The probable molecular association in liquid D-1-propanol through neutron diffraction.

The neutron scattering data of liquid D-1-propanol at room temperature has been carefully analyzed to extract the probable molecular association. The molecular conformation (quite elongated) being very different from its isomer 2-propanol (somewhat spherical) would suggest a different type of molecular association in 1-propanol. The probable molecular associations like open chain trimer (as in recent X-ray work) to pentamer (winding) as in earlier X-ray analysis in addition to hexameric ring clusters (as reported in 2-propanol and other alcohols) are compared. It is surprisingly seen that hexameric rings are most probable molecular association in 1-propanol too.

Retrograde jejunogastric intussusception (JGI) with strangulation following previous gastrojejunostomy.

Jejunogastric intussusception is a rare but potentially very serious complication of gastrectomy or gastrojejunostomy. To avoid mortality early diagnosis and prompt surgical intervention is mandatory. A young man presented with epigastric pain and bilous vomiting followed by haematemesis 15 years after vagotomy & gastrojejunostomy for chronic duodenal ulcer. At presentation the patient was in shock and an emergency laparotomy was done after resuscitation. At laparotomy a retrograde type II JGI was found and managed by resection of the affected segment and partial gastrectomy and jejuno - jejunostomy with closure of the duodenal stump. Postoperative recovery was uneventful. Retrograde JGI is a rare condition and only less than 200 cases have been reported since its first report. Clinical picture of acute intestinal obstruction with suspicion about the condition in patients having a past history of gastrojejunostomy makes the elusive diagnosis definite and demands early surgery to reduce the grave consequences of the disease.

Leiomyoma of the urinary bladder.

Benign mesenchymal tumors of the bladder are rare and comprise less than 1% of the all bladder neoplasms. Leiomyoma is the most common type and comprises 35% of these tumors. These tumors may develop in submucosal (63%), intramural (7%) or subserosal (30%) layer, at any region of the bladder. The clinical presentation is varied and may include obstructive symptoms(50%), irritative symptoms (38%) and hematuria (11%). There are asymptomatic cases (19%), which make the diagnosis more difficult. Occurs more frequently in women than in men (3:1). The most common diagnostic investigations are ultrasonography, intravenous urography, computerized tomography scan and the magnetic resonance imaging. A 66 year old man presented with long standing voiding obstructive symptoms. Various examinations were performed in the last 2 years and was diagnosed either prostatic enlargement or bladder tumor. Cystoscopy was not available for confirming the diagnosis. The surgical exploration revealed a well-circumscribed mass at the bladder neck with moderate enlargement of the prostate. The pathological examination revealed a leiomyoma of the bladder. The post operative period was uneventful and the patient is doing well, without recurrence of the symptoms.

MR-guided laser thermal ablation of primary and secondary liver tumours.

AIM: To test the hypothesis that magnetic resonance (MR)-guided hepatic tumour ablation is (i) safe and feasible, (ii) is associated with favourable patient survival, and (iii) decreases viable tumour. MATERIALS AND METHODS: One hundred and twenty-five MR-guided laser thermal ablations (LTA) were performed on 35 patients with hepatocellular carcinoma (HCC, n=19), hepatic metastases (n=11, mainly colorectal) and carcinoid liver tumours (n=5). RESULTS: Mean overall survival was 14.8 months (HCCs 14.6 months, metastases 15.2 months). Near real-time T1-weighted colourized thermal maps correlated moderately with follow-up gadolinium-enhanced MR imaging in predicting ablated tumour area (Pearson correlation coefficient=0.5). There was a significant difference in percentage enhancing pre- and post-LTA (Wilcoxon signed ranks test=0.0001). An average of 50.7% of tumour was ablated by each treatment. In patients with multiple liver tumours ablated tumours grew significantly less than untreated tumours (108%compared with 196% growth, follow-up period 5.8 months, WSRTp=0.07). CONCLUSION: MR- guided LTA of primary and secondary liver tumours is safe, feasible, and significantly decreased amount of enhancing or viable tumour. MR-guided LTA produces a better survival in patients with HCC than would be expected in untreated patients, and has a mean survival in patients with metastases at least equal to the longest median survival in untreated patients.

