Multimodal photoacoustic imaging as a tool for sentinel lymph node identification and biopsy guidance

As a minimally invasive method, sentinel lymph node biopsy (SLNB) in conjunction with guidance methods is the standard method to determine cancer metastasis in breast. The desired guidance methods for SLNB should be capable of precise SLN localization for accurate diagnosis of micro-metastases at an early stage of cancer progression and thus facilitate reducing the number of SLN biopsies for minimal surgical complications. For this, high sensitivity to the administered dyes, high spatial and contrast resolutions, deep imaging depth, and real-time imaging capability are pivotal requirements. Currently, various methods have been used for SLNB guidance, each with their own advantages and disadvantages, but no methods meet the requirements. In this review, we discuss the conventional SLNB guidance methods in this perspective. In addition, we focus on the role of the PA imaging modality on real-time SLN identification and biopsy guidance. In particular, PA-based hybrid imaging methods for precise SLN identification and efficient biopsy guidance are introduced, and their unique features, advantages, and disadvantages are discussed.

Microbubbles used for contrast enhanced ultrasound and theragnosis: a review of principles to applications

Ultrasound was developed several decades ago as a useful imaging modality, and it became the second most popular diagnostic tool due to its non-invasiveness, real-time capabilities, and safety. Additionally, ultrasound has been used as a therapeutic tool with several therapeutic agents and in nanomedicine. Ultrasound imaging is often used to diagnose many types of cancers, including breast, stomach, and thyroid cancers. In addition, ultrasound-mediated therapy is used in cases of joint inflammation, rheumatoid arthritis, and osteoarthritis. Microbubbles, when used as ultrasound contrast agents, can act as echo-enhancers and therapeutic agents, and they can play an essential role in ultrasound imaging and ultrasound-mediated therapy. Recently, various types of ultrasound contrast agents made of lipid, polymer, and protein shells have been used. Air, nitrogen, and perfluorocarbon are usually included in the core of the microbubbles to enhance ultrasound imaging, and therapeutic drugs are conjugated and loaded onto the surface or into the core of the microbubbles, depending on the purpose and properties of the substance. Many research groups have utilized ultrasound contrast agents to enhance the imaging signal in blood vessels or tissues and to overcome the blood–brain barrier or blood-retina barrier. These agents are also used to help treat diseases in various regions or systems of the body, such as the cardiovascular system, or as a cancer treatment. In addition, with the introduction of targeted moiety and multiple functional groups, ultrasound contrast agents are expected to have a potential future in ultrasound imaging and therapy. In this paper, we briefly review the principles of ultrasound and introduce the underlying theory, applications, limitations, and future perspectives of ultrasound contrast agents.

Photoacoustic Imaging for Differential Diagnosis of Benign Polyps versus Malignant Polyps of the Gallbladder: A Preliminary Study

OBJECTIVE: To investigate the feasibility of ex vivo multispectral photoacoustic (PA) imaging in differentiating cholesterol versus neoplastic polyps, and benign versus malignant polyps, of the gallbladder. MATERIALS AND METHODS: A total of 38 surgically confirmed gallbladder polyps (24 cholesterol polyps, 4 adenomas, and 10 adenocarcinomas) from 38 patients were prospectively included in this study. The surgical specimens were set on a gel pad immersed in a saline-filled container. The PA intensities of polyps were then measured, using two separate wavelength intervals (421–647 nm and 692–917 nm). Mann-Whitney U test was performed for the comparison of normalized PA intensities between the cholesterol and neoplastic polyps, and between the benign and malignant polyps. Kruskal-Wallis test was conducted for the comparison of normalized PA intensities among the cholesterol polyps, adenomas, and adenocarcinomas. RESULTS: A significant difference was observed in the normalized PA intensities between the cholesterol and neoplastic polyps at 459 nm (median, 1.00 vs. 0.73; p = 0.032). Comparing the benign and malignant polyps, there were significant differences in the normalized PA intensities at 765 nm (median, 0.67 vs. 0.78; p = 0.013), 787 nm (median, 0.65 vs. 0.77; p = 0.034), and 853 nm (median, 0.59 vs. 0.85; p = 0.028). The comparison of the normalized PA intensities among cholesterol polyps, adenomas, and adenocarcinomas demonstrated marginally significant differences at 765 nm (median, 0.67 vs. 0.66 vs. 0.78, respectively; p = 0.049). CONCLUSION: These preliminary results indicate that benign versus malignant gallbladder polyps might exhibit different spectral patterns on multispectral PA imaging.

