A Case of Pheochromocytoma Presented with Cardiogenic Shock and Followed by Spontaneous Remission

Pheochromocytoma is derived from the chromaffin cells and patients with pheochromocytoma present with several signs and symptoms by producing, storing and secreting catecholamine. Spontaneous rupture or necrosis of pheochromocytoma is extremely rare, but it can be lethal because of the dramatic change in the circulation such as an acute abdominal emergency or shock. Spontaneous remission of the clinical symptoms due to necrosis of the pheochromocytoma is rare. We describe such a case that presented with cardiogenic shock due to extensive necrosis of the pheochromocytoma and this was followed by spontaneous remission of the clinical symptoms without removal of the pheochromocytoma.

Immediate Breast Reconstruction with Deep Inferior Epigastric Perforator Free Flap

PURPOSE: Breast reconstruction with deep inferior epigastric perforator(DIEP) free flap is known to be the most advanced method of utilizing autologous tissue. The DIEP free flap method saves most of the rectus abdominis muscle as well as anterior rectus sheath. Therefore, the morbidity of the donor site is minimized and the risk of hernia is markedly decreased. METHODS: We chose the internal mammary artery and its venae comitantes as recipient vessels, and deep inferior epigastric vessels as donor vessels. The number and location of the perforators derived from medial or lateral branch of deep inferior epigastric artery(DIEA) in 23 DIEP flaps were identified. Ten patients underwent evaluation of their abdominal wall function preoperatively and 6 months postoperatively by using Lacote's muscle grading system. RESULTS: Of the 23 patients, a patient with one perforator from lateral branch of DIEA experienced partial necrosis of flap. Total flap loss occurred in one patient. Mild abdominal bulging was reported in one patient 4 months postoperatively probably because of early vigorous rehabilitational therapy for her frozen shoulder. Postoperative abdominal wall function tests in 10 patients showed almost complete recovery of muscle function upto their preoperative level of upper and lower rectus abdominis and external oblique muscle function at 6 months postoperatively. All patients have been able to resume their daily activities. CONCLUSION: The breast reconstruction with DIEP free flap is reliable and valuable method which provide ample soft tissue from abdomen without compromising the integrity of abdominal wall. Selection of reliable perforators is important and including more than two perforators may decrease fat necrosis and partial necrosis of flap.

Usefullness with 3D CT Angiography in Microsurgical Reconstruction

Preoperative angiography is frequently used in the planning of microsurgical reconstruction for identification of vascular abnormality that influence the planning of operation. But, recently 3D CT angiography is considered as new technique that can provide detailed information about vascular anatomy as well as soft and bony tissue without the risks of invasive angiography. 3D CT angiograms were performed in 19 patients before microsurgical reconstruction for the lower extremity and hand between May of 2003 and Oct of 2004. Sixteen of the studies were of the donor site and all of 19 studies were of the recipient site. No complications were found from the 3D CT angiograms. In one case of the bone exposed open wound, the injury of anterior tibial artery was identified and the zone of injury was adequately demonstrated. With the improvement in quality of CT imaging, 3D CT angiograms may provide a favorable alternative to invasive angiography. It is capable of providing high-resolution, three dimensional vascular imaging without the need for arterial puncture and prolonged post-procedure observation. The relation among blood vessels, bones, and soft tissue is well demonstrated in 3D CT angiogram. Also The acquisition time and examination cost were considerably lower in comparison with invasive angiography. In conclusion, this study demonstrates that 3D CT angiography may provide accurate, safe, and cost-effective preoperative imaging. The 3D CT angiography with relatively low morbidity, low cost, ease of image acquisition can have an broader role in microsurgical reconstructive surgery.

Hand Reconstruction with Medial Sural Perforator Free Flap

PURPOSE: The main advantages of the perforator flap are minimal donor site morbidity, preservation of any main source artery and its thin characteristics. Most perforator flaps for hand reconstruction need primary and secondary procedures such as a flap debulkiness and liposuction etc. However, flap thickness of calf area is thinner than any other perforator flaps. METHODS: We performed an anatomical study and clinical application of medial sural artery perforator flap. We found that there are two or more medial sural perforators located on a straight line drawn from the mid-point of popliteal crease to the mid-point of medial malleolus. Most pathway of medial sural artery comes along with this line. It is possible to observe the first perforators almost exactly 8 cm from midpoint of popliteal crease in a distal half circle drawn with a radius of 2 cm. RESULTS: We report 12 cases in 11 patients of hand reconstruction with medial sural perforator free flap from Febrary 2003 to Febrary 2006. Complete healing was possible in 11 cases. Total flap loss for venous insufficiency was in 1 patient. During the follow-up, good contour and full range of motion was observed on hand reconstruction with medial sural perforator free flap. CONCLUSION: In the authors' experience, this anatomical study made it possible to prepare a diagram of the exact location of the medial sural perforators. This flap can be used to achieve acceptable functional and aesthetic results for hand reconstruction because of its thin characteristics.

