Intermittent hydronephrosis: a unique feature of ureteropelvic junction obstruction caused by a crossing renal vessel

Obstruction at the ureteropelvic junction (UPJ) is usually intrinsic. Recently, however, 13 (11%) of approximately 120 children with UPJ obstruction were found to have extrinsic obstruction caused by a lower-pole renal vessel. In each case, the obstruction was confirmed at the time of surgery. Most of these patients had intermittent pain. Excretory urograms did not show obstruction between episodes of pain, but when a urogram was obtained during an episode, marked obstruction was noted. Contrast agent trapped in a segment of proximal ureter suggests the presence of an extrinsic obstruction. Properly timed renal imaging, therefore, can identify the urinary tract as the source of the symptoms.     

Postural renal transplant obstruction: a case report and review of the literature.

A 48-year-old woman underwent cadaveric renal transplantation for end-stage renal failure secondary to polycystic kidney disease. Nine months after transplantation, intermittent renal dysfunction and severe graft hydronephrosis developed despite the presence of a ureteric stent. A Tc-99m MAG3 scan performed with the patient standing showed complete transplant obstruction. Rapid tracer clearance with progressive bladder filling was present when the patient was imaged in the supine position. Ureteric obstruction is the most common urologic complication of renal transplantation. However, postural ureteric obstruction has been described only rarely. This case indicates that posture may affect ureteric patency and highlights this potential pitfall in the evaluation of intermittent graft dysfunction by diuretic renography.     

Intermittent axillary vein obstruction in a competitive canoeist.

The case is reported of a competitive canoeist with intermittent axillary vein obstruction secondary to shoulder girdle muscle hypertrophy. The anatomy of the axilla, pathology of the axillary vein, and reported cases of sports injuries involving the axillary vein are discussed. This would appear to be the first report of such an occurrence in a canoeist.     

Enteroliths of small bowel diverticula

The formation of an enterolith within a diverticulum of the small bowel is a very rare occurrence. Complications of this include abscess formation, perforation and obstruction of the small bowel. We report four cases. One patient presented with intermittent pain relieved after calculus removal. One case was an incidental finding on barium follow through but presented with obstruction of the small bowel 3 years later. One patient presented with obstruction and perforation and a fourth patient showed several asymptomatic linear calculi in a single diverticulum.     

Echography and pulsed Doppler of the arteries of the renal parenchyma in obstructive syndromes and dilatation of the excretory cavities of the kidney

Ultrasonography is highly effective in diagnosing pyelocalyceal dilatation. Confirming the distension of these collecting structures, indicating probable obstruction, is more difficult since the degree of dilatation does not always correspond to the degree of distension. Renal studies were performed in 244 patients including 51 patients with dilation or renal obstruction. Doppler ultrasonography was used to measure the Pourcelot's resistive index of arcuate and interlobar arteries for each kidney. Results demonstrate: 1) for healthy patients the average vascular resistive index is 0.54 +/- 0.02 (minimum 0.48 +/- 0.02, maximum 0.60 +/- 0.02). 2) in cases of acute obstruction, this resistive index for pathologic kidney is elevated greater than 0.7. The difference in resistive indices between the pathologic and contralateral kidney was greater than 0.10. 3) in the patients with intermittent junctional syndromes when an intravenous furosemide test is used, there is an increase in the resistive index. 4) in case of chronic obstruction well tolerated, the increase in resistive index is moderate. If there is an acute deterioration, the resistive index become greater than 0.8. Concurrent abnormalities which affect only one kidney (pathology of the renal hilum, tumoral syndromes) may make it difficult to interpret certain results. Ultrasonography together with Doppler scanning may be in certain cases a reasonable alternative with IVP.     

Malrotation and midgut volvulus presenting as malabsorption

Volvulus of the midgut associated with intestinal malrotation classically presents in early life with complete, or intermittent, high intestinal obstruction. We describe the case of a boy presenting at 16 months of age with a history of malabsorption and failure to thrive. The importance of considering this rare diagnosis in such cases is discussed.     

Hepatobiliary scintigraphy and sonography in early biliary obstruction

The authors examined 139 patients thought to have early, partial, or intermittent biliary obstruction, using sonography, hepatobiliary scintigraphy, and in selected cases contrast cholangiography. Of 125 patients with a well-established final diagnosis, sonography and scintigraphy disagreed in 29 (23%). Scintigraphy revealed early or low-grade obstruction in 13 patients who had no evidence of dilated ductules, while 7 patients with dilatation from prior stone passage or biliary surgery showed normal clearance. The authors conclude that in a preselected population in whom early or low-grade biliary obstruction may be present, disagreement between sonography and scintigraphy is not rare, and the absence of sonographically detectable dilatation does not exclude obstruction.     

