Detection of hepatic metastasis: manganese- and ferucarbotran-enhanced MR imaging

PURPOSE: To compare the mangafodipir trisodium (MnDPDP)-enhanced and ferucarbotran-enhanced magnetic resonance imaging (MRI) for the detection of hepatic metastases. MATERIAL AND METHODS: Twenty patients with known hepatic metastasis underwent MR imaging using mangafodipir trisodium and ferucarbotran in at least 1-day intervals. Thirty-eight metastases were confirmed either histologically or clinically. Two radiologists independently reviewed the MnDPDP-enhanced and ferucarbotran-enhanced sets in a random order. The sensitivity and accuracy of lesion detection and the ability to distinguish a benign lesion from a malignant lesion were compared by the areas (Az) under the receiver operating characteristic (ROC) curve. The lesion-liver contrast-to-noise ratios (CNR) were compared by paired t-test. RESULTS: The overall accuracy for detecting metastases was not significantly different between the MnDPDP set (Az=0.912 and 0.913 for reader 1 and 2, respectively) and the SPIO set (Az=0.920 and 0.950). The CNR at the MnDPDP-enhanced images and the SPIO-enhanced images were not significantly different (P=0.146). CONCLUSION: Both MnDPDP- and ferucarbotran-enhanced MRI have a comparable accuracy in detecting hepatic metastasis.     

A case of mesenteric cystic lymphangioma: fat saturation and chemical shift MR imaging

Mesenteric cystic lymphangioma is an uncommon lesion that may be difficult to diagnose radiologically. In our case, a septate cystic mass showed fluid attenuation on a computed tomography scan. We were able to define the fat content within the cystic tumor by magnetic resonance (MR) imaging. The presence of fat within an intra-abdominal cystic mass is suggestive of a dermoid cyst, cystic lymphangioma, or lymphocele. The pathologic diagnosis revealed a cystic lymphangioma, which originated from the mesentery. Although the MR imaging features of dermoid cysts and lymphangiomas are well known, the demonstration of fat content by chemical shift and fat saturation MRI has not yet been reported for a cystic lymphangioma.     

Variation of the time to aortic enhancement of fixed-duration versus fixed-rate injection protocols

OBJECTIVE: The objective of the study was to clarify whether a fixed-duration injection protocol is useful in determining the optimal scan delay time without the need for a bolus-tracking technique. MATERIALS AND METHODS: Three hundred eighteen patients underwent a helical CT examination using a bolus-tracking technique. All the examinations were performed after administering a nonionic contrast medium (300 or 370 mg I/mL; 2 mL/kg of body weight for patients weighing < or = 75 kg, 150 mL for those weighing > 75 kg). The patients were assigned to one of three groups according to the injection protocol. The injection rate was alternated to 3 or 4 mL/sec in group 1. The injection duration was 38 or 47 sec in groups 2 and 3, respectively. The aortic arrival time and the 100-H threshold time in each patient were measured. The mean values and the variations in the aortic arrival time and 100-H threshold time according to the injection protocols and the contrast media were compared. RESULTS: The mean variations (+/- SD) of aortic arrival times and 100-H thresholds in group 2 (aortic arrival time = 16.1 +/- 2.7 sec, 100-H threshold time = 19.6 +/- 2.9 sec) were smaller than in groups 1 (16.3 +/- 3.0 sec and 19.9 +/- 3.7 sec, respectively) and 3 (16.8 +/- 3.5 sec and 20.4 +/- 4.1 sec, respectively). However, the range of aortic arrival times and 100-H threshold times was more than 10 sec for all groups. The mean aortic arrival time and 100-H threshold time for all patients were 16.5 and 20.0 sec, respectively, and did not vary significantly with the injection protocol and concentration of contrast medium. CONCLUSION: The individual variations of the aortic arrival and 100-H threshold times can be reduced using a fixed-duration injection technique, but there are still substantial variations. Therefore, a bolus-tracking technique is recommended for optimal timing of arterial phase scanning.     

Radiation Dose Reduction via Sinogram Affirmed Iterative Reconstruction and Automatic Tube Voltage Modulation (CARE kV) in Abdominal CT

Objective

To evaluate the feasibility of sinogram-affirmed iterative reconstruction (SAFIRE) and automated kV modulation (CARE kV) in reducing radiation dose without increasing image noise for abdominal CT examination.

Materials and Methods

This retrospective study included 77 patients who received CT imaging with an application of CARE kV with or without SAFIRE and who had comparable previous CT images obtained without CARE kV or SAFIRE, using the standard dose (i.e., reference mAs of 240) on an identical CT scanner and reconstructed with filtered back projection (FBP) within 1 year. Patients were divided into two groups: group A (33 patients, CT scanned with CARE kV); and group B (44 patients, scanned after reducing the reference mAs from 240 to 170 and applying both CARE kV and SAFIRE). CT number, image noise for four organs and radiation dose were compared among the two groups.