Lower Extremity Reconstruction of Soft Tissue Defects with Perforator Island Flap

The reconstruction of deep soft tissue defects of lower extremities combined with bone exposure has been difficult problems. When it is impossible to raise local skin flap, we have been usually used the gastrocnemius musculocutaneous flap, cross leg flap or free flaps. However, In musculocutaneous flap, aesthetical appearance of the calf is not appropriate because of too bulky flap. Although the success rate of the free flap has improved, still failure of flap occurs in cases of the chronic ischemic state. As the concepts of perforator flap has recently developed and widely used due to its thin flap thickness. Between January 2002 to December 2004, we treated 7 patients with soft tissue defect in leg with chronic ischemic limbs with perforator island flap. Preoperative angiography were done in all case and we used 2 medial sural perforator flaps, 1 anterior tibial artery perforator flap, 1 posterior tibial artery perforator flap, 3 anterolateral thigh perforator flap. Partial necrosis of flap was seen in one patient but no further surgical procedure was required for wound healed spontaneously. Perforator island flaps are thin, reduce donor site morbidity, conceal donor site with primary closure and it is useful for resurfacing soft tissue defect of lower extremities.

Novel Method of the Upper One Third of Lower Leg and Knee Reconstruction

The coverage of soft tissue defects around the knee joint or upper one third of lower leg presents a difficult challenge to the reconstructive surgeon. Various reconstructive choices are available depending on the location, size and depth of the defect. The authors present their clinical application of a medial sural artery perforator island flap as a useful alternative method for upper one third of lower leg and knee reconstruction. From 2002 to 2004, we operated total 4 patients (total 4 flaps) using the medial sural artey perforator island flap for coverage of the defect on upper one third of lower leg and knee, of 4 patients, 3 patients was men and one was woman. Average patient age was 54.6 years. The largest flap obtained was 10x8cm2. Postoperative follow up of the patients ranged from two to 33 months. In two cases, defects was located on upper one third of lower leg and in other two cases, defects were on the knee. All four cases had bone exposure open wound. In angiography, 2 cases had injured in the anterior tibial artery, 1 case had injured in the posterior tibial artery. There were no diabetes or other vascular disease. All 4 flaps were survived completely, without minor complications such as venous congestion and hematoma. Donor morbidity was restricted substantially to the donor linear scar. There were no functional impairment. As the main advantages of the medial sural perforator island flap, it ensures constant location and reliable blood supply without sacrificing any main source artery or damaging underlying muscle. This procedure is valuable extension of local flap for defect coverage with minimal functional deficit donor site and good aesthetic result on the defect. We consider it as one of the useful methods of the upper one third of lower leg and knee reconstruction.

Distribution of Human Rotavirus G and P Types and G9 VP7 Sequences Circulating in Seoul, Korea

Genotyping of human rotaviruses was performed using 55 rotavirus-positive samples collected from 90 young children with diarrhea at Chung-Ang University Yongsan Hospital between December 2001 and May 2002. G typing of the VP7 protein showed that G2 was the most dominant circulating genotype (32.8%) followed by G1 (21.8%), G4 (12.7%), G3 (10.9%), G9 (1.8%) and a combination of G2/G3 (7.3%). P typing of the VP4 protein revealed that P[4] (60.0%) was the most prevalent strain, followed by P[6] (25.5%), P[8] (3.6%) and P[9] (1.8%). Seven samples (12.7%) for G type and 5 samples (9.1%) for P type remained untypable. The most predominant G-P combination was G2P[4] (29.1%), which is one of the most commonly observed type worldwide. A G9 serotype strain identified in this study shared more than 97% nucleotide homologies with 18 foreign G9 isolates. Therefore, incorporation of G9 rotavirus into current vaccine formula should be considered.