Megacystis-microcolon-intestinal hypoperistalsis syndrome: a new cause of intestinal obstruction in the newborn. Report of radiologic findings in five newborn girls.

Five newborn girls presented with small intestinal obstruction and microcolon and a giant bladder (megacystis). Organic causes of obstruction were not found, and the gastrointestinal tract failed to function after appropriate diversion. Two died in the postoperative period, two lived several months on central venous hyperalimentation, and one died at 34 months of age following chronic though intermittent hyperalimentation. Pathologic studies showed an abundance of ganglion cells in both dilated and narrowed areas of intestine; the combined small bowel-colon length was one-third of normal in the absence of an evident obstructive or vascular insult. The five patients represent the most severe manifestation of defective intestinal peristalsis in a larger group of distended newborns in whom organic gastrointestinal obstruction is not found. Treatment with central venous hyperalimentation may sustain life, and some patients eventually recover gastrointestinal function. The hypoperistalsis is largely refractory to pharmacologic treatment; its cause is unknown.     

Case report: gastroduodenal intussusception of a gastrointestinal stromal tumour

Gastrointestinal stromal tumours (GISTs), previously termed leiomyomas and leiomyosarcomas are relatively common tumours of the gastrointestinal tract, most commonly found in the stomach. Most GISTs are asymptomatic but may cause abdominal pain or bleeding from ulceration of the overlying mucosa. A rare case of gastroduodenal intussusception of a large gastric stromal tumour, which presented with intermittent abdominal pain and gastric outlet obstruction, is reported. Pre-operative diagnosis was made on abdominal CT and confirmed at laparotomy. Pre-operative diagnostic difficulties and management are discussed.     

Persisting intraventricular fat-fluid levels following surgery on a ruptured dermoid cyst of the posterior fossa

Intracranial dermoid cysts occasionally rupture spontaneously into the ventricles or into the subarachnoid space. In such cases, intraventricular fat-fluid levels are invariably evident at computed tomography and may even be visible on a conventional radiograph of the skull. A case is described in which fat was observed to remain in the ventricles long after surgical removal of a dermoid cyst. We think that this fat, by causing obstruction of the cerebrospinal fluid pathways, should be regarded as a potential cause of intermittent elevation of intracranial pressure.     

呼吸机治疗时人机对抗的原因及其防治策略

目的探讨呼吸机治疗患者发生人机对抗的病因及处理策略。方法对29例人机对抗患者进行回顾性分析。结果92例机械通气患者中发生人机对抗29例(31.5%),其中死亡2例(6.9%)。其原因包括:气道阻塞10例,支气管痉挛3例,潮气量不足2例,持续高热4例,急性肺水肿5例,单肺通气2例,呼吸机漏气2例,气胸1例。结论人机对抗的发生均有其诱发因素。气道阻塞、潮气量不足、急性肺水肿等是主要原因。加强气道管理、设置合适的通气量、解除气道痉挛、祛除诱因等,可避免和减少人机对抗的发生。     

SMA-like syndrome with variant mesenteric venous anatomy

Superior mesenteric artery (SMA) syndrome refers to the constellation of symptoms that are associated with intermittent obstruction of the duodenum due to vascular compression. We present a case of SMA-like syndrome related to variant mesenteric venous drainage in the setting of normal aortomesenteric angle (AMA) and borderline reduced aortomesenteric distance (AMD).     

Radiology of colon loop diversion: anatomical and urodynamic studies of the conduit and ureters in children and adults

Colon loop diversion of the urinary stream is a relatively recent procedure designed to decrease the frequent incidence of reflux, infection and calculus formation in ileal loop conduits. Fifty-seven colon conduits and 107 ureters were studied. No reflux occurred in 67 ureters with intracolonic loop pressures exceeding 40 cm H2O. To evaluate and manage possible ureteral obstruction, percutaneous (antegrade) pyelography was utilized in 11 kidneys, ureteral perfusion (pressure-flow) studies in 8, and percutaneous catheter nephrostomy in one.     

Crohn disease obstruction of the biliopancreatic limb in a patient operated for biliopancreatic diversion for morbid obesity

Although rare, patients with biliopancreatic diversion for morbid obesity will be subject to obstruction of the biliopancreatic limb. This condition is commonly due to postoperative adhesions and intussusception and usually presents with misleading clinical and radiographic features that can delay the diagnosis and the treatment. We recently encountered a patient with obstruction of the biliopancreatic limb due to involvement from Crohn disease. We report this case to highlight the clinical and imaging findings of this rare condition.     

