Axillary lymph-node metabolic activity assessment on 18F-FDG-PET/CT in rheumatoid arthritis patients treated with biologic therapies.

Objective: Recent studies have provided new insights into the role of lymph nodes (LNs) in rheumatoid arthritis (RA). The aim of this study was to evaluate the metabolic activity of the axillary LNs in relation to that of the upper limb joints and the clinical assessment of disease activity in RA patients treated with biologic therapies.Method: 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) scans were acquired for 64 patients with RA at baseline and after 6 months of biologic therapy, and the patients' clinical status was evaluated. The maximum standardized uptake value (SUVmax), metabolic active volume, and total lesion glycolysis (TLG) were used to assess glucose metabolism in the LNs and 12 joints. Clinical evaluations included serum markers and the Disease Activity Score based on 28-joint count-erythrocyte sedimentation rate (DAS28-ESR).Results: Changes in the SUVmax and TLG for the axillary LNs correlated significantly with those of the ipsilateral wrist joints. There was a positive correlation between the changes in the three metabolic parameters of the axillary LNs and the changes in disease activity after treatment. After 6 months of biologic therapy, all metabolic parameters for the axillary LNs in patients with a DAS28-ESR < 3.2 were significantly lower than those of patients with a DAS28-ESR ≥ 3.2.Conclusion: A relationship between the glucose metabolism of the axillary LNs and the ipsilateral wrist joints was demonstrated by the 18F-FDG-PET/CT parameters. The metabolic activity and active volume of axillary LNs may reflect the therapeutic response to the biologic treatment of RA.

Local massive venous invasion in colorectal cancer: CT-pathological correlation and its clinical implication.

OBJECTIVE: To identify CT findings of massive venous invasion (MVI) in colorectal cancer, compare them to pathological findings and evaluate its clinical implications. METHODS: Among 423 patients who received surgical resection of colorectal cancer, pre-operative CT of 26 patients (15 males, 11 females; mean age, 63.0 ± 12.1 years) with histopathologially proven MVI and 26 patients (14 males, 12 females; mean age, 71.1 ± 9.6 years) with histopathologically proven lymph node (LN) metastases were reviewed and compared with histopathological findings. We evaluated CT detectability of MVI and the morphologic differences between MVI and LN metastasis. All cases were followed up for at least 6 months after surgery. RESULTS: Pre-operative CT correctly diagnosed only one case as tumour thrombus. 9 lesions were not detected on CT, and others were misdiagnosed pre-operatively as regional LN metastasis (14 cases) and juxtatumoural abscess (2 cases). After reviewing these cases, MVIs were identifiable in 20 of 26 cases. MVI was depicted on CT as nodules (oval, lobulated), abscess-like or intravenous tumour thrombus. MVI was significantly larger than LN metastasis (p < 0.05), while contrast enhancement was significantly lower (p < 0.05), and MVI often had an enhanced rim. Ten patients had synchronous metastases, and six patients had metachronous distant metastases within 5 years. CONCLUSION: Many cases of MVI were distinguishable from LN metastases on pre-operative CT of colorectal cancer, but their appearances were varied, reflecting their histopathological behaviours. The distant metastatic rate was much higher in cases with MVI. ADVANCES IN KNOWLEDGE: Radiologists should be aware of CT findings of MVI in colorectal cancer as a sentinel sign of distant metastasis.

Biological significance of fluorine-18-α-methyltyrosine (FAMT) uptake on PET in patients with oesophageal cancer.

PURPOSE: (18)F-FAMT as an amino-acid tracer for positron emission tomography (PET) is useful for detecting human neoplasms. (18)F-FAMT is accumulated in tumour cells solely via L-type amino-acid transporter 1 (LAT1). This study was conducted to investigate the biological significance of (18)F-FAMT uptake in patients with oesophageal cancer. METHODS: From April 2008 to December 2011, 42 patients with oesophageal cancer underwent both (18)F-FAMT PET/CT and (18)F-FDG PET/CT before surgical treatment. The immunohistochemical analysis of LAT1, CD98, Ki-67, CD34, p53, p-Akt and p-mTOR was performed on the primary lesions. In vitro experiments were performed to examine the mechanism of (18)F-FAMT uptake. RESULTS: High uptake of (18)F-FAMT was significantly associated with advanced stage, lymph node metastasis and the expression of LAT1, CD98, Ki-67 and CD34. LAT1 expression yielded a statistically significant correlation with CD98 expression, cell proliferation, angiogenesis and glucose metabolism. In vitro experiments revealed that (18)F-FAMT was specifically transported by LAT1. CONCLUSIONS: The uptake of (18)F-FAMT within tumour cells is determined by the LAT1 expression and correlated with cell proliferation and angiogenesis in oesophageal cancer. The present experiments also confirmed the presence of LAT1 as an underlying mechanism of (18)F-FAMT accumulation.

