shear wave speed (SWS) values ( M ± SD) of malignant and benign thyroid nodules were 3.131 ± 0.921 m/s and 1.691 ± 0.513 m/s, respectively. A significant difference was observed between the mean SWS values of malignant thyroid nodules and benign thyroid nodules ( p < 0.0001). Applying a cutoff value of 2.53 m/s, the sensitivity, specificity, and the area under the receiver operating characteristic curve for the differentiation were 85.71%, 96.15%, and 0.922, respectively. ARFI quantification is a promising elastography technique that provides quantitative information about tissue stiffness. It provides additional information and complements sonography as an effective diagnostic tool in characterizing and differentiating benign from malignant thyroid nodules.

Early post-operative weight loss after laparoscopic sleeve gastrectomy correlates with the volume of the excised stomach and not with that of the sleeve! Preliminary data from a multi-detector computed tomography-based study.

BACKGROUND: Pre- and post-operative stomach volumes can be important determinants for effectiveness of laparoscopic sleeve gastrectomy (LSG) in causing weight loss. There is little existing data on the volumes of stomach preoperatively and that excised during LSG. This study was designed to evaluate the change in gastric volume after LSG using multi-detector CT and to correlate it with early post-operative weight loss. METHODS: Twenty consecutive patients with BMI ≥ 40 kg/m(2) and medical comorbidities underwent LSG between October 2011 and October 2013 and were analysed prospectively. The pre-operative stomach volume was measured by MDCT done 1-3 days before the surgery. LSG was performed in the standard manner using a 36F bougie. The volume of excised stomach was measured by distending the specimen with saline. MDCT of the upper abdomen was repeated 3 months postoperatively to calculate the gastric sleeve volume. Weight loss and resolution of comorbidities were documented. RESULTS: The mean pre-operative weight of patients was 123.90 kg, and the mean pre-operative stomach volume on MDCT was 1,067 ml. The stomach volume on pre-operative MDCT correlated with pre-operative weight and BMI. The mean volume of the excised stomach was 859 ml when measured by distension of the specimen and 850 ml on MDCT. After 3 months post surgery, the mean volume of gastric sleeve on MDCT was 217 ml, and the mean weight of the patients was 101.22 kg. The volume of the excised stomach calculated by MDCT correlated with the weight loss achieved 3 months postoperatively. However, no correlation was seen between the gastric sleeve volume 3 months postoperatively and weight loss during this period. CONCLUSIONS: MDCT is a good method to measure gastric volume before and after LSG. Early post-operative weight loss (3 months) correlates well with the volume of the excised stomach but not with that of the gastric sleeve.