Volume and landmark analysis: comparison of MRI measurements obtained with an endorectal coil and with a phased-array coil

AIM

To compare prostate volumes and distances between anatomical landmarks on MRI images obtained with a phased-array coil (PAC) only and with a PAC and an endorectal coil (ERC).

MATERIALS AND METHODS

Informed consent was waived for this Health Insurance Portability and Accountability Act-compliant study. Fifty-nine men underwent PAC-MRI and ERC-MRI at 1.5 (n = 3) or 3 T (n = 56). On MRI images, two radiologists independently measured prostate volume and distances between the anterior rectal wall (ARW) and symphysis pubis at the level of the verumontanum; ARW and symphysis pubis at the level of the mid-symphysis pubis; and bladder neck and mid-symphysis pubis. Differences between measurements from PAC-MRI and ERC-MRI were assessed with the Wilcoxon RANK SUM test. Inter-reader agreement was assessed using the concordance correlation coefficient (CCC).

RESULTS

Differences in prostate volume between PAC-MRI and ERC-MRI [median: -0.75 mm(3) (p = 0.10) and median: -0.84 mm(3) (p = 0.06) for readers 1 and 2, respectively] were not significant. For readers 1 and 2, median differences between distances were as follows: -10.20 and -12.75 mm, respectively, ARW to symphysis pubis at the level of the verumontanum; -6.60 and -6.08 mm, respectively, ARW to symphysis pubis at the level of the mid-symphysis pubis; -3 and -3 mm respectively, bladder neck to mid-symphysis pubis. All differences in distance were significant for both readers (p ≤ 0.0005). Distances were larger on PAC-MRI (p ≤ 0.0005). Inter-reader agreement regarding prostate volume was almost perfect on PAC-MRI (CCC: 0.99; 95% CI: 0.98-1.00) and ERC-MRI (CCC: 0.99; 95% CI: 0.99-1.00); inter-reader agreement for distance measurements varied (CCCs: 0.54-0.86).

CONCLUSION

Measurements of distances between anatomical landmarks differed significantly between ERC-MRI and PAC-MRI, although prostate volume measurements did not.

Focal nodular hyperplasia: characterisation at gadoxetic acid-enhanced MRI and diffusion-weighted MRI

PURPOSE

The aim of this study was to assess the enhancement patterns of hepatic focal nodular hyperplasia (FNH) on gadoxetic acid-enhanced MRI and diffusion-weighted (DW) MRI.

METHODS

This retrospective study had institutional review board approval. Gadoxetic acid-enhanced and DW MR images were evaluated in 23 patients with 30 FNHs (26 histologically proven and 4 radiologically diagnosed). The lesion enhancement patterns of the hepatobiliary phase images were classified as heterogeneous or homogeneous signal intensity (SI), and as dominantly high/iso or low SI compared with those of adjacent liver parenchyma. Heterogeneous (any) SI lesions and homogeneous low SI lesions were categorised into the fibrosis group, whereas homogeneous high/iso SI lesions were categorised into the non-fibrosis group. Additionally, lesion SI on T2 weighted images, DW images and apparent diffusion coefficient (ADC) values were compared between the two groups.

RESULTS

The lesions showed heterogeneous high/iso SI (n=16), heterogeneous low SI (n=5), homogeneous high/iso SI (n=7) or homogeneous low SI (n=2) at the hepatobiliary phase MR images. The fibrosis group lesions were more likely to show high SI on DW images and T2 weighted images compared with those in the non-fibrosis group (p<0.05). ADC values tended to be lower in the fibrosis group than those in the non-fibrosis group without significance.

CONCLUSION

FNH showed variable enhancement patterns on hepatobiliary phase images during gadoxetic acid-enhanced MRI. SI on DW and T2 weighted images differed according to the fibrosis component contained in the lesion.

ADVANCES IN KNOWLEDGE

FNH shows a wide spectrum of imaging findings on gadoxetic acid-enhanced MRI and DW MRI.

Initial experience of transurethral resection with pediatric resectoscope for incomplete anterior urethral stricture

PURPOSE

Endoscopic urethrotomy is an alternative method in treatment of urethral stricture. However, it have high recurrence rate because of the remained fibrotic tissue. Removal of the fibrotic tissue can maintain the patency of the urethral lumen after the procedure. We report the therapeutic efficacy of our initial experience using pediatric resectoscope for treating anterior urethral stricture in 16 cases.

