Changes in the blood viscosity and the consistency of artificial thrombi in 17-year-old girls during the menstrual cycle.
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Adolescent↗
Biomedical subjects
J S Yu
Publications and source records attributed to J S Yu.
Comparison of multishot turbo spin echo and HASTE sequences for T2-weighted MRI of liver lesions.
The purpose of this study was to compare the relative usefulness of multishot turbo spin echo (TSE) and half-Fourier single-shot turbo spin echo (HASTE) for determination of optimal breath-hold fast T2-weighted technique in terms of lesion detection, lesion-to-liver contrast-to-noise ratio (CNR), and image quality. The images of TSE with and without fat suppression (FS) and of HASTE with and without FS were retrospectively reviewed for 49 patients with 128 lesions. Without FS, TSE and HASTE images allowed depiction of focal hepatic masses (112 of 128, sensitivity = 87.5%) at the same rate. TSE with FS depicted more focal lesions (115 of 128, 89.8%) than HASTE with FS (109 of 128, 85.2%), but the difference was not statistically significant (P > .05). The CNR of each lesion on HASTE sequences was greater (P < .01) than that on TSE sequences. The CNR of hemangioma was distinct from that of solid tumors and cystic lesions in all sequences, and the range of CNR in each group of pathologies overlapped less and were well separated in the HASTE sequences. HASTE sequences produced better image quality with fewer artifacts (P < .0001). The results of this study suggest that HASTE sequences allow differentiation between solid tumors, hemangiomas, and cystic lesions in terms of CNR, producing fewer image artifacts, with acceptable sensitivity in lesion detection.
Artifacts↗
Primary malignant fibrous histiocytoma of the liver: imaging features of five surgically confirmed cases.
BACKGROUND: The purpose of the present study was to describe the various imaging features of primary malignant fibrous histiocytoma (MFH) of the liver, a rare tumor of mesenchymal origin. METHODS: Sonography (n = 5), computed tomography (CT; n = 5), magnetic resonance (MR) imaging (n = 2), and hepatic arteriography (n = 3) in five patients who underwent partial hepatectomy for tumor resection were retrospectively reviewed and correlated with pathologic findings. RESULTS: All tumors were clearly demarcated from surrounding hepatic parenchyma in sectional imaging with (n = 2) or without (n = 3) a fibrous capsule, which was pathologically verified. Internal architecture of abundant fibrosis, myxoid degeneration, and/or hemorrhagic necrosis reflected the sonographic, CT and MR imaging findings. Marginal tumor staining without definite tumor vasculature was the main feature of hepatic arteriography. There was no intratumoral calcification. All three tumors involving the right lobe of the liver invaded the right hemidiaphragm. CONCLUSION: Although there were no unique findings of primary hepatic MFH, a combined interpretation of various imaging modalities may elucidate the malignant nature of the tumor.
Adult↗
Pneumoperitoneum caused by transhepatic air leak after metallic biliary stent placement.
A self-expanding metallic biliary stent was placed for palliation of a common bile duct obstruction in a 68-year-old male with unresectable pancreatic head cancer 3 days after initial percutaneous right transhepatic catheter decompression. The stent crossed the ampulla of Vater. Three days later, the stent was balloon-dilated and the percutaneous access was removed. At removal, a small contrast leak from the transhepatic tract was seen. Three days later, pneumoperitoneum was found with symptoms of peritoneal irritation and fever. A widely open sphincter of Oddi caused by the metallic stent, accompanied by delayed sealing of the transhepatic tract, may have caused the air and bile leakage into the peritoneal space. This case shows that pneumoperitoneum may occur without ductal tear or bowel injury, with a biliary stent crossing the ampulla of Vater.
Adenocarcinoma↗
Myelofibrosis associated with prominent periosteal bone apposition. Report of two cases.
