Anuj Prabhakar

Blunt traumatic diaphragmatic hernia: Pictorial review of CT signs

Blunt diaphragmatic rupture rarely accounts for immediate mortality and may go clinically silent until complications occur which can be life threatening. Although many imaging techniques have proven useful for the diagnosis of blunt diaphragmatic rupture, multidetector CT (MDCT) is considered to be the reference standard for the diagnosis of diaphragmatic injury. Numerous CT signs indicating blunt diaphragmatic rupture have been described in literature with variable significance. Accurate diagnosis depends upon the analysis of all the signs rather than a single sign; however, the presence of blunt diaphragmatic rupture should be considered in the presence of any of the described signs. We present a pictorial review of various CT signs used to diagnose blunt diaphragmatic injury. Multiplanar reconstruction is very useful; however, predominantly axial sections have been described in this pictorial review as the images shown are from dual-slice CT.

Prevalence of normal head CT and positive CT findings in a large cohort of patients with chronic headaches.

This study was carried out to ascertain the frequency of normal head computed tomography (CT) scans and positive CT scan findings in patients having chronic headache as chief complaint. Head CT scans done over a period of two years were retrospectively evaluated. On the basis of CT reports, the patients were divided into two groups: Group A, having headache as the only complaint, and Group B, having headache and additional neurological signs or symptoms. A total of 2498 patient reports were evaluated. There were 1772 patients in Group A and 726 patients in Group B. In Group A, 82% (n = 1453) patients had normal head CT, whereas in Group B 74.5% (n = 541) patients had a normal CT scan. There were 13.22% head CT scans showing significant findings in Group B, as compared to 6.2% in Group A. Both these differences were found to be statistically significant. CT findings such as infections, neoplasm, hydrocephalus, and extra-axial collections were higher in Group B when compared to Group A. CT examination in patients with isolated chronic headache is normal in high percentage of patients. The frequency and distribution of various CT findings over different age groups in a large cohort of patients presenting with chronic headache are discussed.

Evaluation of MR perfusion abnormalities in organophosphorus poisoning and its correlation with SPECT

Aim: Acute organophosphate (OP) pesticide poisoning causes substantial morbidity and mortality worldwide. Many imaging modalities, such as computerized tomography (CT), magnetic resonance imaging (MRI), and single photon emission computed tomography (SPECT) of the brain, have been used for quantitative assessment of the acute brain insult caused by acute OP poisoning. Perfusion defects on SPECT in acutely poisoned patients with OPs have been described, however, MR perfusion abnormalities have not been described in the literature. MR perfusion Imaging has the advantage of having higher spatial resolution, no radiation, and better availability. Materials and Methods: In this prospective study, 20 patients who ingested OP compounds were included. All the patients underwent brain SPECT on a dual head SPECT gamma camera and MRI brain on a 1.5T MR system. Neurocognitive tests were performed for all patients. Results: SPECT showed perfusion defects in 7 patients and total number of perfusion defects were 29. On MR perfusion, based on the cut-off values of normalized cerebral blood volume (nCBV) ratios and normalized cerebral blood flow (nCBF) ratios, the total number of patients showing perfusion defects were 6 and 8; and the total number of perfusion defects were 29 and 45, respectively. There was significant difference of the nCBV ratios and nCBF ratios between the control group (n = 20) and positive patients group (n = 6 and n = 8, respectively) (P > 0.05). All the defects seen on SPECT were well appreciated on nCBF maps (MRI perfusion) suggestive of 100% correlation. Conclusion: MR perfusion imaging can be used as an effective modality for evaluation in acute OP poisoning.