Interrupted aortic arch in an asymptomatic adult

Isolated interrupted aortic arch is a rare congenital cardiac disorder believed at one time to be incompatible with life once the ductus arteriosus closed. To our knowledge, only 12 cases have been reported in the literature and mostly in children. The diagnosis was made in all of them by catheterization. We report the first adult patient with an asymptomatic interrupted aortic arch diagnosed by computed tomography.

Pancreatic phlegmon: what is it?

In a retrospective study of 264 patients with acute pancreatitis, 22 were identified as having phlegmon by combined radiologic and clinical criteria. The radiologic criteria consisted of demonstration of abnormal lesion on computed tomography scan which was composed of masses of mixed density, free of extraluminal gas and lacking a well-defined wall. The clinical criteria was that the clinical course was free of sepsis. Half of the group thus identified had severe pancreatitis as defined as having three or more poor prognostic signs. Fever, leukocytosis, and serum amylase elevation persisted for a longer period than usual. Complication was infrequent but the lesion could persist for 3 to 4 months without producing symptoms. This is a relatively benign condition and surgery should be avoided.

Imaging for adrenal tumours

Modern medical imaging has transformed the diagnosis and management of adrenal disease. The various types of adrenal tumours bear different aspects of problems in diagnostic imaging. The investigation used must be determined and monitored individually, as directed by the clinical and biochemical findings. CT plays a central role in the localization of the functioning adrenal tumours. It is regarded as the imaging modality of choice because it combines safety with a high rate of detection. It is highly sensitive in the localization of the large adrenal tumours that account for Cushing's syndrome and phaeochromocytomas, as well as the small tumours that account for primary hyperaldosteronism. It is, however, not reliable for the detection of adrenal hyperplasia, and does not yield functional imaging information. For small tumours not detectable by CT, and for ectopic tumours, complementary investigations with appropriate application of venous sampling, radionuclide scintigraphy and occasionally arteriography, will be very useful. CT-guided percutaneous biopsy is employed for the incidentalomas in oncologic patients. MRI appears to hold a great potential for the diagnosis of adrenal disorders, but this modality is awaiting wider availability of instrumentation and clearer documentation of techniques.

Pediatric pyeloplasty: 50 patients with 59 hydronephrotic kidneys

A report of 59 hydronephrotic kidneys due to pelviureteric junction (PUJ) obstruction in 50 children less than 12 years of age is presented. Thirty-two percent of the patients were less than 1 year of age, with their main presenting feature being an abdominal mass (88%). For older children, loin or abdominal pain was the chief presenting symptom (68%). During infancy, the left and right sides were equally affected, followed closely by bilateral involvement. On the other hand, in older children, the left side was predominantly affected, being twice as common as the right, and the latter again was twice as common as bilateral involvement. Dismembered pyeloplasty was the procedure used in most cases (88%); the nephrectomy rate was 8% for grossly dilated or dysplastic kidneys. During follow-up (of 6 months to 10 years) of 54 pyeloplasties, improvement was seen in 36 (67%), 12 were unchanged (22%), and one reverted to normal (2%) after the initial operation. Two (4%) worsened initially but achieved stabilization after reoperation; the remaining 3 patients (6%) showed unsatisfactory results. Stents were used in 65% of the cases and nephrostomies in 53%.

Evaluation of recurrent pyogenic cholangitis with CT: analysis of 50 patients

The use of computed tomography (CT) was investigated in 50 patients with recurrent pyogenic cholangitis, 22 of whom had undergone prior choledochoenterostomy or sphincteroplasty. A spectrum of pathologic features was noted, including intrahepatic ductal dilatation (n = 50), common duct dilatation (n = 34), strictures (n = 11), intrahepatic calculi (n = 37), common duct calculi (n = 15), pneumobilia (n = 26), segmental atrophy (n = 18), and splenomegaly (n = 7). Unilobar disease existed in 14 patients. The left lateral segment was predominantly affected, with ductal dilatation (n = 23) and segmental atrophy (n = 13). During acute exacerbation, additional manifestations were observed: ductal wall enhancement (n = 4), segmental parenchymal enhancement (n = 9), hepatic abscess (n = 9), and biloma (n = 2). CT enables sensitive, complete evaluation of this disorder. It is valuable when results of ultrasonography are non-diagnostic and for planning hepatic resection, evaluating associated mass lesions, and guiding complex interventional procedures.