Myelofibrosis is a myeloproliferative disorder that is characterized by splenomegaly and bone marrow replacement by fibrous tissue. The predominant radiographic feature is osteosclerosis; however, in rare instances, periosteal bone apposition or periostitis is apparent in the metaphysis of the distal femura and proximal tibiae. It has been suggested that periostitis, when associated with fever and bone pain, is indicative of more aggressive disease. We report this unusual radiographic finding and its similar appearance to hypertrophic osteoarthropathy in two patients with myelofibrosis. In our patients, the presence of periosteal bone apposition did not correlate with increased disease aggressiveness.
Aged↗
MR imaging of parosteal osteosarcoma in two skeletally immature patients.
Parosteal osteogenic sarcoma is an unusual tumor in young children. It usually has a tendency to affect people with mature skeletons. The biological behavior of this tumor in children appears to be identical to that in adults, resulting in excellent prognosis after curative operative procedures, even if there is minimal extension to the bone marrow. Magnetic resonance imaging has a significant role in staging the tumor, as other imaging modalities are inferior in demonstrating early bone marrow involvement.
Biopsy↗
MR imaging of a parosteal lipoma.
A case of a parosteal lipoma of the thigh is presented. Very little is known of the enhancement features of this tumor. In this case, mild enhancement of tissue in the region of the pedicle between reactive cortical bone hyperostosis and the lipomatous mass corresponded to fibrous tissue that outlined the hyperostotic reactive bone.
Adult↗
CT of superior mesenteric vein thrombosis complicating periappendiceal abscess.
Acute mesenteric vein thrombosis is a rare complication of appendicitis. In this report we describe the clinical association of these entities and emphasize how early diagnosis by CT can expedite treatment.
Abscess↗
MRI of elastofibroma dorsi.
OBJECTIVE: To determine if the MR features of elastofibroma are sufficient for diagnosis of this neoplasm. MATERIALS AND METHODS: The MR studies of two patients with pathologically proven bilateral elastofibromas were reviewed retrospectively. RESULTS: In each patient, bilateral semilunar soft-tissue masses demonstrating signal intensities isointense to that of muscle were identified in the periscapular regions deep to the posterolateral musculature of the chest. Focal linear areas of fat were present. The biopsy specimens of both patients demonstrated a positive reaction to the elastin stains. CONCLUSION: A periscapular soft-tissue neoplasm demonstrating a pattern of linear alternating regions of high and intermediate signal intensity on T1- and T2-weighted spin-echo MRI should be sufficient to allow the diagnosis of elastofibroma.
Adult↗
Madelung deformity in skeletally immature patients: morphologic assessment using radiography, CT, and MRI.
PURPOSE: The purpose of this study was to define the pathoanatomy of the distal radius and surrounding soft tissues, identify the factors that may contribute to diminished forearm rotation, and relate these findings to alterations in wrist motion in skeletally immature patients with the Madelung deformity. METHOD: Four skeletally immature female patients with bilateral Madelung deformities (eight wrists) underwent evaluation of each wrist with radiography, CT, and MRI to assess the morphology of the deformity. Two patients (four wrists) had isolated idiopathic Madelung deformities, and two patients (four wrists) had Madelung deformities secondary to dyschondrosteosis. RESULTS: Radiographically, all wrists demonstrated dorsal bowing of the radius, marked ulnar tilting of the radius and radial tilting of the ulna, volar tilting of the distal articular surface of the radius, and triangulation of the epiphysis. On CT, patients with the idiopathic deformity demonstrated dorsal ulnar subluxation and relative supination of the carpus with respect to the distal radius. Patients with dyschondrosteosis demonstrated no ulnar subluxation and relative pronation of the carpus. All wrists demonstrated a fixed pronated deformity of the distal radius. On MRI, a physeal bar that bridged the distal metaphysis of the radius to the epiphysis was identified in all eight wrists, located on the volar aspect of the radius at the lunate facet. An anomalous volar ligament, a volar radiotriquetral ligament, and the short radiolunate ligament were hypertrophied in seven wrists. CONCLUSION: Based on its location, it is likely that a physeal bar impedes the normal development of the distal radius ulnarly. Hypertrophy of the short radiolunate ligament may be an important contributing factor to carpal pyramidalization owing to tethering on the volar pole of the lunate. Diminished forearm rotation is likely related to carpal malalignment, a fixed pronated deformity of the distal radius, and dorsal bowing of the radius.
