Hydatid disease: biology, pathology, imaging and classification

Rupture and the sequellae of rupture are more important than the mass effect of hydatid cysts, except in the brain where the mass effect by itself has severe consequences. The biology of hydatid disease, including the complex interaction between primary and secondary hosts, is reviewed. The hydatid cyst always starts as a fluid-filled, cyst-like structure (Type I) which may proceed to a Type II lesion if daughter cysts and/or matrix develop. In some instances the Type II lesion becomes hypermature and due to starvation dies to become a mummified, inert calcified Type III lesion. Type I and II lesions may undergo three types of rupture: contained, communicating and direct. Contained rupture is clinically silent, but communicating rupture may cause biliary obstruction and evacuation or infection of the cyst. Direct rupture has the greatest clinical consequences which include anaphylaxis, dissemination of hydatid disease (secondary hydatosis) within the host, and bacterial infection of the pericyst cavity. The clinical implications of the hydatid disease at different stages are discussed. A plea is made for the development of an international medical hydatid registry employing uniform nomenclature and consistent reporting in order to allow more rational comparisons of different types of management.     

Pictorial review: the imaging features of male breast disease

Although breast carcinoma in men is rare, the presentation of a male patient with evidence of breast enlargement or of a palpable lump, is not uncommon. In such patients, radiological assessment may be requested to exclude malignant change. Mammography has been traditionally the dominant modality of investigation, although ultrasound, using high-frequency linear transducers, is playing an increasingly important role for both imaging and biopsy and the two techniques should be regarded as complementary. In this article the pathological conditions which may affect the male breast are reviewed and the imaging findings presented.     

Primary craniosynostosis: imaging features

In 1851, Virchow introduced the term craniosynostosis to describe a variety of abnormalities in calvarial growth. These skull deformities are usually apparent in infancy. When an abnormal calvarial configuration is detected, a radiologic evaluation is necessary to characterize the deformity and to guide the corrective surgical procedure. Affected children are believed to have an improved outcome when diagnosis and surgical intervention occur at an early age. CT with three-dimensional reconstruction optimally evaluates the presence and degree of sutural involvement and assesses associated facial and intracranial abnormalities. This pictorial essay illustrates the imaging findings, nomenclature, and associated abnormalities of the various types of primary craniosynostosis.     

Diseases of the intracranial meninges: MR imaging features

Although the meninges are often thought of simplistically as a connective tissue sac that contains the CSF and the contents of the CNS, they are far more complex. Anatomically, they comprise several layers. Pathologically, numerous disease processes may affect the meninges; different processes may even involve different areas of the meninges. These factors all influence the MR imaging characteristics of meningeal lesions. This review briefly discusses the anatomy of the meninges, the MR imaging technique when meningeal disease is suspected, and the appearance of the normal meninges. It then focuses on tumors, infections, cysts, and other lesions that primarily involve the meninges, excluding lesions that secondarily involve the meninges.     

Peroneus quartus muscle: MR imaging features

PURPOSE: To determine the prevalence of the peroneus quartus (PQ) muscle, to demonstrate the morphology of this accessory muscle on magnetic resonance (MR) images, and to reassess the reported association of the PQ muscle with a hypertrophic peroneal tubercle. MATERIALS AND METHODS: A retrospective review was performed of 136 consecutive ankle MR imaging studies. The origins, insertions, and variations in size of the muscle and the dimensions of the peroneal tubercle and retrotrochlear eminence were recorded. RESULTS: The prevalence of the PQ muscle was 10% (14 of 136 cases). The accessory muscle and tendon unit descended medial and posterior to the peroneal tendons. The site of insertion was variable and included the calcaneus, peroneus longus tendon, peroneus brevis tendon; and cuboid bone. The calcaneus was the insertion site in 11 cases. The accessory tendon attached to the retrotrochlear eminence of the calcaneus. In the group with the PQ muscle, the retrotrochlear eminence was significantly taller (P < .01) than in the group without the PQ muscle. CONCLUSION: Contrary to previous reports, the peroneocalcaneal variant of the PQ muscle appears to insert in the retrotrochlear eminence of the calcaneus rather than the peroneal tubercle. The presence of the PQ muscle is associated with a prominent retrotrochlear eminence but not with an enlarged peroneal tubercle.     

Virtual colonoscopy: imaging features with colonoscopic correlation

BACKGROUND: We determined whether activation of the nitric oxide/cyclic guanosine monophosphate pathway by sodium nitroprusside (SNP) protects hearts subjected to cardioplegic arrest and prolonged hypothermic storage. METHODS: Isolated rat hearts arrested with St. Thomas' II cardioplegia and stored at 3 degrees +/- 1 degree C for 8 hours were reperfused at 37 degrees C in Langendorff (10 minutes) and working (60 minutes) modes. RESULTS: During reperfusion, left ventricular work was depressed in stored hearts relative to fresh hearts. When present during arrest, storage, and both reperfusion phases, SNP (200 mumol/L) improved work to values close to those in fresh hearts. When added only during the 10-minute period of Langendorff reperfusion, SNP also improved the subsequent recovery of work. This effect was antagonized by the soluble guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). Poststorage coronary perfusion was not increased by SNP. CONCLUSIONS: The ability of SNP to enhance recovery independent of changes in coronary perfusion and in an ODQ-sensitive manner suggests that SNP-induced protection is due to activation of the myocardial nitric oxide/cyclic guanisine monophosphate pathway. These results suggest that supplementing cardioplegic solutions with SNP, administering SNP during early reperfusion, or both may offer additional means to improve donor heart preservation.     

