Motion artifact reduction of diffusion‐weighted MRI of the liver: Use of velocity‐compensated diffusion gradients combined with tetrahedral gradients

Purpose:

To assess the effect of motion artifact reduction on the diffusion‐weighted magnetic resonance imaging (DWI‐MRI) of the liver, we compared velocity‐compensated DWI (VC‐DWI) and VC‐DWI combined with tetrahedral gradients (t‐VC‐DWI) to conventional DWI (c‐DWI) in the assessment of apparent diffusion coefficients (ADCs) of the liver.

Materials and Methods:

In 12 healthy volunteers, the liver was scanned with c‐DWI, VC‐DWI, and t‐VC‐DWI sequences. The signal‐to‐noise ratio (SNR) and ADC of the liver parenchyma were measured and compared among sequences.

Results:

The image quality was visually better for t‐VC‐DWI than for the others. The SNR for t‐VC‐DWI was significantly higher than that for VC‐DWI (P < 0.05) and comparable to that for c‐DWI. ADCs in both hepatic lobes were significantly lower for t‐VC‐DWI than for c‐DWI (P < 0.01). ADC in the left lobe was significantly lower for VC‐DWI than for c‐DWI (P < 0.01). Although ADC in the left lobe was significantly higher for c‐DWI (P < 0.01), no significant differences in ADCs were found between the right and left lobes for VC‐DWI and t‐VC‐DWI.

Conclusion:

The use of a t‐VC‐DWI sequence enables us to correct ADCs of the liver for artificial elevation due to cardiac motion, with preserved SNR. J. Magn. Reson. Imaging 2013;37:172–178. © 2012 Wiley Periodicals, Inc.     

Improved reproducibility of simple quantitative indices from 99mTc-GSA liver functional imaging

Objective

We evaluated intra- and interoperator reproducibilities in calculating the conventional indices HH15 and LHL15 from ^99mTc-diethylenetriamine pentaacetic acid galactosyl human serum albumin (^99mTc-GSA) scintigraphy, and proposed new, simple methods for the calculation of quantitative indices.

Methods

The results of ^99mTc-GSA scintigraphy in 33 patients were retrospectively analyzed. Heart and liver ROIs were drawn manually to cover cardiac blood pool and entire liver, respectively, and HH15 and LHL15 were calculated. In addition, square regions of interest (ROIs) of fixed sizes were placed at the highest activity in blood pool and the liver. Using the square heart ROI, sHH15, an equivalent of HH15, was computed. Fractional liver uptake at 15 min (FLU15) was calculated using the square heart and liver ROIs. Intra- and interoperator reproducibilities, as well as correlation with Indocyanine green retention rate at 15 min (ICG R15), were assessed for these four indices by linear regression analysis.

Results

Substantial intra- and interoperator variabilities were found for HH15 and LHL15. The correlation coefficients for intra- and interoperator comparisons were 0.884 and 0.869 for HH15, respectively, and 0.919 and 0.917 for LHL15, respectively. The use of square ROIs instead of hand-drawn ROIs improved reproducibility. The correlation coefficients for intra- and interoperator comparisons were 0.988 and 0.973 for sHH15, respectively, and 0.989 and 0.975 for FLU15, respectively. Correlation with ICG R15 was better for sHH15 (r = 0.619) and FLU15 (r = ?0.656) than for HH15 (r = 0.439) and LHL15 (r = ?0.490).

Conclusions

HH15 and LHL15 showed substantial intra- and interoperator variabilities, and the use of square ROIs are indicated to provide better reproducibility.     

Preliminary observations and clinical value of lipid peak in high-grade uterine sarcomas using in vivo proton MR spectroscopy

Objective

To retrospectively evaluate the clinical significance of the lipid peak in in vivo proton magnetic resonance spectroscopy (MRS) for the diagnosis of high-grade uterine sarcomas.

Methods

MRS was performed in patients with 38 pathologically diagnosed uterine corpus tumours (26 leiomyomas and 12 sarcomas) at 3 T. Single-voxel MRS data were collected from a single square volume of interest that encompassed the tumours. The concentrations of lipid and total choline compounds (tCho) were classified as high, low or none.

Results

High lipid peaks were observed in all 12 sarcomas and not in benign leiomyomas except for 1 lipoleiomyoma. All 26 leiomyomas and 10 of the 12 sarcomas showed tCho peaks, whereas 2 sarcomas with massive necrosis showed no tCho peak. The presence of a high lipid peak for the diagnosis of sarcoma had a sensitivity of 100 %, specificity of 96 %, positive predictive value of 92 % and negative predictive value of 100 %.

Conclusions

The high lipid peaks in high-grade malignant tumours may be observed in both viable and necrotic areas, and may be useful in distinguishing uterine sarcomas from benign leiomyomas.

