Comparison of helical and axial mode indirect computed tomographic venography in patients with pulmonary thromboembolism.

OBJECTIVE: To compare the helical and axial modes of indirect computed tomographic (CT) venography (CTV) for accuracy for diagnosing deep venous thrombosis (DVT) of the lower extremities as well as for their radiation burden in patients proven to have pulmonary thromboembolism (PTE) on CT pulmonary angiography (CTPA). SUBJECTS AND METHODS: Of patients evaluated with CTPA for suspected acute PE, 20 of patients who were found to have PTE underwent both indirect CTV of the lower extremities and color Doppler examination. For indirect CTV, patients were randomly assigned to helical and axial modes. The CTV and Doppler findings were interpreted by two experienced radiologists who were blinded to the results of each other. RESULTS: Out of total of 260 venous segments analyzed (130 venous segments each by helical or axial CTV), thrombi were seen in 43 venous segments (15 and 28 each by helical or axial CTV respectively). On comparison with Doppler, helical CTV had 82.35% sensitivity and 99.11% specificity, whereas axial CTV had 96.6% sensitivity and 100% specificity. The mean radiation dose was significantly higher for helical (1153.57 mgy.cm) as compared to axial mode CTV (806.28 mgy.cm) with P value of <0.0001. CONCLUSION: Axial CTV results in decreased radiation dose without significant change in the accuracy, as compared to helical CTV in the evaluation of DVT.

Tuberculous meningo-encephalitis mimicking herpes simplex encephalitis on MRI.

A 30-year-old man was admitted in PGIMER with the complaints of fever, altered sensorium and seizures. Magnetic resonance imaging (MRI) showed bilateral symmetrical temporal and frontal hyperintensities, which were highly suggestive of herpes simplex encephalitis. However, brain autopsy revealed it to be tuberculous meningo-encephalitis.

Multidetector CT angiography in Takayasu arteritis.

OBJECTIVE: To analyse the spectrum of Takayasu's arteritis (TA) on multidetector CT angiography (MDCTA). MATERIALS AND METHODS: A retrospective analysis of the MDCTA findings was performed on 15 patients clinically diagnosed as Takayasu's arteritis. The spectrum and incidence of imaging findings on CTA were compared to studies in literature on catheter angiography in Takayasu's arteritis. Laboratory parameters were available in nine patients. The disease was considered active if erythrocyte sedimentation rate (ESR) levels were elevated and 'C' reactive protein (CRP) was positive. An attempt was made to correlate disease activity with the imaging findings. RESULTS: Ascending aorta, arch of aorta and descending thoracic aorta were involved in 14 out of 15 (93%) patients. The wall thickness varied between 1 and 10mm with maximal involvement in arch and descending thoracic aorta. Major neck vessels were involved in 11 (73%) patients with most pronounced changes seen in the brachiocephalic trunk, left common carotid artery (CCA) and left subclavian artery (SCA). Abdominal aorta and its branches were involved in all the 11 (100%) patients in whom abdominal CTA was performed. Celiac axis and SMA were involved in 10 (91%) and seven (64%) patients, respectively while renal artery stenosis was present in five (45%) patients. In six patients, ESR was elevated and CRP was positive indicating active disease. All patients in whom the laboratory parameters were available showed mural thickening in the aorta and at least one of the neck vessels except for one patient with inactive disease who had aortic mural thickening only. CONCLUSION: MDCTA provides information about both the vessel wall and lumen in patients with Takayasu's disease.

Severe acute pancreatitis: the life after.

