Iranian Journal of Radiology
Year:2008 | Volume:5 | Issue:2|Papers Count:12

Background/Objective: Hepatic lesions may be missed in the routine abdominal computed tomography (CT) scan protocol using soft tissue window setting. The ability to find these lesions is very important in the assessment of metastasis and follow-up of patients.Patients and Methods: In this study, 411 patients who underwent abdominal CT for various causes were evaluated separately by two radiologists blindly. All liver images were viewed in two different window settings, soft tissue window setting: window width (WW) of 350–400 Hounsfield units (HU), window level (WL) of 35–50 HU, and liver window setting: WW of 150 HU, WL of 50–100 HU, at the workstation.Results: Out of 411 patients, 181 (44%) were referred for cancer follow-up and 230 (56%) for evaluation of abdominal discomfort. Soft tissue window setting revealed no lesion in 334 (81.26%) patients, single lesion in 30 (7.31%), and multiple lesions in 47 (11.43%) patients. Liver window setting revealed no lesion in 313 (76.2%) patients, single lesion in 35 (8.5%), and multiple liver lesions in 63 (15.3%) patients. Compared to liver window, soft tissue window setting revealed 77.77% of all detectable liver lesions. Liver window showed new lesions in 22 (6.6%) of patients in whom no lesion had been found in soft tissue window setting. Therefore, liver window setting brought 5.3% increase in the diagnostic yield of CT in our series, and changed the decision for treatment in 2.4% of patients studied.Conclusion: Liver window setting added to the standard soft tissue setting protocol of abdominal CT at the workstation can improve the diagnosis and follow-up of patients, especially for those who have known cancer. Image review with this new setting takes a few minutes and the cost is also low; there is no added radiation exposure to patients.

Background/Objective: Digitized mammography has several advantages over screen-film radiography in data storage and retrieval, making it a useful alternative to screen-film mammography in screening programs. The purpose of this study was to determine the diagnostic accuracy of digitized mammography in detecting breast cancer.Patients and Methods: 185 women (845 Images) were digitized at 600 dpi. All images were reviewed by an expert radiologist. The mammograms were scored on a scale of breast imaging reporting and data system (BIRADS). The definite diagnosis was made either on the pathologic results of breast biopsy, or upon the follow-up of at least one year. The overall diagnostic accuracy of digitized mammography was calculated by the area under receiver operating characteristic curve.Results: 242 sets of mammograms had no lesions. The total counts of masses, microcalcifications or both in one breast were 39 (11%), 42 (12%), and 25 (7%), respectively. There were 321 (92%) benign and 27 (8%) definite malignant lesions. The diagnostic accuracy of digitized images was 96.34% (95% CI: 94%–98%).Conclusion: The diagnostic accuracy of digitized mammography is comparably good or even better than the published results. The digitized mammography is a good substitute modality for screen-film mammography in screening programs.

Background/Objective: Chronic rhinosinusitis (CRS) is a common condition in medical practice. The diagnosis generally relies on clinical judgment, but computed tomography (CT) together with sinonasal endoscopy, provide the majority of the objective data.This study was carried out to determine the agreement between preoperative CT findings and intraoperative endoscopic sinus surgery (ESS) findings in patients with CRS.Patients and Methods: Statistical analysis of collected data from paranasal sinus CTs of 51 patients aged between 15 and 77 who subsequently underwent ESS for CRS at two training hospitals during a 2-year period was performed.The agreement between CT and ESS findings was assessed by Kappa statistics, Chi-square and t test were also used for data analysis.Results: The most common co-morbidity found among the patients with chronic sinusitis was allergy in 18 (35%) patients. Hypertrophy of the inferior turbinate was the most obvious finding in CT (71%) and during endoscopic evaluation (69%). No significant correlation was found between clinical symptoms and gender or the length of disease. In 8 unusual patients (one with choanal atresia, one with bone wax in nasal cavity, and 6 with small polyposis), CT could not show the problem. There are good to excellent agreements between the two diagnostic procedures, except for the choanal atresia, which showed no agreement (k=0).Conclusion: The results of nasal fossa findings obtained by nasal endoscopy are more conclusive in the elucidation of diagnosis than those obtained by paranasal sinus CTs. In spite of a good agreement between CT and ESS findings in most patients, it seems in some unusual cases, CT may miss many patients.

The identification of the mandibular canal and its anatomic variations is of great importance in many branches of dentistry, especially in implant dentistry and prior to endosteal implant insertion. This knowledge is even more demanding when the mandible has been compromised by different degrees of atrophy and bone resorption. In this study we describe a rare case of double mandibular canal identified by three-dimensional imaging techniques during the process of diagnosis. It is concluded that mandibular canals may often be undetected during the diagnosing phase of implant treatment, and tomographic imaging is the only way to identify some of these distinctive features.

