Significance of 99mTc-ECD SPECT in Acute and Subacute Ischemic Stroke: Comparison with MR Images Including Diffusion and Perfusion Weighted Images

99mTc-ECD SPECT is valuable for the evaluation of cell viability and function. The purpose of the present study was to evaluate the significance of 99mTc-ECD brain SPECT in ischemic stroke. We compared 99mTc-ECD brain SPECT with perfusion and diffusion weighted images (PWI, DWI). Ten patients with acute and early subacute ischemic stroke were included in this prospective study. T2-weighted images (T2WI), DWI, PWI and 99mTc-ECD SPECT were obtained during both the acute/early subacute and late subacute stages. In the case of PWI, time to peak (TTP) and regional cerebral blood volume (rCBV) maps were obtained. The rCBV map and 99mTc-ECD SPECT images were compared in 8 lesions using delta AI. The asymmetry index (AI) was calculated as (Ci - Cc) X 200 / (Ci + Cc); where Ci is the mean number of pixel counts of an ipsilateral lesion and Cc is the mean number of pixel counts of the normal contralateral hemisphere. delta AI was defined as AIacute - AIsubacute in the ischemic core and periphery. PWI and 99mTc-ECD SPECT detected new lesions of the hyperacute stage or of evolving stroke more accurately than T2WI and DWI. 99mTc-ECD SPECT was able to localize the infarct core and peri-infarct ischemia in all lesions in both the acute and the subacute stages. delta AI was higher in the rCBV map than in the 99mTc-ECD SPECT images in the ischemic core (p = 0.063) and in the periphery (p = 0.091). In the 99mTc-ECD SPECT images, delta AI was higher in the ischemic core than in the periphery (p = 0.028). During the subacute stage, 99mTc-ECD SPECT detected all the lesions without the pseudonormalization seen in the MR images of 5/11 lesions. Based on this study, 99mTc-ECD SPECT is comparable to PWI in terms of its ability to detect acute stroke and is more useful than PWI in the case of subacute infarction.

Capillary Hemangioma of Adult Nasal Cavity: A Case Report

Capillary hemangioma of the adult nasal cavity is rare. We report a case which occurred in the right nasal cavity of a 25-years-old woman, together with the multiphase enhanced CT findings. The patients who had a history of recurrent nasal bleeding, had experienced nasal obstruction and swelling during the two-month period prior to presentation, and one month before presentation, spontaneous vaginal delivery occurred. Physical examination revealed the presence of a well-defined round mass, with redness in the right nasal vestibule. The mass showed rim enhancement at early arterial-phase CT scanning, increased enhancement at the late arterial phase, and moderately homogeneous enhancement at the delayed phase.

Reversal of Apparent Diffusion Coefficient (ADC) Following Transient Focal Cerebral Ischemia in Cats

PURPOSE: To determine the minimal threshold ADC ratio suggesting reversible ischemia in a temporary model of MCAO. MATERIALS AND METHODS: Seven Korean cats weighing 3-3.5 kg were used as a temporary model of MCAO. The MCA was occluded for 1 hour, and diffusion-weighted images (DWI), and ADC and regional cerebral blood volume (rCBV) maps, were obtained at 1, 3, 6 and 24 hours after reperfusion using a 1.5T MR unit. The Cats were sacrificed 24 hours after imaging. Triphenyl tetrazolium chloride (TTC) staining of brain slices was performed, and DWI images and TTC-stained brain slices were compared with the naked eye. Reversible ischemia was defined as the area of high signal intensity at 1-hour DWI that normalized at follow-up DWI and in which TTC staining was normal. Using the ADC image obtained at 1 hour after reperfusion, 60 ADC ratios were obtained in the periphery of the infarct and reversible ischemia. Tissue survival showing normal TTC staining was used for final determination. The sensitivity and specificity of each ADC ratio was obtained and an ROC curve was plotted. RESULTS: Five of seven cats showed the reversible ischemia. An area of high signal intensity was seen on DWI images obtained 1 hour after reperfusion, and this improved at follow-up imaging. The distribution of the ADC ratio in the periphery of the infarct core was 0.71-0.81, and in the periphery of reversible ischemia it was 0.79-0.93. The ADC ratio of 0.80 obtained 1 hr after reperfusion predicted the survival of the ischemic tissue with 93% sensitivity and 90% specificity. The ADC ratio of the reversible ischemia was 0.82+/-0.03 at 1 hour after reperfusion, and this was higher than that of the infarct, which was 0.74+/-0.03. CONCLUSION: The minimal threshold ADC ratio suggesting reversible ischemia in this temporary model of MCAO was 0.80.