Nephrogenic systemic fibrosis: risk factors suggested from Japanese published cases.

The aim of this article is to review the published cases of nephrogenic systemic fibrosis (NSF) in Japan. The Japanese medical literature database and MedLine were searched using the keywords NSF and nephrogenic fibrosing dermopathy (January 2000 to March 2009). Reports in peer-reviewed journals and meeting abstracts were included, and cases with biopsy confirmation were selected. 14 biopsy-verified NSF cases were found. In seven of eight patients reported after the association between gadolinium-based contrast agent (GBCA) and NSF was proposed, GBCA administration was documented: five received only gadodiamide; two received both gadodiamide and gadopentetate dimeglumine. In four cases, the amounts of contrast agent were registered: two received only a single dose (0.1 mmol kg(-1) body weight) whereas the other two received 7-15 ml (the body weight was not disclosed) for each MR examination. Five patients had multiple injections of GBCA before NSF developed. Except for one patient in whom renal assessment was not reported, none of the patients had an estimated glomerular filtration rate >30 ml min(-1) 1.73 m(-2) and all received dialysis. 5 of the 8 patients (63%) in whom GBCA exposure was confirmed were treated with peritoneal dialysis. Skin lesion of the lower extremity was the first symptom in 12 patients (86%), whereas 2 patients had primarily symptoms from the upper extremity. In three cases, GBCA was administered even after onset of the NSF symptoms because of the physicians' lack of knowledge about the possible association between GBCA and NSF. NSF is found among Japanese end-stage renal failure patients even after examinations using a single dose.

The role of the ADC value in the characterisation of renal carcinoma by diffusion-weighted MRI.

The purpose of this study is to evaluate the role of diffusion-weighted imaging (DWI) in combination with T(1) and T(2) weighted MRI for the characterisation of renal carcinoma. The institutional review board approved the study protocols and waived informed consent from all of the patients. 47 patients (32 male and 15 female; age range, 21-85 years; median age, 65 years) who had suspected renal lesions on abdominal CT underwent MRI for further evaluation and characterisation of the lesions from April 2005 to August 2007 in our university hospital. A region of interest was drawn around the tumour area on apparent diffusion coefficient (ADC) maps. Final diagnosis was confirmed by histological examination of surgical specimens from all patients. The ADC value was significantly higher in renal cell carcinoma (RCC) than in transitional cell carcinoma (2.71+/-2.35 x 10(-3) mm(2) s(-1) vs 1.61+/-0.80 x 10(-3) mm(2) s(-1); p = 0.022). While analysing the histological subtypes of RCC, a significant difference in ADC values between clear cell carcinoma and non-clear cell carcinoma was found (1.59+/-0.55 x 10(-3) mm(2) s(-1) vs 6.72+/-1.85 x 10(-3) mm(2) s(-1); p = 0.0004). Similarly, ADC values of RCC revealed a significant difference between positive and negative metastatic lesions (1.06+/-0.38 x 10(-3) mm(2) s(-1) vs 3.02+/-2.44 x 10(-3) mm(2) s(-1); p = 0.0004), whereas intensity on T(1) and T(2) weighted imaging did not reach statistical significance. In conclusion, DWI has clinical value in the characterisation of renal carcinomas and could be applied in clinical practice for their management.

[Aortic dissection after aortic valve replacement with an aorto-left atrial fistula; report of a case].

Aortocameral fistula is a rare complication of aortic dissection. We herein report a case of aortic dissection after aortic valve replacement (AVR) complicated with a fistula to the left atrium. A 76-year-old man who had undergone AVR 1 year previously, was admitted to our hospital because of facial edema and chest discomfort. On auscultation, a continuous murmur was heard at the left lower sternal border. Computed tomography revealed dissecting aneurysm of the ascending aorta and a fistula to the left atrium was suspected. Transesophageal echocardiography showed the fistula between the false lumen of the aneurysm and the left atrium. Ascending aorta replacement and closure of the fistula was performed. There was dense adhesion between the aortic root and the roof of the left atrium. It seems that postoperative adhesion plays an important role in formation of aortocameral fistula.

Expansion of radiofrequency ablation volume by saturated NaCl saline injection in the area of vaporization.