A Case of Type V Hyperlipoproteinemia with Xanthoma Eruptivum / 대한피부과학회지

We report a case of type V hyperlipoproteinemia with xanthoma eruptivum in a 30-year-old male. He had diffuse erythematous yellowish papules on both extremities and the buttock. The laboratory findings showed the increased cholesterol and the triglyceride. Serum electrophoresis showed an increase in pre-beta and chylomicron, suggesting type V hyperlipoproteinemia. The biopsy specimen of an erythematous yellowish colored papule on the right knee showed many aggregates of foam cells without Touton giant cells.

A Case of Multiple Osteoma Cutis of the Face / 대한피부과학회지

We report a case of multiple osteoma cutis of the face in a 51-year-old female. She presented with 1-2mm sized skin colored multiple firm papules involving both cheeks for 2 years. She did not have any family history. Topical isotretinoin was prescribed for 6 months without any effects. Skin biopsy was done. Biopsy specimen of a skin colored papule on the right cheek showed numerous osteocytes and osteoblasts in the bony tissue. Other papules are treated by punch biopsy.

A Case of Type V Hyperlipoproteinemia and Xanthoma Eruptivum Associated with Diabetes Mellitus / 대한피부과학회지

We report a case of type V hyperlipoproteinemia and xanthoma eruptivum associated with diabetes mellitus in a 12-year-old female. She had diffuse erythematous yellowish papules on the extremities and trunk with itching. The laboratory findings showed increased serum blood glucose, cholesterol and triglyceride, increasing pre- and chylomicron bands on electrophoresis of lipoprotein. The biopsy specimen of an erythematous yellowish colored papule on the trunk showed characteristic findings of xanthoma.

A Case of Cystic Hygroma with Unuasal Clinical Manifestation / 대한피부과학회지

Cystic hygroma, or cystic lymphangioma, is a true, benign, congenital multicystic tumor arising from sequestrations of embryonic lymphatic tissue. Most often it occurs at birth or early in life, and it is found most commonly in the neck, and its distribution coincides with that of the primitive lymph sacs. We report herein a case of cystic hygroma on the abdomen in a 6-year- old male child. The soft mass was cystic, and was partially compressible. Biopsy findings showed simple endothelial-lined lymphatic vessel and loose, lace-like fibrous tissue stroma, and dilated muscle space filled with serous fluid.

Brachyonychia with Middle Phalangeal Defect / 대한피부과학회지

Brachyonychia is the condition when the width of the nail plate and nail bed is greater than their length. We describe a 21-year-old man who presented with brachyonychia and a 4th middle phalangeal defect on the left foot. Both the 4th metatarsal bones are shorter than the 5th ones on X-ray examination. He had no family history and other anomalies such as facial abnormalities and mental retardation.

A clinical analysis of 11 patients with chronic actinic dermatitis in Korea

Chronic actinic dermatitis is a rare disease worldwide and also in Korea. However there has been no clinicohistologic and photobiological analysis of chronic actinic dermatitis in Korea. We examined 11 patients who were diagnosed as chronic actinic dermatitis and the results of this study were compared with previous reports. Most patients were elderly men who had erythematous papules or lichenified plaques on sun-exposed areas such as the face, neck, and dorsum of the hands with severe itching sensation. All patients had severe sensitivity to UVB and biopsied specimens showed findings of chronic eczema. Five patients had positive photopatch test materials. The patients were treated with systemic and topical steroid, cyclosporine and antihistamine.

The classification of segmental vitiligo on the face

Segmental vitiligo usually has an onset early in life and spreads rapidly within the affected area. Among 1,300 patients with vitiligo, 191 patients with segmental vitiligo involving the face were evaluated. In this study, the distribution of segmental vitiligo on the face could be classified into 5 patterns which have distinctive features. This classification of facial segmental vitiligo can provide some indication of the future distribution of early lesions if they have begun to spread.

Changes in Corneal Sensitivity after Laser in-situ Keratom ileusis

To evaluate the changes of corneal sensitivity after LASIK, we measured corneal sensitivity threshold at 5 regions of cornea using Cochet-Bonnet aesthesiometer in 41 myopic eyes of 23 patients who underwent LASIK. Corneal sensitivities were tested in the Central, medial, superior, temporal and inferior region of cornea preoperatively and postoperatively. Central corneal sensitivity was reduced to 1.1+/-4.6% of preoperative sensation at 1 day postoperatively and gradually recovered showing 40.3+/-27.8% at 3 months postoperatively. The sensitivity of the central region was the lowest of all significantly and medial region was the highest(p0.05). There were no overall differences in the sensitivities of the superior, temporal and inferior regions(p>0.05) and their sensitivities were higher than that of central region and lower than that of medial region. The amount of preoperative myopia and the thickness of corneal flap showed no significant correlation with the decrease of postoperative corneal sensitivity(r0.05).