BACKGROUND: The present study reports functional and morphological changes noted over long-term follow-up in patients with severe acute pancreatitis. METHODS: Thirty patients who had completed at least 6 months after recovery were included. Fecal fat, urinary D-xylose, blood sugar, C-peptide, pancreatic changes, and recurrences were studied. RESULTS: Etiology was gallstones (12), alcohol (10), both gallstone and alcohol (3), and idiopathic (5). Five patients were managed conservatively while 25 underwent surgery. Mean follow-up was 31.3 months. Exocrine and endocrine insufficiencies were noted in 12 (40%) and were more common in no-necrosis group compared to necrosis group (p = 0.04 and 0.28, respectively) and infected compared to sterile pancreatitis (45% vs. 25%, p = 0.55 and 50% vs. 12%, p = 0.15, respectively). Higher frequency was noted in nonvisualized, partly visualized, and dilated segment of duct. Significant proportion (8/12) had both exocrine and endocrine abnormalities and their incidence decreased as duration of follow-up increased. Urinary D-xylose excretion was abnormal in 16% and noted >1 year postrecovery. Thirty percent required >1 readmission and pain was the commonest cause. CONCLUSIONS: Forty percent had functional abnormality; 16% had mucosal absorption abnormality while 30% required >1 readmission. Exocrine and endocrine insufficiencies were more prevalent in first year, and a significant proportion had both. A trend for higher functional insufficiency was observed in infected necrosis, complete or incomplete visualization of main pancreatic duct (MPD), dilated segment of MPD, and pseudocyst.

Magnetic resonance imaging of brain in patients with cirrhotic and non-cirrhotic portal hypertension.

BACKGROUND: Hyperintense signals in the basal ganglia, namely the globus pallidus, have been reported on magnetic resonance imaging (MRI) in 70-100% of patients with cirrhosis of the liver. Deposition of paramagnetic substances, particularly manganese (Mn), has been reported to be responsible for these hyperintense signals. They are found in cirrhotics with or without overt/subclinical hepatic encephalopathy. Deposition of Mn has been attributed to hepatocellular failure and/or portosystemic shunting. Reports of MRI brain findings in patients with extra hepatic portal venous obstruction (EHPVO) and non-cirrhotic portal fibrosis (NCPF) are scanty in the literature. AIMS: The purpose was to determine the basal ganglia changes on MRI in patients with EHPVO and NCPF and to compare it with patients with cirrhosis of the liver. PATIENTS AND METHODS: A total of 27 patients (EHPVO = 10, mean age 28.4 +/- 19.0 years, NCPF = 7, mean age 37.1 +/- 10.4 years, cirrhosis = 10, mean age 47.0 +/- 19.6 years) was studied prospectively from January to December 2001. MRI of the brain was done with a standard spin echo axial T1- and fast spin echo T2-weighted scan obtained on a 1.5-T MRI unit. Two radiologists in a blinded fashion graded the signal intensity of basal ganglia on T1-weighted (T1 W) sequences by comparing it with the adjacent unaffected grey matter. RESULTS: None of the patients with EHPVO or NCPF had any past history of hepatic decompensation and/or overt encephalopathy. Seven (70%) of the cirrhotics had a past history of overt encephalopathy. None of the patients with EHPVO showed any hyperintensity of basal ganglia on T1-weighted MRI images. Hyperintense globus pallidus was seen in four (57%) and eight (80%) patients with NCPF and cirrhosis, respectively. CONCLUSION: Hyperintense globus pallidus on MRI is common in patients liver cirrhosis and also occurs in patients with NCPF. Patients with EHPVO do not have hyperintense globus pallidus on T1-weighted MRI images.

Dynamic magnetic resonance imaging evaluation of craniovertebral junction abnormalities.