Diffusion-weighted image and MR spectroscopic analysis of a case of MELAS with repeated attacks

We report the clinical and MR manifestations of an 18 year-old girl with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. Recurrent status epilepticus caused reversible cytotoxic edema on diffusion-weighted images (DWI). Initial and one month follow-up MR spectroscopy, after seizure control, showed some discrepancies in the ratio of metabolites. N-acetylaspartate (NAA) partially recovered (NAA/creatine (Cr) ratio: 1.27-->1.84). This was because of a normalization of decreased NAA due to cellular dysfunction as a result of status epilepticus. A low ratio of NAA/Cr due to abnormal mitochondria remained in the decreased state. Reversible NAA/Cr ratios in the acute lesion suggested that NAA reflects the neuronal function as well as the level of neuronal structural damage. The altered NAA/Cr ratio better correlated with the abnormal signal intensity area of T2-weighted images (T2WI) and DWI than the lactate (Lac)/Cr ratio. With conservative treatment with anti-epileptics not accompanied by coenzyme Q or sodium dichloroacetate, lactate persistently increased (Lac/Cr ratio: 1.01-->1.21) because of the continued production of lactate in cells with respiratory deficiency, which is the main pathology of MELAS.

Second Branchial Cleft Cyst of the Oropharyux: A Case Report

We report a very rare type of second branchial cleft cyst located at the oropharynx, and include a review of the literature. CT scans of the neck revealed a homogeneous non-enhancing low-density mass in the right posterolateral mucosal wall of the oropharynx. Only the peripheral capsule of the mass was enhanced. The cyst was resected perorally and proved to be a type-IV second branchial cleft cyst.

Hemorrhagic Shock and Encephalopathy Syndrome: A Case Report

Hemorrhagic shock and encephalopathy syndrome (HSES) is a sudden-onset symptom complex that in-volves multisystem failure and includes encephalopathy, shock, coma, convulsions, prerenal azotemia, hepatic dysfunction, and bleeding coagulopathy and progressive thrombocytopenia in previously healthy infants and children. Its radiologic findings have rarely been reported, and it has not been described in Korea. We present a case of clinically diagnosed HSES, and include the CT and MRI findings.

CT Findings of Diffuse Pneumocephalus due to Bacterial Meningitis: A Case Report

We report a case of diffuse pneumocephalus due to infection. Brain CT revealed diffuse brain swelling and diffuse pneumocephalus in the ventricular system, subarachnoid space, subdural/epidural space and superior sagittal sinus. CSF disclosed the presence of a yellowish-green pus-like liquid. Polymerase chain reaction was positive for Haemophilus influenza Ag.