Idiopathic granulomatous hypophysitis: clinical and imaging features

AIMS/BACKGROUND: The syndrome of ocular histoplasmosis is usually prefaced by "presumed' as the aetiology is not yet clear. The aim of this study was to evaluate the clinical features of a similar ocular syndrome in the Netherlands where the fungus Histoplasma capsulatum is not endemic. METHODS: A retrospective multicentre study in which all patients were included who were diagnosed with a syndrome similar to presumed ocular histoplasmosis and in whom both fluorescein angiogram and all complete patient data were available. Fluorescein angiograms were examined by three authors in a masked fashion. Eighty one patients were selected who fulfilled the ophthalmic criteria for presumed ocular histoplasmosis. Fifty one patients showed the classic clinical picture, while 30 patients had an incomplete form as they did not show numerous histospots. RESULTS: No major difference in clinical characteristics could be identified when comparing the group of patients with the classic syndrome with the one with the incomplete syndrome. Final visual outcome of patients with macular subretinal neovascularisation after laser treatment was better when compared with untreated patients (p < 0.01). CONCLUSIONS: Since the fungus Histoplasma capsulatum is absent in the Netherlands, other aetiological agents must have led to this clinical entity similar to the presumed ocular histoplasmosis syndrome seen in the USA.     

Lymphoproliferative disorders after lung transplantation: imaging features

The intensity of the fluorescence emission of the fluorescent 1,4-dihydropyridine (DHP) derivative felodipine increased upon binding to both isolated cardiac sarcolemma (SLM) and skeletal muscle sarcoplasmic reticulum (SR) preparations, the latter containing SR-transversal tubule junctional diads and triads. The fluorescence enhancement was due to the binding of felodipine to high-affinity (Kd's of 0.35 and 1.25 nM in cardiac SLM and skeletal SR, respectively) 1,4-dihydropyridine sites of the dihydropyridine receptor (DHPR), as evidenced in competition experiments with the DHP analog isradipine. In both cardiac SLM and SR, the felodipine fluorescence was sensitive to conformational changes of the DHPR, as diltiazem that binds to DHPR at a separate site altered the values of both the Kd and the Hill coefficient characteristic for felodipine binding. In skeletal muscle membranes containing intact TT-SR junctions, ryanodine, a specific ligand of the ryanodine receptor calcium release channel (RyRC), also induced changes in felodipine fluorescence, which was eliminated by detergent and high-salt treatment to solubilize the RyRC. These results suggest that i) felodipine fluorescence is useful to probe conformational changes of the DHPR and ii) coupled conformational changes between the DHPR and the RyRC in skeletal muscle indeed occur and could be monitored by measuring felodipine fluorescence.     

Hydatid disease of liver and its complications (author''s transl)

This is a report on 121 cases of hydatid disease of liver. The alteration of the false cyst, explaining the most common complications of the disease, is discussed. Complications were present in 61 (50.41%) of our 121 patients: calcification in 13.22%, infection in 10.74%, perforation in bile ducts in 9.91%, thorax in 5.78% and abdominal cavity in 10.74% of our cases. Diagnostic importances of clinical findings, immunoelectrophoretic studies and radioisotopic liverscanning is emphasized. In 28 cases the complete excision of cysts were carried out, in 110 cases only removal of the hydatid membrane was performed. Other therapeutic methods are discussed. Of 108 treated patients 7 died postoperatively: they were all over 70 years old.     

A modification of eye-head coordination by CNS disease

When a subject, seated and facing ahead, was asked to look toward one side, the result was a combined movement of the eyes and head. Normal subjects began the eye movement just before the onset of head movement; 4 neurologic patients who showed abnormalities in eye movements (saccades that tended to be smaller in amplitude and lower in velocity than those of the control subjects) regularly began eye movement after the onset of head movement. Thus the initiation of the head rotation was not as much retarded in these patients as that of eye movement. Amplitudes of the movements were reduced in the patients, but this change too was less for the head than for the eyes. Because the amplitude and velocity of the head movement were less affected in the patient group, the relative contribution of the head to the total gaze shift was increased. It appears as if, when the oculomotor system is affected, the head can assume a leading role in the initiation and execution of gaze shifts.     

Ga-67 imaging: Kawasaki disease

The authors describe a child with Kawasaki disease (mucocutaneous lymph node syndrome), in whom myocardial inflammation associated with the disease was readily detected with Ga-67 imaging.     

Blount''s disease: magnetic resonance imaging

He often begins to answer before you have finished asking your question, but his replies are to the point. He speaks with emotion about the people he hopes to help, particularly children with fatal genetic diseases. 'I prefer to do something: the outcome of doing nothing is perfectly clear', he says. He began sequencing human genes while others were discussing how and when to do so. His methods have been called inelegant, redundant, wasteful, and too 'industrial'. Will his method fail to detect some infrequently transcribed genes? That's all right with him. He is not concerned with finding all the human genes, but rather with the fastest possible route to a useful catalog of most human genes.