OBJECTIVES: To evaluate the role of dynamic magnetic resonance imaging (MRI) in craniovertebral junction (CVJ) abnormalities. MATERIALS AND METHODS: Twenty-five patients with suspected CVJ abnormalities underwent dynamic MRI of the CVJ, and in 20 of these patients, noncontrast computed tomography scan of the CVJ was done. The images were evaluated for atlantoaxial instability (AAI), spinal canal narrowing, cord compression, presence of altered cord signal intensity, and bony abnormalities in neutral, flexion, and extension. RESULTS: Dynamic MRI detected 15 cases of AAI (10 fixed and 5 mobile AAI), 21 patients had varying degrees of spinal canal narrowing. Five patients showed increased narrowing on flexion/extension. Two patients demonstrated direct cord compression in flexion, whereas in neutral position, only dural compression was seen. One patient had cord compression on extension that was not seen in neutral or flexed position. CONCLUSION: Dynamic MRI was able to detect cases of cord compression that were not seen in neutral position and was diagnostic in all cases of mobile AAI where mobility at this joint affects the treatment options. Dynamic MRI is extremely useful for evaluating craniovertebral junction abnormalities and, in particular, cord compression.

Comparison of multidetector computed tomographic colonography and conventional colonoscopy for detection of colorectal polyps and cancer.

BACKGROUND: Computed tomographic colonography (CTC) is a new technique for detecting colonic neoplasms. Data on the utility of this method in the Indian population are limited. METHODS: Forty-two patients with symptoms of colonic disease underwent CTC and conventional colonoscopy (CC) within one week of each other and the findings at these two investigations were compared. RESULTS: The entire colon could be evaluated in 38 patients on CTC and in 23 patients on CC. Of the 19 patients who had incomplete CC, 14 had occlusive colonic lesions. Of the 86 lesions detected on CC, 76 (88.4%) were correctly identified on CTC with regard to location and size. CTC was false negative for 10 lesions and false positive for 5 lesions in 3 patients. The sensitivity and specificity of CTC were 65% and 77%, respectively, for lesions 1-5 mm; 97% and 83% for 6-9 mm-sized lesions; and 100% and 100% for lesions 10 mm or larger. Extracolonic findings were seen in 24 of 42 patients (57%). CONCLUSIONS: CTC is reliable for detecting lesions 6 mm or larger in size. It permits evaluation of the region proximal to an occlusive growth, which is often not possible with CC.

Comparison between contrast-enhanced magnetic resonance imaging and technetium 99m glucohepatonic acid single photon emission computed tomography with histopathologic correlation in gliomas.

OBJECTIVE: : To determine and compare the accuracy of contrast-enhanced magnetic resonance imaging (MRI) and Technetium 99m glucohepatonic acid single photon emission computed tomography (Tc-GHA SPECT) in grading of gliomas, compared with neuropathologic findings. MATERIALS AND METHODS: : The study included 20 adult patients (13 men and 7 women) with clinical/radiological suspicion of brain tumor (glial tumor) who were subjected to magnetic resonance examination and Tc-GHA brain SPECT.The lesions were evaluated by using MRI imaging score, based on 9 MRI criteria. Based on the discrimination threshold of 0.9 for mean MRI score, the gliomas were graded as low- or high-grade glioma. The Tc-GHA SPECT retention index was calculated as the ratio between delayed and early uptake ratios. Based on the discrimination threshold of 1 for Tc-GHA SPECT retention index, the gliomas were graded as low- or high-grade glioma.The diagnosis was verified by means of histopathologic examination in all patients (open surgery in 19 patients and stereotactic biopsy in 1 patient). Correlation between MRI findings/scores, SPECT scores, and histopathologic grades was done in all the patients, and comparison between MRI and Tc-GHA SPECT was made using paired Student t test and correlation coefficient. RESULTS: : The study revealed significant difference between the mean MRI scores and early uptake ratio, delayed uptake ratio, and retention index of low-grade (grades I-II) and high-grade (grades III-IV) gliomas. No statistically significant difference could be demonstrated between the abilities of contrast-enhanced MRI and Tc-GHA SPECT to allow differentiation between high- and low-grade gliomas. The accuracy of MRI (78.4%), however, was slightly higher than that of Tc-GHA SPECT (73.68%). However, Tc-GHA SPECT allowed differentiation between high-grade gliomas (between grades III and IV gliomas). CONCLUSIONS: : The accuracy of contrast-enhanced MRI in the distinction of high- and low-grade malignancy was higher than that of Tc-GHA SPECT. The performance of Tc-GHA SPECT adds little in determining tumor grade when MRI is performed. However, it may act as a useful adjunct to differentiate between grades III and IV gliomas.