CT and MR Imaging Features in Patients with Intracranial Dolichoectasia

PURPOSE: To describe the CT and MR imaging features in patients with intracranial dolichoectasia. MATERIALS AND METHODS: The CT(n=21), MR(n=20) and MRA(n=11) imaging features seen in 28 patients (M:F=12:16 aged beetween 65 and 82 (mean, 65) years with intracranial dolichoectasia were retrospectively reviewed with regard to involved sites, arterial changes(maximum diameter, wall calcification, high signal intensity in the involved artery, as seen on T1-weighted MR images), infarction, hemorrhagic lesion, compression of brain parenchyma or cranial nerves, hydrocephalus and brain atrophy. Involved sites were classified as either type 1 (involvement of only the posterior circulation), type 2 (only the anterior circulation), or type 3 (both). RESULTS: In order of frequency, involved sites were type 1(43%), type 3(36%) and type 2(22%). Dolichoectasia was more frequently seen in the posterior circulation(79%) than in the anterior (57%). Arterial changes as seen on T1-weighted MR images, included dolichoectasia(mean maximum diameter 7.4mm in the distal internal carotid artery, and 6.7mm in the basilar artery), wall calcification(100% in involved arteries) and high signal intensity in involved. Cerebral infarction in the territory of the involved artery was found in all patients, and a moderate degree of infarct was 87%. Hemorrhagic lesions were found in 19 patients(68%); these were either l o b a r ( 53%), petechial(37%), or subarachnoid (16%), and three patients showed intracranial aneurysms, including one case of dissecting aneurysm. In 19 patients(68 %), lesions were compressed lesions by the dolichoectatic arteries, and were found -in order of descending frequency- in the medulla, pons, thalamus, and cerebellopontine angle cistern. Obstructive hydrocephalus was found in two patients (7 %), and 23 (82 % ) showed a moderate degree of brain atrophy. CONCLUSION: In patients with intracranial dolichoectasia, moderate degrees of cerebral infarction and brain atrophy in the territory of involved arteries, as well as hemorrhagic lesions and compression of the brain stem or cranial nerves, were not infrequently seen on CT and MR images. These changes were in addition to the basic arterial change(dolichoectasia, arterial wall calcification and intraluminal high signal intensity) seen on T1-weighted MR images.

Usefulness of Diffusion-Weighted Images in the Evolving Stroke: Correlation with Clinical Findings

PURPOSE: To determine the usefulness of repeat diffusion-weighted imaging (DWI) during the acute ischemic stroke stage for the prediction of evolving stroke and clinical course. MATERIALS AND METHODS: Fifteen patients with acute ischemic stroke in MCA territory [24 hours, 10 patients; M:F=9:6; age 28 -75 (mean, 61) years] were involved in this prospective study. All patients underwent initial DWI, follow-up DWI (within two weeks of the first attack) and T2WI (2 -5 months later to assess final infarction territory). The National Institute of Health Stroke Scale (NIHSS) was used for clinical evaluation. 'Evolving stroke' was defined as progression of NIHSS after admission. For statistical analysis, Fisher's exact test was used and a p value<0.05 was considered significant. RESULTS: In six patients (40%), the diagnosis was evolving stroke. In four of these (67%), follow-up DWI showed that the infarction territory was more extensive. Evolving stroke occurred 24 -72 hours after the onset of symptoms. DWI obtained 72 hours after onset showed that one patient had developed new infarction. Patients in whom enlarged infarction territory was seen on follow-up DWI showed progression of NIHSS within three days of onset, while those in whom follow-up DWI demonstrated no change showed an improved NIHSS (p < 0.05). Those who underwent initial DWI within 24 hours of onset showed larger infarction territory on follow-up DWI than those who underwent initial DWI later than this (p < 0.05). CONCLUSION: Repeat DWI during the acute ischemic stroke stage might be useful for the evaluation of evolving stroke.

Endobronchial Sarcomatoid Carcinoma of the Lung: A Case Report

Sarcomatoid carcinomas of the lung are rare malignant biphasic tumors composed of carcinomatous and sarcomatous components. We report a case of endobronchial sarcomatoid carcinoma in a 56-year-old man with a history of smoking, in whom the tumor was an endobronchial mass arising from the superior segmental bronchus of the left lower lobe and protruding against the main bronchus without parenchymal invasion. The patient underwent left pneumonectomy but four months later died of mesenteric sarcomatous metastasis.

Atypical CT and MR Features of Chondroid Chordoma at the Base of the Skull: A Case Report

We report a case of chondroid chordoma without calcification in which T2-weighted MR images revealed homogeneous high signal intensity. The tumor was located in the left middle cranial fossa extending to the cerebellopontine angle and with displacement of the pituitary gland to the right side. Precontrast CT scans showed a homogeneous low -density mass, without calcification. T1-weighted MR images of the mass demonstrated relatively homogeneous low signal intensity, T2-weighted images showed homogeneous high signal intensity, and post -contrast T1-weighted images revealed somewhat heterogeneous enhancement.