MATERIALS AND METHODS

From January 2009 to April 2011, transurethral resection with pediatric resectoscope was primarily performed on 16 patients with anterior urethral stricture. Retrograde urethrography, uroflowmetry, postvoid residual volume, IPSS score and QoL score were performed preoperatively. We used 11.5Fr pediatric resectoscope (Wolf) and monopolar electrosurgical generator. The stricture was incised under vision at the 12 o'clock location or the site of maximum scar tissue or narrowing in asymmetric strictures for working space. After incision, transurethral resection with pediatric resectoscope was performed to all scar tissues. Monopolar cutting current was set on 45 watt and coagulation current was set on 30 watt, fulgurate mode. Postoperatively, drainage of the bladder was performed for 7 days using an 18F latex catheter. Patients were followed up by IPSS score, QoL score, uroflowmetry and postvoid residual volume.

RESULTS

Successful results without recurrence were achieved in 11 of 16 patients. Postoperative urethral dilation had been performed average 2.4 times (0~6 times). When we classified the results by etiology, the number of successful results in strictures with a trauma, iatrogenic, or unknown cause was 5 (7/11), 3 (3/4) and 1 (1/1), respectively. In 5 patients who failed treatment, we repeated transurethral resection with pediatric resectoscope in 1 patient, and periodic urethral dilation in 4 patients. No operative complications occurred in any patients.

CONCLUSIONS

Transurethral resection with pediatric resectoscope is an effective therapeutic method for anterior urethral stricture. More long-term follow-up and large scale studies are needed to confirm the efficacy of this procedure.

Interventional management for complications following caesarean section

OBJECTIVES

This study aimed to evaluate the efficacy and safety of interventional management for various intractable complications following caesarean section.

METHODS

Between August 2005 and September 2009, 18 consecutive women were referred to interventional radiology for treatment of complications developing after caesarean section. Complications included vaginal bleeding (n = 14), haemoperitoneum with abdominal wall haematoma (n = 2), caesarean scar pregnancy (CSP) (n = 1) and post-caesarean fluid collection (n = 1).

RESULTS

17 women underwent transcatheter arterial embolisation (TAE) with a variety of embolic materials, and two women underwent percutaneous drainage (PCD) for fluid collection and haemoperitoneum. 5 of the 14 women with vaginal bleeding had extravasation of contrast media on angiography; the other 9 had no visible bleeding foci. The two women with haemoperitoneum with abdominal wall haematoma had injury to the inferior epigastric artery from angiography. TAE and PCD were successfully performed in both women. The CSP was successfully managed and the serum β-human chorionic gonadotropin (β-hCG) level finally normalised. Hysterectomy or dilatation and curretage was required in women with placenta accrete and undetectable bleeding foci.

CONCLUSION

Interventional management including TAE and PCD is effective and safe in controlling complications following caesarean section. Use of these procedures can help avoid high-risk surgery, but subsequent procedures including hysterectomy may be required in cases of placental abnormalities and undetectable bleeding foci.

Percutaneous radiofrequency ablation of small hepatocellular carcinoma invisible on both ultrasonography and unenhanced CT: a preliminary study of combined treatment with transarterial chemoembolisation

The purpose of this study was to assess the feasibility and efficacy of percutaneous radiofrequency ablation combined with transarterial chemoembolisation (TACE) for the treatment of hepatocellular carcinoma that are invisible on both ultrasound and unenhanced CT. 73 patients with a total of 101 nodular hepatocellular carcinomas were referred for possible radiofrequency (RF) ablation. Of these, 14 lesions (14%) in 14 patients were invisible on both ultrasound and unenhanced CT. The invisible nodules averaged 1.2 cm in diameter (range, 0.8-2.0 cm; median, 1.1 cm). After segmental TACE, percutaneous RF ablation was performed if the index tumour was visible on fluoroscopy, ultrasound or CT. All cases of combined treatment were evaluated for size of ablative zone, complications, rate of technical effectiveness at 1-month follow-up CT and local tumour progression. After TACE, percutaneous RF ablation was technically feasible in 10 (71%) of the 14 nodules. RF ablation was performed with the guidance of fluoroscopy (n = 6, 42%), ultrasound (n = 2, 14%) or CT (n = 2, 14%). The mean diameter of the ablative zone by percutaneous RF ablation combined with TACE was 4.8+/-0.7 cm and 3.4+/-0.6 cm in the long and short axis, respectively. No major complications were documented. The primary technical effectiveness rate for nodules treated by combined treatment was 100% (10/10) at 1-month follow-up CT. No local tumour progression was found during the follow-up period (median 15 months; range 4-20 months). Percutaneous RF ablation combined with TACE is a feasible and effective technique for treating small hepatocellular carcinomas that are not visible on ultrasound or unenhanced CT.