Sensory Recovery After Skin Graft Using Allogenic Dermis

It is well known that the thicker dermis is grafted, the lesser adhesion and contracture can be resulted. In spite of all advantages, thicker layer of dermis can also cause pain, infection, hypertrophic scar and delayed healing at the donor site. In addition, full thickness skin graft can result in best quality in recipient site, but it is limited in donor site and harvested size. Processed allogenic dermis(Alloderm(R)) has been developed and applied to solve the above-mentioned problems as permanent dermal augmentation for full thickness skin defect. From March 2002 to December 2003, we have applied allogenic dermis (Alloderm(R)) and ultra-thin split thickness skin graft on 30 patients (Group A) who had hypertrophic scar, 3rd degree burn, full thickness skin defect and various cosmetic problems. The control patients (Group B) are treated by conventional autologous thick split thickness skin graft only. We evaluated wound contracture, degree of sensory recovery, color change, functional and histological aspect between Group A and B. In Group A, by providing a dermal augmentation, the grafted dermal matrix permitted a thin autograft from the donor site. The harvested ultra-thin split-thickness skin remained fewer complications on the donor site and had faster healing process. And allogenic dermis exhibited excellent elastisity and good pigmentation with minimal scarring and wound contracture. But in sensory reinnervation study, Group A was not fully recovered compared to the conventional skin graft in Group B. In histological study, small nerve fiber bundles are scattered in the mid-dermis of processed allogenic dermis in Group A, but in Group B nerve fiber bundles extended into the upper dermis. Most nerve fibers were not sufficiently innervated into upper dermis in allogenic dermis because it was assumed that allogenic dermis play an important role as a barrier. In conclusion, if we perform ultra-thin split thickness skin graft using an allogenic dermis, wounds can be covered in a single stage with an adequate layer of dermal augmentation with minimal donor site morbidity, and we can also get good functional recovery, and avoid undesirable complications. However, application of allogenic dermis in the important area of sensation, such as hands and feet, should be conservative at present. Further scientific refinement is necessary for the improvement of sensory recovery in using allogenic dermis and a large scale experimental study should be performed.

Postoperative Occipital Pressure Sore: A Case Report / 대한마취과학회지

Prolonged soft tissue compression results in discomfort and pain secondary to local ischemia in normal individuals. During surgery, patients are immobile and unable to perceive the discomfort of prolonged pressure, and the anesthetized patient lacks a protective mechanism to prevent pressure sores. Many intrinsic and extrinsic factors are associated with pressure sore development; however, the intensity and duration of pressure are critical components in the etiology of pressure sores. We conclude that interface pressure on a patient lying on an operating table during a long operation is a primary factor of postoperative occipital pressure sores.

Correction of Severe Post-traumatic Enophthalmos through Transconjunctival Approach

Surgical treatment of post-traumatic enophthalmos is one of the most challenging procedures following facial injury. The purpose of this study is to evaluate the advantage of transconjunctival approach and/or medial and lateral extension in reconstruction of orbit in patient with severe post-traumatic enophthalmos. This study includes 7 patients. All operative procedures were performed through preseptal transconjunctival approach and/or medial and lateral extension. After release of scar tissues around orbital contents, reconstruction of orbit was performed using titanium dynamic mesh and silastic sheet. In 5 patients, repositioning of the malunited zygoma was done as concomitant surgery. The aesthetic and functional results were satisfactory. The results were good in 5 patients(72%) and fair in 2 patients(28%). Postoperative improvement of enophthalmos and ocular dystopia were statistically significant by paired t-test(p-value<0.05). No patients complained of postoperative lower lid ectropion. Finally, this approach is much advantageous in patient with severe post-traumatic enophthalmos as wide exposure of lesion and no visible scar on lower lid.

Injectable Cartilage Tissue Engineering Techniques Utilizing Fibrin Glue, Liquid Alginate and Pluronic F-127