Sonographic Evaluation of Plantar Fasciitis

PURPOSE: To evaluate the sonographic findings of plantar fasciitis. MATERIALS AND METHODS: Both feet of 30patients(mean age, 44years) in whom plantar fasciitis had been clinically diagnosed, and those of healthyvolunteers(mean age, 34years) were evaluated with ultrasound(US) using a 7.0MHz linear array transducer. Heel painwas unilateral in 26 patients and bilateral in four. Sagittal sonograms were obtained in the prone position, andthe thickness of the plantar fascia was measured at its proximal end near its insertion into the calcaneus. Wealso evaluated hypoechoic fascia, perifascial fluid collection, fiber rupture, calcaneal spur and calcifications. RESULTS: Plantar fascia thickness was significantly greater in the heels of patients with plantarfasciitis(3.2-8mm; mean, 5.1 +/-1.12) than in their asymptomatic heels(1.3-5mm; mean, 3.5 +/-0.78)(p<0.0001), inwhich it was similar to that of heels of patients in the control group(1.8-5mm; mean, 3.0 +/-0.71)(p<0.0001). Theproximal plantar fascia was hypoechoic in 31 symptomatic heels(91.2%), in four asymptomatic heels(15.4%), and innone of the patients in the control group. Calcaneal spurs were identified in sixteen symptomatic heels(47.1%),and in two which were asymptomatic(7.7%). Perifascial fluid collection was identified in only two symptomaticheels(5.9%). CONCLUSION: In plantar fasciitis, sonography demonstrates that the fascia is thicker as well ashypoechic. For the clinical diagnosis of planter fasciitis, US can therefore be used as an adjunct to clinicaldiagnosis.

Radiologic findings of anthracofibrosis

PURPOSE: To evaluate the CT findings of bronchial anthracofibrosis. MATERIAL AND METHOD: Fourteen patientswith bronchoscopically confirmed anthracofibrosis were involved in this study. CT findings (n=12) wereretrospectively analysed ; the pattern, distribution and extent of bronchial and parenchymal abnormalities andadditional findings such as mediastinal lymphadenopathy and pleural effusion were assessed. Age, sex, andoccupational and disease history were also reviewed. RESULT: Patients were aged between 63 and 95 (mean,71.3)years, and ten were female. Only one patient had an occupational history, but four had a history of pulmonarytuberculosis. Frequent radiologic findings were bronchial wall thickening(n=6), atelectasis(n=8), mediastinallymphadenopathy(n=7) and mass(n=4). Other accompanying findings were bronchial wall calcification(n=3),consolidation(n=2) and pleural effusion(n=2). Right upper (n=7) and right middle lobe(n=7) were the most commonlyinvolved sites, and multifocal involvement(n=7) was frequent. CONCLUSION: Bronchial wall thickening, atelectasisand mediastinal lymphadenopathy were characteristic CT findings of anthracofibrosis. When such findings are notedin older or aged female patients, anthracofibrosis should be included in the differential diagnosis.

Primary Malignant Tumor of the Fallopian Tube: 2 cases Reports Papillary Carcinoma and Choriocarcionma

Primary fallopian tube carcinoma is a very rare gynecologic malignacy, occurring during the fifth or sixthdecade of postmenopausal women. The most common histological type is adenocarcinoma; squamous carcinoma, sarcoma,mixed mullerian tumors, and choriocarcinoma, for example, are exceedingly rare. The author reports one case eachof adenocarcinoma and choriocarcinoma of the fallopian tube both were demonstrated by US, CT, and MRI.

Piezoelectric Extracorporeal Lithotripsy of Gallbladder Stones: New Inclusion Criteria