Giant Angioleiomyoma of the Hand / 대한피부과학회지

Angioleiomyoma is a benign solitary tumor that arises from the medial layer of the vein walls. We encountered a 21-year-old man who was presented with a non-tender, slowly growing, 3 cm x 5 cm-sized mass on the thenar eminence of his left hand. Histopathological examination showed the tumor to be a giant vascular leiomyoma. It is extremely rare for an angioleiomyoma to reach this size as well as occurring on the palm and this is the first report of such a case in Korea.

Effect of Excimer Laser Photorefractive Keratectomy on Density and Morphology of Corneal Endothelial Cells

We investigated the effect of excimer laser photorefractive keratectomy (PRK) on corneal endothelium in both contact lens wearer and non-wearer. Myopes (-3.0D~-9.5D) who underwent excimer laser PRK at Seoul National University Hospital from March to September 1996 were enrolled in this study. Six patients of 9 eyes had no history of contact lens wearing or discontinued wearing contact lens at least 1 year preoperatively (contact lens non-wearers) and 10 patients of 17 eyes wore their contact lenses until 4 weeks before surgery (contact lens wearers). The cnetral corneal endothelial cell density and morphology were evaluated by specular microscopy before and 1week, 3 and 6 months after surgery. In contact lens non-wearer group, no significant postoperative change was observed. But in contact lens wearer group, significnat increase of density and significant decrease fo pleopmorphism index were noted at postoperative 3 and 6 months, respectively. These results suggest that excimer laser PRK does not affect central corneal endothelium and the discontinuation of wearing contact lens may induce postoperative change of corneal endothelim.

The Change of Corneal Astigmatism Following Varying Incision Locations and Methods for Cataract Surgery in Case of Against-the-Rule Astigmatism

Phacoemulsification and foldable PCL implantation was done on 51 eyes with preoperative against-the-rule corneal astigmatism. Different locations and incisions were employed: 18 cases of supeiror scleral pocket incision(Group 1), 16 cases of temporal scleral pocket incison(Group 2), and 17 cases of temporal clear corneal incison(Group 3). Changes in corneal astigmatism were analyzed by vector method following operation. In group 1, the amount of against-the-rule surgically-induced-astigmatism was 0.72 D at potoperative 2 months. Minimal corneal astigmatic chagne was observed in group 2. Change of 0.83 D in the with-the rule direction was in with-the rule direction. In cases of against-the rule corneal astigmatism patients, it is better to use temporal approach considering surgically induced astigmatism, and, at postoperative 2 months, we observed that clear corneal incision induces with-the-rule surgically-induced astigmatism, and reduced total amount of corneal astigmatism.

Comparison of the Effect of Topical Steroid with Nonsteroidal Anti-inflammatory Drugs (NSAIDs) on Corneal Haze and Myopic Regression after Excimer Laser Photorefractive Keratectomy

We wanted to evaluate the effects of topical nonsteroidal antiinflammatory drugs (NSAIDs) on refractive outcome and corneal haze after PRK(photorefractive keratectomy) according to the degree of myopia, and compare their effect with those of topical steroids. We divided our patients into moderate myopes ( OR = -6.0D), and each patient was randomly allocated to one of three drugs for initial management: 0.1% fluorometholone, 0.03% flurbiprofen, 0.1% diclofenac for 4 months after PRK. In moderate myopes, steroid group and NSAIDs group showed no difference in refraction after 6 months, and the subjective haze grading was consistently lower in steroid group after 3 weeks. In high myopes, steroid group and NSAIDs group showed no difference in both refraction and corneal haze after 6 months. Steroid group showed severe myopic regression or corneal haze less frequently than NSAID groups in high myopes. Topical NSAIDs are assumed to be less effective than topical steroids in reducing myopic regression and haze especially in high myopes after PRK.

A Relative Afferent Pupillary Defect in the Contralateral Eye of a Unilateral Cataract

A unilated cataract had been reported to cause a relative afferent pupillary defect (RAPD) in the contralateral eye. After extraction of the cataract, the RAPD disappeared in every case. The ability of cataracts to induce an RAPD in the opposite eye is presumed to increased intraocular scatter of light by the cataract, stimulating more peripheral photoreceptors. This observation has not been reported in Korea. The authors have also observed RAPD in the contralateral eye to the unilateral cataract in six patients, disappearing after cataract surgery. Thus, when an RAPD is seen in an eye with a cataract, a visual pathway defect in that eye should definitely be suspected. In addition, it would be better to hold the brain imaging study when an RAPD is noticed in the contralateral eye to the unilateral cataract and to confirm the normal pupillary reflex in both eyes after the cataract surgery.