Recently, a cartilage tissue utilizing the scaffold with liquid has been introduced for clinical application. In this study, three different bio-materials--fibrin glue, liquid alginate, and Pluronic F-112--were used to observe the feasibility of those liquid bio-materials in cartilage regeneration. The first stage of the experiment comprises gross observation of liquid bio-materials 24 hours after its injected into the subcutaneous pockets of New Zealand white rabbits. These bio-materials shows noticeable changes within the subcutaneous tissue of animal recipients. The second stage of the experiment is cartilage tissue engineering in athymic nude mouse utilizing these liquid bio- materials. Chondrocytes were harvested from the ear cartilage of rabbits. Tissue engineered constructs(TEC) were prepared by mixing the bio-materials and chondrocytes as 3 x 10(6) cells/ml. The TEC were injected into the dorsal subcutaneous tissue of rabbits as autologous grafts. The specimens were then harvested and analysed grossly and histologically at 4 weeks after injection. The sizes of the engineered cartilage tissue specimens varied according to the scaffold materials. The histologic evaluation was also performed after using the H/E stain and alcian blue stain. The specimen using fibrin glue showed homogeneous typical mature cartilage with lacunae surrounded by cartilage matrix. The specimen using liquid alginate showed homogeneous but relatively immature cartilage tissue formation throughout the specimen. The specimen using the Pluronic F-127 complex showed small areas of cartilage tissue islets which were less homogeneous in its distribution. In conclusion, it was possible to produce cartilage tissue by utilizing liquid scaffolds, such as fibrin glue, liquid alginate and Pluronic F-127. The cell-scaffold complex (TEC) could be successfully injected into subcutaneous tissue and changed into a semi-solid gel which ultimately produces a small amount of cartilage. This new concept of non-operative reconstruction method can be used for a variety of clinical purposes in the future.

Comparison of Porous Polyethylene Sheet(Medpor(R)) with Titanium Dynamic Mesh in the Treatment of Blow Out Fracture

The records of the patients with orbital wall fracture were reviewed from March 1997 through February 2001 in the department of plastic and reconstructive surgery, Yeungnam university medical center. One hundred thirty nine patients with blow out fracture were repaired by using porous polyethylene(Medpor(R)) or titanium dynamic mesh. Surgical effect of titanium dynamic mesh was evaluated and compared with that of Medpor(R) in the reconstruction of orbital wall fracture after follow up period of six months. The incidence of the orbital wall fracture was more common in men than in women. The traffic accident was most common cause of the fracture and the most common combined fracture was nasal bone fracture. The sites of fractures were the orbital floor in 51 patients, the medial wall in 18 patients, and both the medial wall and floor in 38 patients. Medpor(R) is easy to handle, shape, contour and position. Titanium dynamic mesh is good device in that it has for good structural stability, excellent strength, high biocompatibility and can be fixed easily. In conclusion, Medpor(R) was suitable for local defect in small fracture and titanium dynamic mesh was suitable for large defect in compound fracture

Repair of Urethral Defect with Vein Graft in Rabbit

There are several methods for the reconstruction of partial urethral defect, including split-thickness skin graft, full-thickness skin graft, and preputial flap and free flap. Despite partial success using these methods, most results are unsatisfactory due to frequent complications such as postoperative infection, fistula formation, hair growth and stricture. There have been several pioneering experiments in this field using autogenous vein graft and the results have been controversial. However, the fact that the endothelial lining is replaced by natural urethral epithlium is generally accepted as a positive effect of this method. This experiment was designed to identify the possibility of using vein graft for the reconstruction of partial urethral defect. Two different types of vein graft method were performed in a total of 20 New Zealand White rabbits with partial urethral defect. Firth, for the patch-graft group, a 1 x 1 cm rectangular vein graft was sutured at a defective area of the same size. Second, for the tubed-graft group, a vein graft segment 1 cm long was replaced at a segmental urethral defect of the same length. Histologic study was performed at three and eight weeks postoperatively in each group. The process of transitional ell epithelial replacement within the grafted vein was uniformly observed in both experimental groups at three weeks postoperatively. At eight weeks postoperatively, the epithelial replacement was almost complete and histologically undistinguishable. In the retrograde urethrogram performed after 8 weeks, the urinary flow in the patch-graft group was normal and showed no stricture, and two of five rabbits in the tubed-graft group showed partial stricture at the graft site. In conclusion, natural urethral epithelium was restored in grafted venous segments irrespective of the type of graft. Partial stricture was observed in 40% of the tubed-graft group while complete reconstruction was possible in the patch-graft group.