PURPOSE: To establish the optimal inclusion criteria for the patients with gallbladder stones to extracorporeal shock wave lithotripsy(ESWL) by retrospectively analyzing our current results. MATERIALS AND METHODS: Data obtained from 201 patients with gallbladder stones treated with ESWL and oral chemolytic agent from November 1989 to July 1992 were restroepectively analyzed. Ninety-six had radiolucent stones and 105 had radiopaque stones. We used piezoelectric lithotriptor(EDAP LT. 01) and there were no limitation in number of sessions or total number of shock waves. ESWL was repeated until the size of the largest fragment is smaller than 4 mm. Follow up ultrasound was done in every three months after the successful fragmentation. Average length of the follow up was 205 days. We analyzed the rate of successful fragmentation, number of shock waves needed to achieve successful fragmentation according to the size, number of stones as well as the presence of the calcification. Stone-free rate after 6 months was also calculated from all subgroups and compared to each other. RESULTS: The rate of successful fragmentation was 76.2% for radiolucent stones and 66.6% for radiopaque stones(p > 0.05) after 46,731 and 56,111 shock waves respectively(p > 0.05). The rate of successful fragmentation was highest in patients with single, radiolucent stone smaller than 2cm(91.7%) followed by single radiolucent stone larger than 2cm(83.3%), multiple calcified stones smaller than 2cm(77.4%) and single calcified stone smaller than 2cm(72.1%). The rate of complete stone clearance after 6 month follow-up was highest in patients with single radiolucent stone smaller than 2cm(63.3%) and followed by multiple calcified stones smaller than 2cm(37.3%), single calcified stone smaller than 2cm(33.9%)(p <0.05). CONCLUSION: To obtain better results with ESWL in patients with gallbladder stone, the authors propose a more strict inclusion criteria, which is the patient with a single, radiolucent stone smaller than 2cm.

Radiologic Findings of Bronchiectasis: Tuberculous versus Non-Tuberculous

PURPOSE: To describe the radiological differences between tuberculous(TBB) and non-tuberculous bronchiectasis(NTBB). MATERIALS AND METHODS: Chest radiographs(n=62), bronchograms(n=18), and CT scans(n=52) of 37 patients with TBB and 25 patients with NTBB were reviewed retrospectively. Diagnostic basis for TBB were positive sputum AFB with or without history of anti-tuberculous chemotherapy(n=35), and radiological findings of pulmonary tuberculosis (n=2). Four of NTBB had a history of severe respiratory tract infection in childhood. RESULTS: Air-fluid levels on chest radiographs were seen in 2% of TBB, and 20% of NTBB. On bronchograms, all patients with TBB had combined focal bronchostenosis, whereas patients with NTBB had tubular(50%), cystic(17%), or mixed(33%) pattern of dilatation without stenosis. On CT scans, focal emphysema was seen in 86% of the patients with TBB, and 38% of the patients with NTBB. Peribronchiolar infiltration were seen in 78% and 44% of patients with TBB and NTBB, retrospectively. CONCLUSION: Basic radiological difference between TBB and NTBB was that the former had coexistent sten.

Pelvic Lymph Node Evaluation in Uterine Cervical Carcinoma Using Contrast Enhanced MR Imaging

PURPOSE: To evaluate the usefulness of Gd-DTPA enhanced MR imaging in determining the metastatic lymph nodes in uterine cervical carcinoma. MATERIALS AND METHODS: Sixty nine patients with histologically proven cervical carcinoma underwent Gd-DTPA enhanced MR imaging. One hundred and thirty-eight pelvic regions(69 right,69 left) in 69 patients were analyzed for lymph node metastases. Pelvic lymph nodes were considered to be abnormal if they were greater than lcm in diameter and were enhanced on postcontrast T1 weighted images. RESULTS: Metastatic lymph nodes were found in 22 pelvic regions by surgicopathologic examinations. On MR imaging there were 14 true positives, 106 true negatives, 10 false positives and 8 false negatives. Gd-DTPA enhanced MR image had an accuracy of 86.9%, a sensitivity of 58.3%, a specificity of 91.4%, a positive predictive value of 58.3% and negative predictive value of 92.9% in evaluation of pelvic lymph node metastases. CONCLUSION: MR imaging with contrast enhancement may be useful in the evaluation of pelvic lymph node metastases in patients with uterine cervical carcinoma.