Results

Image noise increased after CARE kV application (p < 0.001) and significantly decreased as SAFIRE strength increased (p < 0.001). Image noise with reduced-mAs scan (170 mAs) in group B became similar to that of standard-dose FBP images after applying CARE kV and SAFIRE strengths of 3 or 4 when measured in the aorta, liver or muscle (p ≥ 0.108). Effective doses decreased by 19.4% and 41.3% for groups A and B, respectively (all, p < 0.001) after application of CARE kV with or without SAFIRE.

Conclusion

Combining CARE kV, reduction of mAs from 240 to 170 mAs and noise reduction by applying SAFIRE strength 3 or 4 reduced the radiation dose by 41.3% without increasing image noise compared with the standard-dose FBP images.     

Prurigo pigmentosa in Korea: clinicopathological study

Background Prurigo pigmentosa (PP) is an inflammatory dermatosis characterized by recurrent pruritic erythematous papules, mainly located on the trunk. It was first described by Nagashima in 1971 in Japan. Since then, more than 300 cases have been reported in Japan, but reports from other parts of the world are quite rare. Materials and methods We studied clinical and histopathological data from six patients with PP diagnosed in our hospital and 43 patients (18 reports) who were diagnosed with PP in Korea between 1988 and 2008. Results The number of Korean patients reported in recent years is higher than the number of other non‐Japanese patients reported. Clinicopathological characteristics in Korean patients were not significantly different from those previously reported. Therapeutic results with minocycline were successful in our patients. Conclusions We suspect that PP is not uncommon in Korea, and the disease may be underestimated. Strict restriction of diet as well as known associated factors like wet condition are suggested as one of the important factors contributing to the occurrence of PP in Korea.     

Ultrasound in dermatology: Principles and applications

Ultrasonic imaging has been used in the field of dermatology for nearly 30 years. In this review, we seek to explain the basic principles of ultrasound as they relate to the skin. Based on differences in keratin, collagen, and water content, ultrasonic waves are reflected back to a transducer and translated into a gray-scale image for interpretation. The technicalities of the process and its variations (power, continuous wave Doppler ultrasound, ultrasound elastography) are briefly reviewed, and we further highlight many of the applications for ultrasound in the treatment and diagnosis of dermatologic conditions, including melanoma and nonmelanoma skin cancer, benign tumors, inflammatory diseases, and lipoablation. Each of these entities is uniquely characterized using ultrasonic techniques. Based on published sources, we contend that although ultrasound is still being fine-tuned for application in dermatology and largely remains in experimental phases, it has potential for use in many arenas of our specialty.     

Small hypervascular enhancing lesions on arterial phase images of multiphase dynamic computed tomography in cirrhotic liver: fate and implications

OBJECTIVE: Our purpose was to determine the significance of small hypervascular enhancing lesions exclusively on the arterial phase images of dynamic computed tomography in cirrhotic liver. METHODS: One hundred sixty-nine enhancing lesions (>5 and <30 mm) on the arterial phase images of dynamic computed tomography in 67 patients with cirrhotic liver, not distinguished from background hepatic parenchyma on equilibrium phase images without hypoattenuation density on portal phase images, were subjected to a retrospective assessment in terms of the lesion growth in addition to the location, size, and contour of the lesions, depending on the final diagnoses of the individual lesions. RESULTS: Twenty-eight (17%) of the 169 enhancing lesions were hepatocellular carcinomas (HCCs). All of the 43 wedge-shaped, subcapsular lesions were benign, and 126 nodular or irregular lesions were subcapsularly (benign, n = 59; HCC, n = 11) or centrally (benign, n = 39; HCC, n = 17) located. Significant differences were found between HCCs and benign lesions in terms of their shape (P = 0.002) and location (P = 0.041), and the positive and negative predictive values of centrally located lesions for diagnosing HCCs were 21% and 85%, respectively. The positive and negative predictive values for the diagnosis of HCC based on the lesion growth were 90% and 93%, respectively. CONCLUSIONS: Because of the low positive predictive value of non-wedge-shaped, centrally located, early enhancing lesions in the diagnosis of HCC, the serial follow-up for examining lesion growth is essential to the correct diagnosis of small arterial hypervascular lesions in cirrhotic liver.     

Intrauterine device found in an ovarian carcinoma

Displacement of an intrauterine device (IUD) through the perforation site is a rare but one of the major complications. Theoretically, an extrauterine IUD can be located anywhere in the abdominopelvic cavity. It may be asymptomatic or may cause serious complications, including infection, fistula, organ perforation, or bowel obstruction. However, there is no report of IUD located within an ovarian carcinoma to our knowledge, and our report is the first case of an IUD found in the center of an ovarian cancer.