Uttam George

MRI in evaluation of perianal fistula

This essay illustrates the usefulness of MRI in evaluating perianal fistulas, a common disease, notorious for recurrence if not assessed and treated adequately. MRI exquisitely depicts the perianal anatomy and shows the fistulous tracks and their associated ramifications and abscesses. It thus provides an excellent preoperative understanding of the disease, enabling selection of the most appropriate surgical treatment and therefore minimising all chances of recurrence.

Susceptibility-weighted imaging in the evaluation of brain arteriovenous malformations.

BACKGROUND Digital subtraction angiography (DSA) remains the gold standard in the evaluation of arteriovenous malformations (AVMs). Susceptibility-weighted imaging (SWI), a relatively new magnetic resonance imaging (MRI) technique, exploits the magnetic susceptibility differences of various tissues, such as blood, iron and calcification. Earlier studies have shown that the magnitude and phase information of SWI offers improved sensitivity, revealing low-flow vascular malformations that are invisible on conventional gradient-echo (GRE) sequences. AIM To evaluate the imaging appearance of AVMs on SWI. MATERIALS AND METHODS In this retrospective study, the appearance of the various components (feeding artery, nidus, and draining veins) of AVMs on the phase, magnitude, and minimal intensity projection (minIP) images of SWI were analyzed in 14 patients with AVM and compared with conventional sequences. RESULTS Detection and delineation of various components of AVMs was best achieved in the magnitude images. Although minIP was most effective in detecting hemorrhage and calcification, it was the magnitude image that could separate the hemorrhagic and calcified component in the nidus from the remaining nidus. The minIP was less effective in detecting the AVM components, especially nidus and draining vein, whereas conspicuity was poor with the phase images. CONCLUSION The magnitude images of the SWI help in differentiating the different components of AVM and also helps in differentiating nidus from hemorrhage and calcification.

Magnetic resonance "flip-flop" in idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is a headache syndrome with raised CSF pressure in the absence of an intracranial mass lesion. Though earlier confined to excluding intracranial lesions, magnetic resonance imaging (MRI) in recent years has been shown to identify intracranial changes from prolonged raised CSF pressure, suggestive of IIH. We present the MRI and TOF (time-of-flight) venography findings involving the orbit, sella tursica and cerebral venous structures in a 45-year-old lady with IIH and illustrate their reversibility (“flip-flop”) following CSF drainage. Our case highlights the role of imaging in evaluation and follow-up of patients with IIH, without the need for repeated lumbar punctures to monitor pressures.

Retrorectal hamartoma: A 'tail' of two cysts!

Retrorectal hamartomas or tail gut cysts are rare congenital anomalies most commonly seen in a retrorectal location; most common in middle aged women. This article describes the radiological appearance in two cases of tail gut cysts in males, one a child with a visible perianal swelling since birth and the other, a 72-year-old man with symptoms for one week. In both, the tailgut cysts were in a right perirectal location. Presentation in such a location in males, at extremes of age, is unusual for tailgut cysts.

Unusual coexistence of caudal duplication and caudal regression syndromes.

Caudal duplication syndrome includes anomalies of the genitourinary system, gastrointestinal tract, and the distal neural tube. Caudal regression syndrome presents with lumbosacral hypogenesis, anomalies of the lower gastrointestinal tract, genitourinary system, and limb anomalies. Both happen as a result of insult to the caudal cell mass. We present a child having features consistent with both entities.

Vertebrobasilar dolichoectasia and a tale of two brothers

presentation, such as sudden onset of neurological symptoms, a well-defined lesion in a vascular territory and absence of significant mass effect. In our case, presence of heterogeneously enhancing lesion with clear-cut margins and wedge shape in the territory of medial branch of posterior inferior cerebellar artery, were the features that mislead us to diagnose the lesion as subacute cerebellar infarct. DWI and MR spectroscopy are the additional modalities which may be helpful in distinguishing between the two, particularly when the clinical history is obscure. In late subacute-to-chronic infarction, restricted diffusion may not be evident, thus making DWI less useful in making the distinction between a tumor and an infarct, as in our case.

All that is swollen and red is not infection

Unilateral upper limb extremity swelling and pain are common presentations in clinical practice whose differential diagnoses include cellulitis, abscess, lymphoedema, and venous thrombosis. We report here the case of a renal transplant recipient with an unusual cause of upper extremity swelling and pain. His condition of native radiocephalic, arteriovenous (AV), fistula-related, venous hypertension was misdiagnosed and managed as cellulitis. This case illustrates the importance of an index of suspicion and careful clinical examination for diagnosis and thus, avoid potentially dangerous and distressing symptoms. The patient improved with a surgical AV fistula ligation.

Split thalamus: internal medullary involvement in Wilson's disease.

Neurology India | Jul-Aug 2010 | Vol 58 | Issue 4 Figure 1: (a) T2 FLAIR axial image shows the bilateral putaminal (arrowhead) and thalamic involvement. (b) T2-weighted axial image shows the curvilinear hyperintense internal medullary lamina (arrowhead) between the medial and lateral thalamic groups of nuclei with a “split thalamus” appearance. (c) Medial and lateral nuclear groups of the thalamus on either side of the hyperintense internal medullary lamina (arrowhead) seen on the coronal T2 image. Hyperintensity in the fields of florel is also seen (arrow) Neuroimage

Prospective randomized comparative study to evaluate epidural fibrosis and surgical outcome in patients undergoing lumbar laminectomy with epidural autologous free fat graft or gelfoam: A preliminary study

Introduction: Epidural fibrosis (EF) contributes to unsatisfactory relief of symptoms and failed back syndrome after spine surgery. EF around the nerve root can be more refractory to treatment than the original disc herniation itself. Reoperation on the scar can produce more scarring. Few studies have been conducted regarding the type of material to be used for decreasing EF. Materials and Methods: The prospective randomized comparative study was conducted in the Department of Neurosurgery and Radiodiagnosis, of a tertiary care hospital. Informed and written consent was obtained. Patients previously unoperated with symptoms and radiological features of lumbar spinal canal stenosis were included in the study. Fifteen patients were assigned to Group A (free fat graft) and 15 patients in Group B (Gelfoam group). Postoperatively, at 3 and 6 months, clinical outcome was evaluated and EF was assessed on CE-MRI. Results: Age and sex were comparable in both groups. The pain relief at 3 and 6 months was more in Group A as compared to Group B. In Group A, on CEMRI at 3 months, 87% of patients had none to mild fibrosis, with none had extensive fibrosis. The CEMRI at 6 months showed no increase in fibrosis. In Group B, 80% of patients had none to mild fibrosis at the end of 3 months. At 6 months, 13.3% patients had extensive fibrosis. The extent of EF was found to be statistically significant at 6 months postsurgery. Conclusion: Use of free fat graft at laminectomy site helps in reducing EF.

A new approach for the management of esophageal atresia without tracheo-esophageal fistula

Long gap esophageal atresia (OA) is a challenging condition. While discussing the various methods of management available to us, we report the use of magnetic resonance imaging in a case of pure OA to judge the gap between two ends of the esophagus.