Acute Neuropathic Joint in Diabetic Foot: Plain Radiographic Findings

PURPOSE: To determine the plain film findings of acute neuropathic joint in diabetic foot. MATERIALS AND METHODS: Acute neuropathic joint in diabetic foot was considered when fragmentation of the articular ends of bone and subluxation of the affected joint developed within eight weeks after clinical onset of diabetic gangrene. Eight toes of six diabetics were satisfactory to our criteria. We analyzed plain radiographic findings of the affected joint and soft tissue, interval changes in follow-up radiographs, and deformities after healing. RESULTS: The time interval between clinical onset of gangrene and bone destruction ranged from 2 weeks to 4 weeks(mean 2.6 weeks). Plain radiographs showed fragmentation of the articular ends, subluxation, and soft tissue swelling of the metatarsophalangeal joint or interphalangeal joint. The significant feature of these patients was rapid progression of the lesions. Clinically, all patients had diabetic gangrene in affected toes, however, there was no evidence of osteomyelitis in our series. Amputation was done in 2 cases, and lesions in 3 of the remaining 4 cases were repaired spontaneously with regression of gangrene, leaving radiological residua such as pointed-end, tapered-end, and ball and socket deformity. CONCLUSION: Rapid disorganization of the joint with associated evidence of soft tissue gangrene in plain radiograph is believed to be valuable for the diagnosis of diabetic osteoarthropathy.

Joubert Syndrome: Clinical Manifestations and Magnetic Resonance Imaging

PURPOSE: Joubert syndrome presents neonatal respiratory abnormalities and other clinical manifestations. Pathologically the patients show hypoplasia or agenesis of cerebellar vermis and other intracranial anomalies. Our purpose is to evaluate the clinical manifestations and MR findings of Joubert syndrome. MATERIALS AND METHODS: Among the patients presenting with clinical stigmata of Joubert syndrome and agenesis of vermis on MR imaging, eight patients who did not satisfied the criteria of Dandy-Walker malformation, tectocerebellar dysraphia and rhombencephalosynapsis were selected. MR findings and clinical manifestation were analyzed. RESULTS: On MR imaging, agenesis of the cerebellar vermis (all cases), hypoplasia of the cerebellar peduncle (6cases), fourth ventricular contour deformity(6cases), tentorial elevation (4cases), deformity of the lateral ventricles (4cases), dysgenesis of the straight sinus (3cases) were demonstrated. Other findings were abnormalities of corpus callosum (3cases), falx anomalies (3 cases), occipital encephalomeningocele (2 cases) and fluid collection in posterior cranial fossa (2cases). Clinical manifestations were developmental delay (5cases), abnormal eyeball movement (3cases), hypotonia (2 cases), neonatal rerspiratoy abnormality (2cases), etc. CONCLUSION: Joubert syndrome showed various clinical manifestations and intracranial anomalies. MR imaging is an useful modality in detection of the cerebellar vermian agenesis and other anomalies of the patients.

Hrombosed Aortic Dissections and Aortic Aneurysms: MRI Findings and Differential Diagnosis

PURPOSE: MRI is known to be an effective imaging modality of the aorta and its role is steadily increasing in the evaluation of acquired aortic diseases including aortic dissections and aortic aneurysms. However, differentiation of the aortic dissections with thrombosed false lumen from the aortic aneurysm with mural thrombus in MRI has not been easy. Therefore, the authors tried to find the characteristic MR featrses which would to differentiate the two diseases. MATERIALS AND METHODS: MR images of 6 patients with thrombosed aortic dissection and 7 patients with thrombosed aortic aneurysms were reviewed retrospectively and compared in regand to shape and extent of thrombus, dimension of aorta, and luminal flow signal. RESULTS: Thrombosed aortic dissections showed sharply demarcated crescent shaped aortic wall thickening of even thickness involving long segment of the aorta, whereas thrombosed aortic aneurysms showed irregular aortic wall thickening of uneven thickness localized in the short dilated segment of the aorta. Characteristically aortic aneurysm with mural thrombus showed eccentric intraluminal slow flow signal. In contrast to the signal void of the true lumen in aortic dissections, the residual lumen of the aortic aneurysm with mural thrombus revealed intraluminal signal due to slow flow. CONCLUSION: Familiarity to these MRI findings of thrombosed aortic dissections and aortic aneurysms may lead to the accurate differential diagnosis in majority of cases.