Calcified neonatal renal vein and vena caval thrombosis.

We present an unusual case of an extensive venous thrombosis (involving the inferior vena cava, bilateral renal veins, gonadal vein and iliac veins) diagnosed in the neonatal period. The CT images revealed the typical diagnostic pattern.

MDCT in the staging of gallbladder carcinoma.

OBJECTIVE: The purpose of our study was to determine the utility of dual-phase MDCT with 3D reconstruction in the staging and resectability of gallbladder carcinoma. SUBJECTS AND METHODS: Twenty-seven consecutive patients with suspected gallbladder carcinoma on clinical examination and routine sonography were prospectively analyzed with dual-phase MDCT. Of these patients, only 20 who underwent a laparotomy for extended cholecystectomy or a palliative surgery were included in the study. Three-dimensional volume-rendered reconstruction was used for evaluation of the vascular invasion and anatomy. The staging and resectability as determined on CT were compared with preoperative findings. RESULTS: On the basis of the CT findings, eight tumors were resectable and 12 were unresectable. On surgery, 11 tumors were found to be resectable and the remaining were unresectable. Overstaging by CT occurred in three patients due to overassessment of duodenal infiltration. CT had a sensitivity of 72.7%, a specificity of 100%, and an accuracy of 85% for determining resectability of gallbladder carcinoma. For the diagnosis of hepatic and vascular invasion by the tumor, there was 100% correlation between CT and surgery. Vascular variations were found in six of the 11 patients who underwent radical cholecystectomy. CONCLUSION: Dual-phase MDCT with 3D reconstruction is a comprehensive imaging technique for staging gallbladder carcinoma and determining the vascular road map before surgery.

Esophageal duplication cyst: an unusual cause of respiratory distress in infants.

Esophageal duplication cysts are rare congenital anomalies. These should be recognized as a cause of respiratory distress in infants and are usually associated with feeding difficulties. We report 2 such cases of esophageal duplication cyst in infants, causing acute respiratory distress. Excision was curative.

Role of tissue harmonic imaging in focal hepatic lesions: comparison with conventional sonography.

BACKGROUND: The purpose of the present study was to compare iissue harmonic imaging (THI) and conventional sonography in focal hepatic lesions. METHODS: Fifty patients with focal hepatic lesions were enrolled for study. Conventional grayscale and THI was performed in all the patients and two sets of images of the lesions were recorded (one each for THI and conventional) and assessed for fluid-solid differentiation, detail and overall image quality. These images were compared with conventional sonographic images and graded better, same or worse as per the case. Lesions were confirmed by fine-needle aspiration cytology (FNAC)/surgery/other modalities such as computed tomography (CT) or magnetic resonance imaging (MRI). RESULTS: Out of 50 patients with focal hepatic lesions, 21 patients had metastatic lesions (two single; 19 multiple) five patients had hepatocellular carcinoma (HCC), five patients had hydatid cysts, nine had simple hepatic cyst whereas five patients had liver abscess, three had focal fatty infiltration; and lymphoma and hemangioma were seen in one patient each. The first observer ranked THI better than standard sonography in 40 patients (80%) for fluid-solid differentiation, in 38 (76%) for detail and in 39 (78%) for overall image quality. The second observer ranked THI better than standard sonography in 39 patients (78%) for fluid-solid differentiation, in 40 (80%) for detail and in 42 (84%) for overall image quality. Tissue harmonic imaging provided additional information in eight patients (16%) and resulted in treatment alteration in three patients (6%). CONCLUSION: Tissue harmonic imaging was significantly better than conventional sonography for fluid-solid differentiation, detail and total image quality in focal hepatic lesions, especially in obese patients and patients with poor acoustic window.