T-lymphocyte subsets in patients with AJCC stage III gastric cancer during postoperative adjuvant chemotherapy. American Joint Committee on Cancer

BACKGROUND AND AIMS

Advanced neoplastic diseases alter the immune response in cancer patients. The aim of this study was to evaluate the changes of T-lymphocyte subsets during postoperative adjuvant chemotherapy, and the relationship between T-lymphocyte subsets and tumor recurrence in AJCC stage III gastric cancers.

MATERIAL AND METHODS

Analysis of T-lymphocyte subsets was performed in 39 patients with stage III gastric adenocarcinoma who had undergone a curative gastric resection and postoperative chemotherapy. CirculatingT-lymphocyte subsets were measured on venous blood by using flow cytometry and monoclonal antibodies on preoperative day 1, and postoperative months 1, 3, and 6.

RESULTS

The 5-year disease-free survival rates of patients with stage 3a and 3b gastric cancer were 57.1% and 33.3%, respectively (p = 0.06). Values of CD3+ and CD4+ T-cells, and CD4+/CD8+ ratios were consistently lower in the recurrence group throughout the observation period. CD4+ T-cell counts were significantly lower in the recurrence group on preoperative day 1, and postoperative months 1 and 6. However, most values of the T-lymphocyte subsets showed no statistically significant difference when comparing the stage 3a and 3b disease patient groups.

CONCLUSIONS

The results of this study suggest that immunosuppression associated with CD3+ and CD4+ T-cell depression is a risk factor for postoperative recurrence in patients with stage III gastric cancer.

Pseudomonas aeruginosa as a potential cause of antibiotic-associated diarrhea

Although Pseudomonas aeruginosa is not generally considered as a cause of antibiotic-associated diarrhea, several cases of diarrhea caused by P. aeruginosa have been reported. We experienced seven cases of nosocomial diarrhea presumably caused by P. aeruginosa, which was the predominant organism isolated from stool cultures. Clostridium difficile toxin was also positive in one patient. No other potential or recognized enteropathogens were identified from stools. All patients had underlying diseases and had been receiving antibiotics before the diarrheal onset. All of the seven P. aeruginosa isolates were resistant to previously given antibiotics. Diarrhea stopped three days after withdrawal of probable offending antibiotics without specific treatment in two patients. The other five patients having continuous diarrhea despite withdrawal of probable offending antibiotics, were successfully treated with antipseudomonal agents. The median duration of diarrhea after the initiation of treatment was 6.3 days. These data suggest that P. aeruginosa can be a potential cause of antibiotic-associated diarrhea. Further investigations are warranted to evaluate the possible etiologic role of P. aeruginosa in antibiotic-associated diarrhea.

Effects of simultaneous kidney-pancreaticoduodenal transplantation on diabetes-induced renal insufficiency in rats

An investigation of the functional and histological changes was done after en-bloc kidney-pancreaticoduodenal transplantation (kpdt) in the diabetes-induced, renal insufficient Lewis rats. For donor preparation, an end-to-side portocaval shunt was performed, and the aortic, vena caval segments, and ureter-bladder patch were obtained. They were anastomosed microsurgically to recipient's aorta, vena cava, and bladder in end-to-side fashion. Of 15 diabetes-induced kpdt rats, 14 survived. Two of the 14 surviving rats showed ischemic necrosis. The remaining 12 transplants showed well-preserved glomeruli and Langerhans islets for 5 months postoperatively. Biochemical data comparing diabetic and sham-operated rats (six rats each), six diabetic controls, and 12 kpdt rats showed no significant statistical difference at said observation period. The diabetes-induced kpdt rats showed improvement of following biochemical data: within 1 week postoperatively, the glucose level fell from 300 to 115 mg/dL; BUN level from >20 to <20 mg/dL; the creatinine level from 1.5 to <1.2 mg/dL. The insulin level returned to normal, 1.1 ng/mL, in 2 weeks. The results demonstrate that the kpdt model is an effective and successful operative technique in diabetic rats and may provide effective therapeutic methods for diabetes-induced renal insufficiency.

