CT and Angiographic Analysis of Posterior Communicating Artery Aneurysms: What Factors Influence the Amount of Subarachnoid Blood?

PURPOSE: To determine how clinical and angiographic factors relate to the amount of subarachnoid blooddetected by computerized tomography in patients with a ruptured aneurysm. MATERIALS AND METHODS: Between January1996 and December 1997, 22 patients with a posterior communicating artery aneurysm were retrospectively evaluated. RESULTS: Oval(three of four cases), funnel(both cases), and daughter-sac (four of five cases) types of aneurysmalsac were found among the 13 patients with a large amount of subarachnoid blood ; eight of these had a past historyof hypertension or diabetes. Seven of eleven cases of cylindrical-type aneurysmal sac were found among the 9patients with a small amount of sularachnoid blood ; eight of these had no past history of hypertension ordiabetes. The average S/N ratio (ratio of maximum sac length to neck diameter) of patients with a small amount ofblood was higher than that of patients with a large amount of blood(2.72 vs 2.07). CONCLUSION: Although manyfactors influence the amount of subarachnoid blood in an aneurysmal rupture, we found that a large amount of bloodwas frequently present in the oval, funnel and daughter sac types of aneurysm, when S/N ratio was low, and when anunderlying disease such as hypertension or diabetes was present. Conversely, a small amount of blood was presentin the cylindrical type, when S/N ratio was high, and where there was no of underlying disease.

CT-Guided Percutaneous Automated Gun Biopsy of Pulmonary Lesions: Complications and Diagnostic Accuracy

PURPOSE: To determine the frequency of complications and diagnostic accuracy of CT-guided percutaneous automated gun biopsy, and to compare the results with those reported for fine needle aspiration. MATERIALS AND METHODS: Using automated biopsy devices, 118 CT-guided percutaneous biopsies of pulmonary lesions were performed. An 18-gauge needle was used. Final diagnosis was made with operation or other methods. We retrospectively analyzed the frequency of complications and diagnostic yields of 118 biopsies. RESULT: Four of 118(3.3%) patients developed pneumothorax and two of these required chest tube insertion. Other complications were resolved spontaneously. 106 biopsies (89.8%) yielded sufficient tissue for pathologic evaluation. For cases of malignant and of benign disease, sensitivity was 91.8% and 87.7% respectively ; the corresponding figures for diagnostic accuracy were 88.5% and 78.9%. CONCLUSION: CT-guided automated gun biopsy of the pulmonary lesions is safe, witha pneumothorax rate comparable to that of fine needle aspiration. In the absence of a trained cytologist at the time of biopsy, the diagnostic accuracy of automated gun biopsy of pulmonary lesions compared favorably with the reported accuracy of fine needle aspiration.

The Diagnostic Value of Contrast-Enhanced CT in Acute Bilateral Renal Cortical Necrosis: A Case Report

Acute renal cortical necrosis in which there is destruction of the renal cortex and sparing of the renalmedulla, is a relatively rare cause of acute renal failure. A definitive diagnosis of acute renal corticalnecrosis is based on renal biopsy, but on CT(computed tomography) the rather specific contrast-enhanced appearance of acute renal cortical necrosis has been described. As renal biopsy is not available, contrast-enhanced CT is auseful, noninvasive investigate modality for the early diagnosis of acute renal cortical necrosis. We report the characteristic CT findings of acute renal cortical necrosis in a patient with acute renal failure following anoperation for abdominal trauma.

Prevalence of Paranasal Sinus Opacification in Infants and Children without Overt Sinusitis using Computed Tomography

PURPOSE: To evaluate the prevalence of the opacification of paranasal sinuses and to correlate the prevalence and severity of the sinus opacification with presence of upper respiratory infection (URI) in infants and children using CT. MATERIALS & METHODS: We analyzed CT scans of 162 children aged under 16 who have no signs and symptoms of paranasal sinusitis. Both sides of maxillary and ethmoidal sinuses were evaluated. We scored from 0 to 3 according to the degree of soft tissue opacification of each sinus and then summed up the scores of each sinus. We divided the children into 5 groups according to their age. We paid particular attention to the following respects: 1) the prevalence of the opacification of the paranasal sinuses in each group; 2) the difference in the prevalence between the children with and without URI ;3) the correlation between the severity of the sinus opacification and the presence of URI. RESULTS: Of 162 children, one or more paranasal sinus opacification was noted in 76(47 %):31(65%) less than 1 year old;11(52%) between 1 and 2 years old;16(53%) between 2 and 6 years old ;15(28%) between 6 and 12 years old;and 3(33%) above 12 years old. In children less than 1 year old, no significant difference in the prevalence of the sinus opacification was found between URI-positive(71%) and URI-negative(58%) subgroups. In chilren between 1 and 12 years old, although the prevalence of the sinus opacification in URI-positive subgroups was much greater than that in URI-negative subgroup, statistically significant difference was noted only in children between 2 and 6 years old. As to the correlation between the severity of the sinus opacification and the presence of URI, these was a statistically significant difference in children between 2 and 6 years old and between 6 and 12 years old. CONCLUSION: Although the exact pathophysiology is not fully understood, the opacification of the paranasal sinuses is not an uncommon finding at CT in children without the signs and symptoms of sinusitis. We think that the clinical correlation is essential in determining the diagnosis and treatment plan in cases that the sinus radiographs or CT scans show the abnormal findings.

Normal development of the paranasal sinuses in children: a CT study

To evaluate the normal development of the paranasal sinuses in children with CT, authors prospectively studied with brain CT scans of 260 children without known sinus diseases, ranging in age from 7 days to 16 years. Maximal anteroposterior and transverse diameters(mm) and maximal cross-sectional area(mm2) of both sides of the maxillary sinus were measured with the aid of computer device. As to the ethmoidal and sphenoidal sinuses, we simply documented the presence of the aplastic ethmoidal sinus and calculated the age-incidence of the sphenoidal sinus pneumatization, respectively. There noted three phases in the development of the maxillary sinus. The anteroposterior and transverse diameters of the maxillay sinus increased nearly in parallel. The former was always greater than the latter. In no cases was the ethmoidal sinus aplastic and almost all sinuses were pneumatized even in infants as early as 7 days old. CT identified the conchal pattern of sphenoidal sinus pneumatization in infants as early as 11 days old. Sphenoidal sinus pueumatization was seen in 38% of the children under the age of 1 year, 82% of the children between the age of 1 and 2 years, and almost all children older than 2 years. The anteroposterior and transverse diameters of the maxillary sinus seem to reach the adult size by 8 years of age, and the conchal pattern of sphenoidal sinus pneumatization can be recognized earlier with CT than on the plain radiographs.