Adolescent↗
Denervation atrophy caused by suprascapular nerve injury: MR findings.
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Adult↗
Suspected scaphoid fractures in skeletally immature patients: application of MRI.
PURPOSE: The purpose of our study was to evaluate the MR findings in the wrists of pediatric patients who have sustained acute wrist injuries and to determine if this imaging method yields more information than combined serial radiographs and physical examinations. METHOD: Eighteen skeletally immature patients (11 boys and 7 girls, age range 8-15 years) who had presented to the emergency room within 2 days following acute wrist trauma underwent serial clinical, radiographic, and MR examinations if there was a suspicion of a scaphoid fracture. RESULTS: Ten patients had a scaphoid abnormality on MR images. Six had fractures and four had regional bone marrow edema. Initially, all but two fractures were radiographically occult, although the other fractures eventually became evident on later studies. Those with marrow edema did not progress to fractures. Obliteration of the scaphoid fat stripe occurred in five patients with a scaphoid fracture and in six patients who did not have a fracture. Dorsal soft tissue swelling occurred in eight patients, five of whom had scaphoid fractures. Seven patients had evidence of extensor tenosynovitis on MRI. CONCLUSION: A normal initial MR image had a negative predictive value of 100%. Persistent snuffbox pain may represent injury to the scaphoid, extensor tendons, or dorsal soft tissues. An outcome study evaluating the benefits of early application of MR in the pediatric population is warranted.
Acute Disease↗
Retroperitoneal paragonimiasis: a case of ectopic paragonimiasis presenting as periureteral masses.
We describe a case of retroperitoneal paragonimiasis presenting as periureteral masses. CT showed a conglomerate of enhancing nodules with subtle low attenuation in the center at the left iliac fossa and clustered, ring-like, enhancing lesions at the left renal hilum. When a retroperitoneal conglomerate of ring-like, enhancing lesions in association with pleuropulmonary disease suggestive of paragonimiasis can be found in endemic regions or in migrants from those regions, one may expect ectopic-retroperitoneal paragonimiasis.
Abdomen↗
Foot pain after a plantar fasciotomy: an MR analysis to determine potential causes.
PURPOSE: The purpose of this work was to determine potential causes of foot pain in patients who have had a surgical release of the plantar fascia for treatment of fasciitis. METHOD: We studied 17 patients (15 women, 2 men; age range 22-59 years, mean 40 years) with foot pain after undergoing a fasciotomy. Fourteen unilateral and three bilateral procedures accounted for the 20 ankles evaluated. Mean duration after surgery was 22 months (range 3-53 months). Each patient was instructed to localize the pain to a region of the foot; classify the pain as new onset, persistent, or recurrent; and characterize it as to the action that produced the greatest pain. T1-weighted sagittal and dual-echo T2-weighted images in the sagittal, coronal, and axial planes were obtained in a 1.5 T magnet. The MR studies were evaluated for abnormalities of the plantar fascia, perifascial soft tissues, tendons, and osseous structures. RESULTS: The plantar fascia appeared thick in all ankles (mean 8.0 mm, range 6-12 mm). A total of 25 symptomatic sites were assessed. An acute plantar fascia rupture explained plantar symptoms in two feet. In another 16 feet (12 with plantar heel pain and 4 with nonspecific heel pain), 6 had documentation of acute plantar fasciitis and 9 demonstrated perifascial edema. Of the latter nine feet, five demonstrated abnormalities of the posterior tibialis, peroneus longus, and peroneus brevis tendons. The pain localized to the medial arch in six feet; five feet had abnormalities of the posterior tibialis tendon and one foot demonstrated edema in the flexor digitorum brevis muscle. The pain localized to the lateral midfoot in one foot, which had a cuboid stress fracture. CONCLUSION: The cause of foot pain in patients who had a plantar fasciotomy appeared to be multifactorial. Three likely causes of pain were identified: persistent or recurrent acute plantar fasciitis, pathology related to arch instability, and structural failure from overload.