Intestinal neoplasm mimicking a Meckel's diverticulum on scintigraphic imaging.

A 33-year-old man presented with colicky, intermittent, midabdominal pain with nausea and vomiting. A Tc-99m pertechnetate abdominal scan was performed and revealed a focal area of increased uptake in the midabdomen associated with dilated proximal loops of small bowel. Surgery revealed a high-grade partial obstruction of the midportion of the jejunum secondary to an annular adenocarcinoma of the jejunum. This is the first known report of abnormal Tc-99m pertechnetate accumulation in an adenocarcinoma of the small bowel.     

Magnetic resonance in obstructive jaundice

Twelve cases of obstructive jaundice in whom ultrasound failed to demonstrate the site and/or the cause of obstruction of the biliary tract were examined with magnetic resonance imaging (MRI), correctly diagnosing the site and cause of obstruction in 10 of 12 surgically proven cases. In one case of cholangiocarcinoma, the site of obstruction was well shown on MR but a definite cause could not be ascertained. In another patient who developed intermittent jaundice following surgery for choledochal cyst, MR demonstrated a solitary stone in the common hepatic duct. Surgical confirmation could not be achieved as the patient was lost to follow up. There were 6 cases of choledocholithiasis, 3 cases of gall bladder carcinoma and one case each of pancreatic adenocarcinoma and cholangiocarcinoma. It is believed that MRI will provide obstructive jaundice and will be able to minimize the use of percutaneous transhepatic cholangiography (PTC) and endoscopic retrograde cholangiopancreatography (ERCP) in view of its ability to perform multiplanar imaging in multiple sequences.     

Upper airway obstruction during sleep in children.

Cinefluoroscopic findings are described in nine children with sleep-related upper airway obstruction who are asymptomatic while awake. Asleep, these patients show strikingly similar changes in the region of the hypopharynx. During inspiration, the tongue and hypopharyngeal soft tissues are approximate, obliterating the hypopharyngeal air space causing intermittent and almost complete obstruction to air flow. The value of cinefluoroscopic studies on sleeping children with clinical symptoms of airway obstruction during sleep is emphasized.     

The radiological features of chronic radiation enteritis

The radiological findings, using a single-contrast barium infusion technique, are described in a series of 13 patients with chronic radiation enteritis. The signs include evidence of submucosal thickening, single or multiple stenoses, adhesions and sinus or fistula formation. A combination of these signs characterises the condition. This technique is particularly suited to the investigation of radiation enteritis because of its ability to distend maximally the small intestine. A cause, stenosis and/or adhesions, was demonstrated in the eight of the 13 patients presenting with intermittent small-intestinal obstruction. Three patients had diarrhoea as their predominant complaint and a fistula was demonstrated in two.     

Unchanged size of a dilated common bile duct after a fatty meal: results and significance

Sonographic measurement of common bile duct caliber alone is insufficient to ascertain the presence of obstruction. Fatty meal stimulation significantly improves diagnostic accuracy. An increase in caliber of a normal or slightly dilated common duct after the subject has ingested a fatty meal is a strong indicator of biliary obstruction, while a decrease in caliber indicates normal dynamics and virtually excludes obstruction. This study determines the significance of no change in the caliber of the dilated common bile duct of subjects who have eaten a fatty meal. Further imaging studies and clinical/laboratory follow-up of 31 patients showed that in 84% of the cases no obstruction was present. A dilated common duct that does not decrease in size after a fatty meal is not a specific indicator of obstruction. The use of invasive diagnostic procedures in these patients is not advised unless there is other evidence of biliary obstruction.     

Computed tomography enteroclysis in the diagnosis of intestinal diseases

The role of computed tomography (CT) enteroclysis in the imaging of small bowel diseases is expanded with recent technological advances in multidetector CT system. Computed tomography enteroclysis is the examination of choice for patients with symptoms of intermittent small bowel obstruction, especially when there is a history of prior complex abdominal surgery, abdominal tumor, radiation therapy, and also in high grade obstructions with suspicion of extraintestinal internal fistula. Computed tomography enteroclysis is becoming the first-line modality for the evaluation of advanced and complicated small bowel Crohn disease. Computed tomography enteroclysis can also become an important complementary imaging technique to capsule endoscopy in the assessment of small bowel neoplasms and occult gastrointestinal hemorrhage. In this study, the technique and clinical applications of CT enteroclysis are reviewed; its advantages and limitations compared with the other imaging techniques and capsule endoscopy are discussed.