Effects of synthetic Inhibitor of Metalloproteinase and Cyclosporin A on Corneal Haze and Collagen Synthesis after Excimer Laser Photorefractive Keratectomy in Rabbits

Photorefractive keratectomy(PRK) was performed on 60 rabbit eyes, and synthetic inhibitor of metalloproteinase(SIMP) and cyclosporin A(CsA) was topically administered and their effects on coreneal haze were evaluated. They were randeomized to one of four groups: group A received topical SIMP, group B received topical CsA, group C received both SIMP and CsA, and group D received vehicles. At one, two, four, and six weeks after surgery, slit lamp examination was performed, and haze gradings were recorded. Light microscopy, together with immunohistochemistry using antibodies against collagen types III, IV, and VI were performed in corneas from all groups. Slit lamp examination and light microscopy revealed that SIMP significantly reduced corneal haze after PRK and subepithelial deposition of newly synthesized extracellular matrix, but CsA did not. By immunohistochemistry, deposition of types III and IV collagen was noted in ablated area of all groups. Positive staining for type III collagen was less frequent in groups treated with SIMP than in groups not treated with SIMP. In conclusion, SIMP significantly reduced the synthesis of type III collagen in treated area as well as corneal haze after excimer laser PRK in rabbits.

The Effect of Excimer Laser Photorefractory Keratectomy on Density of Corneal Endothelial cells

To investigate the effect of 193 nm ArF excimer laser photorefractive keratectomy(PRK) on corneal endothelium, 18 patients(30 eyes), undergone PRK at department of ophthalmology of Seoul National University Hospital from August to December 1994, were analyzed according to their preoperative contact lens use or not, amount of attempted correction (6D over or under) and postoperative topical steroid use or not. The central corneal endothelial cell density was measured before and 1 week, 2 months after PRK. Differences of the central corneal endothelial cell density between contact lens user and nonuser, myopes over 6D and under 6D, and steroid user and non-user were not statistically significant.

Extracapsular Cataract Extraction Using Scleral Pocket Incision

We analyzed corneal astigmatism 2 months after extracapsular cataract extraction with posterior chamber intraocular lens implantation using scleral pocket incision to minimize postoperative corneal astigmatism. Among the patients who were operated between July 1993 and April 1994, 25 eyes of 20 patients could be followed up over 2 months. Keratometric and refractive measurements were obtained before and at every week after operation. The mean postoperative refractive astigmatism was +1.42D at 1 week, +0.02D at 8 weeks and mean postoperative keratometric astigmatism was +1.58D at 1 week, -0.17D at 8 weeks. Our results suggest that extracapsular cataract extraction using scleral pocket incision has the advantage of decreasing early postoperative astigmatic change.

Cataract Surgery Using a Sleral Pocket Incision of 7 mm in Length

During a eight-month period from june 1993, cataract surgery using a scleral pocket of 7 mm in length was performed on 30 eyes of 26 patients. In order to evaluate the effect of chamber entry length and closure technique on astigmatic changes and visual recovary, three different surgical procedures were carried out and compared retrospectively. The visual acuity, refraction and keratometry were assessed at every week. The H group(15 eyes) had a single horizontal suture after phacoemulsification followed by implantation of a one piece of PMMA lens through 7 mm chamber entry. The F group(6 eyes) had a single horizontal suture followed by implantation of a foldable lens through 4 mm chamber entry. The R group(9 eyes) had a single radial suture followed by implantation of one piece of PMMA lens through 7 mm chamber entry. Overall uncorrected visual acuity of 20/40 or better was 67% at 1 week, 93% at 8 weeks postoperatively and there was no statistically significant difference among the three groups(p>0.05). The overall change of mean refractive astigmatism from 1 to 8 weeks postoperatively was 0.69D and there was no statistically significant difference among the three groups(p>0.05). The overall change of mean keratometric astigmatism method from 1 to 8 weeks postoperatively was 0.12D and there was no statistically significant difference among the three groups(p>0.05). Early clinical observations indicate that cataract surgery using a scleral pocket of 7 mm in length shows early visual recovery and minimizes surgically induced astigmatism without serious complications.