Is a lung perfusion scan obtained by using single photon emission computed tomography able to improve the radionuclide diagnosis of pulmonary embolism?

Planar pulmonary scintigraphy is still regularly performed for the evaluation of pulmonary embolism (PE). However, only about 50-80% of cases can be resolved by this approach. This study evaluates the ability of tomographic acquisition (single photon emission computed tomography, SPECT) of the perfusion scan to improve the radionuclide diagnosis of PE. One hundred and fourteen consecutive patients with a suspicion of PE underwent planar and SPECT lung perfusion scans as well as planar ventilation scans. The final diagnosis was obtained by using an algorithm, including D-dimer measurement, leg ultrasonography, a V/Q scan and chest spiral computed tomography, as well as the patient outcome. A planar perfusion scan was considered positive for PE in the presence of one or more wedge shaped defect, while SPECT was considered positive with one or more wedge shaped defect with sharp borders, three-plane visualization, whatever the photopenia. A definite diagnosis was achieved in 70 patients. After exclusion of four 'non-diagnostic' SPECT images, the prevalence of PE was 23% (n =15). Intraobserver and interobserver reproducibilities were 91%/94% and 79%/88% for planar/SPECT images, respectively. The sensitivities for PE diagnosis were similar for planar and SPECT perfusion scans (80%), whereas SPECT had a higher specificity (96% vs 78%; P =0.01). SPECT correctly classified 8/9 intermediate and 31/32 low probability V/Q scans as negative. It is concluded that lung perfusion SPECT is readily performed and reproducible. A negative study eliminates the need for a combined V/Q study and most of the 'non-diagnostic' V/Q probabilities can be solved with a perfusion image obtained by using tomography.

Duodenal ulcer hemorrhage treated by embolization: results in 28 patients.

BACKGROUND: To assess the effectiveness and prospects of transcatheter gastroduodenal artery embolization in the control of massive duodenal bleeding and to relate our experience. METHODS OF STUDY: The study is based on the retrospective analysis of 165 patients with endoscopically detected bleeding duodenal ulcer who presented between 1991-1998. 28 patients were considered eligible for endovascular treatment either at initial presentation or following hemorrhage recurrence after endoscopic therapy. RESULTS: Technical failure was noted in 3 cases, thereafter treated by surgery. In the other 25 patients, embolization was performed: bleeding recurrence occurred in 7 cases. Four were treated only endoscopically. One was reembolized and the last two were treated by surgery. In 6 cases, a coaxial technique was used (guiding catheter in 2 and 3F microcatheter in 4). No complication related to the catheterization was observed. CONCLUSION: Transcatheter embolization of the gastroduodenal artery appears to be an efficient procedure even in the absence of active bleeding at the time of the procedure. Failure and recurrence rates can be reduced by using a coaxial technique in the uneasy cases. Embolization seems to have a low recurrence rate and a very low complication rate.

Six hundred consecutive carotid endarterectomies with temporary shunt and vein patch angioplasty: early and long-term results.

PURPOSE: This retrospective study evaluates the long-term clinical outcome and the survival of 600 consecutive carotid endarterectomies performed with a temporary shunt. All arteriotomies were closed by vein patch angioplasty. MATERIALS AND METHODS: Between November 1989 and November 1998, 600 isolated carotid endarterectomies (CEA) were performed in 540 patients by a uniform surgical technique at the University Clinic of Mont-Godinne. An intraluminal shunt and patch closure were systematically used. The mean age was 68 yr (ranging from 41 to 91 yr), 400 patients were men. The risk factors included hypertension in 73%, smoking history in 60%, coronary artery disease in 51% and hyperlipidemia in 35%. The indications were asymptomatic stenosis in 47%, transient ischemic attack in 40%, vertebrobasilar symptoms in 7% and stroke in 6%. EARLY RESULTS: The combined 30-day stroke and death rate was 0.9%. There were four deaths. The stroke and TIAs rates were 0.2% and 1.5% respectively. The incidence of early carotid occlusion was 0.5%. Cranial or cervical nerve dysfunction was identified in 6.3%. LATE RESULTS: The median follow-up was 49 months with a range of 2-124 months. Cumulative survival rates at 5 and 10 yr were 92+/-1% and 89+/-2% respectively. Thirty-two patients died during long-term follow-up; the death was stroke-related in only three patients. CONCLUSION: Carotid endarterectomy using an intraluminal shunt and vein patch closure is a safe and effective procedure associated with low morbidity and mortality rates at short and long-term follow-up.

Discrepancy between diffusion and perfusion imaging in a patient with transient ischaemic attack.

We report paradoxical and ambiguous imaging findings in a patient with transient ischaemic attack (TIA). Perfusion-weighted (PW) MRI obtained 2 hours after symptoms onset showed a hypoperfused area in a region compatible with the focal deficit, while diffusion-weighted (DW) MRI was considered negative. Despite the complete resolution of the symptoms which had already begun at the end of the first MR examination, follow up DW MRI at 3 days showed partial conversion to hyperintensity of the initially hypoperfused area. This case illustrates that PW and DW MRI have to be used in combination and at different time points to correctly diagnose and manage ischaemic stroke because PW MRI is more sensitive than DW MRI for very early detection of ischaemia and delayed DW MRI provides the final signature of brain damage even in case of complete clinical recovering.