Treatment of frontal sinus fracture

Although frontal sinus fractures were less common than other facial bone fractures, there have been an increase in frequency. When frontal sinus fracture has developed, depressed anterior wall fracture causes severe deformity and posterior wall fracture may be associated with severe neurosurgical complications. As the importance of external feature increased due to the improvement of life quality and social life style, so accurate diagnosis and appropriate treatment become more important for the prevention of deformity. Mucocele which is one of the most common complication of frontal sinus fracture results in cosmetically serious deformity due to inappropriate treatment Therefore, systematic classification of the fracture and reliable methods of treatment according to the types of fractures are necessary. There has not been any uniform treatment modality according to the types of the frontal sinus fracture. We present the result of 24 patients who were treated at the department of plastic and reconstructive surgery in Yeungnam University Medical Center from Apr. 1994 to Apr. 1996. Anterior wall fracture was reduced by mosaic fixation, mucosal stripping and nasofrontal duct obliteration. Posterior wall fractures were treated by cranialization and naso frontal duct obliteration reinforced with galeal flap. There were no reoperation and the results were good in terms of both function and cosmetics without any major complications.

Treatment of frontal sinus fracture

Although frontal sinus fractures were less common than other facial bone fractures, there have been an increase in frequency. When frontal sinus fracture has developed, depressed anterior wall fracture causes severe deformity and posterior wall fracture may be associated with severe neurosurgical complications. As the importance of external feature increased due to the improvement of life quality and social life style, so accurate diagnosis and appropriate treatment become more important for the prevention of deformity. Mucocele which is one of the most common complication of frontal sinus fracture results in cosmetically serious deformity due to inappropriate treatment Therefore, systematic classification of the fracture and reliable methods of treatment according to the types of fractures are necessary. There has not been any uniform treatment modality according to the types of the frontal sinus fracture. We present the result of 24 patients who were treated at the department of plastic and reconstructive surgery in Yeungnam University Medical Center from Apr. 1994 to Apr. 1996. Anterior wall fracture was reduced by mosaic fixation, mucosal stripping and nasofrontal duct obliteration. Posterior wall fractures were treated by cranialization and naso frontal duct obliteration reinforced with galeal flap. There were no reoperation and the results were good in terms of both function and cosmetics without any major complications.

MR Findings of Vascular Masses of the Head and Neck: Differential Diagnosis and Interventional Treatment Planning

PURPOSE: To characterize the MR findings for a differential diagnosis and to make a plan for treatment by interventional technique of the vascular masses with/without hypertrophic feeding vessels of the head and neck. SUBJCETS AND METHODS: Seven patients with vascular masses of the head and neck proved by pathology, angiography, clinical findings were included. Vascular masses included 4 venous malformations, a capillary hemangioma, and a hemangiopericytoma, a hemangioma combined with arteriovenous malformation. 7 patients had MR studies with 1.0T and 1.5T using routine TI-, T2- weighted spin echo sequences, and contrast enhancement. 4 MR angiography, 3 inversion recovery, and 6 contrast angiography were studied from 7 patients RESULTS: All vascular masses demonstrated higher than muscle signal intensity on Tl-weighted images, bright signal intensity on T2-weighted images, and prominent enhancement, except AV hemangioma combined with prominent arteriovenous malformation on postcontrast scan. Three hemangiomas demonstrated distinct serpiginous signal voids. Venous malformations demonstrated venous lakes seen as homogenous regions of high signal intensity and phleboliths seen as low signal foci on images. Inversion recovery was the best pulse sequence for evaluation of the extent of lesion. CONCLUSION: MR findings of the vascular masses of the head and neck are useful in delineating the extent of the disease, differentiating venous malformation or cavernous hemangioma from other hemangiomatous lesions including hypertrophic feeding vessels, and making a plan for treatment by interventional technique also.

Hematogenous Candida Pneumonia in Major Burn Patients: Plain Chest Radiograph and Thin-section CT Findings

PURPOSE: To describe plain radiographic and thin-section CT findings of hematogenous candida pneumonia in major burn patients. MATERIAL AND METHOD: We reviewed nine cases of hematogenous candida pneumonia in major burn patients who had positive blood culture for candida and findings of pneumonia on plain chest radiograph. On five of nine cases, thin-section CT was done. We evaluated retrospectively nine cases for onset, the pattern, distribution, and size of lesions on plain chest radiograph and thin-section CT. RESULTS: On plain chest radiograph, randomly distributed 2-10mm nodules were seen in six cases(66%) and randomly distributed 10-15mm consolidations in remaining three cases{33% ). Lesion occured in 11th to 75th post-burn day{average, 34th post-burn day). Other findings were cardiomegaly in three cases, atelectasis in three cases, and pulmonary edema in one case. Thin-section CT showed variable shaped subpleural nodules in all five cases. The size of nodules were 1-5mm in two cases(40%) and 5-10mm(60% ) in three cases. Feeding vessel signs were seen in two cases. Other findings were atelectasis in three cases, cardiomegaly in three cases, ground-glass opacity and interlobular septal thickenings by pulmonary edema in two cases. CONCLUSION: Plain chest radiographic findings of hematogenous candida pneumonia in major burn patients are randomly distributed nodules or consolidations of variable size. Thin-section CT findings are variable shaped subpleural nodules less than 1 cm.