Mallory-Weiss syndrome associated with raised intracranial pressure

A case of Mallory-Weiss syndrome associated with raised intracranial pressure resulting from metastatic brain tumor is reported for the first time. Relevant literature is reviewed and possible causes of Mallory-Weiss syndrome are discussed.

Portal thrombosis complicating appendicitis: ultrasound detection and hepatic computed tomography lobar attenuation alteration

Lobar attenuation difference of liver on computed tomography was seen in a case of portal pyemia complicating perforated appendicitis. Left portal vein thrombus was detected first by ultrasound and subsequently confirmed by computed tomography. The left lobe of the liver showed greater contrast enhancement during the dynamic computed tomography study. The possible cause of this lobar attenuation difference is discussed.

Spinal pseudarthrosis in ankylosing spondylitis. Clinicopathological correlation and the results of anterior spinal fusion

We reviewed 40 extensive destructive vertebral lesions in 35 patients with established ankylosing spondylitis. Of these, 31 had presented with localised pain while three had a neurological deficit. The radiographs suggested ununited fractures through either ankylosed discs (37) or vertebral bodies (3). Corresponding fractures were seen in the posterior column in 34 cases. Sixteen patients with 18 lesions underwent anterior spinal fusion, and pseudarthrosis was consistently proven by histopathology. Two pseudarthroses healed in conservatively treated patients. Thirteen of the operated patients were followed for an average of 7 years 7 months. There were two cases of non-union and one required an additional posterior fusion; in the remainder fusion was sound.

Lacunar syndromes due to brainstem infarct and haemorrhage

Nine patients with brainstem infarct and two with brainstem haemorrhage presented with pure motor stroke, pure supranuclear facial palsy, sensorimotor stroke or ataxic hemiparesis. Despite the clinical similarity with hemispheric lacunes, brainstem infarcts causing lacunar syndromes probably have a greater tendency to progress. Small brainstem haemorrhages should also be considered as a cause of lacunar syndromes and the difficulty in differentiating them from small infarcts without CT is emphasised.

Spinal pseudarthrosis complicating ankylosing spondylitis: comparison of CT and conventional tomography

Pseudarthrosis, a functional false joint, is an important mechanical complication of advanced ankylosing spondylitis. For correct determination of prognosis and therapy, the presence and extent of the abnormality must be assessed accurately. CT findings in 18 patients with 22 pseudarthroses were compared with the results of conventional tomography. The condition was confirmed by surgery in nine patients (50%). CT scans clearly characterized the pseudarthrosis, providing data not provided by conventional tomography in 17 (77%) of the 22 lesions. CT showed irregular diskovertebral osteolysis with reactive sclerosis and more frequently detected the vacuum phenomenon and paraspinal swellings. In all cases, CT showed either a fracture of mobile facet joints in the posterior elements and allowed clear differentiation between the two. In four cases, such differentiation was impossible on conventional tomograms. Associated spinal stenosis was suspected on conventional tomograms in three lesions, but it was shown clearly by CT in 10 lesions. Our results suggest that CT offers considerable advantages over conventional tomography in the investigation of spinal pseudarthrosis complicating ankylosing spondylitis.

Dystrophic intracranial calcification: CT evidence of 'cerebral steal' from arteriovenous malformation

Two cases of dystrophic intracranial calcification due to arteriovenous malformations (AVM) are reported. The characteristic distribution is in the watershed areas and away from the AVM. Deposition of calcium on ischaemic brain tissues as a result of 'cerebral steal' by the AVM is the probable pathogenetic mechanism.

Spinal pseudarthrosis in ankylosing spondylitis

Spinal pseudarthrosis is an important mechanical complication in longstanding ankylosing spondylitis. Thirty-five patients with 40 lesions were studied. Three lesions through vertebral bodies resulted from complete fractures. The rest occurred at interspaces, more common at the lower thoracic and upper lumbar segments. Double pseudarthrotic lesions were observed in 5 patients. Progressive osteolysis of the anterior elements was prominent, with variable sclerosis, osteophytes, vacuum phenomenon, subluxation and fragmentation. A posterior element weak link, as a bony break or facet joint non-fusion, was an essential component in every lesion, playing an initiating or perpetuating role in its pathogenesis. Mechanical derangement from trauma, severe round kyphosis, spondylodiscitis, hip disease, spinal operation and unusual activities may be contributing factors. Initial treatment is conservative, but 16 patients required operative stabilisation.