Expression of intercellular adhesion molecule-1 in the cortex of preserved rat kidneys

BACKGROUND

Prolonged cold ischemia has been shown to be an important factor in the development of posttransplant renal dysfunction. The exact mechanisms have not been completely defined. The expression of intercellular adhesion molecule-1 (ICAM-1) (CD 54) in rat kidneys stored in University of Wisconsin (UW) solution was studied in an attempt to correlate ischemia time with immunogenicity of the graft.

METHODS

Kidneys from male Lewis rats were perfused with UW solution, removed, and bathed in UW solution at 4 degrees C for 4, 12, 24, and 48 h. For the evaluation of expression of ICAM-1, immunohistochemical staining, Western blotting, and semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) were performed.

RESULTS

Immunohistochemical staining in normal, nonischemic kidneys revealed that glomerular capillaries expressed ICAM-1 but that tubular cells did not. The preserved kidneys were analyzed by immunohistochemistry, Western blotting, and semiquantitative RT-PCR and showed increased transcription and expression of ICAM-1 in the cortex of the kidney. Expression reached a maximum at 24 h and declined at 48 h. The ICAM-1 protein expression in the preserved kidney cortex relative to control kidneys was increased at 4 h (1.68 +/- 0.60-fold of control kidneys, P = 0.06), 12 h (2.38 +/- 0.90-fold, P = 0.02), 24 h (3.70 +/- 1.29-fold, P = 0.01), and 48 h (2.00 +/- 0.54-fold, P = 0.01). The messenger RNA expression (the ratio of ICAM-1 to glyceraldehyde-3-phosphate dehydrogenase) in preserved kidneys cortex relative to control kidneys was increased at 4 h (1.19 +/- 0.14-fold of control kidneys), 12 h (1.38 +/- 0.16-fold), 24 h (1.77 +/- 0.29-fold), and 48 h (1.19 +/- 0.12-fold) (P < 0.05 for all time points).

CONCLUSIONS

We conclude that cold preservation of rat kidneys in UW solution induces increasing levels of ICAM-1 cell surface expression and gene transcription. Further study is necessary to determine if this increase in adhesion molecule expression increases the immunogenicity of the allograft and contributes to the development of posttransplant renal dysfunction.

The Seoul experience of splenic artery aneurysms

BACKGROUND AND AIMS

Aneurysms of the splenic artery (SAA) are the most common type of aneurysms found in the splanchnic arterial bed (1) and are second in frequency only to aortic and iliac artery aneurysms among intra-abdominal aneurysms (2). Historically rupture occurs in 6-9.2% of asymptomatic cases and in pregnant women rupture occurs in 95% of afflicted women further emphasizing the importance of early diagnosis (3-5). Possible treatments are surgical resection or trans-catheteral arterial embolization.

MATERIAL AND METHODS

The relationship of SAA to pregnancy, pancreatitis and the outcome after surgical resection or arterial embolization was studied. Fifteen patients were diagnosed with SAA between January, 1992 and December 1999. The patients were classified by their clinical characteristics, etiology, size, and location of the aneurysm, relationship to pregnancy in women, clinical outcome of ruptured aneurysms and treatment.

RESULTS

Fifteen patients, male to female ratio of 1.1:1 (eight men, seven women), with splenic artery aneurysm were treated. Patients were mostly in their sixty's and the mean age was 49.07. Chronic pancreatitis and pseudocysts were found in four cases (26.7%). Acute pancreatitis, portal hypertension, splenomegaly, and bronchitis were comorbidities found each in one case (6.7%). Eight cases (53.3%) were without associated disease

CONCLUSIONS

SAA has historically shown predominance in women, but in this study, men showed predominance and no relation to pregnancy could be found. In cases were the aneurysms ruptured and treatment was initiated, one of four patients died. One patient refused treatment and subsequently died. As most of the aneurysms measure over 2 cm at the time of detection, operative resection was recommended in all cases. In the high-risk patients, arterial embolization using coiling can be effective early in treatment, but arterial embolization in SAA secondary to pancreatitis was shown only to be palliative and needed to be complimented with surgical intervention. Arterial embolization is the method of choice in high-risk patients.