Magnetic resonance imaging-guided laser thermal ablation of renal tumours.

OBJECTIVE: To test the hypothesis that magnetic resonance imaging (MRI)-guided laser thermal ablation (LTA) of inoperable renal tumours is a safe, tolerable and potentially effective treatment. PATIENTS AND METHODS: Nine patients (aged 56-81 years) with malignant renal tumours underwent percutaneous LTA under MRI guidance in a 0.5 T open magnet. Real-time colour thermal mapping was used to monitor tumour ablation, and the follow-up was with gadolinium-enhanced MRI at 6 weeks and (where appropriate) 3-4 months after the procedure. Tumour volume and percentage tumour enhancement before and after ablation were compared. The percentage of tumour ablated on real-time T1-weighted thermal maps was compared with that on gadolinium-enhanced follow-up MRI. RESULTS: The mean (range) follow-up was 16.9 (3-32) months after the first ablation. The mean tumour size did not change significantly, but the mean percentage of viable tumour decreased significantly from 73.7% before to 29.5% after ablation (P = 0.012, Wilcoxon signed-ranks test). Thermal maps correlated moderately well with follow-up MRI in predicting the extent of tumour ablation (Pearson correlation coefficient 0.55). There were two minor and one major complication. CONCLUSION: In this pilot study of patients unsuitable for surgery, MRI-guided LTA of renal tumours was safe, feasible (being well tolerated by the patient) and significantly reduced enhancing tumour volume by a mean of 45%.

Magnetic resonance angiography: the state of the art.

Three-dimensional contrast magnetic resonance angiography has rapidly advanced over recent years. It is now a highly accurate and safe method of diagnosing vascular abnormalities of the thoracic, abdominal and peripheral vessels. We describe techniques for the examination of the thoracic and abdominal aorta, the renal arteries and the lower limb vessels together with strategies to improve their diagnostic accuracy.

The value of MnDPDP enhancement during MR guided laser interstitial thermoablation of liver tumors.

Magnetic resonance (MR)-guided thermal ablation procedures are feasible in modern open low field strength MR scanners. The compromises for rapid imaging in this configuration worsen liver lesino conspicuity. To overcome this, we utilize liver-specific contrast Mangafodipir Trisodium (MnDPDP) to improve lesion recognition and targeting and allow a longer contrast-assisted window. Three observers assessed pre- and post-contrast MR scans of 14 liver ablation patients. They assessed the number of lesions, ease of puncture planning, conspicuity of lesions, gallbladder, vessels, and surrounding bowel. There was a significant improvement in lesion conspicuity and ease of puncture planning when MnDPDP was used. In two of the observers, there was also a significant improvement in the number of lesions seen and in bowel conspicuity. No significant difference was shown in the detection of the gallbladder or vessels. We conclude that the liver-specific contrast agent MnDPDP improves the overall accuracy and safety of MR-guided thermal ablation of liver tumors facilitating this procedure at lower field strengths. J. Magn. Reson. Imaging 2001;13:37-41.

Emergency cranial computed tomography in the management of acute febrile encephalopathy in children.

OBJECTIVE: Evaluation of the influence of emergency cranial computed tomography on the management of acute febrile encephalopathy in children. METHODS: A retrospective study in children with acute febrile encephalopathy who underwent emergency cranial computed tomography within 12 hours of admission to the paediatric intensive care unit. All scans were evaluated by two independent radiologists. RESULTS: Thirty nine children were included. Fourteen scans were abnormal and two had clinically insignificant incidental findings. Four children with focal neurological signs had scans demonstrating extra-axial collections. None required neurosurgical intervention. Clinically, raised intracranial pressure was present in 10 patients. Only five had cerebral oedema on computed tomography; these five children died. Emergency cranial computed tomography influenced subsequent management in no child without focal neurological signs and in only one child with focal neurology. CONCLUSION: Emergency cranial computed tomography in acute febrile encephalopathy in children without focal neurological signs has little influence on subsequent management. Where cranial computed tomography is thought to be necessary, it should be carried out when the child's clinical condition has been stabilised.