BACKGROUND: Vaporization around the radiofrequency (RF) electrode after RF application (RFA) limits the RF ablation area. PURPOSE: To determine whether saturated saline injected into the area of vaporization after initial RFA extends ablation area after further RFA. MATERIAL AND METHODS: RFA was performed in 18 ex vivo porcine livers and four in vivo rabbit erector spinae muscles. An RF electrode was used to ablate an area with 40W of parallel current for 15 min. The ablation margin was determined using a thermocouple, and the radius of the ablated area was measured. After RF electrode removal, saturated saline was infused through a percutaneous ethanol injection needle into the site of the original RFA in 11 liver samples and two erector spinae muscles. Three minutes later, RFA was resumed for 15 min. The remaining seven control liver samples and two spinae muscles received RFA without saline injection. The radius of the final ablated area was then measured. RESULTS: In the ex vivo study, injection of saturated saline significantly decreased tissue impedance (87.7+/-9.4 to 51.1+/-9.7 Omega, P<0.0001), and increased the mean radius of the ablated area (15.9+/-3.0 to 25.0+/-3.6 mm, P<0.0001). These significant changes were not observed without injection of saturated saline. Similar trends were found in the in vivo study. CONCLUSION: Injection of saturated saline into the area of vaporization around the RF electrode, followed by additional RFA, caused concentric expansion of the final ablation area, facilitating more efficient tumor ablation.

[Giant cardiac metastasis of myxoid liposarcoma causing cardiac tamponade; report of a case].

We report a very rare case of cardiac metastasis of myxoid liposarcoma. A 55-year-old man presented with dyspnea. Two and a half years ago, he underwent resection of myxoid liposarcoma in the left thigh. Magnetic resonance imaging (MRI) revealed a giant tumor occupying the pericardiac cavity and pressing the heart and consequently causing cardiac tamponade. The patient underwent surgery through a left thoracotomy approach. The pericardiac cavity was filled with a giant tumor with a stalk from the right ventricle and 2 small nodules on the main pulmonary artery. He was relieved from the symptom: however, he had a recurrence of the tumor at the same site 5 months after the operation. He underwent surgery for the removal of the second tumor; however, he died 49 days after the operation. Although cardiac metastasis is a very rare condition, its awareness is essential for careful long-term follow-up for the early detection of a metastatic cardiac liposarcoma after the resection of the primary tumor.

[Surgical technique of aortic valve replacement for small aortic annulus in elderly patients].

Recent reports have shown that aortic valve replacement in elderly patients over 65 years with atherosclerotic aortic stenosis and a small aortic annulus is possible by using a small sized bioprosthesis (Carpentier-Edwards pericardial valve). Here we present out surgical technique. Firstly, the native calcified aortic valve was removed completely to gain total exposure of the surrounding aortic root and sinus of Valsalva like Bentall procedure. Secondly, a small sized bioprosthesis was implanted with intermittent noneverting mattress 2-0 sutures with spaghetti and small polytetrafluoroethylene (PTFE) felt. Aortic annulus is the dilated by inserting Hegar dilator sizing from 25 to 27 mm. Therefore, aortic valve replacement for small aortic annulus in intra- or supra-annular position should be easily accomplished. Good surgical results and hemodynamic state were achieved in 25 consecutive cases using this technique.

[Ventricular free wall re-rupture after surgical treatment of ventricular free wall rupture due to acute myocardial infarction; report of a case].

An in-hospital 72-year-old male with complaint of anterior chest pain was presented with shock. Pericardial effusion was confirmed by echocardiography, and therefore, he was brought to the operating room immediately with diagnosis of ventricular free wall rupture. The repair was performed using fibrin glue, fibrin sheet, and pericardial patch. His post-operative course was uneventful until massive bleeding came through the chest tube on the 5th day from the initial surgery. The emergency sternotomy was made again for hemostasis. In the re-operation, an approximately 20 mm laceration along the proximal circumflex artery was found and this was successfully repaired with 2 pledgetted horizontal mattress sutures. It is important and necessary to treat a postoperative patient taking care of re-rupture.

MR detection of microhemorrhages in neurologically healthy adults.