Pantothenate kinase- associated neurodegeneration (PKAN) or Hallervorden–Spatz syndrome is a rare autosomal recessive disorder characterized by dystonia, Parkinsonism, and iron accumulation in the brain. There are two types of this disease: the classic disease which is characterized by an early onset and rapid progression, and the atypical disease which is characterized by later onset and slow progression. Clinical diagnosis is based on clinical and characteristic magnetic resonance imaging findings. We report two Iranian cases of atypical PKAN, the diagnosis of which was missed till MRI showed classic imaging findings.

Acute disseminated encephalomyelitis (ADEM) and Guillain-Barre syndrome (GBS) are both para infectious demyelinating disorders. While ADEM almost always affects the CNS, GBS affects the PNS. The combined demyelinating process-demyelination of both upper motor neuron (UMN) and lower motor neuron (LMN)-occurs very rarely. Here we report a case of severe combined peripheral and central demyelination, in which the former disorder was preceded by the latter.

Background/Objective: This study was performed to report the ultrasonographic finding and final diagnosis of a group of primary amenorrhea patients.Patients and Methods: Pelvic ultrasonography (US) was employed as the first diagnostic modality to evaluate primary amenorrhea in 53 patients who were admitted to gynecology or endocrinology clinics at Taleghani hospital from 2002 to 2006. US were based upon the presence or absence of the uterus and ovaries and any other abnormal sonographic findings. Karyotype analysis was also performed for all the patients.Results: The uterus was not visualized in 16 (30%) patients: due to müllerian agenesis in 14 and testicular feminization and true hermaphroditism in two other patients. Müllerian anomalies with hematometrocolpos or hematometra were seen in 5 (9%) patients. Thirty-two (60%) patients had a normal or hypoplastic uterus. Pelvic US showed that ovaries were in normal limits in 39 (73%) patients; they were not visible in 9 patients. The report of pelvic US were not conclusive in 3 patients; 2 had an ovarian tumor or cyst. Irrespective of the presence or absence of the uterus, all patients with visible ovaries (except one) had a normal karyotype.Conclusion: US of the pelvis can be the initial diagnostic modality. Based on US findings, we can make decision for further work ups; there is no need to perform all paraclinical investigations for each patient.

Background/Objective: Malfunction of vascular accesses is a common cause of morbidity in hemodialysis patients. The purpose of the present study was to evaluate the flow volume and the diameter of the feeding artery in asymptomatic, well-functioning hemodialysis access with Doppler ultrasound.Patients and Methods: From March 2006 to February 2007, we examined the functioning mature arteriovenous fistula (AVF) of 69 hemodialysis patients by Doppler ultrasound in Imam Reza hospital, Mashhad. The measured flow volume, primary renal disease, AVF type and location, and the demographic data were recorded. All statistical analyses were performed with the Chi square test, the Student’s t test and one-way ANOVA. Pearson correlation coefficient was also calculated.Results: Of the 69 patients, 30 (43%) had an antecubital AVF. Overall, the mean±SD flow volume was 1665±554mL/min. The majority of accesses (n=52) had normal flow volume (500– 1200mL/min), 15 patients had high-flow fistulas (>1200mL/min) and 4 had critical flow rates of <500mL/min. The flow volume was significantly higher in the antecubital AVF than that placed in more distal positions. The mean diameter of the feeding artery at the measurement site was 6.0 mm. There is a linear correlation between the diameter of the feeding artery and the mean flow rate (r=0.76, p<0.001). No significant difference was observed between the type of anastomosis and the flow rate (p=0.14).Conclusion: There is a high level of abnormalities, especially high flow volume, in well functioning mature AVFs. Color Doppler ultrasonography makes early detection of the patients with a higher risk possible and it can also guide the surgeon to select the surgical procedure.

We present a 56-year-old female with end stage renal disease (ESRD). As the patient had no vascular access for hemodialysis, the catheter was inserted in the right subclavian vein without an imaging guide. The woman experienced sudden chest pain and hypotension. Imaging showed a malposition of the catheter in the subclavian artery instead of the subclavian vein with dissection of the thoracic and abdominal aorta. This is a rare complication of subclavian vein catheterization for hemodialysis. We discuss this patient because she is the first in the international bibliography. This case report shows that for patients with poor venous access, catheter placement under angiographic control may be helpful.

48-year-old woman was referred with an anterior midline neck mass which had gradually appeared with out tenderness. The patient had a previous history of frequent painful swelling of the anterior part of her neck.

Thyroglossal duct cyst (TDC) is the most common congenital anomaly of the thyroid gland and the most common congenital anomaly cervical abnormality in childhood. It also is thee most common midline mass (70% abnormality in childhood and 7% in adolescence).

A case of aborted thoracopagus conjoined twins is presented. The fetus was the result of pregnancy in a 20- year-old woman (Gravid 1 Para1), who had no history of congenital malformation or exposure to medical or toxic agents. Finding the malformation on routine obstetrics ultrasonography, the pregnancy was terminated at 14 weeks of gestation.The fetuses were joined at the thorax, with three well developed legs and a rudimentary forth leg. (Figs. 1A and B) MRI revealed a single heart shared by twins. The kidneys and urinary bladder were not developed at all. (Fig. 1C)