Vascular endothelial growth factor in malignant and tuberculous pleural effusions

The purpose of this study is to assess the usefulness of soluble vascular endothelial growth factor (VEGF) in the effusions of patients with malignant and tuberculous diseases. Using a sandwich enzyme-linked immunoadsorbent assay, VEGF concentration was measured in malignant (n=17) and tuberculous (n=11) pleural effusions. Pleural biopsy, cytology or microbiological methods were used to make final diagnoses. Adenosine deaminase (ADA) levels in tuberculous pleural effusions were significantly higher than those in malignant pleural effusions. The median level of VEGF in patients with malignant effusions (median, 2418 pg/mL; range, 97-62103 pg/mL) was significantly higher than tuberculous effusions (median, 994 pg/mL; range, 44-3552 pg/mL). There were no significant differences in pleural VEGF levels in patients with different histological types of lung cancer. The VEGF level was not correlated with ADA, lactate dehydrogenase and total protein levels of pleural fluid. In conclusion, pleural VEGF levels in patients with malignant effusions were significantly higher than tuberculous effusions, and the measurement of pleural VEGF is helpful in discriminating between malignant and tuberculous effusions. Further studies are needed to determine the clinical value of VEGF as a tumor marker and a prognostic factor.

The role of growth factor on regeneration of nitric oxide synthase (NOS)--containing nerves after cavernous neurotomy in the rats

Nitric oxide synthase (NOS) containing nerve regeneration can be seen six months after unilateral cavernous nerve neurotomy in rats. However, its molecular mechanism is still unknown. It is believed that growth factors are involved in this phenomenon. In this study we investigated the change of NOS containing nerve fibers and the RNA expression of insulin like growth factor (IGF)-I, nerve growth factor (NGF), transforming growth factor (TGF)-alpha, TGF-beta 1, TGF-beta 2. TGF-beta 3 and NOS on the penis after cavernous nerve neurotomy in rats. Male rats were divided into three groups: (1) sham operation (N = 10); (2) unilateral neurotomy of a 5 mm segment of the cavernous nerve (N = 15); and (3) bilateral neurotomy (n = 15). Electrostimulation of the intact cavernous nerve or pelvic ganglion was performed at one, three and six months. Nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining was used to identify NOS in the penile nerve fibers. The gene expression for growth factors and bNOS was investigated in corporal tissue by reverse transcriptase-polymerase chain reaction (RT-PCR) using specific oligonucleotide primers. One month after neurotomy, both unilateral and bilateral neurotomy groups showed a significant decrease in NOS-containing nerve fibers on the dorsal and intracavernosal nerves on the side of neurotomy, and a significantly lower mRNA expression of bNOS, IGF-I and TGF-beta 2. At three months, the number of NOS-containing nerve fibers in the unilateral neurotomy group increased only slightly but at six months those in the intracavernosal nerve increased in a significant amount (P < 0.0001), however mRNA expression of bNOS, IGF-I and TGF-beta 2 showed a significant increase as early as at three months. After bilateral neurotomy, the NOS-positive nerve fibers in the dorsal and intracavernosal nerve were significantly decreased at one month and remained so at six months; no erectile response could be elicited by pelvic ganglion stimulation. In the unilateral neurotomy group at six months, more NOS-positive neurons in the pelvic ganglia were found on the intact side than on the side of the neurotomy (P < 0.003), indicating that the regeneration derives from pelvic ganglion neurons on the intact side. Furthermore, electrostimulation in the unilateral neurotomy group revealed a greater maximal intracavernosal pressure and a shorter latency period at six months than at one month (P < 0.014, P < 0.001, respectively). These data suggest that IGF-I and TGF-beta 2 may play a key role in regeneration of NOS-containing nerve fibers in the dorsal and intracavernosal nerves after unilateral cavernous nerve injury.

Cloning of the histidine biosynthetic genes of Corynebacterium glutamicum: organization and sequencing analysis of the hisA, impA, and hisF gene cluster

The hisA and hisF genes of Corynebacterium glutamicum were cloned by transforming histidine auxotrophic Escherichia coli with the genomic DNA library. They are two of the eight genes that participate in the histidine biosynthetic pathway. Cloned DNA fragments containing the genes can also complement hisH and hisI auxotrophs of Escherichia coli, suggesting that the four genes are clustered in the genome. We determined the nucleotide sequences of the minimal fragment containing the hisA and hisF genes, which are separated by the impA gene. The coding regions of the hisA and hisF genes are 245 and 257 amino acids in length with a predicted size of about 26 and 27 kDa, respectively. These are in good agreement with the sizes of proteins expressed in E. coli. A high similarity was observed in comparison of nucleotide sequences of each protein between C. glutamicum and other species, as well as those between hisA and hisF genes of C. glutamicum.