Occurrence of thyroid papillary carcinoma in young patients. A Chernobyl connection?

The risk of thyroid papillary carcinoma is increased by external radiation particularly in children under 15 years of age as shown by a marked increase in those exposed to radiation after Chernobyl. We were recently confronted in Belgium over a short period with four patients (3 F, 1 M) with papillary thyroid carcinoma who were aged 10 years, 2 months, 2 years and 6 years when the Chernobyl accident occurred. We thus raise the question of a possible relationship. The patients were aged 17, 11, 10, 19 years at presentation. They all presented fortuitously over 3 years which was a very unusual increase in our extensive experience in thyroid surgery (62 cases of thyroid cancer among 1014 thyroidectomies in adults vs 4 cases in 18 children since the Chernobyl accident in 1986). Two out of the four patients had psammoma bodies (identifiable on CT scanning and ultrasound) and thyroglobulin autoantibodies (TgAb). The first patient had positive lymph nodes at the time of surgery. The incidence of thyroid cancers in Belarus and Ukraine rose just 4 years after the Chernobyl disaster; because radioactive clouds passed over Belgium, we wonder whether the occurrence of thyroid cancer in our patients could be related to this irradiation. The mechanism of increased incidence of radiation-induced thyroid cancer is thought to be due to rearrangement of the tyrosine kinase domains of the RET and TTK genes. The other important similarities in our patients are the presence of psammoma bodies that can be visualized on radiological examination and the presence of TgAb that are more frequent in differentiated thyroid cancers. Whether or not these cases reflect an increased incidence in the population as a whole, clinicians must remain vigilant for this rare but curable cancer in young patients, especially if suggestive radiological features or TgAb are present.

Pseudoaneurysm of the internal carotid artery: treatment with a covered stent.

Dissection of the cervical segment of the internal carotid artery may occur spontaneously or after trauma. We report the management of a 53-year-old right-handed man with progressive dizziness and neck pain 6 weeks after a motor vehicle collision. The clinical and neurologic examinations were normal. The CT scan led to the diagnosis of a pseudoaneurysm of the right internal carotid artery near the skull base. We successfully treated this post-traumatic lesion with a covered stent. The patient underwent the endovascular procedure under general anesthesia and transcranial Doppler monitoring. No neurologic event was observed. Obliteration of the pseudoaneurysm with preservation of the carotid artery was achieved. The patient was discharged from the hospital 72 hr later with no complications. Clinical and imaging follow-up at 6 months was unremarkable.

[Imaging evaluation of cervical spine trauma]. / Imagerie de la colonne cervicale en 2000.

Evaluation and treatment of patients with suspected cervical vertebral trauma requires close cooperation between multiple medical disciplines. Recognition of the significant signs of cervical spine injury enables accurate interpretation of the radiograph, and if necessary adequate selection of the best imaging method for further evaluation. When judiciously selected, these imaging techniques result in the expeditious gathering of the diagnostic information required for the management of the traumatized patient.

Hypoplasia of the internal carotid artery: a noninvasive diagnosis.

We present the characteristic imaging findings of hypoplasia of the internal carotid artery (ICA) in two cases, one accompanied by an intracranial aneurysm. Finding of a diffuse luminal narrowing of the ICA on MR angiography or digital subtraction angiography (DSA) could wrongly evoke severe acquired diseases such as dissection or atherosclerosis. Absence of associated wall thickening and flow disturbances on color Doppler sonography (CDS) should suggest carotid hypoplasia. Confirmation of the diagnosis is obtained by CT of the skull showing a small carotid canal. Non-invasive procedures are sufficient to differentiate this rare congenital anomaly from acquired string signs.

Limp as unusual presentation of Langerhans' cell histiocytosis.

UNLABELLED: An isolated eosinophilic granuloma involving the posterior elements of a lumbar vertebra is reported in a 3-year-old boy presenting with progressive limp. Radiological investigations revealed osteolysis of the L5 right pedicle. MRI showed a well-defined homogeneous mass with nonspecific signal intensity. An unusual feature was the paravertebral muscular location of the largest part of the tumour indicating a possible soft tissue origin. Immunohistochemical studies were typical for Langerhans' cell histiocytosis. CONCLUSION: A limp can be due to lumbar and paravertebral muscular location of Langerhans' cell histiocytosis.

[Radiation exposure and computed tomography]. / Irradiation en tomodensitométrie thoracique.