When is sensorimotor stroke a lacunar syndrome?

Forty five patients with clear sensorium and no neurological deficits other than unilateral motor and sensory impairment underwent computed tomography (CT). Twenty patients had sensorimotor stroke with impairment of all sensory modalities (type 1). Eight had only impairment of nociceptive sensation (type 2) and 15 had only proprioceptive impairment (type 3). Two patients had sensory impairment in one limb only (type 4). Lacunes were found in patients in the first three groups. However, 80% of those who had hemiparesis and incomplete sensory loss were found to have a lacune or normal CT scan whilst only 33% of those with complete motor or sensory impairment had lacunes. It is proposed that sensorimotor stroke as a lacunar syndrome be best restricted to those with only mild to moderate hemiparesis and sensory impairment in both upper and lower limbs. The degree and extent of sensory and motor involvement may vary, however, possibly dependent on whether the thalamo-geniculate, anterior choroidal or lateral lenticulostriate artery is affected.

Barium intravasation: radiographic and CT findings in a nonfatal case

A woman survived venous intravasation of barium complicating an abdominal barium study. Barium deposition in the reticuloendothelial system was evident by an increase in density in the liver, spleen, and bones on plain radiographs and marked elevation of attenuation values of these organs on computed tomographic scans. The literature on barium intravasation is reviewed.

Direct sagittal CT scan: a new diagnostic approach for surgical neonates

Because of their small body size, neonates can be placed in the plane of the CT scanner gantry (aperture diameter 70 cm) instead of across it. This direct sagittal scanning technique allows accurate delineation of surgical lesions, particularly midline ones, unobtainable with conventional axial imaging. In addition, the sagittal image provides a perspective of anatomic arrangement more familiar to the surgeon than that provided by axial sections and therefore allows for easier interpretation. In imperforate anus, sagittal CT identifies the blind rectal end by the meconium tissue interphase and therefore avoids the pitfalls of invertogram, which depends on the bowel gas pattern for interpretation. With this new approach, we correctly classified six cases of imperforate anus into high types (3) and low types (3), visualized the associated fistula and had knowledge of the exact distance of the blind rectal end from the skin level preoperatively. In tracheoesophageal fistula (2), sagittal CT demonstrated the air-filled blind pouch and fistula to allow preoperative classification and assessment of the gap distance. In sacrococcygeal teratoma (3) and laryngeal cyst (1), its use allowed an accurate assessment of possible extension of the lesion into neighboring structures. Our experience with direct sagittal CT scan therefore suggests that this new and noninvasive technique is a useful adjunct in the management of a variety of common neonatal surgical problems.

Cortical blindness in toxaemia of pregnancy: findings on computed tomography

Two patients with toxaemia of pregnancy presented with cortical blindness. Immediate cranial computed tomography (CT) demonstrated bilateral hypodense areas in the occipital lobes. Both patients underwent Caesarean section for delivery. There was gradual and complete recovery of vision, together with CT documentation of resolution of the cerebral changes, indicative of the reversible nature of the ischaemic lesion.

Sacrococcygeal teratoma: computed tomography evaluation

Axial computed tomography, as well as direct sagittal computed tomography in some cases, was used to evaluate five cases of sacrococcygeal tumors, and the findings are presented. Computed tomography greatly assisted in making a correct preoperative diagnosis and in delineating the extent of the tumors. Direct sagittal scans readily staged these tumors, whereas axial scans revealed extension in the transverse plane, especially for intraspinal extension.

Claude's syndrome: clinical and computed tomography correlations

A patient with Claude's syndrome (ipsilateral fascicular third nerve palsy with contralateral ataxia) in whom computed tomography demonstrated a discrete infarct in the paramedian rostral mesencephalic tegmentum is reported. The vascular supply of the rostral mesencephalon is discussed.