Key Points

? High lipid peak on MR spectroscopy is suggestive of uterine sarcomas. ? Lipid peak is observed in both viable and necrotic areas in sarcomas. ? MR spectroscopy may be useful in distinguishing uterine sarcomas from benign leiomyomas.     

Postoperative cytology for drained fluid from the pancreatic bed after "curative" resection of pancreatic cancers: does it predict both the patient's prognosis and the site of cancer recurrence?

OBJECTIVE: To evaluate the postoperative cytology of drained fluid from the pancreatic bed as a predictive indicator of local recurrence after curative (R0) resection of pancreatic cancer. SUMMARY BACKGROUND DATA: The pancreatic bed offers a common site of cancer recurrence (local recurrence), even after curative (R0) resection is performed for pancreatic cancer. If local recurrence is thereby predicted precisely, soon after surgery, we have a chance to treat it by adding radiation or some other locoregional therapy before it can grow or spread beyond the pancreatic bed. However, there have been no previous reports of cytology performed on the drained fluid after pancreatectomy. METHODS: This study includes 94 patients who had shown negative results in the peritoneal washing cytology before resection and subsequently received pancreatectomies for pancreatic tumors. They consisted of 12 benign tumors, 17 noninvasive or minimally invasive carcinomas and 65 invasive ductal carcinomas (R0 = 58; R1/2 = 7). Postoperatively, the drained fluid from the pancreatic bed was collected for 24 hours and used for cytologic examination. The cytologic results were examined in association with the histopathology of the resected tumor, patient's survival, and mode of cancer recurrence, including local recurrence. RESULTS: Patients with benign tumors or noninvasive/minimally invasive carcinomas had negative result in cytology, and none of them have died of local recurrence (limited to the pancreatic bed) to date. However, patients with invasive ductal carcinoma revealed higher cytology-positive rates: 28% (16/58) in curative (R0) resection; and 71% (5/7) in noncurative (R1/2) resection. Among 58 patients with R0 resection, the 3-year survival rate was 14% in 16 cytology-positive patients and 55% in 42 cytology-negative patients (P < 0.05). The 3-year cumulative rate of local recurrence was 85% and 23%, respectively (P < 0.05). Compared with other histopathologic parameters obtained from the resected specimens, the drain cytology was more specific in predicting the subsequent development of local recurrence. CONCLUSIONS: Drain-cytology was a quick examination that enabled us to specifically indicate both minute residual cancer and subsequent development of local recurrence even after R0 resection of pancreatic cancer.     

Study of nausea and vomiting accompanying intravenous patient-controlled analgesia with fentanyl after cervical spine surgery

BACKGROUND: Serious side effects of postoperative analgesia with opioid drugs include nausea and vomiting. METHODS: We investigated the effects of various factors (patient background, anesthesia duration, and intraoperative drug use) on the frequency and degree of postoperative nausea and vomiting (PONV) during the first 24 hours of intravenous patient-controlled analgesia (PCA) with fentanyl. RESULTS: PONV occurred in 34% of the male patients and 68% of the female, and in 31% and 58% of smokers and non-smokers, respectively. CONCLUSIONS: Consideration should be given to gender and smoking status prior to starting preventive antiemetic therapy using PCA with fentanyl following cervical spine surgery.     

Idiopathic retroperitoneal fibrosis diagnosed by CT-guided needle biopsy: a case report

A 72-year-old man was admitted to another hospital because of general fatigue and dyspnea secondary to renal insufficiency. Abdominal computed tomography (CT) and magnetic resonance imaging showed left atrophic kidney, right hydronephrosis, and an intra-pelvic mass of soft-tissue density located anterior to the sacrum, involving the right ureter at the level between the 5th lumber vertebra and the sacrum. He was referred to our hospital after percutaneous nephrostomy was constructed into right kidney. CT-guided needle biopsy revealed the idiopathic retroperitoneal fibrosis, leading us to give him steroid therapy. Three weeks later, radiographic findings showed a remarkable reduction of the mass and the improvement of the right ureteral stricture.     

Differences in Long-term Outcome and Prognostic Factors According to Viral Status in Patients with Hepatocellular Carcinoma Treated by Surgery

Long-term postoperative survival and prognostic factors were examined retrospectively in patients with hepatocellular carcinoma (HCC) with serum hepatitis B surface antigen (HBsAg) or hepatitis C antibody (HCVAb) and in those without virus infection. Subjects were 265 consecutive HCC patients treated surgically at one institution during the period 1990 to 2006. Postoperative survival was analyzed and compared between HBsAg-positive (B-HCC), HCVAb-positive (C-HCC), and hepatitis B- and C-negative (NBNC-HCC) patients. Prognostic factors for overall and recurrence-free survival were also analyzed. Overall and recurrence-free survival rates were significantly higher in the NBNC-HCC group than in the C-HCC group. Significant prognostic factors for overall survival identified by univariate and multivariate analyses were age, serum alkaline phosphatase (ALP) level, tumor multiplicity, portal vein invasion (Vp), hepatic vein invasion (Vv), and operative blood loss in the B-HCC group; serum albumin level, ALP level, tumor size, and Vv in the C-HCC group; and tumor multiplicity in the NBNC-HCC group. Significant factors for recurrence-free survival were age, ALP level, tumor multiplicity, Vp, and operation time in the B-HCC group; ALP level, prothrombin time, tumor size, Vv, and width of the surgical margin in the C-HCC group; and age, tumor size, tumor multiplicity, and Vp in the NBNC-HCC group. Thus, postoperative survival and prognostic factors in cases of HCC differ according to the presence of serologic viral markers.     