T2*-weighted gradient-echo (GE) magnetic resonance images frequently demonstrate small hypointense lesions in patients with systemic hypertension and spontaneous hematomas. These lesions have been suspected to represent subclinical microhemorrhages. We examined the incidence of these lesions in neurologically healthy adults, and the factors associated with them. Axial T2*-weighted GE images (TR = 1,000 ms, TE = 30 ms, flip angle = 20 degrees) were obtained in addition to conventional T1- and T2-weighted spin echo images in 450 neurologically healthy Japanese adults (289 men and 161 women; age 52.9 +/- 7.7 years, range 24-84). The overall incidence of small hypointense lesions was 3.1% (14/450), and these lesions were closely related to systemic hypertension (P < 0.0001) and heavy cigarette smoking (>20 cigarettes per day; P=0.003). Although the incidence of hypointense lesions was lower in neurologically healthy adults than in the reported incidence in patients with a hemorrhagic history, the presence of these lesions was related to the risk factors for primary intracerebral hemorrhage even in the neurologically healthy adults.

Does the presence of distant and local malignancy alter parenchymal perfusion in apparently disease-free areas of the liver?

Our objective was to investigate if hepatic arterial (HAP) and portal venous perfusion (PVP) in apparently normal areas of liver, as measured by functional CT, are affected by the presence of extra- and intrahepatic malignancy Three patient groups were compared: A, controls with no malignancy (N = 10); B, extrahepatic malignancy without liver involvement (N = 12); and C, subjects with metastases elsewhere in the liver (N = 13). HAP, PVP, and a CT hepatic perfusion index (CT-HPI) calculated as HAP/(HAP + PVP) were calculated on a section free of metastatic disease, using a previously published method. Figures for PVP were (median and interquartile range) in group A were 1.06 (0.9-1.30), in B 1.03 (0.81-1.09), and in C 0.75 (0.54-1.02) ml/min/ml; for HAP group A values were 0.07 (0.052-0.078), in B 0.07 (0.053-0.147), and in C 0.12 (0.091-0.146) ml/min/ml and for CT-HPI Group A values were 4.9% (4.8-6.6%), in B 5.6% (3.8-13.6%), and in C 14.3% (10.4-15.4%). Significant differences in all indices were seen between groups A and C. A significant difference (P = 0.017) was seen between groups B and C in the CT-HPI values. In conclusion, patients with liver metastases show abnormal blood flow in apparently normal liver compared to controls. This difference was not seen in subjects with malignancy without liver metastases. Possible explanations would be either the unmasking of occult metastatic disease or vasoactive or mechanical effects due to liver malignancy.

Ischaemic ileal stenosis following blunt abdominal trauma and demonstrated by CT.

We report a case of blunt abdominal trauma in which delayed ischaemic ileal stenosis occurred. A 24-year-old man presented with symptoms and signs of bowel obstruction 2 weeks after blunt abdominal trauma. Enhanced CT clearly demonstrated a stenotic ileal loop with mural thickening, associated with a mesenteric haematoma. This abnormal ileal loop was resected.

Detection of Cryptosporidium parvum oocysts in environmental water in Hokkaido, Japan.

Control of cryptosporidiosis is important in public health. Rivers that are polluted with Cryptosporidium and drinking water that is treated for drinking water production from polluted rivers could result in the waterborne disease of cryptosporidiosis. We carried out an epidemiological study of natural water supplies in Hokkaido, one of the largest dairy prefectures in Japan. To detect Cryptosporidium oocysts in environmental water, the filtration method was used for 28 samples, which were collected from 10 rivers. A method adapted from the United States Environmental Protection Agency (U.S. EPA) filtration method using a cartridge filter has been used for the collection of samples. Oocysts were separated from a pellet by discontinuous sucrose gradient method. Twelve samples were collected from 10 rivers and parasites were purified by iron (III) flocculation method. Cryptosporidium parvum oocysts were identified with the immunofluorescence antibody technique using DIF kit (Cellabs Pty. Ltd., Sydney/Australia). We detected Cryptosporidium oocysts in 6 out of 10 rivers sampled. Fifty percentage (14/28) of the samples were Cryptosporidium-positive. The average number of Cryptosporidium oocysts was 16.73/100 L (max. 80/100 L).

Determination of glomerular filtration rate per unit renal volume using computerized tomography: correlation with conventional measures of total and divided renal function.