Computed Tomography (CT) is recognized as a relatively high-dose diagnostic procedure. There is some obscurity in the literature about the doses due to conventional CT, spiral CT and High Resolution Computed Tomography (HRCT) of the chest. Conventional chest CT results in a radiation dose approximately 100 times that of a standard chest film and 10 times that of a mammography; on the other hand, conventional chest CT is safe for the lens and the pelvis (ovaries, testes and uterus). Radiation dose associated with helical CT is potentially lower than the dose associated with conventional CT. HRCT, consisting of 1- to 2- mm thick-sections performed at 10 mm intervals, has an effective radiation dose lower than that of conventional CT, even with high-dose techniques (400 mAs). HRCT scans obtained at reduced milliamperage (40-80 mAs), the so-called "low-dose HRCT technique", may provide satisfactory visualization of lung parenchyma in the majority of cases and is recommended in patients in whom radiation dose is a major concern (pediatric population or young women in order to minimize breast irradiation). The awareness of radiation dose will become increasingly important for both referring physicians and radiologists when determining indications and deciding which types of imaging procedures and specific protocols should be used.

[Spontaneous pneumomediastinum in an adolescent: an underestimated cause of chest pain]. / Pneumomédiastin spontané chez un adolescent: une cause sous-estimée de douleurs thoraciques.

CASE REPORT: A case of mediastinal emphysema occurring without etiologic factor except a Valsalva's manoeuvre a few hours before admission in a 15-year-old boy is reported. Symptoms were cervical and chest pain with moderate dysphagia. Diagnosis was confirmed by palpating subcutaneous air in the neck region and mediastinal air on a chest roentgenogram. A CT scan was performed to exclude a concurrent pneumothorax. The patient recovered with bed rest. CONCLUSION: Spontaneous pneumomediastinum results from nontraumatic, mediastinal air leakage without underlying lung disease. It should be considered in the differential diagnosis of chest pain, especially in healthy adolescents and young adults; it is certainly underdiagnosed in this population.

Granulomatous bronchiolitis associated with Crohn's disease.

Symptomatic bronchopulmonary disorders have been only occasionally reported in Crohn's disease, although several studies have documented the possibility of latent involvement of the respiratory tract. We report the case of a patient with long-standing Crohn's disease who presented with acute transient chest pain and a recent history of mild dyspnea and nonproductive cough. Chest radiographs were normal, while high-resolution computed tomography demonstrated a mosaic pattern of attenuation that was consistent with a bronchiolar disorder. Pulmonary function tests showed mild airway obstruction and normal diffusion indices. Thoracoscopic lung biopsy demonstrated focal infiltration of the bronchiolar walls by mononuclear cells and non-necrotizing granulomas. To our knowledge, this is the first account of isolated granulomatous bronchiolitis in Crohn's disease. These findings suggest that a granulomatous inflammatory process of the bronchioles could be involved in the development of airway obstruction in patients with Crohn's disease.

Unusual occipitoatlantal fracture dissociation with no neurological impairment. Case report.

The authors describe an unusual case of a complex traumatic fracture-dissociation injury of the craniovertebral junction, which the patient survived with no neurological damage. This case featured the rare combination of an avulsion of both the right occipital condyle and clivus and a fracture of the left lateral mass of the atlas. Because of the craniocervical ligament injury and the slight anterior occipitoatlantal dislocation, the lesion was considered to be unstable and was treated successfully with a cervical collar. The authors emphasize that thin-slice computerized tomography scanning with multiplanar reconstructions is essential to visualize these fractures, whereas magnetic resonance imaging is useful to assess soft tissues.

An early MR observation of carotid involvement by retropharyngeal abscess.

We report early carotid involvement by retropharyngeal abscess in a 4-year-old boy. MR imaging showed enhancement of the wall and narrowing of the lumen of the internal carotid artery, which were thought to reflect spasm and/or arteritis. Prompt treatment may have prevented hemorrhagic and neurologic complications.

Congenital anomalies of the inferior vena cava and left renal vein: evaluation with spiral CT.

PURPOSE: To determine with spiral computed tomography (CT) the incidence and caval location of left renal vein (LRV) variants that may affect inferior vena cava (IVC) filter placement, spermatic vein embolization, and adrenal or renal venous sampling. MATERIALS AND METHODS: Contrast material-enhanced spiral CT scans of 1,014 patients were evaluated for the incidence and configuration of LRV variants and for the distribution of the entrances of these veins into the IVC. RESULTS: In this series, variants detected were as follows: one azygos continuation of the IVC (0.1%), three bilateral IVCs (0.3%), and 102 LRV variants (10%) including 38 retroaortic renal veins (3.7%) and 64 circumaortic venous rings (6.3%). In the retroaortic renal vein group, the distance between the entrance of the LRV into the IVC and the confluence of the iliac veins was +62.5 mm +/- 8.7. In the circumaortic venous ring group, the distance between the entrances of the retroaortic and preaortic limbs into the IVC was -39.0 mm +/- 17.4; the distance between the entrance of the left retroaortic limb into the IVC and the confluence of the iliac veins was +63.2 mm +/- 17.1. CONCLUSIONS: Detailed knowledge of these anomalies is crucial for IVC filter placement, spermatic vein embolization, and adrenal or renal venous sampling.

Hemorrhagic arachnoid cyst with third nerve paresis: CT and MR findings.

We report the CT and MR appearance of a nontraumatic hemorrhagic arachnoid cyst presenting with a third nerve paresis in a 37-year-old man. The cyst, located in the left suprasellar area, contained a fluid-blood level with stigmata of subacute hemorrhage on both CT and MR studies.