Incidence and outcome of osteoporotic fractures in 2004 in Sado City,Niigata Prefecture,Japan

Osteoporotic fracture in elderly populations is increasing worldwide, but there are few data on the incidence and outcome of osteoporotic fractures, including upper extremity and vertebral fracture, during a certain period in a defined geographic area. The purpose of this study was to determine the incidence of osteoporotic fractures in a particular area: Sado City, Niigata Prefecture, Japan. From January to December 2004, osteoporotic fractures of the vertebra, hip, distal radius, and proximal humerus in Sado City were recorded. The incidence, age, gender, type of fracture (for hip fracture), right or left side (for distal radius, proximal humerus, and hip fracture), place of injury, cause of injury, outcome, hospitalization period, and patient status regarding taking of drugs for osteoporosis treatment were checked for each fracture. The incidence was calculated based on the whole population of Sado City. The incidence per 100,000 population was 232.8, 121.4, 108.6, and 37.1 for fractures of the vertebra, hip, distal radius, and proximal humerus, respectively. The total incidence of these four kinds of fracture was 499.9 per 100,000 persons per year. The average age at the time of injury was 81.4, 77.7, 75.7, and 60.2 years old for fractures of the hip, vertebra, proximal humerus, and distal radius, respectively. As the average age increased, the percentage of fractures that occurred indoors also increased; that is, a higher percentage of hip fractures occurred indoors, followed by fractures of the vertebra, proximal humerus, and distal radius. Most patients were not taking anti-osteoporosis drugs before fractures of the hip or vertebra. We determined the incidence of major osteoporotic fractures in 1 year in a defined geographic area. Our data showed that 81% of hip fracture patients also had a vertebral fracture and that the average age at the time of injury was higher for hip fractures than for vertebral fractures. Therefore, these results suggest that vertebral fracture leads to hip fracture, indicating that early fracture prevention and continuous prevention strategies through positive treatment are of importance in osteoporotic elderly people.     

Serum 25-OHD insufficiency as a risk factor for hip fracture

The aging population and an increasing number of hip fractures worldwide have made prevention of hip fractures a matter of importance. The prevalence of hypovitaminosis D in patients with acute hip fracture has been reported widely in recent years, and the vitamin D nutritional status in such reports is usually evaluated based on serum 25-hydroxyvitamin D (25-OHD). The aim of this article is to review the relationship of serum 25-OHD and osteoporotic fracture and the prevalence of 25-OHD insufficiency in patients with hip fracture, including assessment of nutritional status, oral status, activity, and dementia. We conclude that the serum 25-OHD level may be a useful index for risk of hip fracture in elderly people.     

Flowcharts for the diagnosis and treatment of acute cholangitis and cholecystitis: Tokyo Guidelines

Diagnostic and therapeutic strategies for acute biliary inflammation/infection (acute cholangitis and acute cholecystitis), according to severity grade, have not yet been established in the world. Therefore we formulated flowcharts for the management of acute biliary inflammation/infection in accordance with severity grade. For mild (grade I) acute cholangitis, medical treatment may be sufficient/appropriate. For moderate (grade II) acute cholangitis, early biliary drainage should be performed. For severe (grade III) acute cholangitis, appropriate organ support such as ventilatory/circulatory management is required. After hemodynamic stabilization is achieved, urgent endoscopic or percutaneous transhepatic biliary drainage should be performed. For patients with acute cholangitis of any grade of severity, treatment for the underlying etiology, including endoscopic, percutaneous, or surgical treatment should be performed after the patient's general condition has improved. For patients with mild (grade I) cholecystitis, early laparoscopic cholecystectomy is the preferred treatment. For patients with moderate (grade II) acute cholecystitis, early laparoscopic or open cholecystectomy is preferred. In patients with extensive local inflammation, elective cholecystectomy is recommended after initial management with percutaneous gallbladder drainage and/or cholecystostomy. For the patient with severe (grade III) acute cholecystitis, multiorgan support is a critical part of management. Biliary peritonitis due to perforation of the gallbladder is an indication for urgent cholecystectomy and/or drainage. Delayed elective cholecystectomy may be performed after initial treatment with gallbladder drainage and improvement of the patient's general medical condition.