Digital Subtraction Angiography in Cerebral Infarction

PURPOSE: The usefulness and radiographic findings of the angiography in cerebral infarction are well known. We attempted to evaluate the anglographic causes, findings, and the usefulness of DSA in cerebral infarction. MATERIALS AND METHODS: The authors reviewed retrospectively DSA images of 51 patients who were diagnosed as having cerebral infarction by brain CT and/or MRI and clinical settings. DSA was performed in all 51 patients, and in 3 patients, conventional anglogram was also done. Both carotid DSA images were obtained in AP, lateral, oblique projections, and one or both vertebral DSA images in AP and lateral. The authors reviewed the patient's charts for symptoms, operative findings and final diagnosis, and analysed DSA findings of cerebral atherosclerosis with focus on 6 major cerebral arteries. RESULTS: Among the 51 patients of cerebral infarction 43 patients(84.3%) had cerebral atherosclerosis, 1 dissecting aneurysm, 1 moyamoya disease and 6 negative in anglogram. DSA findings of cerebral atherosclerosis were multiple narrowings in 42 patients(97,7%), tortuosity in 22(51.2%), dilatation in 14, occlusion in 12, avascular region in 8, collaterals in 7, ulcer in 6, and delayed washout of contrast media in 3. In cerebral atherosclerosis, internal carotid artery was involved in 37 patients(86.0%), middle cerebral artery in 29(67.4%), posterior cerebral artery in 28, anterior cerebral artery in 26, vertebral artery in 22, and basilar artery in 15. Intracranial involvement of cerebral atherosclerosis (64.9%) was more common than extracranial involvement(16.2%). CONCLUSION: In cerebral infarction MRA may be the screening test, but for more precise evaluation of vascular abnormality and its extent, DSA should be considered.

Squamous Cell Carcinoma Arising in the Wall of Epidermoid Cyst of Axilla: A case report

PURPOSE: Epidormoid cysts are benign epithelial cysts often ocurring within the skin of face and trunk. But carcinomatous change is rare. The authors experienced a case of squamous cell carcinoma arising from the wall of epidermoid cyst of axilla and report the radiologic and pathologic findings with a brief review of the literatures. METHODS AND MATERIALS: Plain chest radiograph, US and enhanced CT of axilla were takened. We analyzed radiologic findings of squamous cell carcinoma in the wall of epidermoid cyst of axilla and correlated with pathologic findings. RESULTS: Plain chest radiograph revealed a huge axiilary mass without bony destruction or calcification. showed a heterogenous hyperechoic mass with eccentrical cystic lesion. Outer margin of the mass was irregular. No posterior acoustic enhancement was seen. Postcontrast CT scan showed a circumscribed complex mass with irregular enhancing rim. During operation mass was located within subcutaneous layer and internal contents of the mass were brown, necrotic keratinous debries. CONCLUSION: Differentiation from solid tumor was difficult. But intradermal or subcutaneous location and rapid growing were characteristic.

The predictability of the Tc-99m pyrophosphate scan and statistical evaluation of the trade-off point

The technetium (Tc)-99m pyrophosphate scans have been used to diagnose acute myocardial infarctions and to confirm the equivocal cases. Many articles have been reported about its diagnostic performance and pitfalls. But there has been no evaluation of its predictability according to the grades of the radioactivity land statistical evaluation of the trade-off point, i.e., grade 2 and the area under the receiver operating characteristic curve. To achieve the goals, we reviewed 252 cases of Tc-99m pyrophosphate scans (acute transmural infarction [n=99], acute subendocardial infarction [n=7], unstable angina[n=16], old myocardial infarction [n=19] others [n=111]). The predictabilities of the scan are 98% in grade 4, 84% in grade 3, 83% in grade 2, 53% in grade 1 and 18% in non-uptake. The usual trade-off point, grade 2 is not statistically significant(Z=1.945, P=0.0259>0.01). The area under the receiver operating characteristic curve(Az) is 0.885. Our study shows that the probable main cause of the false negative cases is the time interval between the onset of symptoms and the test.