PURPOSE: Previous studies suggest that functional computerized tomography (CT) can measure glomerular filtration rate (GFR) per unit renal volume. We compared this index with conventionally determined GFR measurements. MATERIALS AND METHODS: A total of 16 men and 8 women 63.3 +/- 14.9 years old (range 31 to 88) were studied using with contrast enhanced CT. A single slice of kidney was scanned sequentially after bolus injection (0.5 to 1.0 ml. per second(-1)) of 20 ml. iopamidol (300 mg. iodine per ml.(-1)). GFR per volume of kidney was calculated using a Patlak graphical analysis, and this index was multiplied by renal volume on CT to yield global GFR (ml. per minute(-1)). Divided function was also calculated. GFR and divided renal function were calculated in all cases from radioisotope renography with 99m diethylenetetraminepentaacetic acid. In 12 subjects in whom 24-hour urine collection was possible GFR was also calculated from creatinine clearance. RESULTS: A strong correlation was observed between divided renal function, expressed with respect to the right kidney calculated from CT (52.7 +/- 14.8%, range 19.9% to 97.4%) and by radioisotope renography (51.7 +/- 14.6%, range 18.9% to 92.6%, r = 0.97, p <0.0001). A strong correlation (r = 0.92, p <0.0001) was also seen between global GFR determined by CT (80.1 +/- 43.9 ml. per minute(-1), range 38.2 to 197.9) and creatinine clearance (72.4 +/- 47.5, range 14.6 to 168.5), and was stronger than the correlation between the radioisotope and creatinine clearance method (r = 0.67, p = 0.02) in the same patients. CONCLUSION: Functional CT using nonionic contrast material can measure GFR normalized to renal volume and is an accurate alternative to conventional methods of renal function evaluation.

Relationship between stroke and asymptomatic minute hemorrhages in hypertensive patients.

Asymptomatic small hemorrhages were identified in hypertensive patients by T2*-weighted gradient echo magnetic resonance (MR) imaging to investigate the relationship between hypertensive intracerebral hemorrhage and asymptomatic minute hemorrhages. Forty-eight patients with hypertensive intracerebral hemorrhage or cerebral infarction with hypertension (these diseases were defined as stroke) were treated in National Defense Medical College from April 1998 to February 2000. All patients had no past history of stroke or head injury, underwent MR imaging within 6 months of the stroke attack, were aged from 40 to 80 years, and had no diagnosis of aneurysm, angioma, or moyamoya disease. Patients were divided into the infarction group and hemorrhage group. All foci over 2 mm in size appearing as hypointense on T2*-weighted MR imaging and unrelated to stroke areas were defined as minute hemorrhages. There were no significant differences between the two groups with respect to sex, age, and history of diabetes mellitus. The incidence of minute hemorrhages in the hemorrhage group (21/26) was greater than in the infarction group (9/22, p < 0.01). The incidence of minute hemorrhages in the basal ganglia (18/26) was greater in the hemorrhage group than in the infarction group (4/22, p < 0.001). Symptomatic intracerebral hemorrhage may be preceded by asymptomatic minute hemorrhage.

[Tension pneumothorax after simultaneous bilateral lung resection].

A 72-year-old man was admitted to our hospital because of an abnormal shadow on chest X-ray film. Chest CT showed a mass 6 cm in diameter in left S1 + 2, and a small round mass in right S2. Left side mass was diagnosed squamous cell carcinoma by transbronchial biopsy, but right side mass was unidentified. We performed partial resection for a right S2 mass with VATS, and then left upper lobe lobectomy and mediastinal lymph node dissection simultaneously. Pathological examination revealed the right mass was hamartoma. He discharged on 16 postoperative days uneventfully. But 3 days after he was sent to our hospital on emergency because dyspnea and unconscious. Chest X-ray revealed right side tension pneumothorax, then he was recovered by chest tube insertion. At re-thoracotomy we confirmed air leakage was occurred from a ruptured bulla that was leaved at first operation.

A quantitative analysis of head injury using T2*-weighted gradient-echo imaging.

BACKGROUND: T2*-weighted gradient-echo imaging (T2*-GE) is useful for detecting small hemorrhages. METHODS: Thirty-four patients were prospectively examined, first by magnetic resonance imaging (1.5 T) and then by T2-weighted fast spin echo (T2-FSE) and T2*-GE. Thereafter, the correlations between the T2-FSE or T2*-GE findings and the clinical or computed tomography findings were analyzed. RESULTS: The number of lesions detected by T2*-GE was 14.5 +/- 16.3 (mean +/- SD, n = 34), which was significantly (p < 0.001) greater than that detected by T2-FSE (5.6 +/- 5.6, n = 34). The findings of T2*-GE correlated positively with both the duration of unconsciousness (R2 = 0.74,p < 0.0001) and with Glasgow Outcome Scale (R2 = 0.81, p < 0.0001), whereas those of T2-FSE did not show any significant correlation. T2*-GE imaging could also detect all areas responsible for focal neurologic signs 1 month after in. jury, whereas T2-FSE imaging detected only 22 of 33 such signs. CONCLUSION: T2*-GE was found to be useful for evaluating the clinical symptoms of head injury.