Adult↗
Stress fractures associated with plantar fascia disruption: two case reports involving the cuboid.
Stress fractures involving the cuboid are rare. We have encountered two patients who developed this abnormality as a complication of disruption of the plantar fascia, which likely produced lateral destabilization of the midfoot.
Adult↗
Partial efficacy of clindamycin against Chlamydia trachomatis in men with nongonococcal urethritis.
Tetracyclines are the drugs of choice for treatment of Chlamydia trachomatis infection, but alternative antimicrobial agents are needed. Clindamycin has moderate in-vitro activity against C. trachomatis. In this study clindamycin (600 mg orally three times daily for seven days) was given to 76 men with nongonococcal urethritis. Initial microbiologic and clinical responses were significantly better in men from whom C. trachomatis was initially isolated, compared with men from whom Ureaplasma urealyticum was initially isolated, but by 42 +/- 7 days after initiation of treatment, persistence or recurrence of urethritis had occurred in 39% of men with either organism initially isolated. C. trachomatis was ultimately reisolated at follow-up evaluation from seven of 23 men who initially had had positive cultures for C. trachomatis. There was no apparent relationship between the in-vitro susceptibility of C. trachomatis and the ultimate response. These results indicate that clindamycin cannot be relied upon to eradicate C. trachomatis from men with urethritis.
Adult↗
Urachal remnant diseases: spectrum of CT and US findings.
Computed tomography (CT) and ultrasonography (US) are ideally suited for demonstrating urachal remnant diseases. A patent urachus is demonstrated at longitudinal US and occasionally at CT as a tubular connection between the anterosuperior aspect of the bladder and the umbilicus. An umbilical-urachal sinus manifests at US as a thickened tubular structure along the midline below the umbilicus. A vesicourachal diverticulum is usually discovered incidentally at axial CT, appearing as a midline cystic lesion just above the anterosuperior aspect of the bladder. At US, it manifests as an extraluminally protruding, fluid-filled sac that does not communicate with the umbilicus. Urachal cysts manifest at both modalities as a noncommunicating, fluid-filled cavity in the midline lower abdominal wall located just beneath the umbilicus or above the bladder. Both infected urachal cysts and urachal carcinomas commonly display increased echogenicity at US and thick-walled cystic or mixed attenuation at CT, making it difficult to differentiate between them. Percutaneous needle biopsy or fluid aspiration is usually needed for diagnosis and therapeutic planning. Nevertheless, CT and US can help identify most disease entities originating from the urachal remnant in the anterior abdominal wall. Understanding the anatomy and the imaging features of urachal remnant diseases is essential for correct diagnosis and proper management.
Diagnosis, Differential↗
Forefoot pain involving the metatarsal region: differential diagnosis with MR imaging.
Many disorders produce discomfort in the metatarsal region of the forefoot. These disorders include traumatic lesions of the soft tissues and bones (eg, turf toe, plantar plate disruption, sesamoiditis, stress fracture, stress response), Freiberg infraction, infection, arthritis, tendon disorders (eg, tendinosis, tenosynovitis, tendon rupture), nonneoplastic soft-tissue masses (eg, ganglia, bursitis, granuloma, Morton neuroma), and, less frequently, soft-tissue and bone neoplasms. Prior to the advent of magnetic resonance (MR) imaging, many of these disorders were not diagnosed noninvasively, and radiologic involvement in the evaluation of affected patients was limited. However, MR imaging has proved useful in detecting the numerous soft-tissue and early bone and joint processes that occur in this portion of the foot but are not depicted or as well characterized with other imaging modalities. Frequently, MR imaging allows a specific diagnosis based on the location, signal intensity characteristics, and morphologic features of the abnormality. Consequently, MR imaging is increasingly being used to evaluate patients with forefoot complaints. Radiologists should be familiar with the differential diagnosis and MR imaging features of disorders that can produce discomfort in this region.
Diagnosis, Differential↗