The accuracy of limited CT in the evaluation of chronic rhinosinusitis and for endoscopic sinus surgery: a multicenter study.

Objective: To compare the accuracy of Limited CT with the Full CT as the standard evaluation for inflammatory disease of PNS and the identification of anatomical variations. Methods: From Full CT of PNS, Limited CT were retrieved. Computerized tomographic scans were performed for the preoperative planning of endoscopic sinus surgery (ESS) in 3 tertiary care university hospitals in Thailand. The two types of examinations were reviewed independently and in random order by two experienced radiologists. Using Full CT as the standard, the accuracy of Limited CT were evaluated for 1) the radiologic staging of rhinosinusitis (Lund-Mckay scoring system) and 2) the anatomic variations which are an important landmark for surgical operations in rhinosinusitis. Results: Totally 132 patients were included. Two hundred and sixty four half-faces were reviewed. Lund-McKay radiographic sinus staging system showed 97-99% specificity except for the ostiomeatal complex region. Regarding anatomic variation, Limited CT was able to yield accurate results for the frontal cell type II-IV, Haller cell, Agger nasi cell, paradoxical middle turbinate, concha bullosa and the protrusion of the optic nerve. Conclusion: Limited CT can be used as a surgical roadmap for the cases with the anterior group of sinus involvement. It may be utilized for surgical planning of chronic CRS involving the anterior group of sinuses. For the posterior group of sinuses, it may not yield enough accuracy and the standard Full CT should be requested to prevent erroneous estimation.

CT criteria in vascular dementia: A study in Thai population.

Objective: To evaluate CT criteria for diagnosis of vascular dementia (VaD) in Thai population. Methods: Cranial CT was performed in the elderly from an urban community in the west of Bangkok. The evaluation of infarction (number, location and volume of infarction), white matter low attenuation, and atrophy were performed by neuroradiologists; and, the final diagnoses of dementia were done by neurologists. Results: Ninety-one patients were recruited into the study with their mean age of 70.16 years old (range = 53-90). Twenty-seven patients were males and 64 were females. The final diagnoses were, namely: normal cognition (10=11%), vascular dementia (30=33%), Alzheimer’s disease (AD) (41=45.1%), and mixed VaD and AD (10=11%). On CT, most patients had infarction of less than two lesions and the volume of infarction was less than 25 ml. Two (2.2%) patients who were diagnosed as AD and one who was diagnosed as normal had lesions more than one lesion; whereas 11 (12.1%) patients who were diagnosed as VaD had more than one lesion. No patients who were diagnosed with AD or those who were normal had infarction volume more than 25 ml, except two patients who were diagnosed with VaD had infarction volume more than 25 ml. Most patients who had white matter scale more than 2 were VaD (52%). No significant difference between atrophy and dementia was found. With the CT grading criteria of 0 for non-VaD and combined 1, 2 and 3 for VaD, the sensitivity, specificity and accuracy for diagnosis of VaD were 96%, 64.7%, and 76.5%, respectively. Conclusion: Modified CT criteria for VaD established by reducing volume of infarction regardless of the atrophy are helpful to identify VaD patients with improved diagnostic performance.

A comparison of MR myelography of brachial plexus injury with CT myelography and conventional myelography.

The purpose of study is to assess the accuracy of magnetic resonance myelography (MRM) of the cervical spine in patients with preganglionic Brachial Plexus Injury (BPI) by using CT myelography as the gold standard and comparing this with routine conventional myelography. Patients with a clinically diagnosis of Brachial plexus Injury were studied (9 males, 1 female, aged 16 - 42 years old) [mean age = 25.4 years old]). All patients had undergone clinical evaluation by an orthopedic surgeon and five patients had had additional somatosensory evoked potentials (SEP) performed. All patients were investigated by conventional myelography, computed tomography myelography (CTM) and magnetic resonance myelography (MRM). We used CT myelography as the gold standard and the accuracy of MRM and myelography were assessed in relative to this. The sensitivity in detecting a pseudomeningocele by MRM is 100% and the sensitivity in detecting nerve root abnormality is 90% at the level of the C5, C6 roots and 100% for the C7, C8, T1 roots. MR Myelography had many advantages over conventional and CT myelography which include the absence of radiation and the lack of need for intrathecal injection of contrast medium.

Value of computed tomography in T-stage assessment and therapy of nasopharyngeal carcinoma.

The accurate evaluation of tumor size, localization and spread of nasopharyngeal carcinoma help optimal treatment planning. The purpose of our retrospective study is to compare the T-stage of nasopharyngeal carcinoma between evaluated by physical examination and CT scan and to compare the response to treatment in the group also underwent CT (147 patients) and the group without CT staging (40 patients). The sex ratio, and the mean age of the patients in both groups was not significantly different. Radiological study showed Stage 1 the tumor confined in nasopharyngeal region. Stage II showed tumor spreading with lateral extension to the parapharyngeal region. Stage III and stage IV, the tumor spread in a superior direction to the paranasal sinus and the base of the skull. CT staging resulted in upgrading the T stage in 88/147 cases ( 59.9%). A Complete response was higher in the CT than the non CT Group at the T2 and T4 stage. CT imaging is better than clinical examination and conventional imaging in detecting the involvement of more than one wall, base of skull involvement, differentiating tumor from sinusitis, detecting intracranial invasion and neck node involvement. In Conclusion, a CT scan is require in nasopharyngeal carcinoma patients for accurate staging, modified radiation treatment and improved treatment results.

Tc-99m stannous colloid-labeled leucocyte scintigraphy in the evaluation of brain abscess.

99mTc stannous colloid-labeled leukocyte scintigraphy was used to investigate brain abscesses in patients with underlying arteriovenous malformation or other brain abnormalities. 99mTc stannous colloid-labeled leukocytes are radiolabeled neutrophils and monocytes. The radiolabeled colloid is phagocytosed by the white cells. Six patients with underlying arteriovenous malformation (AVM) post embolisation with clinical diagnosis of brain abscess were studied. The 3 patients with positive 99mTc stannous colloid-labeled leukocyte scans were diagnosed as a cerebral abscess in all cases. One patient who had a negative 99mTc stannous colloid-labeled leukocyte scan did not have a brain abscess. Another with a negative scan had a pathologic diagnosis of chronic inflammation and foreign body reaction. The third with a negative scan was studied after treatment with antibiotic and debridement. In Summary 99mTc stannous colloid-labeled leukocyte scintigraphy is useful in conjungtion with CT scanning in investigating patients with brain abscess who have other underlying brain abnormality or who have an early brain abcess, or in the follow up of patients who have already received treatment in order to evaluate infection is still present and it is appropriate treatment.

Endovascular treatment of brain arteriovenous malformations in Siriraj Hospital.

Objective: To present our experience on endovascular embolization by using N-butyl cyanoacrylate and to demonstrate that this is an effective method in the treatment of brain arteriovenous malformations. Malerials and Methods: From 1992 to 1998, 92 patients with brain arteriovenous malformations who having had endovascular embolization as primary treatment was retrospectively reviewed. Results: 8 patients (8.7%) had completely cure by embolization alone wthout neurological complication. 17 patients (18.5%) were cured after combined treatment, 9 with surgical removal and the other 8 with radiosurgery. The neurological complications occurred in 17 patients (18.5%) with 3 deaths and vegetative stage. Conclusion: The endovascular embolization can cure the arteriovenous malformations that smaller than 3 cm, no matter what its location, and it is effective to reduce the nidus volume of the larger lisions, making them suitable for surgical resection or radiosurgery as to achieve te goal of complete eradication of the malformations.